RU2485699C2 - System of wireless local computer network with multiple inputs and multiple outputs - Google Patents

Abstract

FIELD: radio engineering, communications.

SUBSTANCE: system applies multiplexing with orthogonal frequency division (OFDM) and duplexing with time division (TDD). The system uses a channel structure with several configurable transport channels, supports many speeds of transfer and modes of transfer, which may be configured on the basis of channel conditions and capabilities of user terminals, applies pilot structures with several types of a pilot-signal (for instance, beacon, controlled reference and pilot signal of a carrier) for different functions, realises circuits of transfer speed, synchronisation and capacity control for proper operation of the system, and uses random access for access to the system by user terminals, quick confirmation and quick assignment of resources. Calibration may be carried out to take into account differences in frequency responses of transfer/reception circuits in a point of access and user terminals. Spatial processing may then be simplified by using preferences of reversible nature in uplinks and downlinks and calibration.

EFFECT: invention provides for multiple speeds of transfer and modes of transfer.

30 cl

Description

Priority Statement under § 119 of Chapter 35 of the U.S. Code

This application claims the priority of provisional application US No. 60 / 421.309, entitled "WLAN system with multiple inputs and multiple outputs", filed October 25, 2002.

Technical field

The present invention relates, in General, to data transmission, and more particularly, to a communication system of a wireless local area network (WLAN) (WLAN) with multiple inputs and multiple outputs (MIMO) (MIMO).

State of the art

Wireless communication systems are widely used to provide various types of transmissions, such as voice, packet data, etc. These systems may be multiple access systems capable of communicating with multiple users sequentially or simultaneously by sharing available system resources. Examples of multiple access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems and frequency division multiple access (FDMA) systems.

Wireless local area networks (WLANs) (WLANs) are also widely used to provide communication between wireless electronic devices (such as computers) over a wireless line. WLANs can use access points (or base stations) that act as hubs and provide connectivity for wireless devices. Access points can also associate (or pair) WLANs with wired LANs, thereby providing wireless devices with access to LAN resources.

In a wireless communication system, a modulated high-frequency (HF) signal from a transmitting unit can arrive at the receiving unit over several propagation paths. The characteristics of these propagation paths usually change over time due to factors such as fading and multipath. To provide a diversity mode to counteract the harmful effects on the propagation path and improve performance, multiple transmit and receive antennas can be used. If the propagation paths between the transmitting and receiving antennas are linearly independent (i.e., transmission on one path is not formed as a linear combination of transmissions on other paths), which, in the general case, is true at least to some extent, then the probability of accurate reception of data transmissions increases as the number of antennas increases. Typically, diversity increases and performance improves as the number of transmit and receive antennas increases.

) передающих антенн и множество (

) приемных антенн. Канал МВхМВых, образованный

передающими антеннами и

приемными антеннами, может быть разложен на

пространственных каналов, при

≤ {min

,

}. Каждый из

пространственных каналов соответствует одному измерению (размерности). Система МВхМВых может обеспечить улучшенную производительность (например, увеличенную пропускную способность передачи и (или) бóльшую надежность), если используются дополнительные размерности, созданные множеством передающих и приемных антенн.Systems with multiple inputs and multiple outputs (MVXMVyh) use a lot of (

) transmitting antennas and many (

) receiving antennas. MVxMvy channel formed

transmit antennas and

receiving antennas can be decomposed into

spatial channels, with

≤ {min

,

}. Each of

spatial channels corresponds to one dimension (dimension). The MIMOout system can provide improved performance (for example, increased transmission capacity and / or greater reliability) if additional dimensions created by multiple transmitting and receiving antennas are used.

Resources for a given communication system, as a rule, are limited by various regulatory restrictions and requirements, and other practical considerations. However, the system may be required to support multiple terminals, provide diversity services, achieve certain levels of performance, etc.

Therefore, in technology there is a need for a system of MIMO-WLAN, capable of supporting many users and ensuring high system performance.

SUMMARY OF THE INVENTION

The multiple access system of the WLMX MVkhMvyh system has been announced, which has various capabilities and is able to achieve high performance. In an embodiment, this system utilizes MVxMOv and Orthogonal Frequency Division Multiplexing (OFDM) to achieve high throughput, combat harmful path effects and provide other benefits. Each access point in this system can support multiple user terminals. The allocation of resources downlink and uplink depends on the requirements of user terminals, channel conditions and other factors.

A channel structure is also proposed that supports efficient downlink and uplink transmissions. This channel structure contains a number of transport channels that can be used for functions such as signaling system parameters and resource assignments, data transmission on the downlink and uplink, random access of the system, etc. The various properties of these transport channels are configurable, which allows the system to easily adapt to channel changes and loading conditions.

A plurality of transmission rates and transmission modes are supported by the MWxMVy WLAN system to achieve high throughput when it is supported by channel conditions and capabilities of user terminals. These transmission rates are set based on estimates of channel conditions and can be independently selected for downlink and uplink. Different transmission modes may also be used depending on the number of antennas in user terminals and on channel conditions. Each transmission mode is associated with different spatial processing at the transmitter and receiver and can be selected for use under different operating conditions. Spatial processing facilitates the transmission of data from multiple transmit antennas and / or the reception of data by multiple receive antennas for higher throughput and / or higher diversity.

In an embodiment, the MVxxMO WLAN system uses a single frequency band for both the downlink and the uplink, which share the same working band using time division duplexing (TDD). For the DVR system, the channel responses of the descending and ascending lines are mutually inverse values. Calibration methods are suggested here to locate and account for differences in the frequency responses of the transmit-receive circuits at the access point and user terminals. It also describes methods for simplifying spatial processing at an access point and user terminals by taking advantage of the reversibility of the nature of the downlink and uplink and calibration.

A pilot structure with several types of pilot for various functions is also proposed. For example, a beacon pilot can be used to capture the frequency and detect the system, an MVxMV pilot can be used to estimate the channel, a controlled reference (i.e., a controlled pilot) can be used for improved channel estimation, and a carrier pilot can be used to track phase.

Various control loops are also available for proper system operation. The transmission rate can be controlled independently on the downlink and uplink. Power control may be performed for certain transmissions (for example, fixed rate services). Synchronization control can be used for uplink transmissions to account for different propagation delays for user terminals located throughout the system.

Random access methods are also provided to provide user terminals with access to the system. These methods support access to the system of multiple user terminals, quick notification of access attempts to the system, and quick assignment of downlink / uplink resources.

Various aspects and embodiments of the invention are described in more detail below.

Brief Description of the Drawings

The features and essence of the present invention are explained in the following detailed description, illustrated by the drawings, in which the same reference numerals denote the same elements throughout, and which show the following:

Figure 1 - system WLAN MVhMvyh;

Figure 2 - level structure for the WLAN system MVhMvyh;

3A, 3B and 3C show a TDD-TDM frame structure, an FDD-TDM frame structure, and an FDD-CDM frame structure, respectively;

4 is a TDD-TDM frame structure with five transport channels — BCH, FCCH, FCH, RCH, and RACH;

Figa-5G - various formats of the Protocol data unit (PDU) (PDU) for the five transport channels;

6 is a structure for an FCH / RCH packet;

7 is an access point and two user terminals;

Figa, 9A and 10A are three transmitting blocks for modes of diversity, spatial multiplexing and beam control, respectively;

8B, 9B and 10B are three TX diversity processors for diversity, spatial multiplexing, and beam control modes, respectively;

Figs - modulator OFDM;

Fig. 8D is a symbol of MORC;

Figa - block forming a frame and a scrambler in the data processor TX;

11B is an encoder and a repetition-perforation unit in a TX data processor;

11C is another TX data processor that can be used for spatial multiplexing mode;

12A and 12B are a state diagram for operating a user terminal;

Fig - timeline for RACH;

Figa and 14B are processes for controlling transmission speeds, respectively, of the downward and upward lines;

Fig - illustration of the action of the power control loop; and

Fig. 16 is a process for adjusting uplink synchronization for a user terminal.

Detailed description

The word “exemplary” is used solely as “serving as an example, occasion or illustration”. Any embodiment or project described herein as “exemplary” is not necessarily interpreted as being preferred or advantageous over other embodiments or projects.

I. System Overview

Figure 1 shows a system 100 WLAN Mwmw, which supports many users and is able to implement various embodiments of the invention. The MWxMWL WLAN system 100 includes several access points (APs) 110 (APs) that support communication for multiple user terminals 120 (PTs) (UTs). For simplicity, only two access points 110 are shown in FIG. An access point is usually a fixed station, which is used to communicate with user terminals. An access point may also be defined as a base station or some other terminology.

User terminals 120 may be distributed throughout the system. Each user terminal may be a fixed or mobile terminal that can communicate with an access point. A user terminal may also be referred to as a mobile station, a remote station, an access terminal, a user equipment (software) (UE), a wireless device, or may be referred to by some other terminology. Each user terminal can communicate with one or, possibly, a plurality of access points in a descending and (or) ascending line at any given point in time. A downlink (i.e., a straight line) refers to transmission from an access point to a user terminal, and an uplink (i.e., a return line) refers to transmission from a user terminal to an access point.

1, access point 110a is associated with user terminals 120a-120f, and access point 110b is associated with user terminals 120f-120k. Depending on the specific implementation of the system 100, the access point may communicate with multiple user terminals simultaneously (for example, in a plurality of code channels or subbands) or sequentially (for example, in a plurality of time segments). At any given point in time, the user terminal may receive downlink transmissions from one or multiple access points. The downlink transmission from each access point may include additional overhead data intended for reception by a plurality of user terminals, specific user data intended for reception by a specific user terminal, other types of data, or any combination thereof. Additional overhead may include a pilot, paging messages and broadcast messages, system parameters, etc.

The WLMX system of MVxMVykh is based on a network architecture with a centralized controller. So, the system controller 130 is connected to access points 110 and can further communicate with other systems and networks. For example, the system controller 130 may communicate with a packet data network (PDN), a wired local area network (LAN), a wide area network (WAN), the Internet, and a public switched telephone network ( PSTN) (PSTN), with a cellular network, etc. The system controller 130 can be designed to perform several functions, such as (1) coordination and control for access points connected to it, (2) data routing between these access points, (3) access and control of communication with user terminals served by these points access, etc.

The WFMX system can provide high throughput with the possibility of significantly greater coverage than traditional WLAN systems. The MIMO-WLAN system can support synchronous, asynchronous and isochronous data / voice services. The WLMX system of MVhMVyh can be designed to provide the following characteristics:

- High service reliability

- Guaranteed Quality of Service (QoS) (QoS)

- High instant data rates

- High spectral efficiency

- Extended coverage range.

The MWxMWave WLAN system can operate in various frequency bands (for example, the U-NII 2.4 GHz and 5 x GHz bands), subject to the limitations in bandwidth and radiation characteristic of the selected operating band. The system can be placed both indoors and outdoors, with a typical maximum cell size of 1 km or less. The system supports fixed terminal applications, although some operating modes also support portable and limited mobility terminals.

1. MVhMVyh, MVkhOVy and OVhMVyh

In a specific embodiment, and as described further in the description, each access point is provided with four transmitting and receiving antennas for transmitting and receiving data, the same four antennas being used for transmission and reception. The system also supports the case when the transmitting and receiving antennas of a device (for example, access point, user terminal) are not used together, although this configuration in the normal state provides lower performance than when sharing antennas. The MWxMHV WLAN system can also be designed so that each access point is equipped with some other number of transmit / receive antennas. Each user terminal may be equipped with a single transmit / receive antenna or multiple transmit / receive antennas for transmission and reception. The number of antennas used by each type of user terminal may depend on various factors, such as, for example, the services supported by the user terminal (e.g., speech, data, or both), cost considerations, regulatory restrictions, reliability issues, etc.

передающими антеннами и

приемными антеннами, доступными для использования для передачи данных. Различные каналы МВхМВых формируются между пунктом доступа и различными многоантенными пользовательскими терминалами. Каждый канал МВхМВых может быть разделен на

пространственных каналов, где

≤ min {

,

}.

потоков данных могут передаваться по

пространственным каналам. Пространственная обработка требуется в приемнике и может выполняться или не выполняться в передатчике для передачи множества потоков данных по

пространственным каналам.For a given pair of multi-antenna access point and multi-antenna user terminal, an MVxMv channel is formed

transmit antennas and

receiving antennas available for use for data transmission. Various MVxMv channels are formed between the access point and various multi-antenna user terminals. Each MVxMVy channel can be divided into

spatial channels where

≤ min {

,

}.

data streams can be transmitted over

spatial channels. Spatial processing is required at the receiver and may or may not be performed at the transmitter to transmit multiple data streams over

spatial channels.

пространственных каналов могут быть, а могут и не быть ортогональны друг другу. Это зависит от разных факторов, таких как (1) выполнялась ли пространственная обработка в передатчике, чтобы получить ортогональные пространственные каналы, и (2) была ли пространственная обработка как в передатчике, так и в приемнике успешной при ортогонализации пространственных каналов. Если в передатчике не выполняется никакой пространственной обработки, то

пространственных каналов могут формироваться

передающими антеннами, и маловероятно, что они будут ортогональны друг другу.

spatial channels may or may not be orthogonal to each other. This depends on various factors, such as (1) whether the spatial processing in the transmitter was performed to obtain orthogonal spatial channels, and (2) whether the spatial processing in both the transmitter and the receiver was successful in orthogonalizing the spatial channels. If no spatial processing is performed in the transmitter, then

spatial channels can be formed

transmitting antennas, and it is unlikely that they will be orthogonal to each other.

пространственных каналов могут быть ортогонализированы путем выполнения декомпозиции на матрице канальных откликов для канала МВхМВых, как описано ниже. Каждый пространственный канал упоминается как собственная мода канала МВхМВых, если

пространственных каналов ортогонализированы с помощью декомпозиции, что требует пространственной обработки как в передатчике, так и в приемнике, как описано ниже. В этом случае

потоков данных могут передаваться ортогонально на

собственных модах. Однако собственная мода обычно считается теоретическим построением.

пространственных каналов, как правило, не полностью ортогональны друг другу вследствие различных причин. Например, пространственные каналы не будут ортогональными, если (1) передатчик не имеет информации о канале МВхМВых или (2) передатчик и (или) приемник имеют несовершенную оценку канала МВхМВых. Для простоты, в нижеследующем описании термин "собственная мода" используется для обозначения случая, когда делается попытка ортогонализировать пространственные каналы с использованием декомпозиции, даже если эта попытка может и не быть полностью успешной, например, из-за несовершенной оценки канала.

spatial channels can be orthogonalized by performing decomposition on the channel response matrix for the MVxxM channel, as described below. Each spatial channel is referred to as an eigenmode of the MVxxM channel, if

spatial channels are orthogonalized using decomposition, which requires spatial processing both in the transmitter and in the receiver, as described below. In this case

data streams can be transmitted orthogonally to

own mods. However, a native mode is usually considered a theoretical construct.

spatial channels, as a rule, are not completely orthogonal to each other due to various reasons. For example, spatial channels will not be orthogonal if (1) the transmitter does not have information about the MVxxM channel or (2) the transmitter and (or) the receiver have an imperfect estimate of the MVxx channel. For simplicity, in the following description, the term "eigenmode" is used to indicate a case where an attempt is made to orthogonalize spatial channels using decomposition, even if this attempt may not be completely successful, for example, due to an imperfect channel estimate.

For a given number (for example, four) of antennas at an access point, the number of spatial channels available for each user terminal depends on the number of antennas used by this user terminal and on the characteristics of the wireless MVxMout channel that connects the antennas of the access point and the antennas of the user terminal. If the user terminal is equipped with one antenna, then the four antennas in the access point and the only antenna in the user terminal form a channel with many inputs and one output (MVOHO) (MISO) for a downlink, and a channel with one input and many outputs (OOXMO) (SIMO ) for the ascending line.

The WLMX system of MVxMVyh can be designed to support several transmission modes. Table 1 lists the transmission modes supported by the exemplary design of the MHMX WLAN system.

Table 1 Transmission Modes Description OWxMOut Data is transmitted by a single antenna, but can be received by multiple antennas for diversity reception Explode Data is transmitted redundantly with multiple transmit antennas and / or multiple subbands to provide diversity Beam control Data is transmitted in a single (best) channel at full power using phase control information for the primary eigenmode of the MVxxM channel. Spatial multiplexing Data is transmitted over multiple spatial channels to achieve higher spectral efficiency.

For simplicity, the term “diversity” in the following description refers to transmission diversity, unless otherwise noted.

The transmission modes available for use for the downlink and for the uplink for each user terminal depend on the number of antennas used in the user terminal. Table 2 lists the transmission modes available for different types of terminals for the downlink and uplink, assuming a plurality (for example, four) of antennas at the access point.

table 2 Transmission Modes Descending line Ascending line Single Antenna User Terminal Multi Antenna User Terminal Single Antenna User Terminal Multi Antenna User Terminal MVkhOVykh (on the descending) / OBhMVykh (on the ascending) X X X X Explode X X X Beam control X X X Spatial multiplexing X X

For the downlink, all transmission modes except the spatial multiplexing mode can be used for single-antenna user terminals, and all transmission modes can be used for multi-antenna user terminals. For the uplink, all transmission modes can be used by multi-antenna user terminals, while single-antenna user terminals use the OBxMOvy mode to transmit data with one available antenna. For OBxMout, receive diversity (i.e., receiving transmitted data by a plurality of receiving antennas) as well as beam steering modes can be used.

The MFMWX WLAN system can also be designed to support various other transmission modes, which is also within the scope of the invention. For example, the beamforming mode can be used to transmit data on a single eigenmode using both amplitude and phase information for the eigenmode (instead of only phase information that is only used by the beam control mode). As another example, an “uncontrolled” spatial multiplexing mode can be defined, whereby the transmitter simply transmits multiple data streams with multiple transmit antennas (without any spatial processing), and the receiver performs the spatial processing necessary to isolate and recover the data streams from multiple transmit antennas. As another example, a “multi-user” spatial multiplexing mode can be defined, whereby the access point transmits a plurality of data streams by a plurality of transmit antennas (with spatial processing) to a plurality of user terminals simultaneously on a downlink. As another example, a spatial multiplexing mode can be determined whereby the transmitter performs spatial processing trying to orthogonalize a plurality of data streams sent to a plurality of transmit antennas (which may not be completely successful due to an imperfect channel estimate), and the receiver performs the necessary spatial processing to isolate and recover data streams transmitted by multiple transmit antennas. Thus, spatial processing for transmitting multiple data streams through multiple spatial channels can be performed (1) both in the transmitter and in the receiver, (2) only in the receiver, or (3) only in the transmitter. Various spatial multiplexing modes can be used depending on, for example, the capabilities of the access point and user terminals, available information about the state of the channel, system requirements, etc.

In general, access points and user terminals can be designed with multiple transmit and receive antennas. For clarity, specific embodiments and designs are described below in which each access point is equipped with four transmit / receive antennas and each user terminal is equipped with four or less transmit / receive antennas.

2. MORCH

) ортогональных поддиапазонов. Эти поддиапазоны именуются также тонами, бинами (элементами дискретизации) или частотными каналами. При МОРЧ каждый поддиапазон ассоциируется с соответствующей поднесущей, которая может быть промодулирована данными. Для системы МВхМВых, которая использует МОРЧ, каждый пространственный канал каждого поддиапазона может рассматриваться как независимый канал передачи, где комплексное усиление, связанное с каждым поддиапазоном, эффективно ограничивается по ширине полосы поддиапазона.In an embodiment, the MVxMv WLAN system uses OFDM to effectively divide the entire system bandwidth into several (

) orthogonal subbands. These subbands are also referred to as tones, bins (bins), or frequency channels. In OFDM, each subband is associated with a corresponding subcarrier that can be modulated with data. For an MIMO system that uses OFDM, each spatial channel of each subband can be considered as an independent transmission channel, where the complex gain associated with each subband is effectively limited by the bandwidth of the subband.

=64), которым назначаются индексы от -32 до +31. Из этих 64 поддиапазонов используются для данных 48 поддиапазонов (например, с индексами ±{1, …, 6, 8, …, 20, 22, …, 26}), 4 поддиапазона (например, с индексами ±{7, 21}) используются для пилотного сигнала и, возможно, сигнализации, поддиапазон постоянной составляющей (DC) (с индексом 0) не используется, и остальные поддиапазоны не используются и служат в качестве защитных поддиапазонов. Эта структура поддиапазонов МОРЧ описывается более подробно в документе стандарта 802.11а IEEE "Часть 11: Спецификация управления доступом к среде (МАС) беспроводной ЛВС и физического уровня (PHY): Высокоскоростной физический уровень в диапазоне 5 ГГц", сентябрь 1999, который общедоступен и включен в настоящее описание посредством ссылки. Различное число поддиапазонов и различные иные структуры поддиапазонов МОРЧ могут также воплощаться для системы БЛВС МВхМВых, что также входит в объем изобретения. Например, все 53 поддиапазона с индексами от -26 до +26 могут использоваться для передачи данных. В качестве другого примера, могут использоваться 128-поддиапазонная структура, 256-поддиапазонная структура или поддиапазонная структура с каким-либо иным числом поддиапазонов. Для ясности, ниже описывается система БЛВС МВхМВых с 64-поддиапазонной структурой, описанной выше.In an embodiment, the system bandwidth is divided into 64 orthogonal subbands (i.e.

= 64), which are assigned indices from -32 to +31. Of these 64 sub-bands, 48 sub-bands (for example, with indices ± {1, ..., 6, 8, ..., 20, 22, ..., 26}), 4 sub-bands (for example, with indices ± {7, 21}) are used are used for pilot and possibly signaling, the DC component subband (with index 0) is not used, and the remaining subbands are not used and serve as guard subbands. This OFDM sub-band structure is described in more detail in IEEE 802.11a Standard "Part 11: Wireless LAN and Physical Layer (PHY) Media Access Control (MAC) Specification: 5 GHz High-Speed Physical Layer", September 1999, which is public and enabled in the present description by reference. A different number of subbands and various other structures of the OFDM subbands may also be implemented for the MIMO output WLAN system, which is also within the scope of the invention. For example, all 53 subbands with indices from -26 to +26 can be used for data transmission. As another example, a 128-subband structure, a 256-subband structure, or a subband structure with any other number of subbands may be used. For clarity, the MVxxMO WLAN system with the 64-band structure described above is described below.

поддиапазонов преобразуются во временную область с использованием обратного быстрого преобразования Фурье (ОБПФ) (IFFT) для получения преобразованного символа, который содержит

отсчетов во временной области. Длительность каждого преобразованного символа взаимно обратно связана с шириной полосы каждого символа. В одном конкретном проекте для системы БЛВС МВхМВых ширина полосы системы составляет 20 МГц,

=64, ширина полосы каждого символа составляет 312,5 кГц, а длительность каждого символа равна 3,2 мкс.For OFDM, the data to be transmitted in each subband is first modulated (i.e., symbol mapping) using a particular modulation scheme selected for use in that subband. Zeros correspond to unused subbands. For each symbol period, modulation symbols and zeros for all

subbands are converted to the time domain using the inverse fast Fourier transform (IFFT) to obtain a transformed symbol that contains

samples in the time domain. The duration of each transformed character is mutually inversely related to the bandwidth of each character. In one specific project for the MIMO-WLAN system, the system bandwidth is 20 MHz,

= 64, the bandwidth of each symbol is 312.5 kHz, and the duration of each symbol is 3.2 μs.

OFDM can provide some advantages, such as counteracting the effect of frequency selective fading, which is characterized by different channel gain at different frequencies of the entire system bandwidth. It is well known that frequency selective fading causes intersymbol interference (ISI), due to which each character in the received signal acts as a distortion for subsequent characters in the received signal. MIS distortion degrades performance by affecting the ability to correctly detect received symbols. Frequency selective fading can be controlled using the OFDM by repeating each transformed symbol (or adding a cyclic prefix to each transformed symbol) to form the corresponding OFDM symbol, which is then transmitted.

The length of the cyclic prefix (i.e., the value for repetition) for each OFDM symbol depends on the delay spread of the wireless channel. In particular, to effectively combat ISI, the cyclic prefix should be longer than the maximum expected delay spread for the system.

In an embodiment, for OFDM symbols, cyclic prefixes of different durations may be used, depending on the expected delay spread. For the specific MVhMVy WLAN system described above, a cyclic prefix of 400 μs (8 samples) or 800 μs (16 samples) can be selected for use with OFDM characters. The "short" OFDM symbol uses a cyclic prefix of 400 ns and a duration of 3.6 ks. The "long" OFDM symbol uses a cyclic prefix of 800 ks and has a duration of 4.0 μs. Short OFDM characters can be used if the maximum expected delay spread is 400 µs or less, and long OFDM symbols can be used if the delay spread is more than 400 µs. For use with different transport channels, different cyclic prefixes can be selected, and the cyclic prefix can also be selected dynamically, as described below. By using, when possible, a shorter cyclic prefix, it is possible to increase the throughput of the system, since a larger number of shorter duration OFDM symbols can be transmitted in a given fixed time interval.

The MFMHF WLAN system can also be designed without the use of MORCH, which is also included in the scope of the invention.

3. Level structure

FIG. 2 illustrates a tier structure 200 that can be used with an MVxMWL WLAN system. Layer structure 200 includes (1) applications and upper layer protocols that roughly correspond to Layer 3 or higher in the ISO / OSI reference model (upper layers), (2) protocols and services that correspond to Layer 2 (line layer), and (3) protocols and services that comply with Level 1 (physical layer).

The upper layers include various applications and protocols, such as signaling services 212, data services 214, voice services 214, circuit data applications, etc. Signaling is usually provided as messages, and data as packets. Services and applications at the upper levels initiate and complete messages and packets according to the semantics and synchronization of the communication protocol between the access point and the user terminal. The upper tiers use the services provided by Tier 2.

Layer 2 supports the delivery of messages and packets generated by higher layers. In the embodiment shown in FIG. 2, layer 2 includes a Line Access Control (LAC) sublayer 220 and a Media Access Control (MAC) sublayer 230 (MAC). The UDL sublayer implements a data link protocol that provides for the correct transfer and delivery of messages generated by higher layers. The UDL sublayer uses the services provided by the MAC sublayer and Level 1. The MAC sublayer is responsible for sending messages and packets using the services provided by Level 1. The MAC sublayer controls access to Level 1 resources through applications and services in the upper layers. The UDS sublayer may include a radio link protocol (RLP) 232, which is a retransmission mechanism that can be used to provide higher reliability for packetized data. Level 2 provides Protocol Data Units (PDUs) to Level 1.

Level 1 contains the physical layer 240 and supports the transmission and reception of radio signals between the access point and the user terminal. This physical layer performs coding, interleaving, modulation, and spatial processing for the various transport channels used to send messages and packets generated by higher layers. In this embodiment, the physical layer includes a multiplexing sub-layer 242 that multiplexes the processed LDPEs for various transport channels into a proper frame format. Level 1 provides data in blocks of frames.

FIG. 2 shows a specific embodiment of a tier structure that can be used for an Mwxm WLAN system. Various other suitable tier structures may also be designed and used for the MwxMWx WLAN system, which is also within the scope of the invention. The functions performed by each level are described in more detail below, where appropriate.

4. Transport channels

A system of MHMX WLANs can support a number of services and applications. In addition, for the system to function properly, it may be necessary to transfer other data by the access point or exchange data between the access point and user terminals. A number of transport channels can be defined for the MIMO system for the transfer of different types of data. Table 3 lists an exemplary set of transport channels and also provides a brief description for each transport channel.

Table 3 Transport channels Description Broadcast channel BCH Used by an access point to transmit pilot and system parameters to user terminals Direct control channel FCCH Used by an access point to allocate resources on the downlink and uplink. Resource allocation can be done on a frame by frame basis. Also used to provide acknowledgment for messages received on RACH. Direct channel Fch Used by an access point to transmit user data to user terminals and, possibly, a reference (pilot) signal used by user terminals to estimate the channel. It can also be used in broadcast mode to send paging messages and broadcast messages to a plurality of user terminals. Random access channel Rach Used by user terminals to gain access to the system and send short messages to the access point. Return channel Rch Used by user terminals to transmit data to an access point. It can also carry the reference signal used by the access point for channel estimation.

As shown in Table 3, the downlink transport channels used by the access point include BCH, FCCH, and FCH. Uplink transport channels used by user terminals include RACH and RCH. Each of these transport channels is described in more detail below.

The transport channels listed in Table 3 represent a specific embodiment of the channel structure that can be used for the MVxMWLS system. A smaller number, additional and (or) different transport channels can also be defined for use in the MFMWX WLAN system. For example, some functions may be supported by function-specific transport channels (e.g., pilot, paging, power control, and synchronization channels). Thus, other channel structures with different sets of transport channels can be defined and used in the MFMWX WLAN system, and this is also within the scope of the invention.

5. Frameworks

For transport channels, a number of frame structures can be defined. The specific frame structure to be used in the MIMO output WLAN system depends on various factors, such as, for example, (1) whether the same or different frequency bands are used for the downlink and uplink and (2) the multiplexing scheme used to multiplex transport channels together.

If only one frequency band is available, then the downlink and uplink can be transmitted in different phases of the frame using time division duplexing (TDD), as described below. If two frequency bands are available, then the downlink and uplink can be transmitted in different frequency bands using frequency division duplexing (FDM) (FDD).

For both FDA and FDM, transport channels can be multiplexed by time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (CDM), etc. For MBP, each transport channel is assigned to a different part of the frame. For FIBC, transport channels are transmitted together, but each transport channel is formed by a different channelization code, similar to what is done in a code division multiple access (CDMA) system. For the CDM, each transport channel is assigned a different portion of the frequency band for the line.

Table 4 lists the various frame structures that can be used to carry transport channels. Each of these frame structures is described in more detail below. For clarity, frame structures are described for the set of transport channels listed in Table 3.

Table 4 Shared frequency band for downlink and uplink Separate frequency bands for downlink and uplink Time division The structure of the personnel of the FER-MVR HR-HRM HR structure Code division The structure of the personnel of the DDA-MKR HRM-MKR personnel structure

3A illustrates an embodiment of a DVR-MBP frame structure 300a that can be used if a single frequency band is used for both the downlink and the uplink. Data transmission is carried out by blocks of DVR frames. Each frame DDA can be defined as overlapping a specific time duration. The frame duration can be selected based on various factors, such as, for example, (1) the bandwidth of the operating range, (2) the expected size of the PDU for transport channels, etc. In general, shorter frame durations can provide reduced delays. However, longer frame durations may be more efficient since the header and additional overhead can represent a smaller portion of the frame. In a specific embodiment, each DVR frame has a duration of 2 ms.

Each DVR frame is divided into a downlink phase and an uplink phase. The downlink phase is divided into three segments for the three downlink transport channels — BCH, FCCH and FCH. The uplink phase is divided into two segments for two uplink transport channels, RCH and RACH.

A segment for each transport channel can be defined as having a fixed duration or a variable duration, which can vary from frame to frame. In an embodiment, the BCH segment is defined as having a fixed duration, and the FCCH, FCH, RCH, and RACH segments are defined as having variable durations.

A segment for each transport channel may be used to carry one or more protocol data units (PDUs) for that transport channel. In the specific embodiment shown in FIG. 3A, BCH PBUs are transmitted in the first segment 310, FCCH PDUs are transmitted in the second segment 320, and one or more FCH PDUs are transmitted in the third downlink phase segment 330. In the uplink phase, one or more RCH PDUs are transmitted in the fourth segment 340, and one or more RACH PDUs are transmitted in the fifth segment 350 of the DVR frame.

Frame structure 300a represents a specific arrangement of various transport channels in a frame of a DDA. This arrangement may provide some gains, such as reduced delays for data transmission in the downlink and uplink. The BCH is transmitted first in the DVR frame, since it carries system parameters that can be used for the PDB of the remaining transport channels in the same DVR frame. The FCCH is transmitted next because it carries channel assignment information indicating which user terminal (s) are assigned to receive downlink data on the forward channel (FCH) and which user (s) ) terminal (s) is assigned (s) to transmit the uplink data in the reverse channel (RCH) in the current frame of the DVR. Other DVR-MVR frame structures can also be defined and can be used for the MVxMVy WLAN system, which is also within the scope of the invention.

FIG. 3B illustrates an embodiment of an HDR-MBP frame structure 300b that can be used if the downlink and uplink are transmitted using two separate frequency bands. Downlink data is transmitted in the downlink frame 302a, and uplink data is transmitted in the uplink frame 302b. Each frame of the descending and ascending lines can be defined to overlap a specific time duration (for example, 2 ms). For simplicity, the frames of the downward and upward lines can be defined as having the same duration, and can also be defined for alignment at the borders of the frame. However, for downward and upward lines, different frame durations and / or unaligned (i.e., shifted) frame boundaries can also be used.

As shown in FIG. 3B, a downlink frame is divided into three segments for three downlink transport channels. An uplink frame is split into two segments for two uplink transport channels. A segment for each transport channel may be defined as having a fixed or variable duration, and may be used to carry one or more PDUs for that transport channel.

In the specific embodiment shown in FIG. 3B, a downlink frame carries BCH PBBs, FCCH PDUs and one or more FCH PDUs in segments 310, 320, and 330, respectively. An uplink frame carries one or more RCH PDUs and one or more RACH PDUs in segments 340 and 350, respectively. This particular ordering may provide the gain described above (e.g., reduced latency for data transmission). Transport channels can have excellent PBB formats, as described below. Other HDR-MVR frame structures can also be defined and can be used for the MVxMVy WLAN system, which is also within the scope of the invention.

3C illustrates an embodiment of an HDR-FDM / CDM frame structure 300c, which can also be used if the downlink and uplink are transmitted using separate frequency bands. Downlink data may be transmitted in a downlink frame 304a, and uplink data may be transmitted in an uplink frame 304b. The frames of the downward and upward lines can be defined as having the same duration (for example, 2 ms) and can be aligned at the borders of the frame.

As shown in FIG. 3C, three downlink transport channels are transmitted together in a downlink frame, and two uplink transport channels are transmitted together in an uplink frame. For FIBC, transport channels for each line are formed with different channelization codes, which can be Walsh codes, codes of orthogonal variable spreading coefficient (OPCS) (OVSF), quasi-orthogonal functions (QOF), etc. For CDM, the transport channels for each line are assigned different parts of the frequency band for the line. For different transport channels in each line, different transmit power values may also be used.

Other frame structures may also be defined for downlink and uplink transport channels, which is also within the scope of the invention. In addition, you can use various types of frame structures for the descending and ascending lines. For example, the MBP-based frame structure may be used for the downlink, and the MKP-based frame structure may be used for the uplink.

In the following description, it is assumed that the MFMX WLAN system uses a single frequency band for both downlink and uplink transmissions. For clarity, the frame structure of the DVR-MVR shown in FIG. 3A is used for the MVxMWN WLAN system. For clarity, the specific embodiment of the DVR-MVR personnel structure is described throughout. For this embodiment, the duration of each DVR frame is set to 2 ms, and the number of OFDM symbols per DVR frame is a function of the length of the cyclic prefix used for the OFDM symbols. The BCH has a fixed duration of 80 μs and uses a cyclic prefix of 800 ns for the transmitted MCHR symbols. The rest of the DVR frame contains 480 OFDM symbols if a cyclic prefix of 800 ns is used, and 533 of OFDM symbols plus 1.2 μs of excess time if a cyclic prefix of 400 ns is used. Excess time may be added to the guard interval at the end of the RACH segment. Other frame structures and other embodiments may also be used, and this is within the scope of the invention.

II. Transport channels

Transport channels are used to transmit data of various types and can be classified into two groups: common transport channels and dedicated transport channels. Since the common and dedicated transport channels are used for different purposes, different processing can be applied to these two groups of transport channels, as described in more detail below.

General transport channels. Common transport channels include BCH, FCCH, and RACH. These transport channels are used to transmit data to a plurality of user terminals or to receive data from a plurality of user terminals. To improve reliability, BCH and FCCH are transmitted by the access point using the diversity mode. On the uplink, the RACH is transmitted by user terminals using a beam control mode (if supported by the user terminal). The BCH operates at a known fixed transmission rate, so that user terminals can receive and process the BCH without any additional information. FCCH and RACH support multiple baud rates to provide greater efficiency. The terms “baud rate” or “set of baud rates”, as used herein, are associated with a particular code mode (or coding scheme) and a particular modulation scheme.

Dedicated transport channels. Dedicated transport channels include FCH and RCH. These transport channels are typically used to transmit specific user data to a specific user terminal or to a specific user terminal. FCH and RCH can be dynamically allocated to user terminals as needed or as available. The FCH (forward channel) can also be used in broadcast mode to transmit additional service, search and broadcast messages to user terminals. In general, additional overhead, search, and broadcast messages are transmitted before any specific user data on the FCH.

FIG. 4 illustrates an exemplary BCH, FCCH, FCH, RCH, and RACH transmission based on a DVR-MBP frame structure 300a. In this embodiment, one BCH PDU 410 and one FCCH PDU 420 are transmitted in the BCH segment 310 and the FCCH segment 320, respectively. FCH segment 330 may be used to transmit one or more FCH PDUs 430, each of which may be for a particular user terminal or multiple user terminals. Similarly, one or more RCH PDUs 440 may be transmitted by one or more user terminals in the RCH segment 340. The start of each FCH / RCH PDU is indicated by the shift of the FCH / RCH from the end of the previous segment. A number of RACH PDUs 450 may be transmitted in the RACH segment 350 by several user terminals to access the system and / or transmit short messages, as described below.

For clarity, transport channels are described for the specific frame structure of the DVR-MBP shown in FIGS. 3A and 4.

1. Broadcast channel (BCH) - downlink

The BCH channel is used by an access point to transmit a beacon pilot signal, an MVxMVO pilot signal, and system parameters to user terminals. A beacon pilot is used by user terminals to obtain system clock and frequency. The MVxMVy pilot signal is used by user terminals to evaluate the MVxMVy channel formed by access point antennas and their own antennas. The beacon and MVxMO pilot are described in more detail below. System parameters determine the various properties of the downlink and uplink transmissions. For example, since the durations of the segments FCCH, FCH, RACH, and RCH are variable, the system parameters that determine the duration of each of these segments for the current frame of the DVR are transmitted to the BCH.

5A illustrates an embodiment of a BCH PBB 410. In this embodiment, BCH PBU 410 includes a preamble portion 510 and a message portion 516. Part 510 of the preamble includes a part 512 of the beacon pilot signal and part 514 of the pilot signal MIMOvy. Part 512 contains a beacon pilot and has a fixed duration T _CP = 8 μs. Part 514 contains a pilot signal MVhMVvyh and has a fixed duration T _MP = 32 μs. Part 516 contains the BCH message and has a fixed duration T _VM = 40 μs. The VSN PBB duration is fixed at T _CP + T _MR + T _VM = 80 μs.

The preamble may be used to transmit one or more types of pilot signal and / or other information. The beacon pilot contains a specific set of modulation symbols, which is transmitted by all transmit antennas. The MVxMOf pilot signal contains a specific set of modulation symbols, which is transmitted by all transmit antennas with different orthogonal codes, which then allow the receivers to reconstruct the pilot signal transmitted by each antenna. Different modulation symbol sets may be used for the beacon pilot and the MVxMVO pilot. The generation of the beacon pilot and the MIMOout pilot is described in more detail below.

The BCH message carries system configuration information. Table 5 lists the various fields for an example BCH message format.

Table 5
BCH Post Field / Parameter Names Length (bit) Description Frame counter four DVR frame counter Network ID 10 Network Identifier (ID) ID PD 6 Access Point ID Ur Prd PD four Access Point Transfer Level Ur Prm PD 3 Access Point Reception Level FCCH Length 6 Duration FCCH (in units of characters OFDM) FCCH speed 2 FCCH Physical Layer Rate FCH Length 9 Duration FCH (in units of characters MORCH) RCH Length 9 Duration RCH (in units of characters OFDM) RACH Length 5 RACH duration (in units of RACH intervals) RACH interval size 2 The duration of each RACH interval (in units of characters OFDM) Guard interval RACH 2 Guard interval at the end of the RACH Duration cycle. prefix one Cyclic prefix duration Page beat one "0" = paging message sent on FCH
"1" = paging message not sent Broadcast bit one "0" = broadcast. message sent on FCH
"1" = Broadcast not sent. posts RACH notification bit one "0" = RACH notification sent on FCH
"1" = RACH notifications sent CRC 16 CRC value for BCH messages Trailing bits 6 Finishing bits for a convolutional encoder Reserve 32 Reserved for future use.

The frame counter value can be used to synchronize various processes at the access point and user terminals (e.g., pilot, scrambling codes, covering codes, etc.). The frame counter can be implemented as a 4-bit counter, which counts cyclically. This counter is incremented at the beginning of each DDA frame, and the counter value is included in the frame counter field. The Network ID field indicates the identifier (ID) of the network to which the access point belongs. The PD ID field indicates the access point ID in the network ID. The fields Ur Prm PD and Ur Prm PD indicate the maximum transmit power level and the desired receive power level at the access point, respectively. The desired receive power level may be used by the user terminal to determine the initial uplink transmit power.

The FCCH Length, FCH Length, and RCH Length fields indicate the lengths of the FCCH, FCH, and RCH segments, respectively, for the current DTE frame. The lengths of these segments are specified in units of characters OFDM. The duration of the OFDM symbol for BCH is set to 4.0 μs. The OFDM symbol duration for all other transport channels (i.e., FCCH, FCH, RACH, and RCH) is variable and depends on the selected cyclic prefix, which is determined by the Cycle Prefix Duration field. The FCCH rate field indicates the transmission rate used for the FCCH for the current frame of the DVR.

The RACH Length field indicates the length of the RACH segment, which is specified in units of RACH intervals. The duration of each RACH interval is specified by the RACH interval size field in units of OFDM characters. The RACH Guard Interval field indicates the amount of time between the last RACH interval and the start of the BCH segment for the next DVR frame. These various fields for RACH are described in more detail below.

The paging bit and the broadcast bit indicate whether paging messages and broadcast messages are transmitted in the current DVR frame to the FCH. These two bits can be set independently for each frame of the DVR. The RACH notification bit indicates whether notifications for PDUs transmitted on the RACH in previous frames of the DVR are transmitted on FCCH in the current frame of the DTE.

The CRC field includes a CRC (cyclic code) value for the entire BCH message. This CRC value can be used by user terminals to determine if the BCH message is decoded in a specific way (i.e., good) or in error (i.e., erased). The Finishing Bits field includes a group of zeros used to reset the convolutional encoder to a known state at the end of the BCH message.

As shown in Table 5, the BCH message includes a total of 120 bits. These 120 bits may be transmitted by OFDM symbols using the processing described in more detail below.

Table 5 shows a specific embodiment of the format for the BCH message. Other BCH message formats with fewer fields, additional and (or) other fields can also be defined and used, and this is included in the scope of the invention.

2. Forward Control Channel (FCCH) - Downlink

In an embodiment, the access point is capable of allocating resources for the FCH (forward channel) and RCH (reverse channel) on a frame-by-frame basis. FCCH is used by an access point to transmit resource allocation for FCH and RCH (i.e., channel assignment).

5B illustrates an embodiment of FCCH PDU 420. In this embodiment, the FCCH PDU includes only a portion 520 for the FCCH message. The FCCH message has a variable duration, which can vary from frame to frame depending on the amount of scheduling information carried on the FCCH for that frame. The duration of the FCCH message is equal to the even number of OFDM symbols and is specified by the FCCH Length field in the BCH message. The duration of messages transmitted using the diversity mode (for example, BCH and FCCH messages) is set in an even number of OFDM symbols, because the diversity mode transmits OFDM symbols in pairs, as described below.

In an embodiment, the FCCH may be transmitted using four possible transmission rates. The specific transmission rate used for the FCCH PDU in each frame of the DTE is indicated by the PHY Mode FCCH field of the BCH message. Each FCCH transmission rate corresponds to a specific code rate and a particular modulation scheme and is further associated with a specific transmission mode, as shown in Table 26.

The FCCH message may include zero, one, or multiple information elements (IEs) (IE). Each information element may be associated with a particular user terminal and may be used to provide information indicating the assignment of FCH / RCH resources for that user terminal. Table 6 lists the various fields for an example FCCH message format.

Table 6
FCCH message Field / Parameter Names Length (bit) Description N_IE 6 The number of IEs included in the FCCH message Information elements N_IE, each of which includes: IE type four IE type ID UDS 10 ID assigned by user. terminal Control fields 48 or 72 Control Fields for Channel Assignment Pad bits Variables Padding bits to achieve an even number of OFDM symbols in the FCCH message CRC 16 CRC value for FCCH message Trailing bits 6 Finishing bits for a convolutional encoder

Field N_IE indicates the number of information elements included in the FCCH message sent in the current frame DDA. For each information element (IE) included in the FCCH message, the IE Type field indicates the specific type of this IE. The number of IE types is determined to be used to allocate resources for different types of transmissions, as described below.

The MAC ID field identifies the particular user terminal for which the information element is intended. Each user terminal is registered with an access point at the beginning of a communication session, and the access point assigns it a unique UDS ID. This MAC ID is used to identify the user terminal during the session.

The control fields are used to transmit channel assignment information for the user terminal and are described in more detail below. The padding bit field indicates a sufficient number of padding bits so that the total FCCH message length is equal to an even number of OFDM symbols. The FCCH CRC field includes a CRC value that can be used by user terminals to determine if the FCCH message is decoded correctly or in error. The trailing bit field includes zeros to reset the convolutional encoder to a known state at the end of the FCCH message. Some of these fields are described in more detail below.

A number of transmission modes are supported by the MWxMWSS system for FCH and RCH, as shown in Table 1. In addition, the user terminal may be active or in standby mode during the connection. Thus, a number of IE types are defined for use in allocating FCH / RCH resources for various types of transmissions. Table 7 lists an example set of IE types.

Table 7
IE Types FCCH IE type IE size (bit) IE type Description 0 48 Explode mode Explode mode only one 72 Spatial multiplexing mode Spatial Multiplexing Mode - Variable Speed Services 2 48 Free mode Free Mode - Variable Speed Services 3 48 RACH Notice RACH Notification - Diversity Mode four Beam control mode Beam control mode 5-15 - Reserved Reserved for future use.

For IE types 0, 1, and 4, resources are allocated to a particular user terminal for both FCH and RCH (i.e., in a pair of channels). For type 2 IEs, minimum resources are allocated to the user terminal in the FCH and RCH to maintain an updated line estimate. An example format for each type of IE is described below. In general, transmission rates and durations for FCH and RCH can be assigned to user terminals independently.

A. Types of IE 0, 4 - Diversity mode - beam control

IE types 0 and 4 are used to allocate FCH / RCH resources for diversity and beam control modes, respectively. For services with fixed low speeds (for example, voice), the transmission rate remains fixed during the call. For variable rate services, the transmission rate may be independently selected for FCH and RCH. The FCCH IE indicates the location of the PDUs in the FCH and RCH assigned to the user terminal. Table 8 lists the various fields of an example information element of type 0 and 4 IE.

Table 8
Type 0 and 4 IE FCCH Field / Parameter Names Length (bit) Description IE type four IE type ID UDS 10 Temporary ID assigned to user terminal Shift fch 9 FCH shift from the beginning of the DVR frame (in characters OFDM) Preamble Type FCH 2 FCH preamble size (in MORCH characters) FCH speed four Baud Rate for FCH RCH Shift 9 RCH shift from the beginning of the DVR frame (in characters OFDM) RCH Preamble Type 2 RCH Preamble Size (in MORCH Symbols) RCH speed four Baud Rate for RCH Sync adjustment Rch 2 RCH Sync Adjustment Option RCH power control 2 Power Control Bits for RCH

The FCH and RCH Shift fields indicate the time offset from the beginning of the current DTE frame to initiate the FBU and RCH PDUs, respectively, assigned by the information element. The FCH and RCH rate fields indicate the transmission rates for FCH and RCH, respectively.

The FCH and RCH preamble type fields indicate the size of the preamble in the PDU for FCH and RCH, respectively. Table 9 lists the values for the FCH and RCH preamble type fields and their associated preamble sizes.

Table 9
Preamble Type Type of Bits Preamble Size 0 00 0 characters MORCH one 01 1 character MORCH 2 10 4 characters MORCH 3 eleven 8 characters MORCH

The RCH Sync Adjustment field includes two bits used to adjust the uplink transmission synchronization from the user terminal identified by the MAC ID field. This timing adjustment is used to reduce interference in the structure of DVR-based frames (such as the one shown in FIG. 3A) when the downlink and uplink transmissions are time division duplex. Table 10 lists the values for the RCH Timing Adjustment field and the associated actions.

Table 10
RCH Timing Adjustment Bits Description 00 Keep current sync 01 Move forward uplink transmission timing by one count 10 Delay uplink transmission synchronization by 1 count eleven Not used

The RCH power control field includes two bits used to adjust the transmit power in the uplink transmission from the identified user terminal. This power control is used to reduce uplink interference. Table 11 lists the values for the RCH Power Management field and the associated actions.

Table 11
RCH power control Bits Description 00 Keep current sync 01 Increase the uplink transmit power by δ dB, where δ dB is a system parameter 10 Decrease uplink transmit power by δ dB, where δ dB is a system parameter eleven Not used

-го кадра ДВР, что упоминается как планирование с децимацией (прореживанием) кадров ДВР. Различные типы назначения могут указываться полем Тип назначения в информационном элементе FCCH.The channel assignment for the identified user terminal may be provided in various ways. In an embodiment, FCH / RCH resources are assigned to the user terminal only for the current frame of the DVR. In another embodiment, FCH / RCH resources are assigned to the terminal for each DTE frame until cancellation occurs. In yet another embodiment, FCH / RCH resources are assigned to a user terminal for each

-th frame of the DVR, which is referred to as planning with decimation (decimation) of the frames of the DVR. Different destination types can be indicated by the Destination Type field in the FCCH information element.

B. Type IE 1 - Spatial Multiplexing Mode

Type IE 1 is used to allocate FCH / RCH resources to user terminals using the spatial multiplexing mode. The baud rate for these user terminals is variable and can be independently selected for FCH and RCH. Table 12 lists the various fields of an example information element of Type IE 1.

Table 12
Type IE 1 FCCH Field / Parameter Names Length (bit) Description IE type four IE type ID UDS 10 Temporary ID assigned to user terminal Shift fch 9 FCH shift from the beginning of the DVR frame (in characters OFDM) Preamble Type FCH 2 FCH preamble size (in MORCH characters) Spatial Channel Speed 1 FCH four Baud rate for spatial channel 1 FCH Spatial Channel Speed 2 FCH four Baud rate for spatial channel 2 FCH Spatial Channel Speed 3 FCH four Baud rate for spatial channel 3 FCH Spatial Channel Speed 4 FCH four Baud rate for spatial channel 4 FCH RCH Shift 9 RCH shift from the beginning of the DVR frame (in characters OFDM) RCH Preamble Type 2 RCH Preamble Size (in MORCH Symbols) Spatial Channel Speed 1 RCH four Baud rate for spatial channel 1 RCH Spatial Channel Speed 2 RCH four Baud rate for RCH spatial channel 2 Spatial Channel Speed 3 RCH four Baud rate for spatial channel 3 RCH Spatial Channel Speed 4 RCH four Baud rate for RCH spatial channel 4 RCH Timing Adjustment 2 RCH Sync Adjustment Option Reserved 2 Reserved for future use.

For type IE 1, the transmission rate for each spatial channel may be independently selected on the FCH and RCH. The interpretation of the transmission rates for the spatial multiplexing mode consists, in general, in that it can determine the transmission rate per spatial channel (for example, for spatial channels of up to four in the embodiment shown in Table 12). The baud rate is set to be in its own mode if the transmitter performs spatial processing to transmit data in its own modes. The transmission rate is set to the antenna if the transmitter simply transmits data by the transmitting antennas and the receiver performs spatial processing to isolate and recover the data (for the spatial multiplexing mode without beam control).

The information element includes the transmission rates for all allowed spatial channels and zeros for not allowed. User terminals with less than four transmit antennas set the unused FCH / RCH Spatial Channel Velocity fields to zero. Since the access point has four transmit / receive antennas, user terminals with more than four transmit antennas can use them to transmit independent data streams of up to four.

C. Type IE 2 - Standby

Type IE 2 is used to provide control information for user terminals operating in the Standby state (described below). In an embodiment, when the user terminal is in the Standby state, the control vectors used by the access point and the user terminal for spatial processing are continuously updated so that data transmission can begin quickly when it resumes. Table 13 lists the various fields of an example IE 2 type information element.

Table 13
Type IE 2 FCCH Field / Parameter Names Length (bit) Description IE type four IE type ID UDS 10 Temporary ID assigned to user terminal Shift fch 9 FCH shift from the beginning of the DVR frame (in characters OFDM) Preamble Type FCH 2 FCH preamble size (in MORCH characters) RCH Shift 9 RCH shift from the beginning of the DVR frame (in characters OFDM) RCH Preamble Type 2 RCH Preamble Size (in MORCH Symbols) Reserved 12 Reserved for future use.

D. Type IE 3 - RACH Quick Notification

Type IE 3 is used to provide quick notification for user terminals trying to access the system through RACH. In order to access the system or send a short message to an access point, the user terminal may transmit the RACH PDUs on the uplink. After the user terminal sends the RACH PDU, it monitors the BCH to find if the RACH notification bit is set. This bit is set by the access point if any user terminal has successfully gained access to the system, and a notification is sent for at least one user terminal on the FCCH. If this bit is set, then the user terminal processes the FCCH for a notification sent to the FCCH. Information elements such as IE 3 are sent if the access point wishes to notify that it has correctly decoded the RACH PDUs from user terminals without assigning resources. Table 14 lists the different fields of an exemplary information element of type IE 3.

Table 14
Type IE 3 FCCH Field / Parameter Names Length (bit) Description IE type four IE type ID UDS 10 Temporary ID assigned to user terminal Reserved 34 Reserved for future use.

Single or multiple types of notifications can be determined and sent to the FCCH. For example, quick notification and appointment-based notification can be defined. A quick notification can be used to simply notify that the RACH PDU is received by the access point, but that no FCH / RCH resources are assigned to the user terminal. Assignment-based notification includes assignments for the FCH and / or RCH for the current frame of the DVR.

FCCH may be embodied in other ways and may also be transmitted in various ways. In one embodiment, the FCCH is transmitted at a single transmission rate that is signaled in a BCH message. This speed may be selected, for example, based on the lowest signal-to-noise-and-noise (S / N) (SNR) ratio of all user terminals for which FCCH is sent in the current DVR frame. Different transmission rates may be used for different DVR frames, depending on the channel conditions of the receiving user terminals in each DVR frame.

In another embodiment, the FCCH is implemented with multiple (e.g., four) FCCH subchannels. Each FCCH subchannel is transmitted at an excellent speed and is associated with an excellent required S / N to recover this subchannel. FCCH subchannels are transmitted in order from the lowest rate to the highest transmission rate. Each FCCH subchannel may or may not be transmitted in a given frame of the TDD. The first FCCH subchannel (with the lowest bit rate) is transmitted first and can be received by all user terminals. This FCCH subchannel indicates whether each of the remaining FCCH subchannels will be transmitted in the current DTE frame. Each user terminal may process the transmitted FCCH subchannels to obtain its FCCH information element. Each user terminal can complete FCCH processing if the following occurs: (1) failure to decode the current FCCH subchannel, (2) receive its FCCH information element in the current FCCH subchannel, or (3) all transmitted FCCH subchannels are processed. The user terminal may complete FCCH processing as soon as it encounters a failure to decode the FCCH because the FCCH subchannels are transmitted with increasing transmission rates, and it is unlikely that the user terminal could decode subsequent FCCH subchannels transmitted at higher transmission rates.

3. Random access channel (RACH) - uplink

RACH is used by user terminals to gain access to the system and send short messages to the access point. RACH operation is based on the Aloha Segmented Random Access Protocol, which is described below.

5C illustrates an embodiment of a RACH PBU 450. In this embodiment, the RACH PDU includes a preamble part 552 and a message part 554. Preamble portion 552 may be used to transmit a controlled reference (i.e., a controlled pilot) if the user terminal is equipped with multiple antennas. A controlled reference is a pilot signal consisting of a set of modulation symbols that undergoes spatial processing before transmitting on the uplink. Spatial processing allows the pilot signal to be transmitted on a particular eigenmode of the MVxxM channel. Processing for a guided reference is described in more detail below. Part 552 of the preamble has a fixed duration of at least 2 characters OFDM. Message part 554 carries a RACH message and has a variable duration. The duration of the RACH PBB is thus variable.

In an embodiment, four different transmission rates are supported for RACH. The specific rate used for each RACH message is indicated by a two-bit RACH data rate indicator (IDI) (DRI), which is embedded in the preamble of the RACH PDU, as shown in FIG. 5C. In an embodiment, four different message sizes are also supported for RACH. The size of the RACH message is indicated by the Duration of the message field included in the RACH message. Each RACH transmission rate supports 1, 2, 3, or 4 message sizes. Table 15 lists the four RACH rates, their associated coding and modulation parameters, and the message sizes supported by these RACH rates.

Table 15 RACH Transmission Rates RACH message sizes (in bits and characters of MORCH) Bit in sec / Hz Code rate Modulation ISD 96 bits 192 bits 384 bits 768 bits 0.25 0.25 Bpsk (1,1) 8 - - - 0.5 0.5 Bpsk (1, -1) four 8 - - one 0.5 QPSK (-1.1) 2 four 8 - 2 0.5 16 QAM (-1, -1) one 2 four 8

The RACH message contains short messages and access requests from the user terminal. Table 16 lists the various fields of an example RACH message format and the size of each field for each of four different message sizes.

Table 16 Field / Parameter Names RACH message sizes Description 96 bits 192 bits 384 bits 768 bits Message Duration 2 2 2 2 Message Duration Type PBB MAS four four four four RACH message type ID UDS 10 10 10 10 ID UDS Interval id 6 6 6 6 Interval ID Payload 44 140 332 716 Information bits CRC 24 24 24 24 CRC value for RACH message Trailing bits 6 6 6 6 Trailing bits

The Message Duration field indicates the size of the RACH message. The MAC PDU Type field indicates the type of RACH message. The MAC ID field contains a MAC ID that uniquely identifies the user terminal sending the RACH message. During initial access to the system, a unique MAC ID is not assigned to the user terminal. In this case, the registration of the MAC ID (for example, a specific value reserved for registration purposes) can be included in the MAC ID field. The interval ID field indicates the RACH control interval on which the RACH PDU was sent (synchronization and RACH transmission is described below). The Payload field includes information bits for the RACH message. The CRC field contains the CRC value for the RACH message, and the trailing bits field is used to reset the convolutional encoder for the RACH. The operation of RACH in conjunction with BCH and FCCH to access the system is described in more detail below.

RACH can also be implemented as a fast RACH (F-RACH) and a slow RACH (S-RACH). F-RACH and S-RACH can be designed to effectively support user terminals in various operating states. For example, F-RACH can be used by user terminals that are (1) registered by the system, (2) can compensate for their delays due to acknowledgment of receipt (RTP) (RTD) by the necessary forward bias of the synchronization of their transmissions, and (3) achieved the required C / Ш for work on F-RACH. S-RACH may be used by user terminals that cannot for any reason use F-RACH.

Various solutions can be used for F-RACH and S-RACH to facilitate quick access to the system at any time and minimize the amount of system resources needed to implement random access. For example, the F-RACH may use a shorter PDU, apply a weaker coding scheme, require the PDUs to arrive at approximately the same time in the access point, and use the Aloha segmented random access scheme. S-RACH can use a longer PDU, apply a stronger coding scheme, allow the S-RACH PDU to arrive at an access point not time-aligned, and use the non-segmented Aloha random access scheme.

For simplicity, the following description assumes that a single RACH channel is used for the MVxMVCH WLAN system.

4. Forward Channel (FCH) - Downlink

The FCH is used by an access point to transmit specific user data to a specific user terminal and paging / broadcast messages to a plurality of user terminals. The FCH may also be used to transmit pilot to user terminals. FCH may be allocated on a frame-by-frame basis. A number of FCH PDU types are provided, taking into account various FCH applications. Table 17 lists the set of FCH PDB types.

Table 17
Types of FCH PBBs The code Type PBB FCH Description 0 Message only Broadcast / FCH service / user paging message one Message and Preamble Message from FCH 2 Preamble only FCH Pending Status

The FCH PDU Type 0 is used to transmit search / broadcast messages and user messages / packets to the FCH and includes only messages / packets. (Data for a particular user terminal may be sent as a message or packet, and the two terms are used interchangeably herein). The FCH PDU Type 1 is used to transmit user packets and includes a preamble. The FCH PDU Type 2 includes only the preamble and has no message / packet, and is associated with FCH traffic in the Standby state.

5D illustrates an embodiment of an FCH PDU 430a for Type 0 FCH PDU. In this embodiment, the FCH PDU 430a includes only a message portion 534a for a search / broadcast message or user packet. The message / packet may have a variable length, which is specified by the FCH message length field in the FCH PDB. The message length is specified by the integer number of PHY frames (described below). The rate and transmission mode for the paging message / broadcast message are defined and described below. The rate and transmission mode for the user packet are defined in the associated FCCH information element.

5E illustrates an embodiment of an FCH PDU 430b for a Type 1 FCH PDU. In this embodiment, the FCH PDU 430b includes a preamble part 532b and a message / packet part 534b. The preamble portion 532b is used to transmit an MVxMOut or pilot reference pilot and has a variable length, which is determined by the FCH preamble type field in the associated FCCH information element. Part 534b is used to transmit the FCH packet and also has a variable length (total number of PHY frames), which is determined by the FCH message length field in the FCH PDU. An FCH packet is transmitted using the rate and transmission mode determined by the associated FCCH information element.

5F illustrates an embodiment of an FCH PDU 430c for a Type 2 FCH PDU. In this embodiment, the FCH PDU 430c includes only part of the preamble 532c and does not have a message part. The length of the preamble is indicated by the FCCH IE. The FCH PDU Type 2 may be used to enable the user terminal to update its channel estimate in the Standby state.

Several types of FCCH messages are provided, taking into account the different uses of the FCH. Table 18 lists an example set of FCH message types.

Table 18
FCH Message Types The code Type PBB FCH Description 0 Paging message Paging message - diversity mode, speed = 0.25 bits per second / Hz one Broadcast message Broadcast message - diversity mode, speed = 0.25 bits per second / Hz 2 Custom package Dedicated channel operation - user-specific PDU terminal, speed is defined in FCCH 3-15 Reserved Reserved for future use.

A paging message may be used for paging a plurality of user terminals and transmitted using FCH PDB Type 0. If the Paging Bit in the BCH message is set, then one or more PDUs with paging messages (or "Paging PDBs") are transmitted first on the FCH. In the same frame, multiple paging PDUs can be sent that are transmitted using the diversity mode and the lowest bit rate of 0.25 bits per second / Hz to increase the likelihood of user terminals receiving correctly.

A broadcast message can be used to transmit information to multiple user terminals, and is transmitted using Type 0 FCH PDUs. If the Broadcast Bit in the BCH message is set, then one or more FCH PDUs with broadcast messages (or "broadcast PDUs") are sent on the FCH immediately after the paging PDUs transmitted on the FCH. Broadcast PBUs are also transmitted using the diversity mode and the lowest bit rate of 0.25 bits per second / Hz to increase the likelihood of correct reception.

A user packet may be used to transmit specific user data, and may be transmitted using a Type 1 or 2 FCH PDU. Type 1 or 2 FCH PDUs are transmitted on the FCH following any paging PDUs and broadcast PDUs transmitted on the FCH. Each user PDU may be transmitted using diversity, beam control, or spatial multiplexing. FCCH information elements determine the rate and transmission mode used for each user PDU transmitted over the FCH.

A message or packet transmitted over the FCH contains an integer number of PHY frames. In an embodiment and as described below, each PHY frame may include a CRC value for checking individual PHY frames in the FCH PDU and, if necessary, retransmitting them. For synchronous services, RLP can be used to segment, retransmit, and reassemble PHY frames in a given FCH PDU. In another embodiment, a CRC value is provided for each message or packet instead of each PHY frame.

6 illustrates an embodiment of a structure for FCH packet 534. The FCH packet contains an integer number of 610 PHY frames. Each PHY frame includes a payload field 622, a CRC field 624, and terminating bit field 626. The first PHY frame for the FCH packet includes a header field 620 that indicates the type and duration of the message. The last PHY frame in the FCH packet includes an empty bit field 628 that contains zero padding bits at the end of the payload to populate the last PHY frame. In an embodiment, each PHY frame contains 6 OFDM symbols. The number of bits included in each PHY frame depends on the bit rate used for this FCH frame.

Table 19 lists the various fields for an exemplary FCH PDU format for FCH PDU Types 0 and 1.

Table 19
PBB format FCH Field / Parameter Names Length (bits) Description First frame PHY FCH Message Type four FCH Message Type FCH Message Length 16 The number of bits in the FCH PBB Payload Variable Payload Bits CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder Each middle frame PHY Payload Variable Payload Bits CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder Last PHY frame Payload Variable Payload Bits Empty bits Variable Empty bits to fill the PHY frame CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder

The FCH Message Type and FCH Message Length fields are transmitted in the header of the first PHY frame in the FCH PDU. The payload, CRC, and trailing bit fields are included in each PHY frame. A portion of the payload of each FCH PDU contains information bits for a paging / broadcast message or a specific user packet. The empty bits are used to fill the last PHY frame in the FCH PDU, if required.

A PHY frame may also be defined to include a different number of OFDM characters (for example, one, two, four, eight, etc.). A PHY frame can be determined by an even number of OFDM symbols because the OFDM symbols are transmitted in pairs in explode mode, which can be used for FCH and RCH. The PHY frame size may be selected based on expected traffic to improve efficiency. In particular, if the frame size is too large, then the decrease in efficiency is caused by the use of a large PHY frame to transmit a small amount of data. Alternatively, if the frame size is too small, then the overhead information represents most of the frame.

5. Return Channel (RCH) - Uplink

RCH is used by user terminals to transmit uplink data and pilot to an access point. RCH may be allocated to each frame of the DVR. One or more user terminals may be assigned for transmission on the RCH in any given frame of the DVR. There are several types of RCH PDUs, taking into account the different operating modes in the RCH channel. Table 20 lists an example set of RCH PDB types.

Table 20
Types of RCH PBBs The code PBB Type RCH Description 0 Message only Custom RCH message, without preamble one Message and Preamble, Not Pending RCH Custom Preamble Message 2 Message and Preamble, Pending State RCH Pending Status Message with Preamble

The RCH PDU Type 0 is used to transmit a message / packet on the RCH and does not include a preamble. The RCH PDU Type 1 is used for message / packet transmission and includes a preamble. The RCH PDU Type 2 includes a preamble and a short message and is associated with RCH channel traffic in the Standby state.

Fig. 5D illustrates an embodiment of an RCH PDU for Type 0 RCH PDU. In this embodiment, the RCH PDU includes only a message portion 534a for a variable length RCH packet with a given integer number of PHY frames The RCH message length field in the RCH PDU. The rate and transmission mode for the RCH packet are defined in the associated FCCH information element.

5E illustrates an embodiment of an RCH PDU for Type 1 RCH PDU. In this embodiment, the RCH PDU includes a preamble portion 532b and a packet portion 534b. The preamble portion 532b is used to transmit a reference (e.g., an MVxMOUT pilot or a controlled reference) and has a variable length, which is determined by the RCH preamble type field in the associated FCCH information element. Part 534b is used to transmit the RCH packet and also has a variable length, which is determined by the RCH message length field in the RCH PDU. An RCH packet is transmitted using the rate and transmission mode defined in the associated FCCH information element.

5G illustrates an embodiment of an RCH PDU 350d for Type 2 RCH PDU. In this embodiment, the RCH PDU includes a preamble part 532d and a message part 536d. The preamble portion 532d is used to transmit the reference, and has a length of 1, 4, or 8 OFDM symbols. Part 536d is used to transmit a short RCH message, and has a fixed length of one OFDM symbol. A short RCH message is transmitted using a specific rate and transmission mode (for example, 1/2 rate or 1/4 rate and DPSK modulation).

An RCH transmitted packet (for PDU Types 0 and 1) contains an integer number of PHY frames. The structure for the RCH packet (for PDU Types 0 and 1) is shown in FIG. 6 and is the same as for the FCH packet. The RCH packet contains an integer number of 610 PHY frames. Each PHY frame includes a payload field 622, an optional CRC field 624, and final bit field 626. The first PHY frame in the RCH packet includes a header field 620, and the last PHY frame in the packet includes an empty bit field 628.

Table 21 lists the various fields for an exemplary RCH PDU format for RCH PDU Types 0 and 1.

Table 21
RCH PBB format (Types 0 and 1 PBB) Field / Parameter Names Length (bits) Description First frame PHY RCH message type four RCH message type RCH message length 16 The number of bits in the RCH PBB FCH Speed Indicator 16 Indicates the maximum speed for each spatial channel on the FCH. Payload Variable Payload Bits CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder Each middle frame PHY Payload Variable Payload Bits CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder Last PHY frame Payload Variable Payload Bits Empty bits Variable Empty bits to fill the PHY frame CRC 16 CRC value for PHY frame (optional) Trailing bits 6 Finishing bits for a convolutional encoder

The RCH message type, RCH message length, and FCH rate indicator fields are transmitted in the header of the first PHY frame in the RCH PDU. The FCH speed indicator field is used to transmit FCH speed information (for example, the maximum transmission speeds supported by each of the spatial channels) to the access point.

Table 22 lists the various fields for an example RCH PDU format for Type 2 RCH PDUs.

Table 22
RCH message for RCH PDB Type 2 Field / Parameter Names Length (bits) Description FCH Speed Indicator 16 Indicates the maximum speed for each spatial channel on the FCH. RCH request one User terminal request to send additional data Reserved one Reserved for future use. Trailing bits 6 Finishing bits for a convolutional encoder

The RCH Request field is used by the user terminal to request additional uplink throughput. This short RCH message does not include CRC and is transmitted in a single OFDM symbol.

6. The activity of the selected channel

Data transmission on FCH and RCH can occur independently. Depending on the transmission modes selected for using FCH and RCH, one or a plurality of spatial channels (for beam control and diversity modes) may be active and used to transmit data for each dedicated transport channel. Each spatial channel may be associated with a particular transmission rate.

When only the FCH or only the RCH has all four transmission rates set to zero, the user terminal is idle on this line. The idle terminal still transmits the Waiting PDUs on the RCH. When both FCH and RCH have all four transmission rates set to zero, then both the access point and the user terminal are turned off and not transmitting. User terminals with less than four transmit antennas set the fields of unused transmission rates to zero. User terminals with more than four transmit antennas use no more than four spatial channels for data transmission. Table 23 shows the transmission status and channel activity when the transmission rates in all four spatial channels of each of the FCH or RCH (or both) are set to zero.

Table 23 FCH speeds RCH speeds Channel activity Transmission Status At least one speed on FCH ≠ 0 At least one RCH скорость 0 channel speed FCH and RCH are active FCH and / or RCH transmit At least one speed on FCH ≠ 0 All speeds on the channel RCH = 0 FCH active, RCH pending All speeds at FCH = 0 At least one RCH скорость 0 channel speed FCH pending, RCH active All speeds at FCH = 0 All speeds on the channel RCH = 0 FCH and RCH are off No gears

There may also be a situation where both the FCH and the RCH are idle (i.e., not transmitting data), but still transmit the preamble. This is defined as a wait state. The control fields used to keep the user terminal in the Standby state are provided in the Type 2 information element of the FCCH IE, which is shown in Table 13.

7. Alternative schemes

For clarity, for an example circuit, specific PBB types, PBB structures, message formats, etc. are described. For use, their smaller number, additional and (or) various types can also be determined, which is also included in the scope of the invention.

III. OFDM subband structures

In the above description, the same sub-band OFDM structure is used for all transport channels. Improved efficiency can be achieved by using different sub-band structures of OFDM for different transport channels. For example, a 64-subband structure may be used for some transport channels, a 256-subband structure may be used for other transport channels, etc. In addition, many sub-band OFDM structures may be used for a given transport channel.

For a given system bandwidth W, the OFDM symbol duration depends on the total number of subbands. If the total number of subbands is N, then the duration of each transformed symbol (without a cyclic prefix) is N / W μs (if W is specified in MHz). A cyclic prefix is added to each converted character to form the corresponding MORCH character. The length of the cyclic prefix is determined by the expected delay extension in the system. The cyclic prefix represents the overhead information that is needed for each OFDM symbol to process a frequency selective channel. This overhead represents a larger fraction of the MORC symbol if this symbol is short and a smaller fraction if the symbol is long.

Since different transport channels are associated with different types of traffic data, a suitable sub-band structure of the OFDM can be selected for use for each transport channel to match the expected type of traffic data. If it is expected that a large amount of data will be transmitted in a given transport channel, a larger subband structure for use for the transport channel can be determined. In this case, the cyclic prefix will represent a smaller fraction of the OFDM symbol, and greater efficiency can be achieved. Conversely, if it is expected that a small amount of data will be transmitted in a given transport channel, then a smaller subband structure for use for the transport channel can be determined. In this case, even if the cyclic prefix represents a larger fraction of the OFDM symbol, greater efficiency can still be achieved by reducing the amount of excessive bandwidth by using the smaller OFDM symbol. The OFDM symbol can thus be regarded as a “container” that is used for data transmission, a “container” of the proper size can be selected for each transport channel depending on the amount of data expected to be transmitted.

For example, for the embodiment described above, data on the FCH and RCH is transmitted in PHY frames, each of which contains 6 OFDM symbols. In this case, for use for the FCH and RCH, a different OFDM structure may be defined. For example, a 256-subband structure may be defined for FCH and RCH. The “large” OFDM symbol for a 256-subband structure will be approximately four times longer than the “small” OFDM symbol for a 64-subband structure, but will have four times greater data transfer capability. However, for one large OFDM symbol, only one cyclic prefix is needed, whereas for equivalent four small OFDM symbols, four cyclic prefixes are needed. Thus, overhead for cyclic prefixes can be reduced by 75% using a larger 256-subband structure.

This concept can be expanded so that different sub-band OFDM structures can be used for the same transport channel. For example, RCH supports various types of PBBs, each of which may be associated with a specific size. In this case, a larger sub-band structure can be used for the larger RCH PDU type, and a smaller sub-band structure can be used for the smaller RCH PDU type. A combination of different subband structures can also be used for a given PBB. For example, if one long OFDM character is equivalent to four short OFDM characters, then PBBs can be transmitted using N _large large OFDM characters and N _small small OFDM characters, where N is _large ≥ 0 and 3 ≥ N is _small ≥ 0.

The various subband structures of the OFDM are associated with the OFDM symbols of various lengths. Thus, if different sub-band OFDM structures are used for different transport channels (and / or for the same transport channel), then it is necessary to determine the FCH and RCH offsets for the FCH and RCH PDUs with an appropriate temporal resolution that is less than the symbol period MORCH. In particular, the time increment for the FCH and RCH PBBs can be specified in integers of the cyclic prefix length instead of the OFDM symbol period.

IV. Speeds and transmission modes

The transport channels described above are used to transmit various types of data for various services and functions. Each transport channel may be designed to support one or more speeds and one or more transmission modes.

1. Transmission Modes

For transport channels, several transmission modes are supported. Each transmission mode is associated with a particular spatial processing at the transmitter and receiver, as described below. Table 24 lists the transmission modes supported by each of the transport channels.

Table 24 Transport channels Transmission Modes OWxMOut Diversity Beam control Prost. multiplex. BCH - X - FCCH - X - - Rach X - X - Fch - X X X Rch X X X X

For the diversity mode, each data symbol is transmitted redundantly through a plurality of antennas, a plurality of subbands, a plurality of symbol periods, or combinations thereof to realize spatial, frequency, and / or temporal diversity. For the beam control mode, a single spatial channel is used for data transmission (usually the best spatial channel), and each data symbol is transmitted in a single spatial channel using the total transmit power available for transmitting antennas. For the spatial multiplexing mode, a plurality of spatial channels are used for data transmission, and each data symbol is transmitted on one spatial channel, the spatial channel may correspond to its own mode, transmitting antenna, etc. The beam control mode can be considered as a special case of the spatial multiplexing mode, and only one spatial channel is used for data transmission.

Diversity mode can be used for common transport channels (BCH and FCCH) for the downlink from the access point to user terminals. Diversity mode can also be used for dedicated transport channels (FCH and RCH). The use of diversity mode on the FCH and RCH may be negotiated upon call setup. The diversity mode transmits data in one “spatial channel” using a pair of antennas for each subband.

The beam control mode can be applied on the RACH channel by user terminals with multiple transmit antennas. The user terminal may evaluate the MVxMVy channel based on the MVxMVy pilot sent over the BCH channel. This channel estimate can then be used to perform beam control on the RACH to access the system. The beam control mode can also be used for dedicated transport channels (FCH and RCH). The beam control mode can provide a higher ratio of the received signal to noise and interference (S / N) in the receiver than the diversity mode due to the use of antenna array gain in the transmitter. In addition, part of the PBB preamble can be reduced, since the managed reference includes only symbols for a single “controlled” antenna. Diversity mode can also be used for the RACH channel.

The spatial multiplexing mode can be used for FCH and RCH to achieve higher throughput supported by channel conditions. The spatial multiplexing and beam control modes are controlled by reference and require closed loop control for proper operation. Essentially, resources are allocated to the user terminal in both the FCH and the RCH to support the spatial multiplexing mode. The FCH and RCH can support up to four spatial channels (limited by the number of antennas at the access point).

2. Coding and modulation

A number of different transmission rates are supported for transport channels. Each rate is associated with a specific coding rate and a specific modulation scheme, which together is manifested in a specific spectral efficiency (or data rate). Table 25 lists the various baud rates supported by the system.

Table 25 Speed word Spectral Efficiency (bits per second / Hz) Code rate Modulation scheme Information bits / character MORCH Code bits / character MORCH 0000 0,0 - absent - - 0001 0.25 1/4 Bpsk 12 48 0010 0.5 1/2 Bpsk 24 48 0011 1,0 1/2 QPSK 48 96 0100 1,5 3/4 QPSK 72 96 0101 2.0 1/2 16 QAM 96 192 0110 2,5 5/8 16 QAM 120 192 0111 3.0 3/4 16 QAM 144 192 1000 3,5 7/12 64 QAM 168 288 1001 4.0 2/3 64 QAM 192 288 1010 4,5 3/4 64 QAM 216 288 1011 5,0 5/6 64 QAM 240 288 1100 5.5 11/16 256 QAM 264 384 1101 6.0 3/4 256 QAM 288 384 1110 6.5 13/16 256 QAM 312 384 1111 7.0 7/8 256 QAM 336 384

Each common transport channel supports one or more transmission rates and one transmission mode (or, possibly, more, as in the case of the RACH channel). BCH is transmitted at a fixed speed using the diversity mode. FCCH can be transmitted at one of the possible speeds, as indicated by the Phy FCCH Mode field in the BCH message, using the diversity mode. In one embodiment, the RACH may be transmitted at one of the possible speeds, as indicated by the RACH IDD embedded in the RACH PDU preamble, and each RACH message has one of four possible sizes. In another embodiment, the RACH is transmitted at a single speed. Table 26 lists the encoding, modulation, and transmission parameters and message sizes supported by each transport channel.

Table 26
Parameters for shared transport channels Transport channel Spectrum. efficiency (bits per second / Hz) Coding rate Modulation scheme Transmission mode Message Size BCH 0.25 1/4 Bpsk Explode 120 bits 10 Char MORCH FCCH 0.25 1/4 Bpsk Explode AC AC “ 0.5 1/2 Bpsk Explode AC AC “ 1,0 1/2 QPSK Explode AC AC “ 2.0 1/2 16 QAM Explode AC AC Rach 0.25 1/4 Bpsk Beam control 96 8 “ 0.5 1/2 Bpsk Beam control 96, 192 4, 8 “ 1,0 1/2 QPSK Beam control 96, 192, 384 2, 4, 8 “ 2.0 1/2 16 QAM Beam control 96, 192, 384, 768 1, 2, 4, 8

The FCCH message is variable in size and is specified by an even number of OFDM characters.

FCH and RCH support all the rates listed in Table 25. Table 27 lists the encoding, modulation, and transmission parameters and message sizes supported by FCH and RCH.

Table 27
Parameters for FCH and RCH PHY frame size Code bits Modulation Symbols Symbols MORCH 0.25 ^A 1/4 Bpsk 72 72 144 288 6 0.5 1/2 Bpsk 144 144 288 288 6 1,0 1/2 QPSK 288 288 576 288 6 1,5 3/4 QPSK 432 144 576 288 6 2.0 1/2 16 QAM 576 576 1152 288 6 2,5 5/8 16 QAM 720 432 1152 288 6 3.0 3/4 16 QAM 864 288 1152 288 6 3,5 7/12 64 QAM 1008 720 1728 288 6 4.0 2/3 64 QAM 1152 576 1728 288 6 4,5 3/4 64 QAM 1296 432 1728 288 6 5,0 5/6 64 QAM 1440 288 1728 288 6 5.5 11/16 256 QAM 1584 720 2304 288 6 6.0 3/4 256 QAM 1728 576 2304 288 6 6.5 13/16 256 QAM 1872 432 2304 288 6 7.0 7/8 256 QAM 2016 288 2304 288 6

Note A: each bit of the code at 1/2 rate is repeated in two subbands to obtain an effective code rate of 1/4. Parity bits represent redundant bits introduced by coding and are used by the receiver to correct errors.

The PHY frame size in Table 27 indicates the number of code bits, modulation symbols, and OFDM symbols for each PHY frame. If 48 data subbands are used for data transmission, then each OFDM symbol includes 48 modulation symbols. For the diversity and beam control modes, one symbol stream is transmitted, and the PHY frame size corresponds to the only bit rate used for this symbol stream. For the spatial multiplexing mode, a plurality of symbol streams may be transmitted in a plurality of spatial channels, and the total PHY frame size is found by summing the PHY frame sizes for the individual spatial channels. The PHY frame size for each spatial channel is determined by the speed used for that spatial channel.

As an example, suppose that the MVxMvch channel is capable of supporting four spatial channels operating at spectral efficiencies of 0.5, 1.5, 4.5 and 5.5 bits per second / Hz. The four bit rates selected for the four spatial channels will correspond to those shown in Table 28.

Table 28
Approximate transmission with spatial multiplexing Channel space index Spectrum. efficiency (bits per second / Hz) Code rate Modulation scheme Payload (bits / frame PHY) PHY frame size Code bits Modulation Symbols Symbols MORCH one 0.5 1/2 Bpsk 144 288 288 6 2 1,5 3/4 QPSK 432 576 288 6 3 4,5 3/4 64 QAM 1296 1728 288 6 four 5.5 11/16 256 QAM 1584 2304 288 6

The total PHY frame size is then 144 + 432 + 1296 + 1584 = 3456 information bits or 288 + 576 + 1728 + 2304 = 4896 code bits. Even though each of the four spatial channels supports a different number of payload bits, the overall PHY frame can be transmitted in 6 OFDM symbols (for example, 24 μs, assuming 4 μs per OFDM symbol).

V. Physical layer processing

FIG. 7 shows a block diagram of an embodiment of an access point 110x and two user terminals 120x and 120y with an MwxMWL system.

In the downlink at access point 110x, a transmit (TX) data processor 710 receives traffic data (ie, information bits) from a data source 708 and signaling and other information from a controller 730 and possibly a scheduler 734. These various data types can be transmitted in different transport channels. The TX data processor 710 “frames” the data (if necessary), scrambles the cropped / unframed data, encodes the scrambled data, interleaves (i.e. reorders) the encoded data, and maps the interleaved data to modulation symbols. For simplicity, the term "data symbol" refers to a modulation symbol for traffic data, and the term "pilot symbol" refers to a modulation symbol for a pilot signal. Scrambling randomizes data bits. Coding increases the reliability of data transmission. Interleaving provides temporal, frequency and / or spatial diversity for code bits. Scrambling, coding, and modulation may be performed based on control signals provided by the controller 730, and are described in more detail below. The TX data processor 710 provides a modulation symbol stream for each spatial channel used for data transmission.

The TX spatial processor 720 receives one or more modulation symbol streams from the TX data processor 710 and performs spatial processing of the modulation symbols to obtain four streams of transmitted symbols, one stream for each transmit antenna. Spatial processing is described in more detail below.

Each modulator (MOD) (MOD) 722 receives and processes a corresponding stream of transmitted symbols to provide a corresponding stream of characters OFDM. Each OFDM symbol stream is further processed to provide a corresponding modulated downlink signal. Four modulated downlink signals from modulator 722a through 722d are then transmitted by four antennas 724a through 724d, respectively.

At each user terminal 120, one of the plurality of antennas 752 receives the transmitted downlink modulated signals, and each receive antenna supplies the received signal to a corresponding demodulator (DEMOD) 754. Each demodulator 754 performs processing complementary to that performed by the modulator 722 and provides received characters. A receive (RX) (RX) spatial processor 760 then performs spatial processing of the received symbols from all demodulators 754 to obtain recovered symbols, which are estimates of the modulation symbols transmitted by the access point.

The PXP data processor 770 receives and demultiplexes the recovered symbols into their respective transport channels. For the recovered symbols for each transport channel, symbol-wise reverse mapping, de-interleaving, decoding, and descrambling may be performed to obtain decoded data for this transport channel. The decoded data for each transport channel may include recovered packet data, messages, signaling, etc., which are provided to a data receiver 772 and / or a controller 780 for further processing.

The processing by access point 110 and downlink terminal 120 is described in more detail below. The processing for the uplink may be the same or different from the processing for the downlink.

For the downlink in each active RXP user terminal 120, the spatial processor 760 estimates the downlink to obtain channel status information (CSI). The CSI may include estimates of channel responses, S / N ratios for the received signal, etc. The PXP data processor 770 may also provide downlink packet / frame status. Controller 780 receives channel status information and packet / frame status and determines feedback information to be transmitted back to the access point. This feedback information is processed by the TX data processor 790 and the TX spatial processor 792 (if any), converted by one or more modulators 754, and transmitted by one or more antennas 752 back to the access point.

At access point 110, the transmitted uplink signal (s) are received by antennas 724, demodulated by demodulators 722, and processed by the RLP spatial processor 740 and the RLP data processor 742 in a complementary manner to what was performed in the user terminal. The restored feedback information is then supplied to the controller 730 and the scheduler 734.

Scheduler 734 uses feedback information to perform a number of functions, such as (1) selecting a set of user terminals for downlink and uplink data transmission, (2) selecting speed (s) and transmission mode for each selected user terminal, and (3) Assigning available FCH / RCH resources to selected terminals. Scheduler 734 and / or controller 730 then use information (e.g., vector control) obtained from the uplink transmission to process the downlink transmission, as described in more detail below.

A number of transmission modes are supported for downlink and uplink data transmission. The processing for each of these transmission modes is described in more detail below.

1. Diversity Mode — Transmission Processing

FIG. 8A shows a block diagram of an embodiment of a transmitting unit 800 for performing transmission processing for a diversity mode. The transmitting unit 800 may be used for the transmitting part of the access point and user terminal.

In the transmit data processor 71-a, the frame-forming unit 808 “frames” the data for each packet to be transmitted on the FCH and RCH. Framing is not necessary for other transport channels. Framing may be performed, as illustrated in FIG. 6, to generate one or more PHY frames for each user packet. The scrambler 810 then scrambles the framed / unframed data for each transport channel to randomize the data.

Encoder 812 receives and encodes the scrambled data in accordance with a selected coding scheme to provide code bits. The repeat / decimation unit 814 then repeats or decimates (i.e., erases) some of the code bits to obtain the desired code rate. In an embodiment, encoder 812 is a binary convolutional encoder with a rate of 1/2 and a restriction length of 7. A code rate of 1/4 can be obtained by repeating each code bit once. Code rates greater than 1/2 can be obtained by erasing some of the code bits from encoder 812. The specific construction of a framing unit 808, a scrambler 810, an encoder 812, and a repeat / decimation unit 814 are described below.

The interleaver 818 then interleaves (i.e., reorders) the code bits from block 814 based on the selected interleaving scheme. In an embodiment, each group of successive code bits to be transmitted in a given spatial channel is expanded across 48 data subbands (or data subbands) to provide frequency diversity. Interleaving is described in more detail below.

The character mapping unit 820 then displays the interleaved data in accordance with a particular modulation scheme to obtain modulation symbols. As shown in Table 26, BPSK, 4 QAM, or 16 QAM may be used for the diversity mode, depending on the selected transmission rate. In explode mode, the same modulation scheme is used for all data subbands. Symbol-by-symbol mapping can be achieved (1) by grouping sets of B bits to form B-bit values, where B ≥ 1, and (2) by displaying each B-bit value for a point in the signal group corresponding to the selected modulation scheme. Each displayed signal point is a complex value and corresponds to a modulation symbol. A character mapping unit 820 provides a modulation symbol stream to the transmit processor TX diversity processor 720a.

In an embodiment, the diversity mode uses the space-time transmission diversity (STTD) to double transmit diversity on the subbands. PVRP supports simultaneous transmission of independent symbol streams by two transmitting antennas while maintaining orthogonality in the receiver.

и

, подлежат передаче в заданном поддиапазоне. Передатчик генерирует два вектора

и

, где "

" обозначает сопряженное значение, а "

" означает транспонирование. Каждый вектор включает в себя два элемента, которые подлежат передаче двумя передающими антеннами в одном символьном периоде. (Т.е. вектор

передается двумя антеннами в первый символьный период, а вектор

передается двумя антеннами в следующий символьный период).Scheme PVRP works as follows. Suppose two modulation symbols, denoted as

and

are to be transmitted in a given subband. The transmitter generates two vectors

and

where "

"denotes the conjugate value, and"

"means transposition. Each vector includes two elements that are to be transmitted by two transmitting antennas in one symbol period. (i.e., a vector

transmitted by two antennas in the first symbol period, and the vector

transmitted by two antennas in the next symbol period).

If the receiver is equipped with a single receiving antenna, then the received symbols can be expressed as:

и

являются двумя символами, принятыми в приемнике в двух следующих друг за другом символьных периодах;Where

and

are two characters received at the receiver in two consecutive symbol periods;

и

являются коэффициентами усиления трассы от двух передающих антенн к приемной антенне для рассматриваемого поддиапазона, причем усиления трассы предполагаются постоянными по поддиапазону и статическими по двухсимвольному периоду; и

and

are the amplification factors of the path from two transmitting antennas to the receiving antenna for the subband under consideration, and the path gain is assumed to be constant over the subband and static over the two-character period; and

и

являются шумами, связанными с двумя принятыми символами

и

, соответственно.

and

are noises associated with two received characters

and

, respectively.

и

следующим образом:The receiver may then obtain estimates of the two transmitted symbols

and

in the following way:

и

и передавать эти два вектора последовательно в двух символьных периодах двумя передающими антеннами. Принятые символы могут затем быть выражены как:Alternatively, the transmitter may generate two vectors

and

and transmit these two vectors sequentially in two symbol periods by two transmit antennas. Accepted characters can then be expressed as:

The receiver may then obtain estimates of the two transmitted characters as follows:

и

, подлежат передаче на заданном поддиапазоне

. Передатчик генерирует два вектора

и

, или, эквивалентно, два набора символов

и

. Каждый набор символов включает в себя два элемента, которые подлежат передаче последовательно в двух символьных периодах соответствующей передающей антенной в поддиапазоне

(т.е. набор символов

передается в поддиапазоне

из антенны

в двух символьных периодах, а набор

символов передается в поддиапазоне

антенной

в том же самом двухсимвольном периоде).The above description may be extended to a MWxMWSS system with two or more transmit antennas, N _R receive antennas, and multiple subbands. Two transmit antennas are used for any given subband. Suppose two modulation symbols, denoted as

and

to be transmitted on a given subband

. The transmitter generates two vectors

and

, or, equivalently, two character sets

and

. Each symbol set includes two elements that are to be transmitted sequentially in two symbol periods by a corresponding transmitting antenna in a subband

(i.e. character set

transmitted in subband

from antenna

in two character periods, and the set

characters transmitted in a subrange

antenna

in the same two-character period).

The vectors of the received symbols in the receiving antennas in two symbol periods can be expressed as:

и

являются двумя символьными векторами, принятыми в двух следующих друг за другом символьных периодах на поддиапазоне

в приемнике, причем каждый вектор включает в себя

принятых символов для

приемных антенн;Where

and

are two symbol vectors received in two consecutive symbol periods on a subband

in the receiver, with each vector including

accepted characters for

receiving antennas;

и

являются векторами коэффициентов усиления трассы от двух передающих антенн

и

к

приемным антеннам для поддиапазона

, причем каждый вектор включает в себя усиления каналов от связанной с ним передающей антенны к каждой из

приемных антенн, где усиления трассы предполагаются постоянными по поддиапазону и статическими за двухсимвольный период; и

and

are trace gain vectors from two transmit antennas

and

to

receiving antennas for subband

wherein each vector includes channel gains from its associated transmit antenna to each of

receiving antennas, where the path gain is assumed to be constant over the subband and static over a two-character period; and

и

являются шумовыми векторами, связанными с двумя принятыми векторами

и

, соответственно.

and

are noise vectors associated with two received vectors

and

, respectively.

и

следующим образом:The receiver may then extract estimates of the two transmitted symbols

and

in the following way:

и

символов и передавать эти наборы символов двумя передающими антеннами

и

. Векторы принятых символов могут тогда быть выражены как:Alternatively, the transmitter may generate two sets

and

characters and transmit these character sets with two transmit antennas

and

. The vectors of the received symbols can then be expressed as:

The receiver may then isolate the estimates of the two transmitted symbols as follows:

The PVRP scheme is described in S.M. Alamouti "A Simple Transmit Diversity Technique for Wireless Communications", IEEE Journal on Selected Areas in Communications, Vol. 16, No. 8, October 1998, pp. 1451-1458. The PVRP scheme is also described in US patent application No. 09 / 737.602 on "A method and system for increasing the bandwidth efficiency in channels with multiple inputs and multiple outputs", filed January 5, 2001, and in US patent application No. 10 / 179.439 on "Modes diversity transmissions for MVXMVCH OF communication systems "), filed June 24, 2002.

The PVRP scheme efficiently transmits one modulation symbol per subband by two transmit antennas in each symbol period. However, this PVRP scheme distributes information in each modulation symbol over two consecutive OFDM symbols. Thus, the symbol recovery at the receiver is performed based on two consecutive received OFDM symbols.

The PVRP scheme uses one pair of transmit antennas for each data subband. Since the access point includes four transmit antennas, each antenna can be selected for use for half of the 48 data subbands. Table 29 lists exemplary subband antenna assignment schemes for the STPD scheme.

Table 29 Subband Indices PRD antenna Bit index Subband Indices PRD antenna Bit index Subband Indices PRD antenna Bit index Subband Indices PRD antenna Bit index - - - -13 1,2 26 one 3.4 one fifteen 1,2 33 -26 1,2 0 -12 3.4 32 2 1,2 7 16 2,4 39 -25 3.4 6 -eleven 1,1 38 3 2,4 13 17 1.3 45 -24 1.3 12 -10 2,4 44 four 1.3 19 eighteen 2,3 5 -23 2,4 eighteen -9 1.4 four 5 2,3 25 19 1.4 eleven -22 1.4 24 -8 2,3 10 6 1.4 31 twenty 3.4 17 -21 one P0 -7 2 P1 7 3 P2 21 four P3 -twenty 2,3 thirty -6 1,2 16 8 3.4 37 22 1,2 23 -19 1,2 36 -5 3.4 22 9 1,2 43 23 2,4 29th -eighteen 3.4 42 -four 1.3 28 10 2,4 3 24 1.3 35 -17 1.3 2 -3 2,4 34 eleven 1.3 9 25 2,3 41 -16 2,4 8 -2 1.4 40 12 2,3 fifteen 26 1.4 47 -fifteen 1.4 fourteen -one 2,3 46 13 1.4 21 - - - -fourteen 2,3 twenty 0 - - fourteen 3.4 27 - - -

As shown in Table 29, transmit antennas 1 and 2 are used for subbands with indices -26, -19, -13, etc., transmit antennas 2 and 4 are used for subbands with indices -25, -18, -12 and t etc., transmitting antennas 1 and 3 are used for subbands with indices -24, -17, -11, etc. There are six different antenna pairs for four transmit antennas. Each of the six antenna pairs is used for 8 subbands, which are distributed approximately evenly across 48 data subbands. Antenna pairs are assigned to the subbands so that different antennas are used in adjacent subbands, which can provide greater frequency and spatial diversity. For example, antennas 1 and 2 are used for the -26 subband, and antennas 3 and 4 are used for the -25 subband.

The assignment of the antenna subbands in Table 29 is such that four transmit antennas are used for each code bit for the lowest transmission rate of 1/4, which can maximize spatial diversity. For a rate of 1/4, each code bit is repeated and transmitted in two subbands (also called double-repetition coding). The two subbands used for each code bit are mapped to different antenna pairs so that all four antennas are used to transmit this code bit. For example, bit indices 0 and 1 in Table 29 correspond to the same code bit for explode mode, where bit with index 0 is transmitted by antennas 1 and 2 in subband -26, and bit with index 1 is transmitted by antennas 3 and 4 in subband 1 As another example, bit indices 2 and 3 in Table 29 correspond to the same code bit, where the bit with index 2 is transmitted by antennas 1 and 3 in the subband -17, and the bit with index 3 is transmitted by antennas 2 and 4 in the subband 10 .

и

, генерируются и отображаются на два смежных поддиапазона символа МОРЧ. Для ПЧРП передатчик будет передавать символы

и

двумя антеннами в поддиапазоне

и будет передавать символы

и

теми же самыми двумя антеннами в поддиапазоне

. Смежные поддиапазоны используются для пары символов модуляции, потому что канальный отклик предполагается постоянным для передачи этих двух пар символов. Обработка в приемнике для восстановления символов модуляции является той же самой, что и для схемы ПВРП за исключением того, что обрабатываются принятые символы для двух поддиапазонов вместо двух символьных периодов МОРЧ.The system may support other transmission diversity schemes, and this is within the scope of the invention. For example, a system may support spatial frequency transmit diversity (PFD) (SFTD), which may provide spatial and frequency diversity based on subband pairs. An exemplary PCRP scheme works as follows. Suppose two modulation symbols, denoted as

and

are generated and mapped onto two adjacent subranges of the OFDM symbol. For IFR, the transmitter will transmit characters

and

two antennas in the subband

and will transmit characters

and

the same two subband antennas

. Adjacent subbands are used for a pair of modulation symbols because the channel response is assumed to be constant for the transmission of these two symbol pairs. The receiver processing for modulation symbol recovery is the same as for the STDP scheme except that the received symbols are processed for two subbands instead of two OFDM symbol periods.

FIG. 8B shows a block diagram of an embodiment of an TX of an explode processor 720a implementing an STD scheme for an explode mode.

модуляции из ПРД процессора 710а данных в 48 подпотоков, обозначенных как

-

, для 48 поддиапазонов данных. Каждый поток символов модуляции для каждого символьного периода включает в себя один символ модуляции, который соответствует скорости передачи символов (Т_МОРЧ)^-1, где Т_МОРЧ представляет собой длительность одного символа МОРЧ. Каждый поток символов модуляции подается на соответствующий ПРД процессор 840 поддиапазонного разнесения.In the TX transmit processor 720a, a demultiplexer 832 receives and demultiplexes a symbol stream

modulations from the data processor of the data processor 710a into 48 substreams designated as

-

, for 48 data subbands. Each modulation symbol stream for each symbol period includes one modulation symbol, which corresponds to a symbol transmission rate (T _OFDM ) ^-1 , where T _OFDM is the duration of one OFDM symbol. Each modulation symbol stream is supplied to a corresponding subband diversity processor 840.

и

в двух последовательностях, чтобы сформировать два символьных набора

и

для двух передающих антенн. Каждый набор символов включает в себя два символа, по одному символу от каждой из двух последовательностей. Набор

символов генерируется путем обеспечения символа

первым, а символа

следующим, где

получается через переключатель 856а, а

получается взятием сопряженной величины от

блоком 852а и задержкой сопряженного символа на один символьный период блоком 854а задержки. Аналогично, набор

символов генерируется путем обеспечения символа

первым, а символа

следующим, где

получается посредством переключателя 856b, а

получается взятием отрицательной сопряженной величины от

блоком 852b и задержкой отрицательного сопряженного символа на один символьный период блоком 854b задержки. Два набора

и

символов подлежат передаче двумя антеннами

и

, назначенными поддиапазону, как указывается в Таблице 29. Пространственно-временной кодер 850 обеспечивает первый набор

символов в буфер/мультиплексор 870 для первой передающей антенны

, а второй набор

символов в другой буфер/мультиплексор 870 для второй передающей антенны

. Два символа, обеспеченные пространственно-временным кодером 850 для каждого символьного периода, называются символами ПВРП.In each TX subband diversity transmit processor 840, a demultiplexer 842 demultiplexes demodulation symbols for a subband in two symbol sequences, each sequence having a symbol rate (2T _OFDM ) ^-1 . The space-time encoder receives two sequences of modulation symbols and uses two symbols for each two-character period

and

in two sequences to form two character sets

and

for two transmit antennas. Each character set includes two characters, one character from each of the two sequences. Set

characters generated by providing a character

first and character

next where

obtained through switch 856a, and

obtained by taking the conjugate

block 852a and a conjugate symbol delay of one symbol period by delay block 854a. Similarly, the set

characters generated by providing a character

first and character

next where

obtained by the switch 856b, and

obtained by taking the negative conjugate quantity from

block 852b and a negative conjugate symbol delay of one symbol period by delay block 854b. Two sets

and

characters to be transmitted by two antennas

and

assigned to a subband as indicated in Table 29. The time-space encoder 850 provides a first set

characters to buffer / multiplexer 870 for the first transmitting antenna

, and the second set

characters to another buffer / multiplexer 870 for the second transmit antenna

. The two symbols provided by the space-time encoder 850 for each symbol period are referred to as PVRP symbols.

The buffers / multiplexers 870a-870d are used to buffer and multiplex the STD symbols from all diversity processors 840. Each buffer / multiplexer 870 receives pilot symbols and STRP symbols from the corresponding TX subband diversity transmit processor 840, as determined by Table 29. For example, buffer / multiplexer 870a receives modulation symbols for subbands -26, -24, -22, -19, etc. . (i.e., all subbands mapped to antenna 1), buffer / multiplexer 870b receives modulation symbols for subbands -26, -23, -20, -19, etc. (i.e., all subbands mapped to antenna 2), buffer / multiplexer 870c receives modulation symbols for subbands -25, -24, -20, -18, etc. (i.e., all subbands mapped to antenna 3), and buffer / multiplexer 870d receives modulation symbols for subbands -25, -23, -22, -18, etc. (i.e., all subbands mapped to antenna 4).

для одной передающей антенны. Каждый поток символов передачи содержит конкатенированные последовательности из 64 символов передачи, по одной последовательности для каждого символьного периода. Согласно фиг.8А, ПРД процессор 720а разнесения обеспечивает четыре потока передаваемых символов,

, для четырех модуляторов 722а-722d МОРЧ.Each buffer / multiplexer 870 then, for each symbol period, multiplexes four pilots, 24 PVRP symbols and 36 zeros for four pilot subbands, 24 data subbands and 36 unused subbands, respectively, to form a sequence of 64 transmitted symbols for all 64 subbands. Although there are 48 subbands, only 24 subbands are used for each transmit antenna for the diversity mode, and the effective total number of unused subbands for each antenna will thus be 36 instead of 12. Each transmitted symbol is a complex value (which may be zero for an unused subband) which is sent in one subband in one symbol period. Each buffer / multiplexer 870 supplies a stream of characters

for one transmit antenna. Each transmission symbol stream contains concatenated sequences of 64 transmission symbols, one sequence for each symbol period. 8A, an transmit diversity transmit processor 720a provides four streams of transmitted symbols,

, for four modulators 722a-722d OFDM.

и преобразует каждую последовательность из 64 передаваемых символов в ее представление во временной области (которое называется преобразованным символом) с использованием 64-точечного обратного быстрого преобразования Фурье. Каждый преобразованный символ содержит 64 отсчета во временной области, соответствующих 64 полным поддиапазонам.FIG. 8C shows a block diagram of an embodiment of an OFDM modulator 722x that can be used for each of the OFDM modulators 722a through 722d in FIG. 8A. In a 722x modulator, an inverse fast Fourier transform unit 852 receives a stream of transmitted symbols

and converts each sequence of 64 transmitted characters into its time-domain representation (called a transformed character) using a 64-point inverse fast Fourier transform. Each transformed symbol contains 64 samples in the time domain corresponding to 64 full subbands.

For each transformed symbol, the cyclic prefix generator 854 repeats a portion of the transformed symbol to form the corresponding OFDM symbol. As noted above, one of two different cyclic prefix lengths may be used. The cyclic prefix for BCH is fixed and equal to 800 ns. The cyclic prefix for all other transport channels can be selected (either 400 ns or 800 ns) and is indicated by the Duration of the cyclic prefix field in the BCH message. For a system with a bandwidth of 20 MHz, a sampling period of 50 ns, and 64 subbands, each transformed symbol has a duration of either 3.6 ms or 4.0 ms, depending on whether a cyclic feature of 400 ns or 800 ns is used for the OFDM symbol.

Fig. 8D illustrates an OFDM symbol. The OFDM symbol consists of two parts: a cyclic prefix having a duration of 400 or 800 ns (8 or 16 samples), and a transformed symbol with a duration of 3.2 ms (64 samples). The cyclic prefix is a copy of the last 8 or 16 samples (i.e., a cyclic continuation) of the transformed character and is entered before the transformed character. The cyclic prefix ensures that the OFDM symbol retains its orthogonality property in the presence of a multipath delay spread, thereby improving performance under harmful path effects such as multipath propagation and channel dispersion caused by frequency selective fading.

The cyclic prefix generator 854 supplies the OFDM symbol stream to transmitter 856 (TX) (TMTR). A transmitter 856 converts the OFDM symbol stream into one or more analog signals and then amplifies, filters, and upconverts the analog signals to form a modulated signal suitable for transmission by the corresponding antenna.

The baseband signal for the OFDM symbol may be expressed as:

обозначает символьный период (т.е. индекс символа МОРЧ);Where

denotes a symbol period (i.e., the index of the symbol OFDM);

обозначает индекс поддиапазона;

denotes a subband index;

является числом поддиапазонов пилот-сигнала и данных;

is the number of pilot subbands and data;

обозначает символ, переданный на поддиапазоне

символьного периода

; и

denotes a character transmitted on a subband

symbol period

; and

является длительностью циклического префикса;Where

is the duration of the cyclic prefix;

есть длительность символа МОРЧ; и

there is the duration of the symbol MORCH; and

есть ширина полосы частот каждого поддиапазона.

there is a bandwidth of each subband.

2. Spatial Multiplexing Mode — Transmission Processing

пространственных каналов выбираются для использования для передачи данных, где

≤

≤min{

,

}.Fig. 9A shows a block diagram of a transmitting unit 900 providing transmission processing for a spatial multiplexing mode. Transmission unit 900 is another embodiment of the transmitting part of the access point and user terminal. For the spatial multiplexing mode, again suppose that four transmit antennas and four receive antennas are available, data can be transmitted in spatial channels of up to four. For each spatial channel, a different transmission rate may be used depending on the transmission capacity. Each bit rate may be associated with a particular code rate and modulation scheme, as shown in Table 25. In the following description, it is assumed that

spatial channels are selected for use for data transmission, where

≤

≤min {

,

}.

пространственных каналах в 6 символах МОРЧ. Скремблер 810 скремблирует данные для каждого транспортного канала. Кодер 812 принимает и кодирует скремблированные данные в соответствии с выбранной схемой кодирования для получения кодовых битов. В варианте осуществления используется общая кодирующая схема, чтобы кодировать данные для всех

пространственных каналов, а разные кодовые скорости для разных каналов получаются прореживанием кодовых битов разными прореживающими шаблонами. Блок 814 прореживания тем самым прореживает кодовые биты, чтобы получить желательную кодовую скорость для каждого пространственного канала. Прореживание для режима пространственного мультиплексирования более подробно описано ниже.In the TX data processor 710b, a frame generator 808 frames data for each FCH / RCH packet to generate one or more PHY frames for the packet. Each PHY frame includes several data bits that can be transmitted in all

spatial channels in 6 characters OFDM. A scrambler 810 scrambles data for each transport channel. Encoder 812 receives and encodes the scrambled data in accordance with the selected coding scheme to obtain code bits. In an embodiment, a common coding scheme is used to encode data for all

spatial channels, and different code rates for different channels are obtained by decimating the code bits with different decimating patterns. The decimation unit 814 thereby decimates the code bits to obtain the desired code rate for each spatial channel. Decimation for the spatial multiplexing mode is described in more detail below.

потоков кодовых битов для

пространственных каналов, выбранных для использования. Каждый поток кодовых битов подается на соответствующий перемежитель 818, который перемежает кодовые биты в потоке по 48 поддиапазонам данных. Кодирование и перемежение для режима пространственного мультиплексирования более подробно описано ниже. Перемеженные данные из каждого перемежителя 818 подаются на соответствующий блок 820 посимвольного отображения.Demultiplexer 816 receives and demultiplexes code bits from decimation unit 814 to obtain

code bit streams for

spatial channels selected for use. Each code bit stream is supplied to a corresponding interleaver 818, which interleaves the code bits in the stream over 48 data subbands. The coding and interleaving for the spatial multiplexing mode is described in more detail below. The interleaved data from each interleaver 818 is supplied to a corresponding character-mapping unit 820.

In the spatial multiplexing mode for four spatial channels, up to four different transmission rates may be used depending on the S / N ratio for the received signal received for these spatial channels. Each rate is associated with a particular modulation scheme, as shown in Table 25. Each symbol mapping 820 displays interleaved data in accordance with a particular modulation scheme selected for the associated spatial channel to obtain modulation symbols. If all four spatial channels are selected for use, then the character mapping units 820a through 820d provide four modulation symbol streams for the four spatial channels to the TX spatial processor 720b.

, где

=±{1, …, 6, 8, …, 20, 22, …, 26} для описанной выше структуры поддиапазонов МОРЧ.The TX spatial processor 720b performs spatial processing for the spatial multiplexing mode. For simplicity, the following description assumes that four transmit antennas, four receive antennas, and 48 data subbands are used for data transmission. Data subband indices are set by

where

= ± {1, ..., 6, 8, ..., 20, 22, ..., 26} for the above-described structure of sub-bands of OFDM.

The model for the MVhMvyh-MORCH system can be expressed as:

является "принятым" вектором с четырьмя составляющими для символов, принятых четырьмя приемными антеннами для поддиапазона

(т.е.

);Where

is a “received” four-component vector for symbols received by four receive antennas for a subband

(those.

);

является "переданным" вектором четырьмя составляющими для четырех символов, переданных четырьмя передающими антеннами для поддиапазона

(т.е.

);

is a four-component “transmitted” vector for four symbols transmitted by four transmit antennas for a subband

(those.

);

- матрица канальных откликов размером (

×

) для поддиапазона

; и

- channel response matrix of size (

×

) for subband

; and

- вектор аддитивного белого Гауссовского шума (АБГШ) (AWGN) для поддиапазона

.

- vector of additive white Gaussian noise (AWGN) (AWGN) for the subband

.

имеет компоненты с нулевым средним и ковариационной матрицей

, где

- единичная матрица, σ² - дисперсия шума.It is assumed that the noise vector

has components with zero mean and covariance matrix

where

is the identity matrix, σ ² is the noise variance.

канальных откликов для поддиапазона

может быть выражена как:Matrix

channel response for subband

may be expressed as:

, для

∈{1,2,3,4} и

∈{1,2,3,4}, представляет собой связь (т.е. комплексное усиление) между передающей антенной

и приемной антенной

для поддиапазона

. Для простоты, предполагается, что матрицы

канальных откликов для

∈

известны или могут быть установлены как передатчиком, так и приемником.where is the component

for

∈ {1,2,3,4} and

∈ {1,2,3,4}, represents the connection (ie complex gain) between the transmitting antenna

and receiving antenna

for subband

. For simplicity, it is assumed that the matrices

channel responses for

∈

known or can be installed by both the transmitter and the receiver.

канальных откликов для каждого поддиапазона может быть сделана "диагональной" для получения для этого поддиапазона

собственных мод. Этого можно достичь путем выполнения декомпозиции по собственным значениям корреляционной матрицы от

, определяемой соотношением

, где

обозначает сопряженную транспозицию от

. Декомпозиция по собственным значениям корреляционной матрицы

может быть выражена как:Matrix

channel responses for each subband can be made "diagonal" to obtain for this subband

own mods. This can be achieved by decomposing the eigenvalues of the correlation matrix from

defined by the relation

where

denotes a conjugate transposition from

. Decomposition of the eigenvalues of the correlation matrix

may be expressed as:

является единичной матрицей размером (

×

), столбцы которой представляют собой собственные значения

(т.е.

, где каждое

является собственным вектором для одной собственной моды); иWhere

is a unit matrix of size (

×

) whose columns are eigenvalues

(those.

where each

is an eigenvector for one eigenmode); and

является диагональной матрицей размером (

×

) собственных значений

.

is a diagonal matrix of size (

×

) eigenvalues

.

. Собственные векторы

для

∈{1,2,3,4} называются также векторами управления передачей для каждого из пространственных каналов.The identity matrix is characterized by the property

. Custom vectors

for

∈ {1,2,3,4} are also called transmission control vectors for each of the spatial channels.

канальных откликов может быть также преобразована в диагональную с использованием декомпозиции по сингулярным значениям, что может быть выражено как:Matrix

channel responses can also be converted to diagonal using decomposition according to singular values, which can be expressed as:

является матрицей, столбцы которой представляют собой правые собственные векторы

;Where

is a matrix whose columns are right eigenvectors

;

является диагональной матрицей, содержащей сингулярные значения

, которые являются положительными корнями квадратными диагональных элементов

, собственных значений

; и

is a diagonal matrix containing singular values

which are the positive roots of the square diagonal elements

, eigenvalues

; and

представляет собой матрицу, столбцы которой являются левыми собственными векторами

.

is a matrix whose columns are left eigenvectors

.

являются собственными векторами

, а также правыми собственными векторами

. Столбцы матрицы

являются собственными векторами

, а также левыми собственными векторами

.The decomposition of singular values is described in Gilbert Strang's book “Linear Algebra and Its Applications”, Second Edition, Academic Press, 1980. As shown in equations (7) and (8), the columns of the matrix

are eigenvectors

as well as right eigenvectors

. Matrix Columns

are eigenvectors

as well as left eigenvectors

.

для каждого поддиапазона содержит неотрицательные действительные значения вдоль диагонали и нули в остальных позициях. Собственные значения

обозначаются как

или

для

∈{1,2,3,4}.Diagonal matrix

for each subrange contains non-negative real values along the diagonal and zeros in other positions. Eigenvalues

are denoted as

or

for

∈ {1,2,3,4}.

канальных откликов для каждого из 48 поддиапазонов данных, чтобы найти четыре собственных моды для этого поддиапазона (в предположении, что каждая матрица

является полноранговой). Четыре собственных значения для каждой диагональной матрицы

можно упорядочить так, что

, где

является наибольшим собственным значением, а

является наименьшим собственным значением для поддиапазона

. Когда собственные значения для каждой диагональной матрицы

упорядочены, собственные векторы (или столбцы) связанной матрицы

также упорядочены соответственно.Eigenvalue decomposition can be performed independently for the matrix

channel responses for each of the 48 data subbands to find four eigenmodes for that subband (assuming each matrix

is full-ranking). Four eigenvalues for each diagonal matrix

can be ordered so that

where

is the largest eigenvalue, and

is the smallest eigenvalue for a subband

. When the eigenvalues for each diagonal matrix

ordered, eigenvectors (or columns) of the associated matrix

also ordered accordingly.

включает в себя собственные моды

всех поддиапазонов). Каждая широкополосная собственная мода ассоциируется с соответствующим набором собственных векторов для всех поддиапазонов. "Главная" широкополосная собственная мода ассоциируется с наибольшим сингулярным значением в каждой из матриц

после упорядочения.A “wideband” eigenmode can be defined as a set of eigenmodes of the same order of all subbands after ordering (i.e., a wideband eigenmode

includes own mods

all subranges). Each broadband eigenmode is associated with a corresponding set of eigenvectors for all subbands. The “main” broadband eigenmode is associated with the largest singular value in each of the matrices

after streamlining.

для включения в него собственного значения

-го ранга для всех 48 поддиапазонов данных. Этот вектор

может быть выражен как:Then you can form a vector

to include in it an eigenvalue

rank for all 48 data subbands. This vector

may be expressed as:

включает в себя собственные значения для наилучшей или главной широкополосной собственной моды. Для системы МВхМВых-МОРЧ с четырьмя передающими антеннами и четырьмя приемными антеннами (т.е. система 4×4) имеется до четырех широкополосных собственных мод.Vector

includes eigenvalues for the best or mainstream broadband eigenmode. Up to four wideband eigenmodes are available for an MVxMWIN-OFDM system with four transmit antennas and four receive antennas (i.e., a 4 × 4 system).

на дисперсию σ² шума. Для простоты, можно предположить, что дисперсия шума равна единице (т.е. σ²=1).If the dispersion σ ^{2 of} noise in the receiver is constant over the working band and is known in the transmitter, then the S / N ratio in the received signal for each subband of each broadband eigenmode can be found by dividing the eigenvalue

dispersion σ ² noise. For simplicity, we can assume that the noise variance is unity (i.e., σ ² = 1).

передачи, доступная для передатчика, может быть найдена для широкополосных мод на основе различных схем распределения мощности. В одной схеме полная мощность

передачи равномерно распределяется по всем четырем широкополосным собственным модам, так что

=

/4, где

представляет собой мощность, выделенную для широкополосной собственной моды

. В другой схеме полная мощность

передачи распределяется по четырем широкополосным собственным модам с помощью процедуры "разбавления" (создания избытка информации).For spatial multiplexing mode, full power

the transmission available to the transmitter can be found for broadband modes based on various power distribution schemes. In one circuit, full power

the transmission is evenly distributed across all four broadband eigenmodes, so

=

/ 4, where

represents the power allocated for the broadband eigenmode

. In another design, apparent power

Transmissions are distributed over four broadband eigenmodes using the “dilution” procedure (creating excess information).

для четырех широкополосных собственных мод, где

представляет собой коэффициент нормировки для широкополосной собственной моды

и может быть выражен как:The dilution procedure distributes the power so that wideband eigenmodes with higher power amplifications receive most of the total transmit power. The transmit power allocated to a given broadband eigenmode is determined by its S / N ratio in the received signal, which in turn depends on the power gain (or eigenvalues) for all subbands of this broadband eigenmode. The dilution procedure can provide zero transmit power to wideband eigenmodes with fairly weak S / N ratios. Dilution procedure takes

for four broadband eigenmodes, where

is the normalization coefficient for the wideband eigenmode

and can be expressed as:

нормировки поддерживает мощность передачи, выделенную широкополосной моде

, инвариантной после применения инверсии каналов, как описано ниже. Как показано в уравнении (10), коэффициент

нормировки может быть получен на основе собственных значений в векторе

и в предположении, что дисперсия шума равна единице (т.е. σ²=1).Coefficient

normalization supports transmission power allocated to the broadband mode

invariant after applying channel inversion, as described below. As shown in equation (10), the coefficient

normalization can be obtained based on eigenvalues in the vector

and under the assumption that the noise variance is unity (i.e., σ ² = 1).

полной мощности передачи для выделения каждой широкополосной собственной моде на основании набора

так, что спектральная эффективность или какой-либо иной критерий оптимизируется. Мощность передачи, выделенная широкополосной собственной моде

процедурой разбавления может быть выражена как: The dilution procedure then determines the proportion

full transmit power to allocate each broadband eigenmode based on a set

so that the spectral efficiency or some other criterion is optimized. Transmit Power Allocated to Broadband Proprietary

dilution procedure can be expressed as:

=

, для

= {1,2,3,4}. Уравнение (11)

=

for

= {1,2,3,4}. Equation (11)

, где

=1 и

=

. Режим пространственного мультиплексирования может быть выбран для использования, если в наборе

более чем одно значение является ненулевым.Power distributions for four broadband eigenmodes can be specified by

where

= 1 and

=

. The spatial multiplexing mode can be selected for use if in the set

more than one value is nonzero.

The dilution procedure is known in the art and is not described here (see, for example, "Information Theory and Reliable Communication" by Robert G. Gallager, John Wiley and Sons, 1968, which is incorporated herein by reference )

передачи. Для простоты, нижеследующее описание предполагает передачу данных на широкополосных собственных модах. Отношение С/Ш в принятом сигнале для каждой широкополосной собственной моды может быть выражено как:For the spatial multiplexing mode, the transmission rate of each spatial channel or wideband eigenmode can be selected based on the S / N ratio in the received signal achieved by this spatial channel / wideband eigenmode with allocated power

transmission. For simplicity, the following description assumes data transmission on broadband eigenmodes. The S / N ratio in the received signal for each broadband eigenmode can be expressed as:

=

, для

={1,2,3,4}. Уравнение (12)

=

for

= {1,2,3,4}. Equation (12)

In one embodiment, the transmission rate for each wideband eigenmode is based on a table that includes the speeds supported by the system and the range of S / N ratios for each transmission rate. This table can be obtained by computer simulation, empirical measurements, etc. The specific transmission rate for use for each wideband eigenmode is represented by the speed in the table with a range of S / N ratios covering the S / N ratio in the received signal for the wideband eigenmode. In another embodiment, the transmission rate for each broadband eigenmode is selected based on (1) the S / N ratio in the received signal for the wideband eigenmode, (2) the S / N shift used to calculate the estimation error, the volatility in the MVxMO channel and other factors , and (3) tables of supported speeds and their required S / N. For this embodiment, first, the average received S / N for each wideband eigenmode is calculated, as described above, or as the average of the received S / N (in units of dB) for all subbands of the wideband eigenmode. In any case, then the working S / N is then calculated as the sum of the S / N in the received signal and the S / N shift (where both are given in dB). The working S / N is then compared with the required S / N for each of the speeds supported by the system. For the wideband eigenmode, the highest speed is then selected in the table with the required S / N, which is less than or equal to the working S / N. The speed for the transmission diversity mode and the beam control mode can also be found in a similar manner.

передачи, выделенная для каждой широкополосной собственной моды может быть распределена по 48 поддиапазонам данных этой широкополосной собственной моды так, чтобы С/Ш в принятом сигнале для всех поддиапазонов были приблизительно равными. Это неравномерное распределение мощности по поддиапазонам называется инверсией каналов. Мощность

передачи, выделенная каждому поддиапазону, может быть выражена как:Power

The transmission allocated for each wideband eigenmode can be distributed across 48 data subbands of this wideband eigenmode so that the S / N in the received signal for all subbands is approximately equal. This uneven distribution of power across the subbands is called channel inversion. Power

the transmission allocated to each subband may be expressed as:

задается в уравнении (10).Where

is given in equation (10).

передачи распределяется неравномерно по поддиапазонам данных на основе их канальных коэффициентов усиления мощности, что задается собственными значениями

, для

∈

. Распределение мощности таково, что приблизительно равные С/Ш в принятом сигнале достигаются в приемнике для всех поддиапазонов данных каждой широкополосной собственной моды. Эта инверсия каналов выполняется независимо для каждой из четырех широкополосных собственных мод. Инверсия каналов для широкополосной собственной моды более подробно описана в патентной заявке США № 10/229.209 на "Кодированные системы МВхМВых с выборочной инверсией каналов, применяемой для собственной моды", поданной 27 августа 2002.As shown in equation (13), the power

the transmission is distributed unevenly across the data subbands based on their channel power amplification factors, which is determined by the eigenvalues

for

∈

. The power distribution is such that approximately equal S / N in the received signal is achieved at the receiver for all data subbands of each wideband eigenmode. This channel inversion is performed independently for each of the four broadband eigenmodes. Channel inversion for the wideband eigenmode is described in more detail in US Patent Application No. 10 / 229.209 on "MVXMOv Coded Systems with Selective Channel Inversion Applicable for the Eigenmode", filed August 27, 2002.

Channel inversion can be performed in various ways. For complete channel inversion, all data subbands are used for data transmission if a wideband eigenmode is selected for use. For selective channel inversion, all or a subset of the available data subchannels can be selected for use for each broadband eigenmode. Selective channel inversion discards weak subbands with an S / N ratio for the received signal below a specific threshold and performs channel inversion only on selected subbands. Selective channel inversion for each wideband eigenmode is also described in US Patent Application No. 10 / 229.209 to "MVXMO Coded Systems with Selective Channel Inversion Applicable for Eigenmode"), filed August 27, 2002. For simplicity, the following description assumes that full inversion channels are performed for each broadband eigenmode selected for use.

передачи, выделенной этому поддиапазону. Усиление

для каждого поддиапазона данных может быть выражено как:The gain to use for each subband of each broadband eigenmode can be found based on the power

transmission allocated to this subband. Gain

for each data subband can be expressed as:

усиления. Эта матрица

включает в себя коэффициенты усиления для четырех собственных мод для поддиапазона

вдоль диагонали и может быть выражена как:

.For each subband, you can define a diagonal matrix

gain. This matrix

includes gains for four eigenmodes for the subband

along the diagonal and can be expressed as:

.

передачи для каждого поддиапазона может быть выражен как:For spatial multiplexing mode, the vector

Transmissions for each subband can be expressed as:

включает в себя четыре символа модуляции, подлежащих передаче на четырех собственных модах для поддиапазона

, а вектор

включает в себя четыре символа передачи, подлежащие передаче четырьмя антеннами для поддиапазона

. Для простоты, уравнение (15) не включает в себя коэффициенты коррекции, используемые для расчета различий между цепями передачи/приема в пункте доступа и пользовательском терминале, что более подробно описано ниже.Vector

includes four modulation symbols to be transmitted on four eigenmodes for the subband

, and the vector

includes four transmit symbols to be transmitted by four antennas for a subband

. For simplicity, equation (15) does not include correction factors used to calculate the differences between the transmit / receive circuits at the access point and the user terminal, which is described in more detail below.

FIG. 9B shows a block diagram of an embodiment of an TX of a spatial processor 720b for performing spatial processing for a spatial multiplexing mode. For simplicity, the following description assumes that all four broadband eigenmodes are selected for use. However, less than four broadband eigenmodes may also be selected for use.

-

), подлежащих передаче на четырех широкополосных собственных модах, демультиплексирует каждый поток на 48 подпотоков для 48 поддиапазонов данных, и подает четыре подпотока символов модуляции для каждого поддиапазона данных к соответствующему ПРД поддиапазонному пространственному процессору 940. Каждый процессор 840 выполняет обработку, показанную в уравнении (15) для одного поддиапазона.In processor 720b, demultiplexer 932 receives four modulation symbol streams (denoted as

-

), to be transmitted on four broadband eigenmodes, demultiplexes each stream into 48 substreams for 48 data subbands, and provides four modulation symbol substreams for each data subband to the corresponding TX subband spatial processor 940. Each processor 840 performs the processing shown in equation (15 ) for one subband.

-

) подаются на четыре перемножителя 942а-942d, которые также принимают усиления

,

,

и

для четырех собственных мод ассоциированного поддиапазона. Каждый коэффициент

усиления может быть найден на основании мощности

передачи, выделенной этому поддиапазону/собственной моде, как показано в уравнении (14). Каждый перемножитель 942 масштабирует свои символы модуляции их коэффициентами

, чтобы обеспечить масштабированные символы модуляции. Перемножители 942а-942d подают четыре подпотока масштабированных символов модуляции на четыре формирователя 950а-950d луча, соответственно.There are four modulation symbol substreams (denoted as

-

) are fed to four multipliers 942a-942d, which also take amplifications

,

,

and

for four eigenmodes of the associated subband. Each coefficient

gain can be found based on power

transmission allocated to this subband / eigenmode as shown in equation (14). Each multiplier 942 scales its modulation symbols with their coefficients

to provide scaled modulation symbols. Multipliers 942a through 942d provide four sub-streams of scaled modulation symbols to four beam formers 950a through 950d, respectively.

символов и один собственный вектор

для ассоциированного собственного режима. В частности, формирователь 950а луча принимает собственный вектор

для первой собственной моды, формирователь 950b луча принимает собственный вектор

для второй собственной моде и т.д. Формирование луча выполняется с помощью собственного вектора для ассоциированной собственной моды.Each beamformer 950 performs beamforming to transmit one stream of symbols on one eigenmode of one subband. Each beam former 950 receives one substream

characters and one own vector

for an associated native mode. In particular, the beam former 950a receives an eigenvector

for the first eigenmode, the beamformer 950b takes an eigenvector

for a second own fashion, etc. Beam formation is performed using the eigenvector for the associated eigenmode.

,

,

и

собственного вектора

для ассоциированной собственной моды. Каждый перемножитель 952 затем перемножает масштабированные символы модуляции с их значением

собственного вектора для получения символов "сформированного луча". Перемножители 952а-952d подают четыре подпотока символов сформированного луча (которые должны передаваться четырьмя антеннами) на сумматоры 960а-960d, соответственно.In each beam former 950, the scaled modulation symbols are provided to four multipliers 952a-952d, which also take four elements:

,

,

and

eigenvector

for associated own fashion. Each multiplier 952 then multiplies the scaled modulation symbols with their value

eigenvector to obtain the "formed beam" symbols. Multipliers 952a through 952d provide four sub-streams of beamform symbols (which must be transmitted by four antennas) to adders 960a through 960d, respectively.

Each adder 960 receives and sums four beamform symbols for four eigenmodes for each symbol period to supply a pre-transformed symbol to a respective transmit antenna. Adders 960a through 960d provide four substreams of pre-transformed symbols for four transmit antennas to buffers / multiplexers 970a through 970d, respectively.

передачи для одной передающей антенны, где поток символов передачи содержит конкатенированные последовательности из 64 символов передачи. Символы передачи могут масштабироваться коэффициентами коррекции с учетом различий между цепями передачи/приема в пункте доступа и пользовательском терминале, как описано ниже. Последующая модуляция МОРЧ для каждого потока символов модуляции описана выше.Each buffer / multiplexer 970 receives pilot symbols and pre-transformed symbols from the TX subband spatial processors 940a through 940k for 48 data subbands. Then, each buffer / multiplexer 970, for each symbol period, multiplexes 4 pilot symbols, 48 pre-converted symbols and 12 zeros for 4 pilot subbands, 48 data subbands and 12 unused subbands, respectively, to form a sequence of 64 transmission symbols for this symbol period . Each buffer / multiplexer 970 supplies a stream of characters

transmitting for one transmit antenna, where the transmit symbol stream contains concatenated sequences of 64 transmit symbols. Transmission symbols can be scaled with correction factors, taking into account the differences between the transmission / reception circuits at the access point and the user terminal, as described below. Subsequent OFDM modulation for each modulation symbol stream is described above.

Parallel symbol streams can also be transmitted by four transmit antennas without spatial processing at the access point using the uncontrolled spatial multiplexing mode. For this mode, the channel inversion process and beamforming by the beam former 950 may be omitted. For each modulation symbol stream, then OFDM processing is provided and transmitted by the corresponding transmit antenna.

The uncontrolled spatial multiplexing mode can be used for various situations, such as if the transmitter is not able to perform the spatial processing necessary to maintain beam control based on decomposition according to eigenmodes. This may be due to the fact that the transmitter has not completed the calibration procedure, cannot generate a sufficiently good channel estimate, or does not have the ability to calibrate and process its own modes. For uncontrolled spatial multiplexing mode, spatial multiplexing is still used to increase transmission throughput, and spatial processing to separate the individual symbol streams is performed by the receiver.

For the uncontrolled spatial multiplexing mode, the receiver performs spatial processing to recover the transmitted symbol streams. In particular, the user terminal may implement a channel correlation matrix inversion (CCMI) method, a minimum mean square error (MMSC) method, a receiver interference suppression processing method, or some other spatial processing method in the receiver. These methods are described in detail in US Patent Application No. 09 / 993.087 to the "MVxMBx Multiple Access Communication System" filed November 6, 2001. Uncontrolled spatial multiplexing can be used for downlink and uplink transmissions.

The multi-user spatial multiplexing mode supports transmitting data to a plurality of user terminals simultaneously in a downlink based on “spatial signatures” of the user terminals. The spatial signature for the user terminal is defined by the channel response vector (for each subband) between the antennas of the access point and each antenna of the user terminal. An access point may receive spatial signatures, for example, based on a managed reference transmitted by user terminals. An access point can process spatial signatures for user terminals that require data transfer in order to (1) select a set of user terminals for simultaneous data transmission on the downlink and (2) select control vectors for each of the independent data streams for transmission to the selected user terminals .

The steering vectors for the multi-user spatial multiplexing mode can be obtained in various ways. Two exemplary circuits are described below. For simplicity, the following description is presented for one subband and assumes that each user terminal is equipped with a single antenna.

одноантенных пользовательских терминалов для одновременной передачи по нисходящей линии. Пункт доступа получает вектор-строку канальных откликов размером 1×

для каждого выбранного пользовательского терминала и формирует матрицу

канальных откликов размером

×

с

векторами-строк для

пользовательских терминалов. Затем пункт доступа получает матрицу

из

управляющих векторов для

выбранных пользовательских терминалов как

=

. Пункт доступа может также передать управляемый эталон на каждый выбранный пользовательский терминал. Каждый пользовательский терминал обрабатывает свой управляемый эталон для оценки усиления и фазы канала и когерентно демодулирует принятые символы для своей единственной антенны с оценками усиления и фазы канала для получения восстановленных символов.In the first scheme, the access point receives control vectors using channel inversion. Access Point can choose

single-antenna user terminals for simultaneous downlink transmission. The access point receives a 1 × channel response row size of 1 ×

for each selected user terminal and forms a matrix

channel response size

×

from

row vectors for

custom terminals. Then the access point receives the matrix

of

control vectors for

selected user terminals as

=

. The access point may also transmit a managed reference to each selected user terminal. Each user terminal processes its own controlled reference to estimate the gain and phase of the channel and coherently demodulates the received symbols for its only antenna with estimates of the gain and phase of the channel to obtain the recovered symbols.

потоков символов для передачи к

пользовательским терминалам, так что эти потоки символов испытывают малые перекрестные помехи в пользовательских терминалах. Пункт доступа может формировать матрицу

канальных откликов для

выбранных пользовательских терминалов и выполнить разложение на множители QR над

так, что

=

, где

представляет собой нижнюю левую треугольную матрицу,

а

является единичной матрицей. Затем пункт доступа предварительно кодирует

потоков символов данных матрицей

для получения

потоков

предварительно кодированных символов, и далее обрабатывает потоки предварительно кодированных символов единичной матрицей

для получения

потоков передаваемых символов для передачи на

пользовательских терминалов. Пункт доступа может также передавать управляемый эталон на каждый пользовательский терминал. Каждый пользовательский терминал использует управляемый эталон для когерентной демодуляции принятых символов для получения восстановленных символов.In the second scheme, the access point precodes

character streams to transmit to

user terminals, so that these symbol streams experience little crosstalk in user terminals. An access point may form a matrix

channel responses for

selected user terminals and multiply QR over

so that

=

where

represents the lower left triangular matrix,

but

is the identity matrix. Then the access point precodes

matrix character data streams

for getting

flows

precoded characters, and then processes the streams of precoded characters with a unit matrix

for getting

streams of transmitted characters for transmission to

custom terminals. An access point may also transmit a managed reference to each user terminal. Each user terminal uses a managed reference to coherently demodulate received symbols to obtain recovered symbols.

потоков символов, переданных одновременно

пользовательскими терминалами с использованием обработки приемника МСКО, успешного подавления помех или какого-нибудь другого метода обработки в приемнике. Пункт доступа может оценивать канальный отклик восходящей линии для каждого пользовательского терминала и использовать оценку канальных откликов для пространственной обработки в приемнике и для планирования передач восходящей линии. Каждый одноантенный пользовательский терминал может передавать ортогональный пилот-сигнал по восходящей линии. Пилот-сигналы восходящей линии от

пользовательских терминалов могут быть ортогональны по времени и (или) частоте. Временная ортогональность может достигаться тем, что каждый пользовательский терминал модулирует свой пилот-сигнал восходящей линии ортогональной последовательностью, назначенной этому пользовательскому терминалу. Частотная ортогональность может достигаться тем, что каждый пользовательский терминал передает свой пилот-сигнал восходящей линии в отличающемся наборе поддиапазонов. Передачи восходящей линии от пользовательских терминалов должны быть приблизительно совмещены по времени в пункте доступа (например, совмещены по времени в пределах циклического префикса).For an uplink in multi-user spatial multiplexing mode, the access point may recover

character streams transmitted simultaneously

user terminals using ISCED receiver processing, successful interference suppression, or some other processing method at the receiver. An access point may estimate the uplink channel response for each user terminal and use the channel response estimate for spatial processing at the receiver and for scheduling uplink transmissions. Each single-antenna user terminal may transmit an orthogonal pilot on the uplink. Uplink pilot signals from

user terminals may be orthogonal in time and / or frequency. Temporary orthogonality can be achieved in that each user terminal modulates its uplink pilot with an orthogonal sequence assigned to that user terminal. Frequency orthogonality can be achieved by the fact that each user terminal transmits its uplink pilot in a different set of subbands. Uplink transmissions from user terminals should be approximately time aligned at the access point (eg, time aligned within a cyclic prefix).

3. Beam control mode - transmission processing

10A shows a block diagram of a transmitting unit 1000 capable of performing transmission processing for a beam control mode. The transmitting unit 1000 is another embodiment of the transmitting part of the access point and user terminal.

In the TX data processor 710c, a frame forming unit 808 frames data for each FCH / RCH packet to generate one or more PHY frames for the packet. The scrambler 810 then scrambles the data for each transport channel. The encoder 812 thereafter encodes the cropped data in accordance with the selected coding scheme to obtain code bits. The decimation unit 814 then decimates the code bits to obtain the desired code rate for the wideband eigenmode used for data transmission. The code bits from decimation unit 818 are interleaved across all data subbands. The symbol mapper 820 then displays the interleaved data in accordance with the selected modulation scheme to obtain modulation symbols. The TX spatial processor 720c then performs a transmission processing procedure on the modulation symbols for the beam control mode.

является ненулевой. В то время как режим пространственного мультиплексирования выполняет формирование луча для каждой из выбранных собственных мод каждого поддиапазона на основе собственного вектора, режим управления лучом выполняет управление лучом на основе "нормированного" собственного вектора для главной собственной моды каждого поддиапазона для передачи данных на этой единственной собственной моде.The beam control mode can be used to transmit data in a spatial channel or on a broadband eigenmode — as a rule, it is associated with the largest eigenvalues for all data subbands. The beam control mode can be selected if the distribution of transmit power over wideband eigenmodes leads to the fact that only one component in the set

is nonzero. While the spatial multiplexing mode performs beamforming for each of the selected eigenmodes of each subband based on the eigenvector, the beam control mode performs beam control based on the “normalized” eigenvector for the main eigenmode of each subband to transmit data on this single eigenmode .

для

∈

для главной собственной моды могут иметь различные величины. Четыре предварительно преобразованных символа, полученных на основе четырех элементов собственного вектора

для каждого поддиапазона, могут тогда иметь разные величины. Следовательно, четыре вектора передачи на каждую антенну, каждый из которых включает в себя предварительно обработанные символы для всех поддиапазонов данных для заданной передающей антенны, могут иметь различные величины. Если мощность передачи для каждой передающей антенны ограничена (к примеру, из-за ограничений усилителей мощности), то метод формирования луча может не полностью использовать полную мощность, доступную для каждой антенны.Four elements of each eigenvector

for

∈

for the main eigenmodes can have different values. Four pre-converted characters derived from four eigenvector elements

for each subband, can then have different values. Therefore, four transmission vectors per antenna, each of which includes preprocessed symbols for all data subbands for a given transmit antenna, can have different values. If the transmit power for each transmit antenna is limited (for example, due to the limitations of power amplifiers), then the beamforming method may not fully utilize the full power available for each antenna.

для

∈

для главной собственной моды и нормирует каждый собственный вектор так, чтобы все четыре элемента в собственном векторе имели равные величины. Нормированный собственный вектор

для поддиапазона

может быть выражен как:The beam control mode uses only phase information from eigenvectors

for

∈

for the main eigenmode and normalizes each eigenvector so that all four elements in the eigenvector have equal values. Normalized eigenvector

for subband

may be expressed as:

является постоянной (например,

=1); иWhere

is constant (e.g.

= 1); and

является фазой для поддиапазона

передающей антенны

, которая задается как:

is the phase for the subrange

transmit antenna

, which is set as:

получается из соответствующего элемента собственного вектора

(т.е.

получается из

, где

).As shown in equation (17), the phase of each element in the vector

obtained from the corresponding element of the eigenvector

(those.

obtained from

where

)

, выделенная каждому поддиапазону данных для режима управления лучом, может быть выражена как:Channel inversion can also be performed for the beam control mode so that the total transmission rate can be used for all data subbands. Power

allocated to each data subband for the beam control mode can be expressed as:

является коэффициентом нормировки, который хранит инвариант полной мощности передачи после того, как применена инверсия каналов;Where

is the normalization coefficient that stores the invariant of the total transmit power after the channel inversion is applied;

является мощностью передачи, выделенной каждой из четырех антенн; и

is the transmit power allocated to each of the four antennas; and

представляет собой коэффициент усиления мощности для поддиапазона

главной собственной моды для режима управления лучом.

represents the power gain for the subband

main eigenmodes for beam control mode.

нормировки может быть выражен как:Coefficient

normalization can be expressed as:

передачи может задаваться как

=

(т.е. равномерное распределение полной мощности передачи по четырем передающим антеннам). Коэффициент

усиления мощности может быть выражен как:Power

transmission can be set as

=

(i.e., uniform distribution of the total transmit power over the four transmit antennas). Coefficient

power amplification can be expressed as:

для

∈

для 48 поддиапазонов данных. Усиление для каждого поддиапазона данных может затем быть задано как

.Channel inversion leads to power distribution

for

∈

for 48 data subbands. The gain for each data subband may then be specified as

.

передачи для каждого поддиапазона может быть выражен как:For beam control mode, the vector

Transmissions for each subband can be expressed as:

Again, for simplicity, equation (21) does not include correction factors used to calculate the differences between the transmit / receive circuits at the access point and the user terminal.

для каждого поддиапазона имеют равную величину, но, возможно, разные фазы. Таким образом, управление лучом генерирует один вектор

передачи для каждого поддиапазона с четырьмя элементами

, имеющими одну и ту величину, но, возможно, разные фазы.As shown in equation (16), the four elements of the normalized control vector

for each subband they have equal magnitude, but possibly different phases. Thus, beam control generates a single vector

gears for each subband with four elements

having the same value, but possibly different phases.

FIG. 10B shows a block diagram of an embodiment of an TX of a spatial processor 720c for performing spatial processing for a beam control mode.

символов модуляции в 48 подпотоков для 48 поддиапазонов данных (обозначенных как

-

). Каждый подпоток символов подается на соответствующий ПРД поддиапазонный процессор 1040 управления лучом. Каждый процессор 1040 выполняет обработку, показанную в уравнении (14), для одного поддиапазона.In process 720c, demultiplexer 1032 receives and demultiplexes the stream

modulation symbols in 48 substreams for 48 data subbands (denoted as

-

) Each symbol substream is provided to a respective TX subband processor 1040 of the beam control. Each processor 1040 performs the processing shown in equation (14) for one subband.

усиления для ассоциированного поддиапазона. Перемножитель 1042 масштабирует затем символы модуляции коэффициентом

усиления, чтобы получить масштабированные символы модуляции, которые затем подаются в блок 1050 управления лучом.In each TX subband processor 1040 beam control sub-stream of modulation symbols is supplied to the multiplier 1042, which also takes a coefficient

gains for the associated subband. A multiplier 1042 then scales the modulation symbols by a factor

amplification to obtain scaled modulation symbols, which are then supplied to the beam control unit 1050.

для ассоциированного поддиапазона. В блоке 1050 управления лучом масштабированные символы модуляции подаются на четыре перемножителя 1052а-1052d, которые также соответственно принимают четыре элемента

,

,

и

нормированного собственного вектора

. Каждый перемножитель 1052 перемножает свои масштабированные символы модуляции со значением

нормированного собственного вектора, чтобы обеспечить предварительно преобразованные символы. Перемножители 1052а-1052d подают четыре предварительно преобразованных подпотока в буферы/мультиплексоры 1070а-1070d, соответственно.The beam control unit 1050 also receives a normalized eigenvector

for the associated subband. At a beam control unit 1050, the scaled modulation symbols are provided to four multipliers 1052a-1052d, which also respectively take four elements

,

,

and

normalized eigenvector

. Each multiplier 1052 multiplies its scaled modulation symbols with a value

normalized eigenvectors to provide pre-converted characters. Multipliers 1052a-1052d feed four pre-converted substreams to buffers / multiplexers 1070a-1070d, respectively.

передачи в одну передающую антенну. Последующая модуляция МОРЧ для каждого символа передачи описана выше.Each buffer / multiplexer 1070 receives pilot symbols and pre-transformed symbols from the transmit-band sub-bandwidths of the beam steering processors 1040a-1040k for 48 data subbands, multiplexes pilot and pre-transformed symbols and zeros for each symbol period, and provides a symbol stream

transmissions into one transmitting antenna. Subsequent OFDM modulation for each transmission symbol is described above.

The processing for the beam control mode is described in more detail in US Patent Application No. 10 / 228.393 on "Beam Control and Beam Forming in MVXMB Broadband Systems" filed August 27, 2002. The system can also be designed to maintain the beam forming mode whereby the data stream is transmitted on the main eigenmode using an eigenvector instead of a normalized eigenvector.

4. Crop for PHY frames

11A shows an embodiment of a frame forming unit 808 that is used to frame data for each FCH / RCH packet before subsequent processing of the TX data by the data processor. This framing function may not be used for messages sent over the BCH, FCCH, and RACH. The framing unit generates an integer number of PHY frames for each FCH / RCH packet, where each PHY frame spans 6 OFDM symbols for the embodiment described here.

For diversity and beam control modes, only one spatial channel or wideband eigenmode is used for data transmission. The speed for this mode is known, and the number of information bits that can be sent in the payload of each PHY frame can be calculated. For the spatial multiplexing mode, multiple spatial channels may be used for data transmission. Since the transmission rate of each spatial channel is known, the number of information bits that can be sent in the payload of each PHY frame for all spatial channels can be calculated.

) для каждого пакета FCH/RCH подаются в генератор 1102 CRC и мультиплексор 1104 в блоке 808 формирования кадров. Генератор 1102 CRC генерирует значение CRC для битов в заголовке (если он есть) и полях полезной нагрузки каждого кадра PHY и подает биты CRC в мультиплексор 1104. Мультиплексор 1104 принимает информационные биты, биты CRC, биты заголовка и заполняющие биты (например, нули) и подает эти биты в должном порядке, как показано на фиг.6, на основании сигнала управления кадрами PHY. Функция кадрирования может не использоваться при подаче информационных битов непосредственно через мультиплексор 1104. Кадрированные или некадрированные биты (обозначенные как

) подаются в скремблер 810.As shown in FIG. 11A, information bits (denoted as

) for each packet, the FCH / RCH is supplied to a CRC generator 1102 and a multiplexer 1104 in a frame forming unit 808. A CRC generator 1102 generates a CRC value for the bits in the header (if any) and payload fields of each PHY frame and feeds the CRC bits to the multiplexer 1104. The multiplexer 1104 receives information bits, CRC bits, header bits, and pad bits (e.g., zeros) and supplies these bits in order, as shown in FIG. 6, based on the PHY frame control signal. The framing function may not be used when supplying information bits directly through a multiplexer 1104. Framed or unframed bits (denoted as

) are fed to scrambler 810.

5. Scrambling

In an embodiment, data bits for each transport channel are scrambled before encoding. Scrambling randomizes the data so that a long sequence of all ones or all zeros is not transmitted. This can reduce the changes between the peak and average power of the oscillation of OFDM. Scrambling may be omitted for one or more transport channels and may also be selectively enabled or disabled.

11A also shows an embodiment of a scrambler 810. In this embodiment, the scrambler 810 implements a generator polynomial:

Other generator polynomials can also be used, and this is within the scope of the invention.

As shown in FIG. 11A, the scrambler 810 includes seven delay elements 1112a through 1112g connected in series. For each clock period, adder 1114 modulo 2 adds two bits stored in delay elements 111d and 1112g and provides a scramble bit to delay element 1112a.

) подаются в сумматор 1116, который также принимает биты скремблирования из сумматора 1114. Сумматор 1116 выполняет сложение по модулю 2 каждого бита

с соответствующим битом скремблирования, чтобы получить бит скремблирования

. Скремблер 810 выдает последовательность битов скремблирования, которые обозначены как

.Framed / Unframed Bits (

) are supplied to adder 1116, which also receives scrambling bits from adder 1114. Adder 1116 performs modulo 2 addition of each bit

with the corresponding scrambling bit to get the scrambling bit

. Scrambler 810 provides a sequence of scrambling bits, which are denoted as

.

The initial state of the scrambler (i.e., the contents of the delay elements 1112a-1112g) is set to a 7-bit non-zero number at the beginning of the DVR frame. The three most significant bits (MSB) (ie, the delay element 1112e-1112f) are always set to one ("1"), and the four least significant bits (LSB) are set respectively to the DTE frame counter, as indicated in the BCH message.

6. Coding / thinning

In an embodiment, a single base code is used to encode data before transmission. This base code generates code bits for a single code rate. All other code rates supported by the system (as listed in Table 25) can be obtained either by repeating or decimating these code bits.

=7), с генераторами из 133 и 171 (октальными).11B shows an embodiment of an encoder 812 that embodies a base code for a system. In this embodiment, the base code is a convolutional code with a rate of 1/2, a restriction length of 7 (

= 7), with generators from 133 and 171 (octal).

At encoder 812, multiplexer 1120 receives and multiplexes scrambling bits and tail bits (e.g., zeros). Encoder 812 further includes six delay elements 1122a through 1122f connected in series. Four adders 1124a-1124d are also connected in series and are used to implement the first generator (133). Similarly, four adders 1126a-1126d are connected in series and are used to implement the second generator (171). These adders are also connected to delay elements for realizing two generators 133 and 171, as shown in FIG. 11B.

, а кодовые биты, генерированные вторым генератором, обозначаются как

. Мультиплексор 1128 затем принимает и мультиплексирует два потока кодовых битов из этих двух генераторов в единый поток кодовых битов, которые обозначаются как

. Для каждого бита скремблирования

генерируются два кодовых бита

и

, что приводит к кодовой скорости 1/2.The scrambling bits are provided to the first delay element 1122a and to adders 1124a and 1126a. For each clock period, adders 1124a through 1124d add modulo 2 of the incoming bit and the four previous bits stored in delay elements 1122b, 1122c, 1122e, and 1122f to obtain the first code bit for this clock period. Similarly, adders 1126a through 1126d perform modulo 2 addition of the incoming bit and the four previous bits stored in delay elements 1122a, 1122b, 1122c, and 1122f to obtain a second code bit for this clock period. The code bits generated by the first generator are denoted as

, and the code bits generated by the second generator are denoted as

. Multiplexer 1128 then receives and multiplexes two code bit streams from these two generators into a single code bit stream, which are denoted as

. For each scrambling bit

two code bits are generated

and

, which leads to a code rate of 1/2.

11B also shows an embodiment of a repeat / decimation unit 814 that can be used to generate other code rates based on a base rate 1/2. At block 814, code bits with a rate of 1/2 from encoder 812 are provided to a repeater unit 1132 and a decimation unit 1134. A repeater unit 1132 repeats each code bit at a rate of 1/2 once to obtain an effective code rate of 1/4. The decimation unit 1134 deletes some of the code bits at a rate of 1/2 based on the particular decimation pattern to obtain the desired code rate.

Table 30 lists example thinning patterns that can be used for the various code rates supported by the system. Other thinning patterns may also be used, and this is within the scope of the invention.

Table 30 Code rate Thinning Pattern 1/2 eleven 7/12 11111110111110 5/8 1110111011 2/3 1110 11/16 1111101111111010011100 3/4 111001 13/16 01111011111101110000101100 5/6 1110011001 7/8 11101010011001

, прореживающий блок 1134 обеспечивает

кодовых битов для каждой группы из

кодовых битов со скоростью 1/2, принятых от кодера 812. Таким образом,

кодовых битов удаляются из каждой группы в

кодовых битов. Биты, подлежащие удалению из каждой группы, обозначаются нулями в прореживающем шаблоне. Например, чтобы получить кодовую скорость 7/12, два бита удаляются из каждой группы в 14 кодовых битов из кодера 812, причем удаляемыми битами являются 8-й и 14-й кодовые биты в группе, как обозначено прореживающим шаблоном "11111110111110". Никакого прореживания не выполняется, если желательной кодовой скоростью является 1/2.To get the code rate

thinning block 1134 provides

code bits for each group of

1/2 code bits received from encoder 812. Thus,

code bits are removed from each group in

code bits. Bits to be removed from each group are indicated by zeros in the decimation pattern. For example, to get a 7/12 code rate, two bits are removed from each group of 14 code bits from encoder 812, the 8th and 14th code bits in the group being deleted as indicated by the decimation pattern “11111110111110”. No decimation is performed if the desired code rate is 1/2.

A multiplexer 1136 receives a code bit stream from a repeater 1132 and a code bit stream from a decimator 1134. A multiplexer 1136 then provides code bits from a repeater 1132 if the desired code rate is 1/4, and code bits from the decimator 1134 if the desired code speed is 1/2 or higher.

Other codes and thinning patterns than those described above may also be used, and this is within the scope of the invention. For example, a turbo code, block code, some other codes, or a combination thereof, can be used to encode data. In addition, different coding schemes can be used for different transport channels. For example, convolutional coding can be used for common transport channels, and turbo coding can be used for dedicated transport channels.

7. Alternation

In an embodiment, the code bits to be transmitted are interleaved across 48 data subbands. For diversity and beam control modes, one stream of code bits is transmitted and interleaved across all data subbands. For the spatial multiplexing mode, up to four code bit streams can be transmitted on spatial channels of up to four. The interleaving can be performed separately for each spatial channel, so that each code data stream is interleaved over all data subbands of the spatial channel used to transmit this stream. Table 29 shows an exemplary assignment of code bits, subbands, that can be used for interleaving for all transport modes.

In one embodiment, interleaving is performed across all 48 data subbands in each interleaving interval. For this embodiment, each group of 48 code bits in a stream is allocated across 48 data subbands to provide frequency diversity. The 48 code bits in each group can be assigned indices from 0 to 47. Each code bit index is associated with a corresponding subband. All code bits with a specific index are transmitted in the associated subband. For example, the first code bit (with index 0) in each group is transmitted in the sub-band -26, the second code bit (with index 1) is transmitted in the sub-band 1, the third code bit (with the index 2) is transmitted in the sub-band -17, etc. The interleaving scheme can be used for diversity modes, beam control and spatial multiplexing. An alternative interleaving scheme for the spatial multiplexing mode is described below.

The interleaving may alternatively or additionally be performed in time. For example, after interleaving over data subbands, the code bits for each subband may be interleaved (for example, one PHY frame or one PDU) to provide temporal diversity. For the spatial multiplexing mode, interleaving can also be performed over multiple spatial channels.

Additionally, interleaving can be applied according to the dimensions of the QAM symbols, so that the code bits forming the QAM symbols are mapped to different bit positions of the QAM symbols.

8. Character mapping

) компоненту, другая половина битов отображается в квадратурную (

) компоненту.Table 31 shows the symbol mapping for the various modulation schemes supported by the system. For each modulation scheme (except for BPSK), half of the bits are mapped to common mode (

) component, the other half of the bits are mapped to quadrature (

) component.

, так и в

компонентах) отличаются только одной битовой позицией. Отображение Грея снижает число битовых ошибок для более вероятных ошибочных событий, что соответствует принятому символу, отображаемому в местоположение вблизи правильного местоположения, в каковом случае только один кодовый бит будет принят с ошибкой.In an embodiment, a group of signals for each supported modulation scheme may be determined based on a Gray mapping. When displaying Gray, neighboring points in the signal group (as in

so in

components) differ in only one bit position. Gray mapping reduces the number of bit errors for more likely error events, which corresponds to a received symbol mapped to a location near the correct location, in which case only one code bit will be received in error.

Table 31 Bpsk 256 QAM

0 -one 0 0000 -fifteen 0000 -fifteen one one 0 0001 -13 0001 -13 0011 -eleven 0011 -eleven QPSK 0010 -9 0010 -9

0110 -7 0110 -7 0 -one 0 -one 0111 -5 0111 -5 one one one one 0101 -3 0101 -3 0100 -one 0100 -one 16 QAM 1100 one 1100 one

1101 3 1101 3 00 -3 00 -3 1111 5 1111 5 01 -one 01 -one 1110 7 1110 7 eleven one eleven one 1010 9 1010 9 10 3 10 3 1011 eleven 1011 eleven 1001 13 1001 13 64 QAM 1000 fifteen 1000 fifteen

000 -7 000 -7 001 -5 001 -5 Coefficient

normalization 011 -3 011 -3 Modulation scheme Value 010 -one 010 -one Bpsk 1,0 110 one 110 one QPSK

111 3 111 3 16 QAM

101 5 101 5 64 QAM

one hundred 7 one hundred 7 256 QAM

и

для каждой схемы модуляции, показанной в Таблице 31, масштабируются коэффициентом

нормировки так, что средняя мощность всех сигнальных точек в ассоциированной группе сигналов равно единице. Коэффициент нормировки для каждой схемы модуляции показан в Таблице 31. Квантованные значения для коэффициентов нормировки для поддерживаемых схем модуляции также могут использоваться. Символ

модуляции из конкретной группы сигналов будет иметь следующий вид:Values

and

for each modulation scheme shown in Table 31, scaled by a factor

normalization so that the average power of all signal points in the associated signal group is equal to unity. The normalization coefficient for each modulation scheme is shown in Table 31. The quantized values for the normalization coefficients for the supported modulation schemes can also be used. Symbol

modulations from a specific group of signals will have the following form:

и

являются значениями в Таблице 31 для группы сигналов.Where

and

are the values in Table 31 for a group of signals.

For a given PBB, the modulation may differ in PBB and may differ for many spatial channels used for data transmission. For example, for the BCH PBB, various modulation schemes may be used for the beacon pilot, the MVxMVI pilot, and the BCH message.

9. Processing for spatial multiplexing mode

For the spatial multiplexing mode, PBBs can be transmitted over multiple spatial channels. Various schemes may be used to process data for transmission over multiple spatial channels. Two specific processing schemes for the spatial multiplexing mode are described below.

пространственных каналов для использования для передачи данных ранжируются от наивысшего к наинизшему отношению С/Ш для принятого сигнала. Данные для всего ПБД сначала кодируются, чтобы получить поток кодовых битов со скоростью 1/2. Эти кодовые биты затем прореживаются, чтобы получить желательную кодовую скорость для каждого пространственного канала.In the first processing scheme, coding and decimation are performed for each spatial channel to achieve the desired code rate for each spatial channel.

spatial channels for use for data transmission are ranked from the highest to the lowest S / N ratio for the received signal. The data for the entire PDU is first encoded to obtain a stream of code bits at 1/2 rate. These code bits are then thinned out to obtain the desired code rate for each spatial channel.

пространственных каналов от наилучшего (т.е. наивысшего С/Ш) к наихудшему (т.е. наинизшему С/Ш) пространственному каналу. В частности, прореживающий блок сначала выполняет прореживание для наилучшего пространственного канала с наивысшим отношением С/Ш для принятого сигнала. Когда правильное число кодовых битов генерированы для наилучшего пространственного канала, прореживающий блок затем выполняет прореживание для второго лучшего пространственного канала со следующим по величине отношением С/Ш для принятого сигнала. Этот процесс продолжается до тех пор, пока не будут генерированы кодовые биты для всех

пространственных каналов. Порядок для прореживания - от наибольшего к наименьшему С/Ш для принятого сигнала независимо от конкретной кодовой скорости, используемой для каждого пространственного канала.Thinning can be performed sequentially for

spatial channels from the best (i.e., the highest S / N) to the worst (i.e., the lowest S / N) spatial channel. In particular, the decimation unit first performs decimation for the best spatial channel with the highest S / N ratio for the received signal. When the correct number of code bits are generated for the best spatial channel, the thinning unit then performs thinning for the second best spatial channel with the next largest S / N ratio for the received signal. This process continues until code bits are generated for all

spatial channels. The order for decimation is from the largest to the smallest S / N for the received signal, regardless of the specific code rate used for each spatial channel.

For the example shown in Table 28, 3456 information bits to be transmitted in the common PHY frame are first encoded with the base code at 1/2 rate to obtain 6912 code bits. The first 3168 code bits are punctured using a puncturing pattern for 11/16 code rate to obtain the 2304 code bits that are provided in the PHY frame for the first spatial channel. The next 2592 code bits are then punctured using a puncturing pattern for a 3/4 code rate to obtain the 1728 code bits that are provided in the PHY frame for the second spatial channel. The next 894 code bits are then punctured using a puncturing pattern for a 3/4 code rate to obtain 576 code bits that are provided in the PHY frame for the third spatial channel. The last 288 code bits for the PHY frame are then punctured using a puncturing pattern for 1/2 code rate to obtain the 288 code bits that are provided in the PHY frame for the last spatial channel. These four separate PHY frames are further processed and transmitted on four spatial channels. Decimation for the next common PHY frame is performed in the same way. The first processing scheme can be implemented by the data processor 710b of FIG. 9A.

In a second processing scheme, encoding and decimation are performed for a pair of subbands. In addition, coding and decimation are repeated over all selected spatial channels for each pair of subbands.

обозначает число кодовых битов на символ модуляции для пространственного канала

(или, эквивалентно, число кодовых битов, посылаемых на каждом поддиапазоне данных пространственного канала

), а

обозначает кодовую скорость, используемую для пространственного канала

. Значение для

зависит от размера группы сигналов для схемы модуляции, используемой для пространственного канала

. В частности,

=1, 2, 4, 6 и 8 для BPSK, QPSK, 16-QAM, 64-QAM и 256-QAM, соответственно.11C shows a flowchart that illustrates an TX data processor 710d that implements a second processing circuit. Encoder 812 convolutionally encodes at 1/2 bit rate of scrambling from scrambler 810. Each spatial channel is assigned a specific bit rate, which is associated with a particular combination of code rate and modulation scheme, as shown in Table 25. Let

denotes the number of code bits per modulation symbol for a spatial channel

(or, equivalently, the number of code bits sent on each spatial channel data subband

), but

denotes the code rate used for the spatial channel

. Value for

depends on the size of the signal group for the modulation scheme used for the spatial channel

. In particular,

= 1, 2, 4, 6, and 8 for BPSK, QPSK, 16-QAM, 64-QAM, and 256-QAM, respectively.

кодовых битов в буфер 813а для пространственного канала 1, следующих

кодовых битов - в буфер 813b для пространственного канала 2 и т.д. Каждый буфер 813 принимает

кодовых битов каждый раз, как демультиплексор 816 проходит через все четыре пространственных канала. Все из

кодовых битов со скоростью 1/2 подаются на четыре буфера 813а-813d для каждого периода. Демультиплексор 816, таким образом, проходит по всем четырем позициям для четырех пространственных каналов для каждых

кодовых битов, что является числом кодовых битов, которые могут быть переданы в паре поддиапазонов с использованием всех четырех пространственных каналов.Encoder 812 supplies the code bit stream at 1/2 rate to demultiplexer 816, which demultiplexes the received code bit stream into four sub-streams for four spatial channels. Demultiplexing provides direction to the first

code bits to buffer 813a for spatial channel 1, the following

code bits to buffer 813b for spatial channel 2, etc. Each buffer 813 accepts

code bits every time the demultiplexer 816 passes through all four spatial channels. All of

1/2 code bits are supplied to four buffers 813a-813d for each period. The demultiplexer 816 thus passes through all four positions for four spatial channels for each

code bits, which is the number of code bits that can be transmitted in a pair of subbands using all four spatial channels.

кодовыми битами для соответствующего пространственного канала, кодовые биты в буфере прореживаются, чтобы получить кодовую скорость для этого пространственного канала. Поскольку

кодовых битов со скоростью 1/2 охватывают целое число периодов прореживания для каждого прореживающего шаблона, точно

кодовых битов обеспечиваются после прореживания для каждого пространственного канала

.

кодовых битов для каждого пространственного канала затем распределяются (перемежаются) по поддиапазонам данных.When each buffer 813 is full

code bits for the corresponding spatial channel, the code bits in the buffer are punctured to obtain the code rate for this spatial channel. Insofar as

1/2 code bits cover an integer number of decimation periods for each decimation pattern, exactly

code bits are provided after decimation for each spatial channel

.

the code bits for each spatial channel are then allocated (interleaved) over data subbands.

, где

= 0, 1, 2, …. Может иметься счетчик

для каждого пространственного канала для подсчета каждой группы из

кодовых битов, обеспеченных прореживающим блоком для этого пространственного канала. Например, для QPSK с

=2 счетчик будет устанавливаться на

=0 для кодовых битов

-

, обеспеченных прореживающим блоком,

=1 после кодовых битов

-

и т.д. Значение

счетчика для пространственного канала

может быть выражено как:In an embodiment, interleaving is performed for each spatial channel in groups of 6 subbands simultaneously. The decimation code bits for each spatial channel may be numbered sequentially as

where

= 0, 1, 2, .... May have a counter

for each spatial channel to count each group of

code bits provided by a decimation unit for this spatial channel. For example, for QPSK with

= 2 counter will be set to

= 0 for code bits

-

provided with a decimation unit,

= 1 after code bits

-

etc. Value

spatial channel counter

may be expressed as:

, сначала для этого кодового бита находится битовый индекс следующим образом:To find the subband to which the code bit is assigned

, first for this code bit is the bit index as follows:

The bit index is then mapped to the corresponding subband using Table 29.

-

связывается с битовыми индексами 0-5, соответственно, вторая группа из 6 кодовых битов

-

также связывается с битовыми индексами 0 - 5, соответственно. Кодовые биты

и

будут отображаться в поддиапазон -26, кодовые биты

и

будут отображаться в поддиапазон 1 и т.д., как показано в Таблице 29. Пространственная обработка может затем начинаться для этой первой группы из 6 поддиапазонов. Третья группа из 6 кодовых битов

-

(с

=1) связывается с индексами 6 - 11, соответственно, а четвертая группа из 6 кодовых битов

-

также связывается с битовыми индексами 6 - 11, соответственно. Кодовые биты

и

будут отображаться в поддиапазон -25, кодовые биты

и

будут отображаться в поддиапазон 2 и т.д. Пространственная обработка может затем начинаться для этой следующей группы из 6 поддиапазонов.For the above example, the first group of 6 code bits

-

associated with bit indices 0-5, respectively, the second group of 6 code bits

-

also associated with bit indices 0 - 5, respectively. Code bits

and

will be displayed in a sub-range of -26, code bits

and

will be displayed in subband 1, etc., as shown in Table 29. Spatial processing may then begin for this first group of 6 subbands. Third group of 6 code bits

-

(from

= 1) is associated with indices 6 - 11, respectively, and the fourth group of 6 code bits

-

also associated with bit indices 6 - 11, respectively. Code bits

and

will be displayed in a sub-range of -25, code bits

and

will be displayed in subband 2, etc. Spatial processing may then begin for this next group of 6 subbands.

кодовых битов для одного символа МОРЧ для каждого пространственного канала.The number 6 in equation (24) follows from the fact that interleaving is performed in groups of six subbands. The operation (mod 8) in equation (23) follows from the fact that there are eight interleaved groups for 48 data subbands. Since at each period, the demultiplexer 816 shown in FIG. 11C generates enough code bits to fill two subbands for each broadband eigenmode, all 24 periods are necessary to provide

code bits for one OFDM symbol for each spatial channel.

Interleaving in groups of 6 sub-bands at the same time can reduce processing delays. In particular, spatial processing may begin when each group of 6 subbands is available.

поддиапазонов одновременно, где

может быть любым целым числом (например,

может быть равно 48 для перемежения по всем 48 поддиапазонам данных).In alternative embodiments, interleaving may be performed for each spatial channel in groups of

subbands simultaneously where

can be any integer (e.g.

may be 48 for interleaving across all 48 data subbands).

VI. Calibration

представляет матрицу канальных откликов из антенной решетки

в антенную решетку

для поддиапазона

, то обратимый канал подразумевает, что связь от решетки

к решетке

задается транспозицией

, которая представляет собой

.For the DVR system, the downlink and uplink share the same frequency band in time division duplex mode. In this case, as a rule, a high degree of correlation exists between the channel responses of the downward and upward lines. This correlation can be used to simplify channel estimation and spatial processing. For a DVR system, each subband of a wireless link may be assumed to be reversible. That is, if

represents a matrix of channel responses from an antenna array

into the antenna array

for subband

, then the reversible channel implies that the connection from the lattice

to the grate

set by transposition

which is

.

However, the responses (gain and phase) of the transmit and receive circuits at the access point usually differ from the responses of the transmit and receive circuits at the user terminal. In order to find the difference in the frequency responses of the transmit / receive circuits at the access point and the user terminal and take this difference into account, calibration can be performed so that the calibrated downlink and uplink responses can be expressed in terms of each other. When the transmit / receive circuits are calibrated and taken into account, the measurement for one line (for example, downstream) can be used to obtain control vectors for another line (for example, upstream).

и

нисходящей и восходящей линий, которые включают в себя отклики соответствующих цепей передачи и приема в пункте доступа и пользовательском терминале, могут быть выражены как:Efficient Channel Responses

and

downlink and uplink, which include the responses of the respective transmission and reception circuits at the access point and user terminal, can be expressed as:

и

являются диагональными матрицами размера

×

с составляющими для комплексных коэффициентов усиления, связанных с цепью передачи и цепью приема, соответственно, для

антенн в пункте доступа для поддиапазона

;Where

and

are diagonal matrices of size

×

with components for complex gains associated with the transmission circuit and the reception circuit, respectively, for

antennas at access point for subband

;

и

являются диагональными матрицами размера

×

с составляющими для комплексных коэффициентов усиления, связанных с цепью передачи и цепью приема, соответственно, для

антенн в пользовательском терминале для поддиапазона

; и

and

are diagonal matrices of size

×

with components for complex gains associated with the transmission circuit and the reception circuit, respectively, for

antennas in the user terminal for the subband

; and

является матрицей канальных откликов размером

×

для нисходящей линии.

is a channel response matrix of size

×

for the downward line.

Combining these two equations in the set (25) of equations, we can obtain the following relation:

и

для эффективных канальных откликов нисходящей линии и восходящей линии, соответственно, как показано в уравнении (26), позволяет выразить калиброванные канальные отклики для нисходящей и восходящей линий как транспозиции друг друга. Диагональная матрица

размером

×

для пункта доступа является отношением отклика

приемной цепи к отклику

передающей цепи (т.е.

), где это отношение берется на по-элементной основе. Аналогично, диагональная матрица

размером

×

для пользовательского терминала является отношением отклика

приемной цепи к отклику

передающей цепи.The left side of equation (26) represents the “true” calibrated channel response in the uplink, and the right side represents the transposition of the “truly” calibrated channel response in the downlink. Using diagonal matrices

and

for effective channel responses of the descending line and the ascending line, respectively, as shown in equation (26), allows expressing the calibrated channel responses for the descending and ascending lines as transpositions of each other. Diagonal matrix

the size

×

for access point is the response ratio

receive chain to response

transmission chain (i.e.

), where this relation is taken on an elemental basis. Similarly, the diagonal matrix

the size

×

for user terminal is the response ratio

receive chain to response

transmission chain.

и

включают в себя значения, которые могут учитывать различия в цепях передачи/приема в пункте доступа и пользовательском терминале. Это затем позволит выразить канальный отклик для одной линии через канальный отклик для другой линии, как показано в уравнении (26).Matrices

and

include values that may account for differences in transmit / receive chains at the access point and user terminal. This then allows us to express the channel response for one line through the channel response for another line, as shown in equation (26).

и

. Как правило, истинный канальный отклик

и отклики цепи передачи/приема неизвестны и не могут быть точно или легко установлены. Вместо этого можно оценить эффективные канальные отклики нисходящей и восходящей линий

и

, соответственно, на основании пилот-сигналов, посланных по нисходящей и восходящей линиям, как описано ниже. Оценки матриц

и

, которые называются корректировочными матрицами

и

, можно затем выделить на основании оценок

и

канальных откликов нисходящей и восходящей линий, как описано ниже. Матрицы

и

включают в себя корректировочные коэффициенты, которые могут учитывать различия в цепях передачи/приема в пункте доступа и пользовательском терминале.Calibration can be performed to find matrices

and

. Typically true channel response

and the responses of the transmit / receive chain are unknown and cannot be accurately or easily set. Instead, you can evaluate the effective channel responses of the downward and upward lines

and

, respectively, based on the pilot signals sent on the downlink and uplink, as described below. Matrix Estimates

and

called adjustment matrices

and

can then be distinguished based on estimates

and

channel responses of the descending and ascending lines, as described below. Matrices

and

include correction factors that can account for differences in transmit / receive chains at the access point and user terminal.

The “calibrated” channel responses of the downlink and uplink observed by the user terminal and access point, respectively, can be expressed as:

и

являются выражениями "истинного" калиброванного канального отклика в уравнении (26). Комбинируя два уравнения в наборе (27) уравнений с использованием выражения в уравнении (26), можно показать, что

≈

. Точность соотношения

≈

зависит от точности матриц

и

, которая, в свою очередь, обычно зависит от качества оценок

и

канальных откликов нисходящей и восходящей линий.Where

and

are expressions of the “true” calibrated channel response in equation (26). Combining the two equations in the set (27) of equations using the expression in equation (26), we can show that

≈

. Ratio accuracy

≈

depends on the accuracy of the matrices

and

, which, in turn, usually depends on the quality of the ratings

and

channel responses of the descending and ascending lines.

Calibration can be performed using various schemes. For clarity, a specific calibration scheme is described below. To perform the calibration, the user terminal first obtains the synchronization and frequency of the access point based on the beacon pilot transmitted over the BCH channel. The user terminal then sends a message on the RACH to initiate the calibration procedure by the access point. This calibration can be performed in parallel with registration / authentication.

Since the frequency responses of the transmit / receive circuits at the access point and user terminal are generally uniform over most of the band of interest, the gain / phase differences of the transmit / receive circuits can be characterized by a small number of subbands. Calibration can be performed for 4, 8, 16, 48, or some other number of subbands that can be specified in the message sent to initiate the calibration. Calibration may also be performed for pilot subbands. Calibration constants for subbands on which calibration is not performed explicitly can be calculated by interpolation on calibrated subbands. For clarity, it is further assumed that calibration is performed for all data subbands.

For calibration, the access point allocates enough time on the RCH to the user terminal to send an uplink MVxMB pilot of sufficient duration plus a message. The duration of the uplink MVxMV pilot signal may depend on the number of subbands for calibration. For example, 8 OFDM symbols may be sufficient if calibration is performed for four subbands, and more (e.g. 20) OFDM symbols may be needed for a larger number of subbands. The total transmit power is usually fixed, so if the MVXMO pilot signal is transmitted in a small number of subbands, higher transmit powers can be used for each of these subbands, and the S / N ratio for each subband is high. Conversely, if the MVxMOut pilot signal is transmitted in a large number of subbands, lower transmission power values can be used for each subband, and the S / N ratio for each subband is reduced. If the S / N of each subband is not high enough, then more OFDM symbols may be sent for the MVxMVO pilot and will be integrated in the receiver to obtain a higher S / N ratio for the subband.

восходящей линии для каждого из поддиапазонов данных. Оценки канальных откликов восходящей линии квантуются (например, на 12-битовые комплексные значения с синфазной (

) и квадратурной (

) компонентами) и посылаются к пользовательскому терминалу.The user terminal then transmits to the RCH an MVxMv pilot, which is used by the access point to extract an estimate of the effective channel response

an uplink for each of the data subbands. The uplink channel response estimates are quantized (e.g., to 12-bit complex values with common mode (

) and quadrature (

) by components) and are sent to the user terminal.

эффективного канального отклика нисходящей линии для каждого из поддиапазонов данных на основании пилот-сигнала МВхМВых, посланного на ВСН. По получении эффективных оценок

и

канальных откликов восходящей и нисходящей линий для всех поддиапазонов данных пользовательский терминал находит корректировочные коэффициенты

и

для каждого из поддиапазонов данных, которые подлежат использованию пунктом доступа и пользовательским терминалом, соответственно. Может быть определен корректировочный вектор

, чтобы включить только диагональные элементы

, и может быть определен корректировочный вектор

, чтобы включить только диагональные элементы

.The user terminal also gives out a rating

effective downlink channel response for each of the data subbands based on the MVxMv pilot sent to the BCH. Upon receiving effective grades

and

uplink and downlink channel responses for all data subbands, the user terminal finds the correction factors

and

for each of the data subbands to be used by the access point and user terminal, respectively. A correction vector can be defined.

to include only diagonal elements

, and a correction vector can be determined

to include only diagonal elements

.

Correction factors can be distinguished in various ways, including calculating the ratio of matrices and calculating ISCED. Both of these calculation methods are described in more detail below. Other calculation methods that are within the scope of the invention may also be used.

1. Calculation of the ratio of matrices

и

, сначала для каждого поддиапазона данных при заданных эффективных оценках

и

канальных откликов восходящей и нисходящей линий вычисляется матрица

размера (

), следующим образом:To find correction vectors

and

, first for each data subband at given effective estimates

and

uplink and downlink channel responses matrix is calculated

size (

), in the following way:

может, таким образом, вычисляться как:where the relationship is taken on an elemental basis. Every item

can thus be computed as:

является (

,

)-м элементом (строкой столбцом)

,

является (

,

)-м элементом

, а

является (

,

)-м элементом

.Where

is an (

,

) th element (row column)

,

is an (

,

) th element

, but

is an (

,

) th element

.

для пункта доступа далее равен среднему от нормированных строк

. Каждая строка

сначала нормируется путем масштабирования каждого из

элементов в строке первым элементом в этой строке. Таким образом, если

является

-й строкой

, то нормированная строка

может быть выражена как:Adjustment vector

for the access point is further equal to the average of the normalized rows

. Each line

first normalized by scaling each of

items in a row is the first item in that row. So if

is an

row

, then the normalized string

may be expressed as:

нормированных строк, поделенной на

, что можно выразить как:The average of the normalized rows is then the sum

normalized strings divided by

that can be expressed as:

является единицей.Due to normalization, the first element

is a unit.

для пользовательского терминала равен среднему от инверсий нормированных столбцов

.

-й столбец

нормируется первым путем масштабирования каждого элемента в столбце

-м элементом вектора

, который обозначается как

. Таким образом, если

является

-м столбцом

, то нормированный столбец

может быть выражен как:Adjustment vector

for the user terminal is equal to the average of the inversions of normalized columns

.

column

normalized first by scaling each item in a column

vector element

which is designated as

. So if

is an

column

then the normalized column

may be expressed as:

нормированных строк, поделенной на

, что можно выразить как:The average of the inversions of the normalized columns is then the sum of the inversions

normalized strings divided by

that can be expressed as:

от нормированных столбцов выполняется поэлементно.where is the inversion

from normalized columns is performed elementwise.

2. Calculation of ISCED

и

выделяются из эффективных оценок

и

канальных откликов восходящей и нисходящей линий, так что среднеквадратичная ошибка (СКО) (MSE) между калиброванным канальным откликом нисходящей линии и калиброванным канальным откликом восходящей линии минимизируется. Это условие можно выразить как:To calculate ISCED correction factors

and

stand out from effective ratings

and

uplink and downlink channel responses, so that the mean square error (MSE) between the calibrated downlink channel response and the calibrated uplink channel response is minimized. This condition can be expressed as:

which can also be written as:

=

, поскольку

является диагональной матрицей.Where

=

, insofar as

is a diagonal matrix.

устанавливается на единицу (т.е.

=1). Без этого ограничения будет получено тривиальное решение со всеми элементами матриц

и

), установленными на нуль. В уравнении (34) матрица

получается как

. Квадрат абсолютного значения получается затем для каждой из

·

составляющих матрицы

. Среднеквадратичная ошибка (или квадрат ошибки, поскольку деление

·

на опускается) равна тогда сумме всех

·

квадратных значений.For equation (34) there is a restriction according to which the leading element

set to one (i.e.

= 1). Without this restriction, a trivial solution with all elements of the matrices will be obtained

and

) set to zero. In equation (34), the matrix

it turns out how

. The square of the absolute value is then obtained for each of

·

constituent matrix

. RMS error (or squared error since division

·

on falls) is then equal to the sum of all

·

square values.

и

для поддиапазона. Вычисление МСКО для одного поддиапазона описывается ниже. Для простоты, индекс

поддиапазона опускается в нижеследующем описании. Также для простоты, элементы оценки

нисходящей линии обозначаются как {

}, элементы оценки

восходящей линии обозначаются как {

}, диагональные элементы матрицы

обозначаются как {

}, а диагональные элементы матрицы

обозначаются как {

}, где

={1 …

} и

={1 …

}.ISCED calculation is performed for each assigned subband to obtain correction factors

and

for subband. The calculation of ISCED for one subband is described below. For simplicity, the index

subband is omitted in the following description. Also for simplicity, evaluation elements

descending lines are denoted as {

}, evaluation elements

ascending lines are denoted as {

}, diagonal elements of the matrix

are denoted as {

}, and the diagonal elements of the matrix

are denoted as {

} where

= {1 ...

} and

= {1 ...

}.

The standard error can be rewritten from equation (34) as follows:

=1. Минимальная среднеквадратичная оценка может быть получена взятием частичных производных от уравнения (35) по

и

и установкой этих частичных производных на нуль. Результатами этих операций являются следующие наборы уравнений:again there is a restriction

= 1. The minimum root mean square estimate can be obtained by taking the partial derivatives of equation (35) with respect to

and

and setting these partial derivatives to zero. The results of these operations are the following sets of equations:

=1, так что для этого случая нет частной производной и индекс

изменяется от 2 до

.In equation (36a)

= 1, so for this case there is no partial derivative and the index

varies from 2 to

.

+

-1) уравнений в наборе уравнений (36а) и (36b) может быть более традиционно выражен в матричной форме следующим образом:A set of (

+

-1) of the equations in the set of equations (36a) and (36b) can be more traditionally expressed in matrix form as follows:

Where

включает в себя (

+

-1) строк, причем первые

-1 строк соответствуют

-1 уравнениям из набора (36а) уравнений, а последние

строк соответствуют

уравнениям из набора (36b) уравнений. В частности, первая строка матрицы

генерируется из набора (36а) уравнений при

=2, вторая строка генерируется при

=3, и т.д.

-я строка матрицы

генерируется из набора (36b) уравнений при

=1, и т.д., а последняя строка генерируется при

=

. Как показано выше, составляющие матрицы

и составляющие вектора

могут быть получены на основании составляющих матриц

и

.Matrix

includes (

+

-1) lines, with the first

-1 lines correspond

-1 equations from the set of equations (36a), and the latter

lines match

equations from the set of equations (36b). In particular, the first row of the matrix

generated from set (36a) of equations for

= 2, the second line is generated when

= 3, etc.

matrix row

generated from the set of equations (36b) for

= 1, etc., and the last line is generated when

=

. As shown above, the constituent matrices

and vector components

can be derived from component matrices

and

.

, который можно получить как:Correction factors are included in the vector

, which can be obtained as:

и

, которые минимизируют среднеквадратичную ошибку в калиброванных канальных откликах нисходящей и восходящей линий, как показано в уравнении (34). Поскольку матрицы

и

получены на основании оценок

и

канальных откликов восходящей и нисходящей линий, качество корректировочных матриц

и

, таким образом, зависит от качества канальных оценок

и

. Пилот-сигнал МВхМВых может усредняться в приемнике, чтобы получить более точные оценки для

и

.ISCED calculation results are adjustment matrices

and

which minimize the root mean square error in the calibrated downlink and uplink channel responses, as shown in equation (34). Since matrices

and

derived from estimates

and

channel responses of ascending and descending lines, the quality of correction matrices

and

thus depends on the quality of the channel estimates

and

. The MVxMOf pilot may be averaged at the receiver to obtain more accurate estimates for

and

.

и

, полученные на основании вычисления МСКО, в общем лучше, чем корректировочные матрицы, полученные на основании вычисления отношения матриц. Это особенно правильно, когда некоторые из канальных коэффициентов усиления малы, и измеренный шум может сильно ухудшить канальные коэффициенты усиления.Adjustment matrix

and

obtained from ISCED calculations are generally better than adjustment matrices obtained from matrix ratio calculations. This is especially true when some of the channel gains are small and the measured noise can greatly degrade the channel gains.

3. Subsequent calculation

и

может быть найдена для каждого из поддиапазонов данных. Поскольку смежные поддиапазоны вероятнее всего коррелированы, вычисление можно упростить. Например, вычисление можно выполнять для каждого

-го поддиапазона вместо каждого поддиапазона, где

может быть найдено через ожидаемый отклик цепей передачи/приема. Если калибровка выполняется для менее чем всех поддиапазонов данных и пилот-сигналов, то корректировочные коэффициенты для "некалиброванных" поддиапазонов могут быть получены интерполяцией корректировочных коэффициентов, полученных для "калиброванных" поддиапазонов.Pair of Correction Vectors

and

can be found for each of the data subbands. Since adjacent subbands are most likely correlated, the calculation can be simplified. For example, a calculation can be performed for each

th subband instead of each subband, where

can be found through the expected response of the transmit / receive chains. If calibration is performed for less than all of the data and pilot subbands, then the correction factors for the “uncalibrated” subbands can be obtained by interpolating the correction coefficients obtained for the “calibrated” subbands.

и

для пункта доступа и пользовательского терминала, соответственно. Однако описанная выше схема позволяет получить "совместимые" корректировочные векторы для пункта доступа, когда калибровка выполняется различными пользовательскими терминалами.Various other calibration schemes can also be used to highlight correction vectors.

and

for the access point and user terminal, respectively. However, the scheme described above allows one to obtain “compatible” correction vectors for an access point when calibration is performed by various user terminals.

для всех поддиапазонов данных назад в пункт доступа. Если пункт доступа уже откалиброван (к примеру, другими пользовательскими терминалами), то текущие корректировочные векторы обновляются вновь принятыми корректировочными векторами. Таким образом, если пункт доступа использует корректировочные векторы

для передачи пилот-сигнал МВхМВых, из которого пользовательский терминал находит новые корректировочные векторы

, тогда обновленные корректировочные векторы являются произведением текущего и нового корректировочных векторов, т.е.

=

·

, где перемножение осуществляется на по-элементной основе. Обновленные корректировочные векторы

могут затем использоваться пунктом доступа до тех пор, пока они не будут снова обновлены.After this receipt, the user terminal sends correction vectors

for all data subbands back to the access point. If the access point has already been calibrated (for example, by other user terminals), then the current correction vectors are updated with the newly received correction vectors. Thus, if the access point uses correction vectors

for transmitting the pilot signal MxMVy, from which the user terminal finds new correction vectors

, then the updated correction vectors are the product of the current and new correction vectors, i.e.

=

·

where the multiplication is carried out on an elemental basis. Updated Correction Vectors

can then be used by the access point until they are updated again.

и

могут быть получены тем же самым или иными пользовательскими терминалами. В одном варианте осуществления обновленные корректировочные векторы определяются как

=

·

, где перемножение осуществляется на по-элементной основе. В другом варианте осуществления обновленные корректировочные векторы могут быть определены повторно как

=

·

, где α является коэффициентом, используемым для обеспечения взвешенного усреднения (т.е. 0<α<1). Если обновления калибровки нечасты, то α близкий к единице, может обеспечивать лучший результат. Если обновления калибровки часты, но зашумлены, то лучшим будем меньшее значение для α. Обновленные корректировочные векторы

могут затем использоваться пунктом доступа до тех пор, пока они не будут снова обновлены.Correction vectors

and

can be received by the same or other user terminals. In one embodiment, the updated correction vectors are defined as

=

·

where the multiplication is carried out on an elemental basis. In another embodiment, the updated correction vectors may be redefined as

=

·

, where α is the coefficient used to provide weighted averaging (i.e. 0 <α <1). If calibration updates are infrequent, then α close to unity may provide a better result. If calibration updates are frequent but noisy, then a lower value for α will be best. Updated Correction Vectors

can then be used by the access point until they are updated again.

и

или соответствующие корректировочные матрицы

и

, для

∈

, чтобы масштабировать символы перед передачей, как описано ниже. Калиброванные каналы нисходящей и восходящей линий, которые наблюдают пользовательский терминал и пункт доступа, показаны в уравнении (27).The access point and user terminal use their respective correction vectors

and

or corresponding adjustment matrices

and

for

∈

to scale the characters before transmission, as described below. The calibrated downlink and uplink channels that the user terminal and access point observe are shown in equation (27).

VII. Spatial processing

=

. Калибровочный канальный отклик восходящей линии равен

=

≈

.The spatial processing at the access point and user terminal can be simplified for the DDA system after calibration is performed to calculate the difference in the transmit / receive circuits. As noted above, the calibrated downlink channel response is

=

. The uplink calibration channel response is

=

≈

.

1. Spatial uplink processing

калиброванных канальных откликов восходящей линии может быть выражена как:Decomposition by singular matrix values

calibrated uplink channel responses can be expressed as:

является единичной матрицей размера (

×

) левых собственных векторов

;Where

is the identity matrix of size (

×

) left eigenvectors

;

диагональной матрицей размера (

×

) сингулярных значений

; и

diagonal size matrix (

×

) singular values

; and

является единичной матрицей размера (

×

) правых собственных векторов

.

is the identity matrix of size (

×

) right eigenvectors

.

калиброванных канальных откликов восходящей линии может быть выражена как:Accordingly, the decomposition of the singular values of the matrix

calibrated uplink channel responses can be expressed as:

и

являются также матрицами левых и правых собственных векторов, соответственно,

. Как показано в уравнениях (39) и (40) и основано на вышеприведенном описании, матрицы левых и правых собственных векторов для одной линии являются комплексно сопряженными матрицами правых и левых собственных векторов, соответственно, для другой линии. Матрицы

,

,

и

являются различными формами матрицы

, а матрицы

,

,

и

являются также различными формами матрицы

. Для простоты, ссылка на матрицы

и

в нижеследующем описании может также относиться к их различным иным формам. Матрицы

и

используются пунктом доступа и пользовательским терминалом, соответственно, для пространственной обработки и обозначаются как таковые своими подстрочными индексами. Собственные векторы часто также называются "управляющими" векторами.Matrices

and

are also matrices of left and right eigenvectors, respectively,

. As shown in equations (39) and (40) and based on the above description, the matrices of left and right eigenvectors for one line are complex conjugate matrices of right and left eigenvectors, respectively, for another line. Matrices

,

,

and

are different forms of matrix

, and the matrices

,

,

and

are also different forms of matrix

. For simplicity, a link to the matrix

and

in the following description may also refer to their various other forms. Matrices

and

are used by the access point and the user terminal, respectively, for spatial processing and are indicated as such by their subscripts. Eigenvectors are often also called "control" vectors.

калиброванных канальных откликов нисходящей линии, для

∈

, чтобы получить диагональную матрицу

и матрицу

левых собственных векторов

. Эта декомпозиция по сингулярным значениям может быть задана как

=

, где символ ("^") над каждой матрицей указывает, что это оценка действительной матрицы.The user terminal may evaluate the calibrated downlink channel responses based on the MVxxM pilot sent by the access point. The user terminal may then decompose the singular valuation values

calibrated downlink channel responses, for

∈

to get the diagonal matrix

and matrix

left eigenvectors

. This decomposition by singular values can be defined as

=

, where the symbol ("^") above each matrix indicates that it is an estimate of the real matrix.

калиброванных канальных откликов восходящей линии, для

∈

, чтобы получить диагональную матрицу

и матрицу

левых собственных векторов

. Эта декомпозиция по сингулярным значениям может быть задана как

=

.Similarly, the access point may evaluate the calibrated uplink channel responses based on the MVxxM pilot sent by the user terminal. The access point may then decompose singular values to evaluate

calibrated uplink channel responses, for

∈

to get the diagonal matrix

and matrix

left eigenvectors

. This decomposition by singular values can be defined as

=

.

размера (

×

) может быть определена как:Matrix

size (

×

) can be defined as:

нисходящей линии и матрицы

левых собственных векторов

, которые используются для обновления матрицы

.The user terminal, when active, supports a valid calibration channel estimate

downlink and matrix

left eigenvectors

that are used to update the matrix

.

для пространственной обработки для режимов управления лучом и пространственного мультиплексирования. Для режима пространственного мультиплексирования вектор

передачи для каждого поддиапазона может быть выражен как:User terminal uses matrix

for spatial processing for beam control and spatial multiplexing modes. For spatial multiplexing mode, the vector

Transmissions for each subband can be expressed as:

является вектором данных, содержащим до

символов, подлежащих передаче на

собственных режимах поддиапазона

;Where

is a data vector containing up to

characters to be transmitted to

native subband modes

;

заменяет

в уравнении (15), а масштабирование сигнала, посредством

для реализации инверсии каналов, для простоты, опускается в уравнении (42); и

replaces

in equation (15), and scaling the signal by

for channel inversion, for simplicity, is omitted in equation (42); and

является вектором передачи для восходящей линии для поддиапазона

.

is an uplink transmission vector for a subband

.

для передачи восходящей линии можно выразить как:At the access point, the received vector

for uplink transmission can be expressed as:

является принятым вектором для поддиапазона

восходящей линии; иWhere

is the accepted vector for the subband

ascending line; and

является аддитивным белым Гауссовским шумом (АБГШ) для поддиапазона

.

is additive white Gaussian noise (ABGS) for the subband

.

и

=

. Как показано в уравнении (43), в пункте доступа принятая передача восходящей линии преобразуется посредством:

, что является матрицей

левых собственных векторов

, масштабированной диагональной матрицей

сингулярных величин.Equation (43) uses the following relationships:

and

=

. As shown in equation (43), at the access point, the received uplink transmission is converted by:

what is the matrix

left eigenvectors

scaled diagonal matrix

singular quantities.

. Управляемый эталон является передачей пилот-сигнала на одной широкополосной собственной моде с использованием управления лучом или формирования луча, и более подробно описан ниже. В пункте доступа принятый управляемый эталон восходящей линии (в отсутствие шума) приблизительно равен

. Пункт доступа может затем получить оценку единичной матрицы

и диагональной матрицы

на основании управляемого эталона, посланного пользовательским терминалом. Различные методы оценки могут использоваться для получения оценки единичной и диагональной матриц.The user terminal transmits the uplink managed reference using a matrix

. The controlled reference is the transmission of a pilot signal on one wideband eigenmode using beam control or beamforming, and is described in more detail below. At the access point, the received uplink controlled reference (in the absence of noise) is approximately

. The access point may then obtain an estimate of the identity matrix

and diagonal matrix

based on the managed template sent by the user terminal. Various estimation methods can be used to obtain estimates of the unit and diagonal matrices.

, принятый вектор

для управляемого эталона для поддиапазона

широкополосной собственной моды

сначала умножается на комплексно сопряженное от символа

пилот-сигнала МОРЧ, посланного в качестве управляемого эталона. Генерирование управляемого эталона и символа пилот-сигнала МОРЧ более подробно описано ниже. Результат затем интегрируется по множеству принятых управляемых эталонных символов для каждой широкополосной собственной моды, чтобы получить оценку

, которая масштабируется левым собственным вектором

для широкополосной собственной моды

. Поскольку собственные векторы имеют единичную мощность, сингулярные значения (или

) в

могут быть оценены на основании принятой мощности управляемого эталона, которую можно измерить для каждого поддиапазона каждой широкополосной собственной моды.In one embodiment, to obtain an estimate

accepted vector

for controlled reference for sub-range

broadband own fashion

first multiplied by the complex conjugate of the symbol

OFDM pilot sent as a controlled reference. The generation of the controlled reference and the OFDM pilot symbol is described in more detail below. The result is then integrated over a plurality of accepted controlled reference symbols for each broadband eigenmode to obtain an estimate

which is scaled by the left eigenvector

for broadband native fashion

. Since eigenvectors have unit power, singular values (or

) at

can be estimated based on the received power of the controlled reference, which can be measured for each subband of each broadband eigenmode.

на основании принятого вектора

для управляемого эталона.In another embodiment, the ISCED method is used to obtain an estimate

based on the accepted vector

for managed reference.

A controlled reference can be transmitted for one wideband eigenmode in any given symbol period and, in turn, can be used to obtain an estimate of one eigenvector for each subband of this wideband eigenmode. Thus, the receiver is able to obtain an estimate of one eigenvector in the identity matrix for any given symbol period. Since estimates of the set of eigenvectors for the identity matrix are obtained from different symbol periods, and due to noise and other sources of degradation in the transmission path, the estimated eigenvectors for the identity matrix are probably not orthogonal. If the estimated eigenvectors are then used for spatial processing of data transmission in another line, then any errors in orthogonality in these estimated eigenvectors will lead to crosstalk for the eigenvectors, which may impair operation.

, вычисление минимальной квадратичной ошибки, полярная декомпозиция и т.д. Разложение на множители

осуществляет декомпозицию матрицы

(с неортогональными столбцами) в ортогональную матрицу

и верхнюю треугольную матрицу

. Матрица

образует ортогональный базис для столбцов

. Диагональные элементы

задают длину компонентов в столбцах

в направлениях соответствующих столбцов

. Матрица

может использоваться для пространственной обработки по нисходящей линии. Матрицы

и

могут использоваться для получения матрицы улучшенного согласованного фильтра для восходящей линии. Разложение на множители

может выполняться разными способами, в том числе процедурой Грам-Шмидта, вспомогательным преобразованием и т.д.In an embodiment, the estimated eigenvectors for each unit matrix are forcibly made orthogonal to each other. This orthogonalization of eigenvectors can be achieved using different methods, such as factoring

, calculation of the minimum quadratic error, polar decomposition, etc. Factorization

decomposes the matrix

(with non-orthogonal columns) into an orthogonal matrix

and upper triangular matrix

. Matrix

forms an orthogonal basis for columns

. Diagonal elements

set the length of the components in the columns

in the directions of the respective columns

. Matrix

can be used for downlink spatial processing. Matrices

and

can be used to obtain an improved matched uplink filter matrix. Factorization

can be performed in various ways, including the Gram-Schmidt procedure, auxiliary transformation, etc.

Other methods for evaluating the unit and diagonal matrices based on a controlled reference can also be used, and they are included in the scope of the invention.

, так и

на основании управляемого эталона, переданного пользовательским терминалом, без необходимости выполнять декомпозицию по сингулярным значениям над

.The access point may therefore evaluate as

and

based on the controlled reference transmitted by the user terminal, without the need for decomposition according to singular values over

.

согласованного фильтра для передачи восходящей линии от пользовательского терминала может быть выражена как:Normalized matrix

the agreed filter for uplink transmission from the user terminal may be expressed as:

Agreed filtering at the access point for uplink transmission can then be expressed as:

является оценкой вектора символов

модуляции, переданных пользовательским терминалом для режима пространственного мультиплексирования. Для режима управления лучом только одна строка матрицы

используется для обеспечения одной оценки

символа собственной моды, используемой для передачи данных.Where

is a character vector estimate

modulations transmitted by the user terminal for the spatial multiplexing mode. For beam control mode, only one row of the matrix

used to provide one grade

symbol of own mode used for data transmission.

2. Downlink spatial processing

размера (

×

) для пространственной обработки. Эту матрицу можно выразить как:For the downlink, the access point uses the matrix

size (

×

) for spatial processing. This matrix can be expressed as:

выводится пользовательским терминалом и передается назад в пункт доступа во время калибровки. Матрица

может быть получена на основании управляемого эталона, переданного по восходящей линии пользовательским терминалом.Correction matrix

displayed by the user terminal and transmitted back to the access point during calibration. Matrix

can be obtained based on a managed uplink transmitted by the user terminal.

передачи для каждого поддиапазона может быть выражен как:For spatial multiplexing mode, the vector

Transmissions for each subband can be expressed as:

является вектором передачи,

является вектором данных для нисходящей линии, а масштабирование сигнала посредством

для достижения инверсии каналов, для простоты, опускается в уравнении (47).Where

is a transmission vector,

is a data vector for the downlink, and scaling the signal by

to achieve channel inversion, for simplicity, is omitted in equation (47).

для передачи нисходящей линии может быть выражен как:In the user terminal, the received vector

for downlink transmission can be expressed as:

, которое является матрицей

левых собственных векторов

, масштабированной диагональной матрицей

сингулярных величин.As shown in equation (48), in the user terminal, the received downlink transmission is converted by

which is a matrix

left eigenvectors

scaled diagonal matrix

singular quantities.

согласованного фильтра для передачи по нисходящей линии от пункта доступа может быть выражена как:Normalized matrix

a matched filter for downlink transmission from an access point may be expressed as:

и матрица

левых собственных векторов могут быть выведены пользовательским терминалом посредством выполнения декомпозиции по сингулярным значениям над оценкой

калиброванных канальных откликов нисходящей линии, как описано выше.Diagonal matrix

and matrix

left eigenvectors can be displayed by the user terminal by performing decomposition by singular values over the estimate

calibrated downlink channel responses as described above.

Consistent filtering in the user terminal for downlink transmission can be further expressed as:

3. Spatial processing of the access point and user terminal

Due to the reversibility of the channel for the DDA system and calibration, spatial processing at both the access point and the user terminal can be simplified. Table 32 summarizes the spatial processing at the access point and user terminal for transmitting and receiving data.

Table 32 Ascending line Descending line User terminal

Broadcast:

Reception:

Access point Reception:

Broadcast:

Spatial processing for receiving data is also commonly called consistent filtering.

является матрицей правых собственных векторов

(для передачи) и левых собственных векторов

(для приема) для пользовательского терминала. Аналогично,

является как матрицей правых собственных векторов

(для передачи) и левых собственных векторов

(для приема) для пункта доступа. Декомпозицию по сингулярным значениям необходимо выполнять пользовательским терминалом для оценки

калиброванных канальных откликов нисходящей линии, чтобы получить

и

. Пункт доступа может выводить

и

на основании управляемого эталона, переданного пользовательским терминалом, и не нуждается в выполнении декомпозиции по сингулярным значениям над оценкой

канальных откликов восходящей линии. Пункт доступа и пользовательский терминал могут иметь разные варианты матрицы

вследствие различных средств, используемых пунктом доступа и пользовательским терминалом, чтобы получить

. Кроме того, матрица

, полученная пунктом доступа на основании управляемого эталона, как правило, отличается от матрицы

, полученной пользовательским терминалом с использованием декомпозиции по сингулярным значениям. Для простоты, эти различия не показаны в вышеприведенном выводе.Due to reversible channel

is a matrix of right eigenvectors

(for transmission) and left eigenvectors

(for reception) for the user terminal. Similarly

is like a matrix of right eigenvectors

(for transmission) and left eigenvectors

(for reception) for the access point. Singular value decomposition must be performed by the user terminal for evaluation

calibrated downlink channel responses to get

and

. Access point may display

and

based on the managed reference transmitted by the user terminal and does not need to be decomposed according to singular values over the estimate

uplink channel responses. The access point and user terminal may have different matrix options

due to various means used by the access point and user terminal to obtain

. In addition, the matrix

obtained by the access point based on the controlled reference is usually different from the matrix

obtained by the user terminal using decomposition according to singular values. For simplicity, these differences are not shown in the above conclusion.

4. Beam control

For some channel conditions, it is better to transmit data only on one broadband eigenmode, usually the best or main broadband eigenmode. This can be the case if the S / N ratios in the received signal for all other broadband eigenmodes are bad enough, so that improved performance is achieved by using all the available transmit power on the main broadband eigenmode.

или

, для

∈

, для главной широкополосной собственной моды (т.е. первый столбец

или

после упорядочивания). Для управления лучом символы модуляции пространственно обрабатываются набором "нормированных" (или "насыщенных") собственных векторов

или

, для

∈

, для главной широкополосной собственной моды. Для ясности, управление лучом описывается ниже для восходящей линии.Data transmission on one wideband eigenmode can be implemented using beamforming or beam control. To form a beam, the modulation symbols are spatially processed by eigenvectors

or

for

∈

, for the main broadband eigenmode (i.e., the first column

or

after ordering). To control the beam, the modulation symbols are spatially processed by a set of “normalized” (or “saturated”) eigenvectors

or

for

∈

, for the main broadband of its own fashion. For clarity, beam control is described below for the uplink.

, для

∈

, для главной широкополосной собственной моды могут иметь разные величины. Таким образом, предварительно преобразованные символы для каждого поддиапазона, которые получаются перемножением символа модуляции для поддипазона

с элементами собственного вектора

для поддиапазона

, могут тогда иметь разные величины. Следовательно, векторы передачи на каждую антенну, каждый из которых включает в себя предварительно преобразованные символы для всех поддиапазонов данных для заданной передающей антенны, могут иметь разные величины. Если мощность передачи для каждой передающей антенны ограничена (к примеру, из-за ограничений усилителей мощности), тогда управление лучом может не полностью использовать полную мощность, доступную для каждой антенны.For the ascending line, the elements of each eigenvector

for

∈

, for the main broadband eigenmode can have different values. Thus, the pre-converted symbols for each subband, which are obtained by multiplying the modulation symbol for the subband

with eigenvector elements

for subband

can then have different values. Therefore, the transmission vectors for each antenna, each of which includes pre-converted symbols for all data subbands for a given transmit antenna, can have different values. If the transmit power for each transmit antenna is limited (for example, due to the limitations of power amplifiers), then beam control may not fully utilize the full power available for each antenna.

, для

∈

, для главной широкополосной собственной моды и нормирует каждый собственный вектор так, что все элементы в собственном векторе имеют равные величины. Нормированный собственный вектор

для поддиапазона

может быть выражен как:Beam control uses only phase information from eigenvectors

for

∈

, for the main broadband eigenmode and normalizes each eigenvector so that all elements in the eigenvector have equal values. Normalized eigenvector

for subband

may be expressed as:

является постоянной (например,

=1); иWhere

is constant (e.g.

= 1); and

является фазой для поддиапазона

передающей антенны

, которая задается как:

is the phase for the subrange

transmit antenna

, which is set as:

получается из соответствующего элемента собственного вектора

(т.е.

получается из

, где

=[

…

]

).as shown in equation (52), the phase of each element in the vector

obtained from the corresponding element of the eigenvector

(those.

obtained from

where

= [

...

]

)

5. Uplink beam control

Spatial processing by a user terminal for uplink beam control can be expressed as:

является символом модуляции, подлежащим передаче в поддиапазоне

; иWhere

is a modulation symbol to be transmitted in the subband

; and

является вектором передачи для поддиапазона

для управления лучом.

is a transmission vector for a subband

to control the beam.

элементов нормированного управляющего вектора

для каждого поддиапазона имеют одинаковую величину, но, возможно, разные фазы. Таким образом, управление лучом генерирует один вектор

передачи для каждого поддиапазона с

элементами

, имеющими одну и ту же величину, но, возможно, разные фазы. As shown in equation (53),

elements of the normalized control vector

for each subband they have the same magnitude, but possibly different phases. Thus, beam control generates a single vector

transmissions for each subband with

elements

having the same magnitude but possibly different phases.

The received uplink transmission at the beam control access point may be expressed as:

является принятым вектором для восходящей линии для поддиапазона

для управления лучом.Where

is the received vector for the uplink for the subband

to control the beam.

согласованного фильтра для передачи по восходящей линии с использованием управления лучом может быть выражен как:String Vector

a matched filter for uplink transmission using beam control can be expressed as:

согласованного фильтра можно получить как описано ниже. Пространственная обработка (или согласованная фильтрация) в пункте доступа для принятой передачи восходящей линии с управлением лучом может быть выражена как:Vector

A matched filter can be obtained as described below. The spatial processing (or matched filtering) at the access point for the received uplink transmission with beam control can be expressed as:

(т.е.

является внутренним произведением

и ее сопряженной транспозиции),Where

(those.

is an internal work

and its conjugate transposition),

является оценкой символа

модуляции, переданного пользовательским терминалом по восходящей линии, и

is a character rating

modulation transmitted by the user terminal in an uplink, and

является шумом после обработки.

is noise after processing.

6. Downlink beam control

Spatial processing by an access point for downlink beam control can be expressed as:

является нормированным собственным вектором для поддиапазона

, который генерируется на основе собственного вектора

для главной широкополосной собственной моды, аналогично тому, как описано выше для восходящей линии.Where

is a normalized eigenvector for a subband

which is generated based on the eigenvector

for the main broadband eigenmode, similar to that described above for the ascending line.

согласованного фильтра для передачи по нисходящей линии с использованием управления лучом может быть выражен как:String Vector

a matched filter for downlink transmission using beam control can be expressed as:

Spatial processing (or matched filtering) in a user terminal for a received downlink transmission can be expressed as:

(т.е.

является внутренним произведением

и ее сопряженной транспозиции).Where

(those.

is an internal work

and its conjugate transposition).

7. Spatial processing with channel inversion

передачи для режима пространственного мультиплексирования может быть получен пользовательским терминалом как:For ascending line vector

transmissions for the spatial multiplexing mode may be received by the user terminal as:

является диагональной матрицей коэффициентов усиления для инверсии каналов, описанной выше. Уравнение (60) аналогично уравнению (15) за исключением того, что вместо

используется

. Элементы

подаются на перемножители 952 в формирователях 950 луча на фиг.9В.Where

is the diagonal gain matrix for channel inversion described above. Equation (60) is similar to equation (15) except that instead of

is used

. Items

served on multipliers 952 in the beam shapers 950 beam figv.

передачи для режима управления лучом может быть получен пользовательским терминалом как:For ascending line vector

transmissions for the beam control mode can be received by the user terminal as:

является вектором с четырьмя элементами, имеющими равную величину, но фазы, полученные на основании собственного вектора

для главной собственной моды. Вектор

может быть получен аналогично тому, как это показано выше в уравнениях (16) и (17). Усиление

реализует инверсию каналов и может быть получено аналогично тому, как показано выше в уравнениях (18)-(20), за исключением того, что

используется для уравнения (20). Элементы

подаются на перемножители 1052 в блоке 1050 управления лучом на фиг.10В.Where

is a vector with four elements of equal magnitude, but the phases obtained from the eigenvector

for the main own fashion. Vector

can be obtained in the same way as shown above in equations (16) and (17). Gain

implements channel inversion and can be obtained in the same way as shown above in equations (18) - (20), except that

used for equation (20). Items

served on multipliers 1052 in block 1050 beam control on figv.

передачи для режима пространственного мультиплексирования может быть получен пользовательским терминалом как:For the downlink vector

transmissions for the spatial multiplexing mode may be received by the user terminal as:

используется

. Элементы

подаются на перемножители 952 в формирователях 950 луча на фиг.9В.Equation (62) is similar to equation (15) except that instead of

is used

. Items

served on multipliers 952 in the beam shapers 950 beam figv.

передачи для режима управления лучом может быть получен пользовательским терминалом как:For the downlink vector

transmissions for the beam control mode can be received by the user terminal as:

является вектором с четырьмя элементами, имеющими равную величину, но фазы, полученные на основании собственного вектора

для главной собственной моды. Усиление

реализует инверсию каналов и может быть получено аналогично тому, как показано выше в уравнениях (18)-(20), за исключением того, что

используется для уравнения (20). Элементы

подаются на перемножители 1052 в блоке 1050 управления лучом на фиг.10В.Where

is a vector with four elements of equal magnitude, but the phases obtained from the eigenvector

for the main own fashion. Gain

implements channel inversion and can be obtained in the same way as shown above in equations (18) - (20), except that

used for equation (20). Items

served on multipliers 1052 in block 1050 beam control on figv.

Viii. Pilot structure

The pilot signal structure is provided by the MVxMVW WLAN system to allow access points and user terminals to synchronize and receive frequencies, channel estimation and other functions necessary for the proper operation of the system. Table 33 lists four types of pilot and their description for an exemplary pilot structure. Fewer, additional, and / or distinct transport channels may also be defined for use in the pilot structure.

Table 33
Types of Pilot Signals Pilot type Description Beacon pilot The pilot signal is transmitted by all transmitting antennas and is used to synchronize and receive frequency. Pilot signal The pilot signal is transmitted by all transmit antennas with different orthogonal codes and is used for channel estimation. Guided Reference or Guided Pilot The pilot signal is transmitted on specific eigenmodes of the channel for a particular user terminal and is used to estimate channels and possibly control the transmission rate. Carrier Pilot The pilot signal is used to track the phase of the carrier signal.

The guided reference and the guided pilot are synonymous expressions.

In an embodiment, the pilot structure includes (1) for the downlink, the beacon pilot, the MVXMOUT pilot, the controlled reference, and the carrier pilot transmitted by the access point, and (2) for the uplink, the pilot MVxMout, controlled reference and carrier pilot transmitted by the user terminal.

The downlink beacon pilot and the MVxMBy pilot are sent over the BCH (as shown in FIG. 5A) in each frame of the TDD. The beacon pilot can be used by user terminals to synchronize and obtain frequency and estimate Doppler shift. The MVxMOv pilot signal can be used by user terminals to (1) obtain an estimate of the downlink MVxMV channel, (2) extract control vectors for uplink transmission (if beam control or spatial multiplexing is supported), and (3) select a matched filter for downlink transmission. The downlink managed reference may also be used by a particular user terminal for channel estimation.

A managed uplink reference is transmitted by each active user terminal that supports beam control or spatial multiplexing and can be used by an access point to (1) extract control vectors for downlink transmission and (2) allocate a matched filter for uplink transmission. In general, a controlled reference is sent only to those user terminals or those user terminals that support beam control and / or spatial multiplexing modes. Sending a reference works regardless of whether it is properly managed (for example, due to poor channel estimation). That is, the reference becomes orthogonal to each transmit antenna, since the steering matrix is diagonal.

, для

∈

, где

является столбцом

для главной собственной моды. Если пользовательский терминал не калиброван, то он может передавать пилот-сигнал по каналу RACH с использованием вектора

, для

∈

. Вектор

для каждого поддиапазона включает в себя

случайных управляющих коэффициентов, у которых фазы

, для

∈{1, 2, …,

}, могут выбираться в соответствии с псевдослучайной процедурой. Поскольку имеют значение только относительные фазы среди

управляющих коэффициентов, фаза первого управляющего коэффициента может быть установлена на нуль (т.е.

=0). Фазы остальных

-1 управляющих коэффициентов могут изменяться для каждой попытки доступа, так что все 360° покрываются каждым управляющим коэффициентом в интервалах 360°/

, где

является функцией от

. Возмущения фаз

элементов управляющего вектора

на каждой попытке в канале RACH при использовании канала RACH в режиме управления лучом перед калибровкой, таковы, что пользовательский терминал не использует плохой управляющий вектор для всех попыток доступа. Пилот-сигнал МВхМВых может посылаться для пользовательских терминалов или пользовательскими терминалами, которые не поддерживают режимы управления лучом и (или) пространственного мультиплексирования.If the user terminal is calibrated, then it can transmit a controlled standard on the main eigenmode on the RACH channel using the vector

for

∈

where

is a column

for the main own fashion. If the user terminal is not calibrated, then it can transmit the pilot on the RACH using the vector

for

∈

. Vector

for each subband includes

random control coefficients in which phases

for

∈ {1, 2, ...,

}, can be selected in accordance with a pseudo-random procedure. Since only the relative phases among

control coefficients, the phase of the first control coefficient can be set to zero (i.e.

= 0). Phases of the rest

-1 control coefficients can be changed for each access attempt, so that all 360 ° are covered by each control coefficient in 360 ° intervals /

where

is a function of

. Phase perturbations

control vector elements

on each attempt in the RACH channel when using the RACH channel in the beam control mode before calibration, such that the user terminal does not use a bad control vector for all access attempts. The MVxMvout pilot signal may be sent for user terminals or user terminals that do not support beam control and / or spatial multiplexing modes.

An access point does not have channel information for any user terminal as long as this user terminal communicates directly with the access point. When the user terminal wishes to transmit data, it first estimates the channel based on the MVxMv pilot sent by the access point. The user terminal then sends a managed reference in the RACH preamble when it tries to access the system. An access point uses this reference in the RACH preamble for signal detection and channel estimation.

After the user terminal is allowed access to the system and the FCH / RCH resources are assigned as the access point, the user terminal sends a reference (for example, an MVxMO pilot) at the beginning of each of the RCH PDUs that it transmits. If the user terminal uses the diversity mode, then the pattern is sent to the RCH without control. If the user terminal uses the beam control or spatial multiplexing mode, then the controlled reference is sent via RCH, allowing the access point to determine an eigenvector for the main eigenmode (for the beam control mode) or a set of four eigenvectors (for the spatial multiplexing mode) for each of 48 data subbands. A controlled reference allows the access point to improve its channel estimate and track the channel.

1. Beacon Pilot - Downlink

The downlink beacon pilot is included in the first part of the BCH (as shown in FIG. 5A) and transmitted in each frame of the TDD. The beacon pilot signal includes a specific OFDM symbol (denoted as “B”), which is transmitted to each of the four antennas at the access point. The same OFDM symbol B is transmitted twice in a two-character duration for the beacon pilot.

модуляции BPSK для 12 конкретных поддиапазонов, которые показаны в Таблице 34.In a specific embodiment, the MORCH symbol comprises a set of 12 characters

BPSK modulations for 12 specific subbands, which are shown in Table 34.

Table 34
Pilot characters Subdivision Index
range

Beacon pilot

Pilot signal

Subdivision Index
range Beacon pilot

Pilot signal

Subdivision Index
range Beacon pilot

Pilot signal

Subrange index Beacon pilot

Pilot signal

N 0 0 -13 0 one-

one 0 one-

fifteen 0 1+

-26 0 -one-

-12 -one-

one-

2 0 -one-

16 1+

-1+

-25 0 -1+

-eleven 0 -one-

3 0 -one-

17 0 -1+

-24 1+ -1+

-10 0 -one-

four -one-

-one-

eighteen 0 one-

-23 0 -1+

-9 0 one-

5 0 -1+

19 0 1+

-22 0 one-

-8 -one-

-one-

6 0 1+

twenty 1+

-1+

-21 0 one-

-7 0 1+

7 0 -one-

21 0 1+

-twenty -one-

1+

-6 0 -1+

8 -one-

-1+

22 0 -1+

-19 0 -one-

-5 0 -one-

9 0 -one-

23 0 1+

-eighteen 0 -1+

-four 1+

-1+

10 0 -one-

24 1+

-1+

-17 0 1+

-3 0 -1+

eleven 0 1+

25 0 one-

-16 1+

-1+

-2 0 one-

12 1+

one-

26 0 -one-

-fifteen 0 one-

-one 0 -1+

13 0 -1+

N 0 0 -fourteen 0 1+

0 0 0 fourteen 0 -one-

) модуляции BPSK для поддиапазонов -24, -16, -4, 12, 16, 20 и 24, (2) символ -(1+

) модуляции BPSK для поддиапазонов -20, -12, -8, 4 и 8, и (3) сигнальные значения нуля для остальных 52 поддиапазонов. Символ МОРЧ В специально рассчитан, чтобы облегчить синхронизацию и получение частоты пользовательскими терминалами. Однако для маякового пилот-сигнала могут использоваться и другие символы МОРЧ, которые входят в объем изобретения.For the beacon pilot embodiment shown in Table 34, the OFDM symbol contains (1) the symbol (1+

) BPSK modulations for sub-bands -24, -16, -4, 12, 16, 20 and 24, (2) symbol - (1+

) BPSK modulation for the -20, -12, -8, 4 and 8 subbands, and (3) zero signal values for the remaining 52 subbands. The MORCH symbol B is specially designed to facilitate the synchronization and reception of frequency by user terminals. However, other OFDM symbols may be used for the beacon pilot, which are included in the scope of the invention.

2. Pilot signal MVhMVykh - downlink

пилот-сигналов/символов данных с одинаковым значением) перемножается со всеми

элементами

-элементной ортогональной последовательности для получения

покрытых символов, которые затем передаются. Вскрытие есть комплементарный процесс, посредством которого принятые символы перемножаются с

элементами

-элементной ортогональной последовательности для получения

вскрытых символов, которые затем накапливаются для получения оценки переданного пилот-сигнала/символа данных. Покрытие обеспечивает ортогональность между

передачами пилот-сигнала

передающими антеннами и позволяет пользовательским терминалам различать отдельные передающие антенны. Покрытие может быть реализовано последовательностями Уолша или другими ортогональными последовательностями.The pilot signal of the MVxMB downlink is included in the second part of the BCH (as shown in FIG. 5A) and is also transmitted in each frame of the TDD. The MVxMVy pilot signal includes a specific OFDM symbol (denoted as “P”), which is transmitted to each of the four antennas at the access point. The same OFDM symbol P is transmitted eight times in an 8-character duration for the MVxMv pilot signal. However, eight OFDM P symbols for each antenna are “covered” with a different 4-element Walsh sequence assigned to that antenna. Coverage is the process by which a given pilot signal or data symbol (or a set of

pilot signals / data symbols with the same value) is multiplied with all

elements

-element orthogonal sequence to obtain

covered characters, which are then transmitted. An autopsy is a complementary process by which the received characters are multiplied with

elements

-element orthogonal sequence to obtain

opened symbols, which are then accumulated to obtain an estimate of the transmitted pilot / data symbol. The coating provides orthogonality between

pilot transmissions

transmit antennas and allows user terminals to distinguish between separate transmit antennas. Coverage can be implemented by Walsh sequences or other orthogonal sequences.

модуляции МОРЧ для 48 поддиапазонов данных и 4 пилотных поддиапазонов, которые показаны в Таблице 34. Сигнальные значения нуля передаются в остальных 12 поддиапазонах. Символ МОРС Р содержит уникальное "слово" из 52 символов модуляции QPSK, которое сформировано для облегчения оценки канала пользовательскими терминалами. Это уникальное слово также выбирается, чтобы минимизировать измеренные значения отношения пиковой к средней мощности в передаваемом пилот-сигнале МВхМВых. Это может также снизить величину искажений и нелинейности, генерируемых приемной схемой в пользовательских терминалах, что может обеспечить улучшенную точность оценки канала. Однако для пилот-сигнала МВхМВых можно использовать и другие символы МОРЧ, которые входят в объем изобретения.In a particular embodiment, the MORCH symbol P comprises a set of 52 characters

OFDM modulation for 48 data subbands and 4 pilot subbands, which are shown in Table 34. Signal values of zero are transmitted in the remaining 12 subbands. The MORS P symbol contains a unique “word” of 52 QPSK modulation symbols, which is formed to facilitate channel estimation by user terminals. This unique word is also chosen to minimize the measured peak-to-average power ratios in the transmitted MVxMOv pilot signal. It can also reduce the amount of distortion and non-linearity generated by the receiver in user terminals, which can provide improved channel estimation accuracy. However, other OFDM symbols may be used for the MIMO pilot, which are included in the scope of the invention.

In an embodiment, four-element Walsh sequences W ₁ = 1111, W ₂ = 1010, W ₃ = 1100, and W ₄ = 1001 for the MVxMO pilot signal are assigned to four antennas at the access point. For a given Walsh sequence, a value of “1” indicates that an OFDM-P symbol is being transmitted, and a value of “0” indicates that an OFDM-P symbol is being transmitted (i.e., each of the 52 modulation symbols in P is inverted).

Table 35 lists the OFDM symbols to be transmitted to each of the four antennas at the access point for the beacon pilot and the MIMO pilot. The characters MORCH B and P are as described above.

Table 35
Beacon and MVhMvyh pilot signals Pilot signal MORCH symbol Antenna 1 Antenna 2 Antenna 3 Antenna 4 Beacon pilot one B B B B 2 B B B B Pilot signal 3 + P + P + P + P four + P -P + P -P 5 + P + P -P -P 6 + P -P -P + P 7 + P + P + P + P 8 + P -P + P -P 9 + P + P -P -P 10 + P -P -P + P

пункта доступа и принятый антенной

пользовательского терминала, пилот-сигнал, принятый антенной

терминала, сначала перемножается с последовательностью Уолша, назначенной антенне

пункта доступа. Восемь вскрытых символов МОРЧ для всех восьми символьных периодов для пилот-сигнала МВхМВых затем накапливаются, причем накопление выполняется по отдельности для каждого из 52 поддиапазонов, используемых для переноса пилот-сигнала МВхМВых. Результатами накопления являются

, для

=±{1, …, 26}, что является оценкой калиброванного канального отклика нисходящей линии из антенны

пункта доступа к антенне

пользовательского терминала для 52 поддиапазонов данных и пилот-сигнала.The MVxMOf pilot may be used by the user terminal to estimate the channel response in the downlink. In particular, to restore the pilot signal sent from the antenna

access point and received by antenna

user terminal, the pilot received by the antenna

terminal, first multiplied with the Walsh sequence assigned to the antenna

access point. The eight opened OFDM symbols for all eight symbol periods for the MVxMVI pilot signal are then accumulated, and accumulation is performed separately for each of the 52 subbands used to carry the MVxMVI pilot signal. The results of accumulation are

for

= ± {1, ..., 26}, which is an estimate of the calibrated downlink channel response from the antenna

antenna access point

a user terminal for 52 data and pilot subbands.

·

значений для каждого из 52 поддиапазонов, где

обозначает число антенн в пункте доступа, а

обозначает число антенн в пользовательском терминале.

·

значений для каждого поддиапазона являются элементами оценки

калиброванных канальных откликов нисходящей линии для этого поддиапазона.The same pilot processing may be performed by the access point to restore the pilot signal transmitted from each antenna of the access point to each antenna of the user terminal. The pilot signal transmitted by each antenna of the access point can be reconstructed by tampering using the Walsh sequences assigned to this antenna. Pilot processing provides

·

values for each of the 52 subbands, where

indicates the number of antennas at the access point, and

indicates the number of antennas in the user terminal.

·

values for each subrange are elements of the estimate

calibrated downlink channel responses for this subband.

The MVxMOut pilot may also be transmitted in the uplink by the user terminal for calibration and diversity mode. The same processing described above for the user terminal for reconstructing the MVxMVO pilot sent by the access point may also be performed by the access point to restore the MVxMVO pilot sent by the user terminal.

3. Guided Reference

The managed reference may be transmitted in part of the preamble of the RACH PDUs (as shown in FIG. 5C) or the RCH PDUs (as shown in FIGS. 5E and 5G) by each active user terminal. The controlled reference may also be transmitted in part of the FCH channel PDU preamble (as shown in FIGS. 5E and 5F) by the access point to the active user terminal.

A. Guided reference and spatial multiplexing

The managed reference contains a specific OFDM symbol (for example, the same OFDM symbol P used for the MVxMO pilot), which is transmitted by all transmit antennas in the user terminal (for the uplink) or access point (for the downlink). However, the OFDM symbol P for each symbol period is processed spatially (i.e., by beamforming) by a control vector for one eigenmode.

The first character of the managed reference transmitted by the user terminal in the preamble of the RACH can be expressed as:

является вектором передачи для поддиапазона

;Where

is a transmission vector for a subband

;

является корреляционной матрицей для поддиапазона

для пользовательского терминала;

is a correlation matrix for a subband

for user terminal;

является управляющим вектором для поддиапазона

главной широкополосной собственной моды;

is a steering vector for a subband

Main Broadband Own Fashion;

является пилотным символом для поддиапазона

; и

is a pilot symbol for a subband

; and

={-32,…,31} является набором индексов для всех 64 поддиапазонов.

= {- 32, ..., 31} is a set of indices for all 64 subbands.

включает в себя четыре символа передачи для каждого значения

, которые подлежат передаче четырьмя антеннами в пользовательском терминале. Управляющий вектор

является первым столбцом матрицы

правых собственных векторов оценки

калиброванных канальных откликов восходящей линии, где

, а

является

-м столбцом

. Выше предполагается, что сингулярные значения в

и столбцы

упорядочиваются, как описано выше.Vector

includes four transfer characters for each value

which are to be transmitted by four antennas in a user terminal. Control vector

is the first column of the matrix

right eigenvalue vectors

calibrated uplink channel responses where

, but

is an

column

. It is assumed above that the singular values in

and columns

are ordered as described above.

, как показано в Таблице 15. Символ

затем перемножается с пилотным символом

перед выполнением пространственной обработки. Второй символ управляемого эталона для RACH может быть выражен как:The second managed reference symbol transmitted by the user terminal in the RACH preamble includes a data rate indicator (IDI) (DRI) for the RACH PDU. The ISD indicates the rate used for the RACH message sent in the RACH PDU. ISD is embedded in the second symbol of the controlled standard by displaying the ISD in a specific symbol of MORCH

as shown in Table 15. Symbol

then multiplied with the pilot symbol

before performing spatial processing. The second character of the managed reference for RACH can be expressed as:

для главного широкополосной собственной моды используется для управляемого эталона для RACH.As shown in equations (64) and (65), only the eigenvector

for the main broadband native mode is used for the controlled reference for RACH.

The managed reference symbol transmitted by the user terminal in the preamble of the RACH can be expressed as:

является вектором передачи для поддиапазона

широкополосной собственной моды

; иWhere

is a transmission vector for a subband

broadband own fashion

; and

является управляющим вектором для поддиапазона

широкополосной собственной моды

(т.е.

-м столбцом

.

is a steering vector for a subband

broadband own fashion

(those.

column

.

The managed reference symbol transmitted by the access point in the FCH preamble may be expressed as:

является вектором передачи для поддиапазона

широкополосной собственной моды

;Where

is a transmission vector for a subband

broadband own fashion

;

является корректировочной матрицей для поддиапазона

для пункта доступа; и

is the adjustment matrix for the subrange

for access point; and

является управляющим вектором для поддиапазона

широкополосной собственной моды

.

is a steering vector for a subband

broadband own fashion

.

является

-м столбцом матрицы

правых собственных векторов оценки

калиброванных канальных откликов нисходящей линии, где

.Control vector

is an

th matrix column

right eigenvaluation vectors

calibrated downlink channel responses where

.

The managed reference can be transmitted in various ways. In one embodiment, one or more eigenvectors are used for the controlled pattern for each DDA frame and depend on the duration of the controlled pattern, which is indicated by the FCH / RCH preamble type fields in the FCCH information element. Table 36 lists example eigenvectors used for the preamble for FCH and RCH for various preamble sizes.

Table 36 Type of Preamble Size Used eigenvectors 0 0 characters MORCH No preamble one 1 character MORCH

, где

=счетчику кадров по модулю 4Own fashion

where

= frame counter modulo 4 2 4 characters MORCH The cycle for all 4 own mods in the preamble 3 8 characters MORCH A cycle for all 4 eigenmodes twice in the preamble

-го символа МОРЧ в преамбуле для канала RCH, может быть выражен как:As shown in Table 36, a guided reference is transmitted for all four eigenmodes in a single DDA frame when the preamble size is four or eight OFDM symbols. Managed reference transmitted by the user terminal for

-th character OFDM in the preamble for the channel RCH, can be expressed as:

является размером преамбулы, т.е.

=4 для Типа 2 и

=8 для Типа 3.Where

is the size of the preamble, i.e.

= 4 for Type 2 and

= 8 for Type 3.

-го символа МОРЧ в преамбуле для канала FCH, может быть выражен как:Similarly, the managed reference transmitted by the access point for

the Fifth symbol in the preamble for the FCH channel may be expressed as:

mod 4) для управляющего вектора. Эта схема может использоваться, если канал изменяется более быстро и (или) на ранней стадии соединения, когда нужно быстро получить хорошую оценку канала для правильной работы системы.As shown in equations (68) and (69), the four eigenmodes are cyclically repeated every 4-character period through the operation (

mod 4) for the control vector. This scheme can be used if the channel changes more quickly and (or) at an early stage of connection, when you need to quickly get a good channel estimate for the correct operation of the system.

,

,

и

могут использоваться пользовательским терминалом для первого, второго, третьего и четвертого кадров ДВР, соответственно. Конкретный используемый управляющий вектор может конкретизироваться двумя младшими битами значения счетчика кадров в сообщении канала ВСН. Эта схема позволяет использовать более короткую часть преамбулы в ПБД, но может потребовать более длительного периода времени, чтобы получить хорошую оценку канала.In another embodiment, a guided reference is transmitted for one wideband eigenmode for each DTE frame. The guided reference for four broadband eigenmodes can be cyclically repeated across four FER frames. For example, control vectors

,

,

and

can be used by the user terminal for the first, second, third and fourth frames of the DVR, respectively. The particular control vector used can be instantiated with the two least significant bits of the frame counter value in the BCH channel message. This design allows the use of a shorter portion of the preamble in the PDB, but may require a longer period of time to obtain a good channel estimate.

For both of the embodiments described above, a controlled reference can be transmitted on all four eigenmodes for data transmission, even when less than four eigenmodes are currently being used (for example, due to the fact that unused eigenmodes are of poor quality and are discarded due to create redundancy). The transmission of the controlled reference to the currently unused eigenmode allows the receiver to determine when the eigenmode is sufficiently improved to select it for use.

B. Guided beam control reference

≠

). Управляемый эталон, генерируемый с использованием набора нормированных собственных векторов для всех поддиапазонов, может затем передаваться передатчиком и использоваться приемником для выделения векторов согласованных фильтров для этих поддиапазонов для режима управления лучом.For the beam control mode, spatial processing on the transmitting side is performed using a set of normalized eigenvectors for the main broadband eigenmode. The general transfer function by the normalized eigenvector is different from the general transfer function by the non-normalized eigenvector (i.e.

≠

) A controlled reference generated using a set of normalized eigenvectors for all subbands can then be transmitted by the transmitter and used by the receiver to extract matched filter vectors for these subbands for the beam control mode.

For the uplink, the guided reference for the beam control mode can be expressed as:

At the access point, the received uplink guided pattern for the beam control mode can be expressed as:

согласованного фильтра для передачи по восходящей линии с управлением лучом, принятый вектор

для управляемого эталона сначала перемножается с

. Результат затем интегрируется по множеству принятых символов управляемого эталона для формирования оценки

. Вектор

является сопряженной транспозицией от этой оценки.To get a row vector

matched filter for uplink transmission with beam control, received vector

for a controlled reference is first multiplied with

. The result is then integrated over the plurality of received symbols of the controlled reference to form an estimate

. Vector

is a conjugate transposition of this estimate.

, один или более символов с использованием собственного вектора

для главной широкополосной собственной моды и, возможно, один или более символов с использованием собственных векторов для других широкополосных собственных мод. Символы управляемого эталона, генерируемые в помощью

, могут использоваться пунктом доступа для получения вектора

согласованного фильтра. Символы управляемого эталона, генерируемые с помощью

, могут использоваться для получения

, который может затем использоваться для получения нормированного собственного вектора

, который используется для управления лучом в нисходящей линии. Символы управляемого эталона, генерируемые собственными векторами

-

для других собственных мод, могут использоваться пунктом доступа для получения

-

и сингулярных значений для этих других собственных мод. Эта информация может затем использоваться пунктом доступа, чтобы определить, используется ли режим пространственного мультиплексирования или режим управления лучом для передачи данных.When operating in the beam control mode, the user terminal can transmit multiple symbols of a controlled reference, for example, one or more symbols using a normalized eigenvector

, one or more characters using an eigenvector

for the main broadband eigenmode, and possibly one or more characters using eigenvectors for other broadband eigenmodes. Managed Reference Symbols Generated Using

, can be used by an access point to obtain a vector

matched filter. Managed Reference Symbols Generated Using

can be used to obtain

which can then be used to obtain a normalized eigenvector

which is used to control the beam in a downward line. Eigenvector driven reference symbols

-

for other own mods, can be used by an access point to receive

-

and singular values for these other eigenmodes. This information can then be used by the access point to determine if the spatial multiplexing mode or the beam control mode is used for data transmission.

для режима управления лучом на основе оценки

калиброванных канальных откликов нисходящей линии. В частности, пользовательский терминал имеет

из декомпозиции по сингулярным значениям

и может получить нормированный собственный вектор

. Пользовательский терминал может затем перемножить

с

, чтобы получить

, и далее может получить

на основе

. Альтернативно, управляемый эталон может быть передан пунктом доступа с помощью нормированного собственного вектора

, и этот управляемый эталон может обрабатываться пользовательским терминалом так, как описано выше для получения

.For the downlink, the user terminal may receive a vector

for evaluation based beam control mode

calibrated downlink channel responses. In particular, the user terminal has

from decomposition by singular values

and can get a normalized eigenvector

. The user terminal can then multiply

from

, To obtain

, and can get further

based

. Alternatively, the controlled reference may be transmitted by the access point using a normalized eigenvector

, and this managed reference can be processed by the user terminal as described above to obtain

.

4. Carrier Pilot - Uplink

The described OFDM subband structure includes four pilot subbands with indices of -21, -7, 7, and 21. In one embodiment, the carrier pilot signal is transmitted in four pilot subbands in all OFDM symbols that are not parts of the preamble. The carrier pilot may be used by the receiver to track phase changes due to drift in the generators in both the transmitter and the receiver. This can provide improved performance when demodulating data.

,

,

и

, которые передаются в четырех поддиапазонах пилот-сигналов. Пилотные последовательности могут быть определены как:The carrier pilot signal contains four pilot sequences,

,

,

and

which are transmitted in four pilot subbands. Pilot sequences can be defined as:

есть индекс для символьного периода МОРЧ.Where

there is an index for the character period MORCH.

генерируется на основании полинома

, где начальное состояние устанавливается на все нули, а выходные биты отображаются в значения сигнала следующим образом: 1 ⇒ -1 и 0 ⇒ 1. Пилотная последовательность

для

={1, 2, …, 127} может быть выражена как:Pilot sequences can be determined based on different data sequences. In an embodiment, the pilot sequence

generated based on polynomial

, where the initial state is set to all zeros, and the output bits are mapped to the signal values as follows: 1 ⇒ -1 and 0 ⇒ 1. Pilot sequence

for

= {1, 2, ..., 127} can be expressed as:

могут отображаться в пилотные символы с помощью конкретной схемы модуляции. Например, с помощью BPSK "1" может отображаться в 1+

, а "-1" может отображаться в -(1+

). Если имеется более 127 символов МОРЧ, то пилотная последовательность может повторяться, так что

=

(

mod 127) для

>127.The values "1" and "-1" in the pilot sequence

can be mapped to pilot symbols using a specific modulation scheme. For example, using BPSK "1" can be displayed in 1+

, and "-1" can be displayed in - (1+

) If there are more than 127 OFDM symbols, then the pilot sequence may be repeated, so that

=

(

mod 127) for

> 127.

In one embodiment, four pilot sequences are reset for each transport channel. Thus, in the downlink, the pilot sequences are reset for the first OFDM symbol of the BCH channel, reset again for the first OFDM symbol of the FCCH message, and reset for the first OFDM symbol transmitted on the FCH. In another embodiment, the pilot sequences are reset at the beginning of each DTE frame and repeated as often as necessary. For this embodiment, the pilot sequences may be stopped during the preamble of the BCH and FCH.

используется для поддиапазона -21 антенны 1,

используется для поддиапазона -7 антенны 2,

используется для поддиапазона 7 антенны 3, а

используется для поддиапазона 21 антенны 4. Каждая пилотная последовательность затем передается на связанных с ней поддиапазоне и антенне.In explode mode, four pilot sequences are mapped to four pairs of subbands / antennas, as shown in Table 29. In particular,

used for sub-band -21 of antenna 1,

used for sub-band -7 antenna 2,

used for subband 7 of antenna 3, and

used for subband 21 of antenna 4. Each pilot sequence is then transmitted on its associated subband and antenna.

In spatial multiplexing mode, four pilot sequences are transmitted on the main eigenmode of their respective subbands. Spatial processing for pilot carrier symbols is similar to that performed for modulation symbols, as described above. In beam control mode, four pilot sequences are transmitted on their respective subbands using beam control. Beam control for pilot carrier symbols is also similar to that performed for modulation symbols.

The specific structure of the pilot signal is described above for the MFMWX WLAN system. Other pilot structures may also be used for this system, which are within the scope of the invention.

IX. System operation

12A shows a specific embodiment of a state diagram 1200 for operating a user terminal. This state diagram includes four states - state 1210 Initiation, state 1220 Inactive, state 1230 Access, and state 1240 Connection. Each of states 1210, 1220, 1230, and 1240 may be associated with several substates (not shown in FIG. 12A for simplicity).

In the Initiation state, the user terminal receives the system frequency and synchronization, and receives system parameters sent over the BCH channel. In the Initiation state, the user terminal can perform the following functions:

- System definition - the user terminal determines at which carrier frequency to capture the system.

- Frequency / sync capture - the user terminal captures the beacon pilot and adjusts its frequency and timing accordingly.

- Parameter capture - the user terminal processes the BCH to obtain system parameters associated with the access point from which the downlink signal is received.

Upon completion of the functions required for the Initiation state, the user terminal switches to the Inactive state.

In the Inactive state, the user terminal periodically monitors the BCH channel for updated system parameters, indications of search calls and broadcast messages sent on the downlink, etc. No radio resources are allocated to the user terminal in this state. In the Inactive state, the user terminal can perform the following functions:

- If registration is provided, the user terminal enters the Access state with a registration request.

- If transmitter / receiver calibration is provided, the user terminal enters the Access state with a calibration request.

- The user terminal monitors the BCH for indications of search calls and broadcast messages sent over the FCH.

- If the user terminal has data to send it on the uplink, it enters the Access state with a resource request.

- The user terminal performs operational procedures such as updating system parameters and monitoring the channel.

- The user terminal may enter intermittent operation to save power, if this mode is supported by the user terminal.

If the user terminal needs radio resources from the access point for any task, it goes into the Access state. For example, a user terminal may transition to the Access state in response to a paging call or DST indicator sent in a BCH channel message to register or request calibration, or to request allocated resources.

In the Access state, the user terminal is in the process of accessing the system. The user terminal may send short messages and / or requests for FCH / RCH resources using the RACH channel. Operation on the RACH channel is described in more detail below. If the user terminal is disconnected from the access point, then it goes back to the Inactive state. If resources are assigned to the user terminal for the downlink and / or uplink, then it transitions to the Connection state.

In the Connection state, FCH / RCH resources are assigned to the user terminal, although not necessarily for each DTE frame. The user terminal may actively use the allocated resources or may be waiting (while maintaining a connection) in the Connection state. The user terminal remains in the Connection state until it is disconnected by the access point or if it expires after inactivity for a specific period of inactivity, in which case it switches back to Inactive.

When in the Inactive, Access or Connection state, the user terminal switches back to the Initiation state if its power is turned off or if the connection is dropped.

12B shows a specific embodiment of a state diagram for a state 1240 Connection. In this embodiment, the Connection state includes three substates — Substate 1260 Installation, Substate 1270 Open, and Substate 1280 Standby. The user terminal enters the Installation substate when receiving an assignment on FCCH.

In the Installation substate, the user terminal is in the process of establishing a connection and is not yet exchanging data. Establishing a connection may include channel estimation for an access point, finding a transmission rate, negotiating services, etc. Upon entering the substate Installation, the user terminal sets the timer to a specific time value. If the timer expires before the user terminal exits from this substate, then it goes back to the Inactive state. The user terminal goes into the Open sub-state when the connection is completed.

In the substate, the Open user terminal and access point exchange data on the downlink and / or uplink. In the substate, the Open user terminal monitors the BCH channel for the presence of system parameters and the indication of the paging / broadcast messages. If the BCH channel message cannot be correctly decoded in a specific number of DVR frames, the user terminal switches back to the Initiation state.

The user terminal also monitors the FCCH for the presence of channel assignment information, rate control, RCH timing control, and power control. The user terminal estimates the S / N ratio for the received signal using the BCH beacon pilot and the FCH channel preamble, and finds the maximum transmission rate that can be reliably supported on the FCH.

The assignments of the FCH and RCH channels for the user terminal for each DVR frame are specified by the information elements in the FCCH channel PDUs transmitted in the current (or, possibly, in the previous) DVR frame. The user terminal may not be assigned to transmit data on the FCH and / or RCH for any given DVR frame. For each frame of the DVR, in which the user terminal is not planned for data transmission, it does not receive the FCH of the FCH on the downlink and does not transmit on the uplink.

For each DVR frame planned for the user terminal, downlink and / or uplink data transmissions are performed using the RCH channel transmission speed and shift mode (for the uplink) specified in the FCCH channel assignments (i.e., information elements FCCH addressed to this user terminal). The user terminal receives, demodulates, and decodes the FCH channel PDUs sent to it. The user terminal also transmits RCH PDUs, which include the preamble and the FCH data rate indicator. The user terminal adjusts the rate used in the RCH according to the rate control information contained in the FCCH assignment. If power control is used for uplink transmission, the user terminal adjusts its transmit power based on the control commands included in the FCCH assignment. The data exchange may be packetized, in which case the user terminal may enter the Waiting sub-state whenever there is no data exchange. The user terminal enters the Wait sub-state at the direction of the access point. If the access point does not assign the FCH or RCH channel to the user terminal in a specific number of DDA frames, then the user terminal goes back to Inactive and saves its MAC ID.

In the Substate, Waiting, both the ascending line and the descending line are unoccupied. No data is sent in any direction. However, lines are supported using a managed reference and control messages. In this substate, the access point periodically assigns the Waiting PDUs to the user terminal on the RCH and possibly the FCH (not necessarily at the same time). The user terminal can maintain the Connection state indefinitely, provided that the access point periodically assigns the FWA and RCH Standby PBUs to support the line.

While in the Standby sub-state, the user terminal controls the BCH channel. If the BCH channel message is not decoded correctly in a specific number of DVR frames, then the user terminal switches back to the Initiation state. The user terminal also monitors the FCCH for channel assignment, rate control, RCH timing control, and power control information. The user terminal may also evaluate the S / N ratio in the received signal and determine the maximum transmission rate supported by the FCH. The user terminal transmits the Wait PDUs on the RCH when it is assigned, and sets the RCH Request bit to the Wait PDUs if it has data to transmit. If the access point does not assign the FCH or RCH channel to the user terminal in a specific number of DDA frames, then the user terminal goes back to Inactive and saves its MAC ID.

The watchdog timer (downtime) can be set to a specific value when entering any of the three substates. This timer will then decrease its value if there is no activity in this substate. The terminal will switch from the Installation, Active, and Standby back states to the Inactive state after the set time of the watchdog timer expires, and to the Initiation state if the connection is reset. From the Active or Pending sub-state, the terminal will go back to the Inactive state if the connection is disconnected.

12A and 12B show a specific embodiment of a state diagram that can be used for a user terminal. For the system, various other state diagrams can be used with fewer states and substates, additional and (or) excellent states and substates, which is also included in the scope of the invention.

X. Random Access

In an embodiment, a random access scheme is used to provide user terminals with access to an MxMWH WLAN system. In an embodiment, the random access scheme is based on the Aloha segmented scheme whereby the user terminal transmits at a randomly selected RACH channel time interval in order to try to access the system. The user terminal may send multiple transmissions on the RACH channel until it gains access or until the maximum number of access attempts is reached. The various parameters for each transmission on the RACH may be varied to increase the likelihood of success, as described below.

13 illustrates a timeline for a RACH channel, which is divided into time intervals (segments) of the RACH channel. The number of RACH slots available for use in each DVR frame and the duration of the RACH slot are configurable parameters. A maximum of 32 RACH slots may be available for use in each frame of the DDA. The guard interval between the end of the last RACH time interval and the start of the BCH PBB for the next DTE frame is also a configurable parameter. These three parameters for RACH can vary from frame to frame and are indicated by the RACH length, RACH time slot size and RACH guard interval RACH fields.

When the user terminal wishes to access the system, it first processes the BCH channel messages to obtain the necessary system parameters. The user terminal then sends the RACH PDUs on the RACH channel. This RACH PDU includes a RACH message that contains information necessary for an access point to process an access request from a user terminal. For example, the RACH message includes a MAC ID assigned to the user terminal, which allows the access point to identify the user terminal. Registration of the MAC ID (i.e., the specific value of the MAC ID) may be reserved for unregistered user terminals. In this case, the long user terminal ID may be included in the RACH message Payload field along with the registration of the MAC ID.

As described above, the RACH PDU can be transmitted at one of four speeds, which are listed in Table 15. The selected speed is embedded in the RACH PDU preamble (as shown in FIG. 5C). The RACH PDU also has a variable length of 1, 2, 4, or 8 OFDM characters (which is also listed in Table 15), which is indicated in the Message Duration field in the RACH message.

To transmit the RACH PDUs, the user terminal first determines the number of RACH time slots that can be used for transmission (ie, the number of “usable” RACH time slots). This definition is based on (1) the number of RACH time slots available in the current DTE frame, (2) the duration of each RACH time slice, (3) the guard interval, and (4) the length of the RACH PDU to be transmitted. The RACH PDU cannot extend beyond the end of the RACH segment in the DDA frame. Thus, if the RACH PDU is longer than one RACH time slot plus the guard interval, then this PBU may not be transmitted in one or more later RACH time slots. The number of RACH slots that can be used to transmit RACH PDUs may be less than the number of available RACH slots, based on the factors listed above. The RACH segment includes a guard interval, which is provided to prevent mutual interference between uplink transmission from the user terminal and the next BCH channel segment, which is possible for user terminals that do not compensate for their two-way propagation time delays.

The user terminal then randomly selects one of the appropriate RACH time slots to transmit the RACH PDU. The user terminal then transmits the RACH PDUs starting at the selected RACH time slot. If the user terminal knows the time delay of the two-way signal propagation to the access point and vice versa, it can take this delay into account by adjusting its synchronization accordingly.

When the access point receives the RACH PDU, it checks the received RACH message with the CRC included in this message. The access point discards the RACH message. The CRC check is unsuccessful. If the CRC check is successful, the access point sets the RACH acknowledge bit in the BCH channel in the next frame of the DTE and transmits the RACH confirmation in FCCH in two frames of the DTE. There may be a delay between setting the BCH Acknowledgment bit and sending a confirmation via FCCH, which can be used to account for delay planning, etc. For example, if an access point receives a message on the RACH, it can set the Acknowledge bit on the BCH and receive a delayed response on the FCCH. The Acknowledge bit prevents user terminal retries and allows unsuccessful user terminals to retry quickly, except for periods of the busy RACH.

If the user terminal performs the registration, then it uses the registration UDS ID (for example, 0x0001). The access point responds by sending a message Assignment of the MAC ID on the FCH. All other types of RACH transmissions include the UDS ID of the user terminal assigned by the system. The access point explicitly acknowledges all correctly received RACH messages by sending confirmations on the FCCH using the MAC ID assigned to the user terminal.

After the user terminal sends the PDUs over the RACH, it monitors the BCH and FCCHs to determine whether it is received or not and processed by the access point of its RACH PDUs. The user terminal monitors the BCH channel to determine if the RACH acknowledge bit is set in the BCH message. If this bit is set, which indicates that acknowledgment for this and / or some other user terminals is being sent on the FCCH, then the user terminal then processes the FCCH message to obtain IE Type 3 information elements containing acknowledgments. Otherwise, if the RACH acknowledgment bit is not sent, then the user terminal continues to monitor the BCH or resumes its access procedure on the RACH.

Type 3 FCCH IEs are used to quickly transfer acknowledgments for successful access attempts. Each confirmation information element contains a MAC ID associated with a user terminal for which a confirmation is sent. Fast confirmation is used to inform the user terminal that its access request has been accepted, but is not related to the allocation of FCH / RCH resources. If the user terminal receives fast acknowledgment on FCCH, it goes into Inactive status. If the user terminal receives the destination-based acknowledgment, it receives the scheduling information sent along with the acknowledgment, and starts using the FCH / RCHs as assigned in the current frame of the DVR.

The user terminal resumes the access procedure on the RACH if it does not receive acknowledgment on the FCH for a specific number of DVR frames after transmitting the RACH PDU. In this case, the user terminal may assume that the access point did not correctly receive the RACH PDU. A user terminal maintains a counter to count the number of access attempts. This counter can be initialized to zero for the first access attempt and increment by one for each subsequent access attempt. The user terminal will complete the access procedure if the counter reaches the maximum number of attempts.

For each subsequent access attempt, the user terminal first determines various parameters for this access attempt, including (1) the timeout period before transmitting the RACH PDU, (2) the RACH time interval used to transmit the RACH PDU and (3) the transmission rate for the PDU RACH. To determine the timeout period, the user terminal first determines the maximum timeout period for the next access attempt, which is called the "contention window" (OS) (CW). In an embodiment, the contention window (which is specified in units of DDA frames) exponentially increases for each access attempt (i.e., OS = 2 ^{access attempts} ). A contention window may also be determined based on some other function (e.g., a linear function) of the number of access attempts. The timeout period for the next access attempt is then randomly selected between zero and the OS. The user terminal will wait for this period of time before transmitting the RACH PDU for the next access attempt.

For the next access attempt, the user terminal decreases the transmission rate for the RACH PDU if the lowest rate was not used for the last access attempt. The initial transmission rate used for the first access attempt may be selected based on the S / N ratio of the pilot signal for the received signal sent over the BCH channel. Failure to receive acknowledgment may be caused by unsuccessful reception of the RACH PDU by the access point. Thus, the transmission rate for the RACH PDU in the next access attempt is reduced to increase the likelihood of the correct reception by the access point.

After waiting for a randomly selected wait time, the user terminal again randomly selects the RACH time interval for transmitting the RACH PDU. The selection of the RACH time slot for this access attempt can be performed in a similar manner as described above for the first access attempt, except that the RACH parameters (i.e., the number of RACH time slots, the length of the time interval, and the guard interval) for the current DTE frame, as transmitted in the BCH message, are used along with the length of the current RACH PDB. The RACH PDU is then transmitted in a randomly selected RACH time slot.

The access procedure described above continues until either (1) the user terminal receives confirmation from the access point or (2) the maximum number of allowed access attempts is reached. For each access attempt, the timeout period before transmitting the RACH PDU, the used RACH time interval for transmitting the RACH PDU, and the transmission rate for the RACH PDU can be selected as described above. If an acknowledgment is received, then the user terminal operates as indicated by the acknowledgment (i.e., it waits in the Inactive state if a fast acknowledgment is received, or starts using FCH / RCH if an assignment-based acknowledgment is received). If the maximum number of allowed access attempts is reached, then the user terminal enters the Initiation state.

Xi. Speed, power and timing control

The access point schedules downlink and uplink transmissions on the FCH and RCH and controls the transmission rates for all active user terminals. In addition, the access point controls the transmit power of some active user terminals in the uplink. Different loops may be supported to adjust speed, transmit power, and timing for each active user terminal.

1. Fixed and variable speed services

An access point may support both fixed and variable rate services on the FCH and RCH. Fixed speed services can be used for voice, video, etc. Variable speed services can be used to transmit packet data (e.g. web search).

For fixed rate services on FCH / RCH, a fixed rate can be used for the entire connection. Maximum effort delivery is used on the FCH and RCH (i.e., no retransmission). The access point schedules a fixed number of FCH / RCH PDUs for a particular time interval to satisfy QoS service requirements. Depending on the delay requirements, the access point may not need to schedule the FCH / RCH PDUs for each DTE frame. For fixed speed services, power control is performed on the RCH, but not on the FCH.

For variable speed services on FCH / RCH, the transmission rates used for FCH / RCH may vary depending on channel conditions. For some isochronous services (such as video, audio), QoS requirements may impose a minimum rate limit. For these services, the scheduler in the access point adjusts the FCH / RCH distribution to ensure a constant transmission rate. For asynchronous data services (e.g. web search, file transfer, etc.) delivery with maximum effort is provided by the retransmission option. For these services, the transmission rate is the maximum rate that can be reliably supported by channel conditions. FCH / RCH PDU scheduling for user terminals is typically a function of QoS requirements. Whenever there is no data to send on the downlink / uplink, the PDU is freely sent on the FCH / RCH to maintain the line. Closed loop power control is not performed on the FCH or RCH for variable speed services.

2. Speed control

Rate control can be used for variable rate services using FCH and RCH to adapt the FCH / RCH transmission rate to changing channel conditions. The rates for use in the FCH and RCH can be independently controlled. In addition, in the spatial multiplexing mode, the transmission rate for each wideband eigenmode of each dedicated transport channel can be independently controlled. Speed control is performed by the access point based on the feedback provided by each active user terminal. The scheduler at the access point schedules data transmission and determines the speed assignments for active user terminals.

The maximum transmission speed that can be supported on any line is a function of (1) the channel response matrix for all data subbands, (2) the noise level observed by the receiver, (3) the quality of the channel estimate and, possibly, other factors. For a DVR system, a channel can be considered reversible for a downlink and an uplink (after calibration has been performed to account for any differences in the access point and user terminal). However, this reversible channel does not assume that the noise thresholds are the same at the access point and user terminal. Thus, for a given user terminal, the transmission rates on the FCH and RCH can be controlled independently.

Closed loop speed control can be used to transmit data on one or more spatial channels. Closed loop speed control can be implemented using one or multiple loops. The inner loop estimates channel conditions and selects the appropriate transmission rate for each spatial channel used for data transmission. Channel estimation and rate selection may be performed as described above. The external circuit can be used to assess the quality of data transmission received in each spatial channel, and to adjust the operation of the internal circuit. The quality of data transmission can be quantified by the rate of packet errors (STR) (PER), decoder metrics, etc. or a combination thereof. For example, the outer loop can adjust the S / N ratio shift for each spatial channel to achieve the target STR value for that spatial channel. The outer loop may also instruct the inner loop to select a lower transmission rate for the spatial channel if excessive packet errors are detected for this spatial channel.

Downlink Speed Control

Each active user terminal may estimate the downlink channel based on the MVxMvout pilot transmitted over the BCH in each frame of the TDD. An access point may also transmit a managed reference in an FCH PDU sent to a particular user terminal. Using the MVxMVy pilot signal on the BCH channel and (or) the controlled reference on the FCH channel, the user terminal can estimate the S / N ratio in the received signal and determine the maximum transmission rate that can be supported on the FCH channel. If the user terminal operates in spatial multiplexing mode, then the maximum speed can be determined for each broadband eigenmode. Each user terminal can send back to the access point the maximum speed supported by each wideband eigenmode (for spatial multiplexing mode), the maximum speed supported by the main wideband eigenmode (for beam control mode), or the maximum speed supported by the MVxMout channel (for diversity mode) in the FCH speed indicator field in the RCH PDB. These rates can be mapped to S / N ratios for the received signal, which can then be used to perform the aforementioned redundancy creation procedure. Alternatively, the user terminal may send back sufficient information (e.g., S / N ratios for received signals), allowing the access point to determine the maximum transmission rate supported by the downlink.

Determining whether the diversity, beam control, or spatial multiplexing mode is used can be made based on feedback from the user terminal. The number of wideband eigenmodes selected for use can increase the decoupling between control vectors.

14A illustrates a downlink transmission rate control process for a user terminal. The BCH PDU is transmitted in the first segment of each DVR frame and includes a beacon pilot and a MVxMvout pilot signal, which can be used by user terminals for channel estimation and channel tracking. A managed reference may also be sent in the preamble of the FCH PDU sent to the user terminal. The user terminal evaluates the channel based on the MVxMVy and (or) managed reference and finds the maximum speed (s) that can be supported by the downlink. One transmission rate is provided for each broadband eigenmode if the user terminal operates in spatial multiplexing mode. The user terminal then sends a speed indicator for the FCH in the FCH speed indicator field to the RCH PDU, which it sends to the access point.

The scheduler uses the maximum speed that the downlink can maintain for each active user terminal to schedule the transmission of downlink data in subsequent frames of the DTE. Speeds and other channel assignment information for the user terminal are reflected in the information element sent on FCCH. The transmission rate assigned to one user terminal may affect scheduling for other user terminals. The minimum delay between the speed determination by the user terminal and its use is approximately one frame of the DVR.

Using an ordered Gram-Schmidt procedure, an access point can accurately determine the maximum speeds supported in the FCH channel directly from the RCH preamble. This can then greatly simplify speed control.

Uplink Speed Control

Each user terminal transmits a managed reference over the RACH during system access and over the RCH after allocating FCH / RCH resources. The access point can estimate the S / N ratio for the received signal for each of the wideband eigenmodes based on the controlled reference in the RCH and determine the maximum speed supported by each wideband eigenmoder. Initially, an access point may not have a good channel estimate to ensure reliable operation at or near the maximum speed supported by each broadband eigenmode. To improve reliability, the initial speed used on the FCH / RCH can be much lower than the maximum supported speed. An access point may integrate a managed reference across multiple DTE frames to obtain an improved channel estimate. When channel estimation improves, the speed can be increased.

14B illustrates an uplink transmission rate control process for a user terminal. After scheduling uplink transmission, the user terminal transmits an RCH PDU, which includes a reference used by the access point to find the maximum speed in the uplink. The scheduler then uses the maximum speeds that the uplink can maintain for each active user terminal in order to schedule uplink data transmission in subsequent frames of the DTE. Speeds and other channel assignment information for the user terminal is reflected in the information element sent on FCCH. The minimum delay between finding the speed by the access point and its use is approximately one frame of the DDA.

3. Power management

Power control can be used for uplink transmissions on the RCH (instead of speed control) for fixed speed services. For fixed-rate services, the transmission rate is consistent when a call is established and remains fixed for the duration of the connection. Some fixed speed services may be associated with a limited mobility requirement. In an embodiment, power control is implemented for the uplink to counter interference between user terminals, but is not used for the downlink.

A power control mechanism is used to control the uplink transmit power of each active user terminal, so that the S / N ratio for the received signal at the access point is maintained at a level that provides the desired quality of service. This level is often called the target S / N ratio for the received signal, operating point, or set point. For a mobile user terminal, propagation loss will likely change as this user terminal moves. The power control mechanism monitors changes in the channel, so that the S / N ratio in the received signal is maintained near the setpoint.

The power control mechanism can be implemented by two power control loops - an internal loop and an external loop. The inner loop adjusts the transmit power of the user terminal so that the S / N ratio for the received signal at the access point is maintained near the set point. The external circuit adjusts the setpoint to implement a specific level of operation, which can be quantified by means of a specific frame error rate (SCADO) (FER) (e.g. 1% SCADO), packet error rate (STR), block error rate (SBR) (BLER) ), message error rate (COM) (MER), or some other measure.

15 illustrates the operation of internal power control for a user terminal. After the FCH / RCH is assigned to the user terminal, the access point estimates the S / N ratio for the received signal in the RCH and compares it with the setpoint. The initial power to be used by the user terminal can be found when a call is established and usually lies near the maximum transmit power level. For each frame interval, if the S / N ratio for the received signal exceeds the setting for a specific positive margin δ, the access point can instruct the user terminal to reduce its transmit power by a specific amount (for example, 1 dB) in the FCCH information element sent to this user terminal . Conversely, if the S / N ratio for the received signal is lower than the threshold minus the margin δ, the access point may instruct the user terminal to increase the transmit power by a specific amount. If the S / N ratio for the received signal is within the acceptable range, the access point will not request changes in the transmit power of the user terminal. The uplink transmit power is defined as the initial transmit power level plus the sum of all power adjustments received from the access point.

The initial setting in the access point is set to achieve a specific level of operation. This setting is controlled by an external circuit based on SCADO or STR for RCH. For example, if no frame / batch errors occur during a specific time period, the setting can be reduced by a first value (for example, 0.1 dB). If the average SCADO is exceeded by the appearance of one or more frame / burst errors, the setpoint can be increased by a second amount (for example, 1 dB). The setpoint, hysteresis margin and operation of the external circuit corresponds to the specific power control scheme used in the system.

4. Sync Management

Synchronization control can be advantageously used in a DVR-based frame structure, where the downlink and uplink share the same frequency band by time division duplexing. User terminals can be located throughout the system and, thus, can be associated with various propagation delays to the access point. In order to maximize uplink efficiency, the synchronization of uplink transmission on RCH and RACH from each user terminal may be adjusted to account for propagation delay. This will then ensure that uplink transmissions from various user terminals arrive at the access point in a particular time window and do not interfere with each other in the uplink, or downlink transmissions.

16 illustrates an adjustment process for uplink synchronization of a user terminal. Initially, the user terminal sends the RACH PDUs in the uplink to gain access to the system. An access point receives an initial estimate of an acknowledgment delay (RTD) associated with a user terminal. The acknowledgment delay can be estimated based on (1) the moving correlator used in the access point to determine the start of transmission, and (2) the ID of the time slot included in the RACH PDU sent by the user terminal. The access point then calculates an initial timing advance for the user terminal based on the initial STD estimate. An initial timing advance is sent to the user terminal before it is transmitted on the RCH. An initial timing advance may be sent in a message on the FCH, in the field of an information element of the FCCH, or otherwise.

The user terminal receives the initial timing advance from the access point and then uses this timing advance on all subsequent uplink transmissions in both the RCH and the RACH. If FCH / RCH resources are assigned to the user terminal, its timing advance can be controlled by commands sent by the access point in the RCH Timing Adjustment field of the FCCH channel information element. The user terminal will then adjust its uplink transmissions on the RCH based on the current timing advance, which is equal to the initial timing advance plus all timing adjustments sent by the access point to the user terminal.

The various parts of the MFMWSS system and the various methods described herein can be implemented by various means. For example, the processing at the access point and user terminal may be embodied in hardware, software, or a combination thereof. For a hardware implementation, processing can be implemented on one or more application oriented integrated circuits (ASICs), digital signal processors (DSPs), digital signal processor devices (DSPDs), programmable logic devices (PLDs), user programmable gate arrays (FPGAs), processors , controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described here, or combinations thereof.

For a software implementation, processing can be implemented by modules (e.g., procedures, functions, etc.) that perform the functions described herein. Program codes can be stored in a storage unit (for example, memory 732 or 782 in FIG. 7) and executed by a processor (for example, controller 730 or 780). The storage unit may be implemented inside the processor or outside the processor, in which case it can be communicatively connected to the processor through various means, as is known in the art.

Headings are included here for reference and for ease of locating certain sections. These headings are not intended to limit the scope of the concepts described in them, but these concepts may be used in other sections of the description.

The foregoing description of the disclosed embodiments is intended to enable a person skilled in the art to make or use the present invention. Various modifications to these embodiments should be apparent to those skilled in the art, and the basic principles defined herein may be applied to other embodiments without departing from the spirit and scope of the invention. Thus, the present invention is not intended to limit the embodiments shown here, but should correspond to the broadest scope consistent with the disclosed principles and new features.

Claims (30)

1. A method of exchanging data in a wireless communication system with multiple inputs and multiple outputs (MIMO) with time division duplexing (TDD), comprising: receiving a pilot signal on an uplink from a user terminal; obtaining at least one downlink control vector for the user terminal based on the received pilot; and performing spatial processing with said at least one control vector over a first data transmission sent in a downlink to a user terminal. 2. The method according to claim 1, where one control vector is obtained for the downlink for the user terminal, and where spatial processing for beam control is performed on the first data transmission with said one control vector for sending the first data transmission via one downlink spatial channel . 3. The method of claim 1, wherein the plurality of control vectors are obtained for the downlink for the user terminal, and where spatial processing for spatial multiplexing is performed on the first data transmission with said plurality of control vectors to send the first data transmission via the plurality of downlink spatial channels . 4. The method of claim 1, further comprising: obtaining a matched filter for the uplink for the user terminal based on the received pilot; and performing matched filtering of the second data transmission received on the uplink from the user terminal with a matched filter. 5. The method according to claim 4, where the matched filter contains at least one eigenvector for at least one eigenmode of the uplink, and where the said at least one eigenvector for the uplink is equal to the aforementioned at least one control vector for the downlink. 6. A device for exchanging data in a wireless communication system with multiple inputs and multiple outputs (MIMO) with time division duplexing (TDD), comprising: a spatial receiving processor capable of receiving a pilot signal on an uplink from a user terminal; a controller operable to obtain at least one downlink control vector for the user terminal based on the received pilot; and a spatial transmission processor operable to perform spatial processing with said at least one control vector over the first data transmission sent in a downlink to a user terminal. 7. The device according to claim 6, where the controller is operable to obtain one control vector for the downlink for the user terminal, and where the spatial transmission processor is operable to perform spatial processing for beam control over the first data transmission with said one control vector for sending first data transmission through one spatial channel downlink. 8. The device according to claim 6, where the controller is operable to obtain multiple control vectors for the downlink for the user terminal, and where the spatial transmit processor is operable to perform spatial processing for spatial multiplexing on the first data transmission with the said many control vectors for sending first data transmission through a plurality of downlink spatial channels. 9. The device according to claim 6, where the controller is additionally operable to obtain a matched filter for the uplink for the user terminal based on the received pilot signal, and where the spatial receiving processor is further operable to perform matched filtering of the second data transmission received on the uplink communication lines from the user terminal, with an agreed filter. 10. The device according to claim 9, where the matched filter contains at least one eigenvector for at least one eigenmode of the uplink, and where the said at least one eigenvector for the uplink is equal to the aforementioned at least one control vector for the downlink. 11. A device for exchanging data in a wireless communication system with multiple inputs and multiple outputs (MIMO) with time division duplexing (TDD), comprising: means for receiving a pilot signal on the uplink from the user terminal; means for obtaining at least one downlink control vector for the user terminal based on the received pilot; and means for performing spatial processing with said at least one control vector over a first data transmission sent in a downlink to a user terminal. 12. The device according to claim 11, where one control vector is obtained for the downlink for the user terminal, and where spatial processing for controlling the beam is performed on the first data transmission with said one control vector for sending the first data transmission via one downlink spatial channel . 13. The apparatus of claim 11, wherein the plurality of control vectors are obtained for the downlink for the user terminal, and where spatial processing for spatial multiplexing is performed on the first data transmission with said plurality of control vectors to send the first data transmission via the plurality of downlink spatial channels . 14. The device according to claim 11, further comprising: means for obtaining a matched filter for the uplink for the user terminal based on the received pilot; and means for performing matched filtering of the second data transmission received on the uplink from the user terminal with a matched filter. 15. The device according to 14, where the matched filter contains at least one eigenvector for at least one eigenmode of the uplink, and where the said at least one eigenvector for the uplink is equal to the aforementioned at least one control vector for the downlink. 16. A method for transmitting and receiving pilot signals in a wireless communication system with multiple inputs and multiple outputs (MIMO), comprising: transmitting MIMO pilot signal from multiple antennas and on the first communication line, where the MIMO pilot signal contains multiple pilot transmissions sent from said plurality of antennas, and wherein the pilot transmission from each antenna is an identifiable communication entity receiving said MIMO pilot; and receiving the piloted pilot by at least one eigenmode of the second communication link from the communication entity, where the piloted pilot is generated based on said MIMO pilot. 17. The method of claim 16, wherein the first communication line is an uplink, the second communication line is a downlink, and the communication entity is an access point. 18. The method of claim 16, wherein the first communication line is a downlink, the second communication line is an uplink, and the communication entity is a user terminal. 19. The method according to clause 16, where the transmission of the pilot signal from each antenna is associated with a different orthogonal code. 20. The method according to clause 16, where the subjected to control pilot signal is received by means of one eigenmode of the second communication line and is transmitted at full transmit power from multiple antennas in the communication object. 21. The method according to clause 16, where subjected to the control of the pilot signal is received through many eigenmodes of the second communication line. 22. The method according to clause 16, where the subjected to control pilot signal is transmitted by the communication object for a time duration configurable by the system. 23. A device for exchanging data in a wireless communication system with multiple inputs and multiple outputs (MIMO), comprising: a spatial transmission processor capable of generating a MIMO pilot signal for transmission from multiple antennas and on the first communication line, where the MIMO pilot signal contains a plurality of pilot transmissions sent from said plurality of antennas, and where the pilot transmission from each antenna is an identifiable communication entity receiving said MIMO pilot signal; and a spatial receiving processor operable to process the pilot-controlled signal received by at least one eigenmode of the second communication line from the communication entity, where the pilot-controlled signal is generated based on the MIMO pilot. 24. The device according to item 23, where the transmission of the pilot signal from each antenna is associated with a different orthogonal code. 25. The device according to item 23, where the subjected to control pilot signal is received by means of one eigenmode of the second communication line and is transmitted at full transmit power from multiple antennas in the communication object. 26. The device according to item 23, where subjected to the control of the pilot signal is received through many eigenmodes of the second communication line. 27. A device for exchanging data in a wireless communication system with multiple inputs and multiple outputs (MIMO), comprising: means for transmitting MIMO pilot from multiple antennas and on the first communication line, where the MIMO pilot contains multiple transmit pilot signals, sent from said plurality of antennas, and wherein the pilot transmission from each antenna is an identifiable communication entity receiving said MIMO pilot; and means for receiving the piloted pilot signal by at least one eigenmode of the second communication line from the communication entity, where the piloted pilot signal is generated based on said MIMO pilot signal. 28. The device according to item 27, where the transmission of the pilot signal from each antenna is associated with a different orthogonal code. 29. The device according to clause 27, where subjected to the control of the pilot signal is received through one eigenmode of the second communication line and is transmitted at full transmit power from multiple antennas in the communication object. 30. The device according to clause 27, where subjected to the control of the pilot signal is received through many eigenmodes of the second communication line.

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