WO2007003116A1 - Systeme, methode, emetteur et recepteur multimodes pour faire coexister des reseaux multimodes - Google Patents

Systeme, methode, emetteur et recepteur multimodes pour faire coexister des reseaux multimodes Download PDF

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Publication number
WO2007003116A1
WO2007003116A1 PCT/CN2006/001489 CN2006001489W WO2007003116A1 WO 2007003116 A1 WO2007003116 A1 WO 2007003116A1 CN 2006001489 W CN2006001489 W CN 2006001489W WO 2007003116 A1 WO2007003116 A1 WO 2007003116A1
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WO
WIPO (PCT)
Prior art keywords
space
mode
frequency
multimode
time
Prior art date
Application number
PCT/CN2006/001489
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English (en)
French (fr)
Inventor
Ruobin Zheng
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Huawei Technologies Co., Ltd.
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Filing date
Publication date
Application filed by Huawei Technologies Co., Ltd. filed Critical Huawei Technologies Co., Ltd.
Publication of WO2007003116A1 publication Critical patent/WO2007003116A1/zh

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
    • H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
    • H04L1/0618—Space-time coding
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/02—Arrangements for detecting or preventing errors in the information received by diversity reception
    • H04L1/06—Arrangements for detecting or preventing errors in the information received by diversity reception using space diversity
    • H04L1/0606—Space-frequency coding

Definitions

  • the present invention relates to the field of network communication technologies, and in particular, to a system and method for implementing multi-mode network coexistence, a multi-mode transmitter and a receiver.
  • multiple transmit antennas can be used to divide a wireless channel into multiple parallel narrowband channels, which can effectively increase the channel bit transmission rate, and the research results show that the channel capacity increases linearly with the number of antennas.
  • MIMO Multiple Input Multiple Output
  • SDM Space Division Multiplex
  • STC Space-Time Code
  • SFC Space-Frequency Code
  • the space-time code utilizes the spatial diversity that the multi-antenna system can provide, and its performance depends on the number of antennas of the system and the coding of the signal in space and time.
  • the space-time code mainly includes STTC (Space-Time Trellis Code). , Space Time Grid Code) and STBC (Space-Time Block Code).
  • STTC Space-Time Trellis Code
  • STBC Space-Time Block Code
  • the space-time code design assumes a non-multipath channel condition and belongs to a narrowband code.
  • the maximum achievable diversity gain is equal to the product of the number of transmit antennas and the number of receive antennas. Since space-time codes only utilize spatial diversity and fail to utilize channel frequency diversity provided by multipath, the performance of space-time codes is not optimal under wideband multipath channel conditions.
  • the space frequency code is a coding scheme proposed in the multi-antenna system based on OFDM (Orthogonal Frequency Division Multiplex) in a multipath environment, and mainly includes an SFTC (Space-Frequency Trellis Code, Space frequency grid code) ⁇ SFBC (Space-Frequency Block Code).
  • SFTC Space-Frequency Trellis Code, Space frequency grid code
  • SFBC Space-Frequency Block Code
  • the space-time code requirement spans several
  • the channel fading time response of an OFDM character is approximately constant within one code block period, that is, the larger the coherence time is, the better; and the space frequency code requires that the channel fading frequency response of one code block spanning several subcarriers remains approximately unchanged, that is, the coherent bandwidth The bigger the better.
  • the space-time code has better performance in the flat fading channel
  • the space-frequency code has better performance in the fast fading channel.
  • the transmitter cannot predict the channel state information.
  • the advantages of space-time code and space-frequency code can be integrated, and a STFC (Space-Time-Frequency Code) scheme is proposed.
  • the time domain and the frequency domain are jointly considered to achieve maximum diversity gain under the multi-antenna fading channel.
  • the space-time frequency code mainly includes: STFTC (Space-Time- Frequency Trellis
  • the 802.16 standard broadband fixed wireless access version (referred to as "16d,” for example): SC (Single Carrier) modulation mode, 256 FFT (Fast Fourier Transform) OFDM Modulation mode and 2048 FFT OFDMA (Orthogonal Frequency Division Multiplex Access) modulation mode.
  • SC Single Carrier
  • FFT Fast Fourier Transform
  • 2048 FFT OFDMA Orthogonal Frequency Division Multiplex Access
  • the 802.11 standard uses 64 FFT OFDM modulation technology.
  • Digital Audio Broadcasting, Digital Video Broadcasting, DVB (Digital Video Broadcasting) and Hiperlan (High Perfomace Radio Local Area Network) / II standards also use OFDM modulation technology.
  • 3G 3 rf Generation, The third-generation mobile communication system) adopts spread spectrum modulation Surgery.
  • a multimode network system needs to support the access of user stations of various modes of 16d and 16e at the same time, or a heterogeneous network system must support the access of OFDM terminals such as 802.16 and 802.11, or several different-mode network systems. Coexistence, network systems of different modes are likely to work in the same frequency band. In this case, mutual interference of the eight cases as shown in Fig. 1 to Fig. 8 will occur.
  • the modulo i TX represents the transmitting module of the mode i
  • the modulo i RX represents the receiving module of the mode i
  • the BS is the base station
  • the SS is the subscriber station. Therefore, in the prior art, in order to avoid mutual interference when the network systems of different modes coexist Different operating bands must be used.
  • a so-called multi-mode network system refers to a system in which a plurality of networks having completely different modes exist, 'for example, a network system in which 3G and WLAN coexist;
  • a so-called hetero-mode network system refers to a plurality of modes in which there are A network system with basically the same principle but different mode parameters, for example, a network system in which 802.16d and 802.16e coexist.
  • networks of different modes cannot communicate with each other.
  • multimode network systems and heterogeneous network systems are commonly referred to as multimode network coexistence systems.
  • the present invention provides a system and method for realizing multimode network coexistence, a multimode transmitter and a receiver, thereby enabling coexistence of a reliable multimode network with less frequency resources.
  • the present invention provides a multimode transmitter that implements multimode network coexistence, including:
  • each network mode forms a plurality of transmission branch signals
  • a set of transmitting antennas are respectively used for transmitting and processing a plurality of transmitting branch signals in each network mode.
  • the coding unit includes:
  • Space-time/space-frequency/space-time-frequency coding unit It is used to perform space-time/space-frequency/space-time-frequency coding processing on the transmitted signals of each network mode.
  • the transmitter further includes: A set of signal transmission processing units, each signal transmission processing unit corresponding to a corresponding coding unit, configured to perform channel coding, symbol mapping and modulation processing on the transmitted signals, respectively.
  • the signal transmission processing unit includes a channel coding module, a symbol mapping module, and a modulator, and the space/space frequency/space time frequency coding unit is configured to process the channel coding module, the symbol mapping module, or the modulator. Or the processed signal is encoded.
  • the transmitter further includes:
  • the permutation matrix unit is connected to the set of transmitting antennas for performing simultaneous or time-division transmission processing on the transmission signals, and transmitting the transmission signals to the respective transmitting antennas according to the processing result.
  • the present invention also provides a multimode receiver for realizing multimode network coexistence, comprising: a set of receiving antennas for receiving signals of respective network modes;
  • a set of decoding units configured to decode received signals of respective network modes to form a plurality of receiving branch signals
  • a horizontal layered spatial multiplexing decoding unit configured to perform horizontal space demultiplexing on the plurality of received signals.
  • the decoding unit includes:
  • Space-time/space-frequency/space-time-frequency decoding unit It is used to perform space/space/space time-frequency decoding processing on the received signals of each network mode.
  • the receiver further includes:
  • a set of signal receiving processing units for processing received signals in respective network modes.
  • the signal receiving processing unit comprises a channel decoding module, a symbol demapping module and a demodulator, and the space/space frequency/space time frequency decoding unit is used for a channel decoding module, a symbol demapping module or a demodulation
  • the signal before or after processing is decoded.
  • the receiver further includes:
  • Spatial beamforming or selection unit connected to the set of receiving antennas for performing simultaneous or time-sharing reception processing on the received signals.
  • the present invention also provides a system for implementing multi-mode network coexistence, comprising: a multi-mode transmitter: for transmitting a plurality of transmission tributary signals respectively formed by spatial multiplexing coding in each network mode through a set of transmit antennas simultaneously or Time-sharing;
  • Multimode receiver It is used to receive the signal transmitted by the multimode transmitter, decode it to form multiple receiving tributary signals, and perform horizontal layered spatial multiplexing decoding processing to obtain the received signals in each network mode.
  • the multi-mode transmitter includes a space-time/space-frequency/space-time-frequency coding unit: configured to perform space-time/space-frequency/space-time-frequency coding processing on the transmitted signal;
  • the multimode receiver comprises a space time/space frequency/space time frequency decoding unit: for performing space time/space frequency/space time frequency decoding processing on the received signal.
  • the multimode receiver further includes a horizontal layered spatial multiplexing decoding unit, configured to uniformly perform horizontal spatial demultiplexing on the plurality of received signals.
  • the system further includes:
  • Single mode transmitter channel coding, symbol mapping and modulation processing of signals in a certain network mode, and transmitting through a transmitting antenna;
  • Single mode receiver Receives the signal transmitted by the transmitter, performs demodulation, symbol demapping, and channel decoding processing to obtain a received signal in network mode.
  • the base stations of the various modes in the system that require co-location settings are implemented using multi-mode transmitters and multi-mode receivers.
  • the multi-mode receiver needs to be implemented in the same user station or base station that is simultaneously accessed by the same frequency.
  • the system of the present invention includes a base station and a subscriber station, and
  • the base station and the subscriber station use a multimode transmitter and a multimode receiver
  • the base station uses a multimode transmitter and a multimode receiver, and the subscriber station uses a multimode receiver and a single mode transmitter; or,
  • the base station employs a multimode transmitter and a multimode receiver, and the subscriber station uses a single mode receiver and a single mode transmitter;
  • the base station uses a single mode transmitter and a multimode receiver, and the subscriber station uses a multimode receiver and a single mode transmitter;
  • the base station employs a single mode transmitter and a multimode receiver
  • the subscriber station employs a single mode receiver and a single mode transmitter.
  • one or more modes of signals can be selected as received signals from among various signals of different modes received.
  • the present invention also provides a method for implementing multi-mode network coexistence, including:
  • decoding After receiving signals of a plurality of network modes, decoding is performed to form a plurality of receiving branch signals, and then performing horizontal hierarchical spatial multiplexing decoding processing to obtain received signals in each network mode.
  • the spatial multiplexing coding for forming the plurality of transmission tributary signals includes: performing space-time/space-frequency/space-time-frequency coding processing on the transmission signal; and decoding the forming the plurality of reception tributary signals includes: Space-time/space-frequency/space-time-frequency decoding processing is performed.
  • the method also includes:
  • the method further includes: selecting one or more modes of signals from the received signals of the different modes as the received signals.
  • the present invention is capable of effectively overcoming mutual interference in the eight cases described in the prior art.
  • the base station can simultaneously access the user station in multiple modes at the same frequency or time-sharing frequency, and the user station can simultaneously access the base station in multiple modes at the same frequency or time-sharing, and the heterogeneous networks can coexist.
  • the subscriber station can switch between heterogeneous networks in a soft handover manner.
  • Multi-mode or hetero-mode base stations can be co-located to avoid renting land and building a computer room for each base station of different modes or heterogeneous networks.
  • the implementation of the present invention is that the use of MIMO to form a multiplex channel can combat channel fading to a certain extent, since multiple channels are less likely to be deeply fading at the same time, thereby improving link reliability.
  • the space-time/space-frequency/space-time-frequency coding used in the present invention combines coding technology and antenna array technology to realize space division multiple access, improve system anti-fading performance, and can transmit diversity gain and Receive diversity gain provides high rate, high shield data transfer.
  • space/space-frequency/space-time-frequency coding can achieve higher coding gain without sacrificing bandwidth, thereby improving anti-jamming and Anti-noise ability.
  • FIG. 1 to FIG. 8 are scenes in which interference exists in a multimode network in the prior art
  • FIG. 9 is a schematic structural diagram of a first embodiment of a transceiver system according to the present invention
  • FIG. 10 is a schematic structural diagram of a second embodiment of a transceiver system according to the present invention
  • FIG. 12 is a schematic structural view of a fourth embodiment of the transceiver system according to the present invention
  • FIG. 13 is a schematic structural view of a fifth embodiment of the transceiver system according to the present invention.
  • Schematic diagram of an existing single-mode transceiver system applied in the system 15 is a schematic structural diagram of a first embodiment of a multimode communication system according to the present invention
  • FIG. 16 is a schematic structural view of a second embodiment of a multimode communication system according to the present invention
  • FIG. 18 is a schematic structural view of a fourth embodiment of a multimode communication system according to the present invention
  • FIG. 19 is a fifth embodiment of a multimode communication system according to the present invention
  • 20 is a schematic structural view of a sixth embodiment of a multimode communication system according to the present invention
  • FIG. 21 is a schematic structural view of a seventh embodiment of the multimode communication system according to the present invention
  • FIG. 23 is a schematic structural diagram of a ninth embodiment of a multimode communication system according to the present invention
  • FIG. 24 is a schematic diagram of a multimode communication according to the present invention
  • FIG. 25 is a schematic structural diagram of a first embodiment of a Chinese-style transceiver system based on space-time code;
  • 26 is a schematic diagram of a second embodiment of a dual-mode transceiver system based on space-time codes.
  • 27 is a schematic structural diagram of a first embodiment of a dual-mode transceiver system based on a space-frequency code;
  • FIG. 28 is a schematic diagram of a second embodiment of a dual-mode transceiver system based on a space-frequency code;
  • FIG. 30 is a schematic diagram of a specific implementation of a transmitter in the 16e mode of FIG.
  • the core of the present invention is to use space-time/space-frequency/space-time-frequency coding technology to enable simultaneous communication of multiple channels in the same frequency or time-sharing between a base station and a subscriber station in a multi-mode wireless communication system. .
  • the system of the present invention includes a multimode coexisting transmitter and receiver, which will be separately described below in conjunction with the drawings.
  • the multimode coexistence transmitter 100 in the system of the present invention mainly comprises the following components:
  • the unit specifically includes the following modules:
  • Channel coding module 111 Each mode communication system corresponds to a channel coding module, and is used for coding processing based on the transmission mode of the system;
  • the symbol mapping module 112 is configured to perform symbol mapping processing on signals in each mode; Modulation module 113: For modulating the signals in each mode.
  • different modes of channel coding, symbol mapping, and modulation for example, SC modulation, OFDM modulation, OFDMA modulation, and spread spectrum modulation, respectively For different branches;
  • the space-time/space frequency/space time-frequency coding includes: space-time/space-frequency/space-time-frequency coding trellis coding and/or space-time/empty Frequency/space time-frequency coding block coding, that is, space-time/space-frequency/space-time-frequency coding can be used for source signals of all modes, or space-time/space-frequency can be used for source signals of some modes. / space time-frequency coding trellis coding, while the other modes of the source signal are coded by space-time/space-frequency/space-time-frequency coding;
  • the space-time/space-frequency/space-time-frequency coding unit 120 may be disposed at different positions for processing signals before or after channel coding, symbol mapping, and modulation processing; according to different locations of the units.
  • multimode transmitters can be divided into:
  • Multimode transmitter based on bit-level space-time/space-frequency/space-time-frequency code, as shown in Figure 9 or Figure 10, multi-mode transmitter based on symbol-level space-time/space-frequency/space-time-frequency code, as shown in Figure 11 or Figure 12.
  • the minimum coding unit of the bit-level space-time/space-frequency/space-time-frequency encoder is bits
  • the minimum coding unit of the symbol-level space-time/space-frequency/space-time-frequency encoder is a symbol
  • the coded minimum unit in 11 may be a QAM symbol mapped symbol
  • the coded minimum unit in FIG. 12 may be an OFDM modulated OFDM symbol.
  • the weighted permutation matrix unit 130 can also be used as a transmit beamformer. This matrix unit is not required by the system.
  • the weighting permutation matrix unit 130 is used as the switching on.
  • the number of transmit antennas can be greatly reduced.
  • the processed signal by the weighted permutation matrix unit 130 is transmitted through each of the transmitting antennas.
  • the structure of the multi-mode coexistence receiver in the system of the present invention is still as shown in FIG. 9 to FIG. 12, and specifically includes:
  • the N-mode receiving branches share the same set of receiving antennas by the spatial beamforming or selecting unit 210 as a switching switch, so that the number of receiving antennas can be greatly reduced.
  • the unit specifically includes:
  • Demodulator 221 for demodulating a signal in each mode
  • a symbol demapping module 222 configured to perform demapping processing on channel symbols in each mode
  • Channel decoding module 223 for decoding channel signals in each mode; R strip receiving branches of corresponding N different modes of receiving signals, channel decoding modes, symbol de-mapping methods, and demodulation using N different modes Modes such as SC demodulation, OFDM demodulation, OFDMA demodulation, and spread spectrum demodulation, respectively, may be used for different branches;
  • R-receiving branches which may be space-time/space-frequency/space-time-frequency trellis decoding and/or space-time/space-frequency decoding.
  • / space time-frequency packet decoding may be all source signal signals using a space-time / space / space time-frequency decoding, or some of the mode of the source signal using space / space / space Time-frequency trellis decoding, while other modes of source signals are decoded using space-time/space-frequency/space-time-frequency packets; when decoding the i-th mode When receiving a signal, the tributary signals of the first, second (i-1), and (i+1) N modes are treated as interference signals, that is, other tributary signals except the ith mode are regarded as interference signals;
  • the space/space/space time-frequency decoder 230 may be a multi-mode or different-mode receiver based on the bit-level space-time code, as shown in FIG. 9 or FIG.
  • the minimum coding unit of the bit-level space-time/space-frequency/space-time-frequency decoder is bits, while the symbol-level space-time
  • the minimum decoding unit of the null/space time-frequency decoder is a symbol.
  • the decoding minimum unit in FIG. 11 may be a symbol before the QAM symbol is demapped; the decoding minimum unit in FIG. 12 may be an OFDM before OFDM demodulation. symbol.
  • the horizontal hierarchical spatial multiplexing decoding unit 240 is located after the space-time/space-frequency/space-time-frequency decoder 230, but not necessarily immediately, and is used for uniformly performing horizontal layered spatial multiplexing decoding on the N signal receiving branches.
  • horizontal layered spatial multiplexing decoding can be used for signal extraction and interference suppression or cancellation; when decoding the tributary signal of the ith mode, the first 2 (i-1),
  • the (i+1) N mode tributary signal is treated as interference signal processing.
  • N different modes of signals After processing by each unit of the receiver, N different modes of signals can be obtained, and one or more modes of signals can be selected from the received N different modes as useful received signals, and the specific selection
  • the method is not limited in the present invention.
  • the maximum spatial diversity degree can be obtained by using ML (Maximum Likelihood) decoding, but
  • ML Maximum Likelihood
  • sub-optimal algorithms can also be used: including linear algorithms such as zero-forcing (ZF) algorithm and minimum mean square error (MMSE) algorithm, etc.
  • the multimode transmitter or receiver provided by the present invention may need to be simultaneously networked with an existing single mode transmitter or receiver in practical applications, for example, a single mode transmitter is used on the user side, and more is used on the network side.
  • the mode receiver or, is a single mode receiver on the user side, a multimode transmitter on the network side, etc. Therefore, the structure of the single mode transmitter and receiver will be described below.
  • FIG 14 The structure of an existing single mode transmitter or receiver is shown in Figure 14, which is essentially a normal space/space/space time code transmitter or receiver.
  • the space/space/space time frequency encoder 120 and the space/space/space time frequency encoder 230 there may be bit level (source or signal) space/space frequency / space time-frequency code and j-th mode transmitter and receiver based on symbol level (source or signal) space-time/space-frequency/space-time-frequency code.
  • source or signal space/space frequency / space time-frequency code
  • j-th mode transmitter and receiver based on symbol level (source or signal) space-time/space-frequency/space-time-frequency code.
  • FIG. 15 The first application of the present invention is shown in Figure 15:
  • the scheme is applicable to TDD (Time Division Duplex Mode) and FDD (Frequency Division Han Mode) mode; for TDD mode, it is based on the assumption that each mode network sends and receives synchronization.
  • the base station transmitter and receiver are multimode transmitters and multimode receivers
  • the base station has N modes operating simultaneously
  • the subscriber station transmitters and receivers are also multimode transmitters and multimode receivers, ie
  • the subscriber station also has an N-mode operation at the same time.
  • the N-mode network can coexist at the same time, that is, the base station can simultaneously access the subscriber station in N modes at the same frequency, and the subscriber station can be soft-switched. Mobile switching between heterogeneous networks, the base stations of different modes can be co-located.
  • FIG. 15 a schematic diagram of a system for overcoming the interference shown in FIGS. 1 to 4.
  • t in each drawing. t! t r , t k and t k+1 represent different moments; modulo i TX shows the transmitting module of mode i, modulo i RX represents the receiving module of mode i; BS is the base station, SS is the subscriber station; For the downlink frame of mode i, 13 ⁇ 4 is the upstream frame of mode i.
  • BS1 and BS2 are placed in different cells for frequency reuse according to wireless network planning, inter-base station interference. Negligible; Because each mode network sends and receives synchronization, the interference shown in Figure 4 will not be introduced between the different modes of the base station and between the user stations.
  • Figure 16 A second application of the present invention is shown in Figure 16:
  • the scheme is also applicable to the TDD and FDD modes; for the TDD mode, the assumption of synchronization based on each mode network is transmitted and received.
  • the base station transmitter and receiver are multimode transmitters and multimode receivers, ie the base station N mode operates simultaneously; the subscriber station transmitter uses the single mode transmitter as shown in Figure 14, and the subscriber station receiver uses the multimode receiver. That is, the subscriber station transmitter operates in a single mode, and the subscriber station receiver N mode works at the same time, but only one mode is selected as the current effective working mode at a time; then the N-mode network can coexist at the same time, that is, the base station can simultaneously The frequency accesses the subscriber station in N modes, and the subscriber station can access the base station in one or more modes at a time, and the subscriber station can switch between different heterogeneous networks in a soft handover mode. In this way, the number of transmitting antennas of the subscriber station is small, and the base stations of different modes can be co-located.
  • FIG 16 is a schematic diagram of the system to overcome the interference shown in Figure 1 to Figure 4.
  • BS1 and BS2 are placed in different cells for frequency reuse according to the wireless network plan, and inter-base station interference can be neglected. Since the transmission and reception of each mode network is synchronized, the interference shown in Figure 4 will not be introduced between the different modes of the base station and between the user stations.
  • Figure 17 A third application of the present invention is shown in Figure 17:
  • This scheme is applicable to TDD and FDD modes; for TDD mode, it is based on the assumption that each mode network transmits and receives synchronization.
  • the base station transmitter and receiver are multi-mode transmitters and multi-mode receivers, that is, the base station transmitters are operated by N-mode time division, and the base station receivers N-modes work simultaneously; the subscriber stations can adopt single-mode transmitters and single-mode transmitters. a mode receiver; in this case, the base station can simultaneously receive the user station signals from different modes in the same frequency, and the base station can transmit different mode signals to the user stations in different modes at the same time and in time. . In this way, the subscriber station is the most compact, and the number of base station transmit antennas is small, and the base stations in different modes can be co-located.
  • FIG. 17 a schematic diagram of a system for overcoming the interference shown in FIGS. 1 to 4.
  • BS1 and BS2 are placed in different cells for frequency reuse according to the wireless network plan, and inter-base station interference is negligible. Due to the synchronization of the transmission and reception of each mode network, different mode transceivers and subscriber stations of the base station ⁇ i4—
  • FIG. 18 The interference shown in Figure 4 will not be introduced.
  • the fourth application scheme of the present invention is shown in FIG. 18:
  • This scheme is applicable to TDD and FDD modes; for TDD mode, it is based on the assumption that each mode network transmits and receives synchronization.
  • the base station transmitter and receiver are multimode transmitters and multimode receivers, that is, the base station transmitters are operated by N-mode time division, and the base station receivers are operated by N-mode time division; and the subscriber stations can use single-mode transmitters and In the single-mode receiver, the base station can receive the user station signals from different modes in a time-sharing manner, and the base station can transmit different mode signals to the user stations in different modes at the same time and in the same frequency.
  • the subscriber station is the simplest, and the number of base station transmitting and receiving antennas is small, and the base stations in different modes can be co-located.
  • FIG. 18 a schematic diagram of the system to overcome the interference shown in Figures 1 to 4.
  • BS1 and BS2 are placed in different cells for frequency reuse according to the wireless network plan, and inter-base station interference can be neglected. Since the transmission and reception of each mode network is synchronized, the interference shown in Figure 4 will not be introduced between the different modes of the base station and between the user stations.
  • a fifth application of the present invention is shown in Figures 19 and 20:
  • This scheme is applicable to TDD and FDD modes; for TDD mode, the assumption of synchronization is sent based on each mode network.
  • the base station transmitter adopts the single mode transmitter as shown in FIG. 15, and the base station receiver uses the multimode receiver, that is, the base station transmitter operates in a single mode, the base station receiver N mode works simultaneously, but only one mode is selected as the current one at a time.
  • the user stations of the N different modes can simultaneously access the base stations of the N different modes in the N mode at the same frequency, and the user station can move between the heterogeneous networks in a soft handover manner.
  • Switch In this way, the base station transmitter is the simplest, and the base stations in different modes cannot be co-located, but the coverage can be partially superimposed.
  • FIG. 19 is a schematic diagram of a system that overcomes the interference shown in Figures 5 and 6
  • Figure 20 is a schematic diagram of a system that overcomes the interference shown in Figures 7 and 8.
  • the sixth application scheme of the present invention is shown in FIG. 21:
  • the scheme is based on the assumption that each mode network sends synchronization, and is applicable to the TDD mode.
  • the base station transmitter adopts a single-mode transmitter as shown in FIG. 14, and the base station receiver uses a multi-mode receiver, that is, the base station transmitter operates in a single mode
  • the base station receiver N-mode operates simultaneously, but only one mode is selected as the current one at a time.
  • An effective mode of operation, and the base stations of the N different modes transmit in time;
  • the subscriber station transmitter uses a single mode transmitter as shown in FIG. 14, and the subscriber station receiver uses a multimode receiver, ie, a subscriber station transmitter.
  • Single mode operation the subscriber station receiver N mode works at the same time, but only one mode is selected as the current effective working mode at a time; then the base stations of the N different modes can simultaneously receive the same frequency from the N different modes.
  • the subscriber station signal, the base station of the N different modes can transmit N different modes of signals to the subscriber stations of the N modes at the same time and in time.
  • the base station transmitter is the simplest, and the number of base station transmit antennas is small.
  • the base stations in different modes cannot be co-located, but the coverage can be partially superimposed.
  • Figure 21 is a schematic diagram of a system that overcomes the interference shown in Figures 5 and 6
  • Figure 22 is a schematic diagram of a system that overcomes the interference shown in Figures 7 and 8.
  • the seventh application scheme of the present invention is shown in FIG. 23:
  • This scheme is applicable to TDD and FDD modes; for TDD mode, it is based on the assumption that each mode network transmits and receives synchronization.
  • the base station adopts a single-mode transmitter as shown in FIG. 14, and the base station receiver uses a multi-mode receiver, that is, the base station transmitter operates in a single mode, the base station receiver N-mode operates simultaneously, but only one mode is selected as the current one at a time.
  • An effective working mode, and the base stations of the N different modes are time-divisionally transmitted; the subscriber station adopts a single-mode transmitter and a single-mode receiver as shown in FIG. 14; then the base stations of the N different modes can simultaneously receive at the same frequency
  • the user station signals from the N different modes, the base stations of the N different modes can simultaneously transmit N different modes of signals to the user stations of the N modes in the same frequency.
  • the base station transmitter and the subscriber station are the simplest, and the number of base station transmit antennas is small, and the base stations in different modes cannot be co-located, but the coverage can be partially superimposed.
  • FIG. 23 a schematic diagram of a system for overcoming the interference e and the interference f. Since the transmission and reception of each mode network is synchronized, interference g and interference h are not introduced.
  • the eighth application of the present invention is shown in Figure 24:
  • the scheme is applicable to TDD and FDD modes; for TDD mode, based on each mode network The assumption of synchronization.
  • the base stations of the N different modes may receive the same-time and same-frequency reception.
  • the user station signals of the N different modes, the base stations of the N different modes can simultaneously transmit the signals of the N different modes to the user stations of the N modes in the same time and at the same time. In this way, the base station and the subscriber station are the simplest, and the base stations in different modes cannot be co-located, but the coverage can be partially superimposed.
  • the first implementation as shown in Figure 25, specifically includes:
  • the space-time code is mainly for flat fading channels, while in actual high-speed data transmission systems, the channel characteristics are usually frequency selective fading.
  • the OFDM (Orthogonal Frequency Division Multiplexing) technique can divide the frequency selective fading channel into a plurality of parallel correlated flat fading channels, thus exhibiting non-frequency selective fading on each carrier.
  • 802.16 combines space-time codes with orthogonal frequency division multiplexing.
  • This embodiment uses a combination of space time code and orthogonal frequency division multiplexing techniques for dual mode coexistence of 802.16d OFDM systems and 802.16e OFDMA systems.
  • 802.16d based on dual-antenna transmit diversity, single-antenna receive simple space-time code technology
  • the OFDM and 802.16e OFDMA dual-mode coexistence system is shown in Figure 25.
  • For each mode there are 2 transmit antennas at the transmitting end with a distance of at least ⁇ /2 ( ⁇ is the wavelength), that is, the process of transmitting signals in different paths should be approximated as independent attenuation processes.
  • MISO Multiple Input Single Output
  • the 802.16d source and the 802.16e source are respectively 802.16d channel coding/symbol mapping and 802.16e channel coding/symbol mapping; then, the two transmission signals are respectively code-level simple space-time coding; the output four signals are respectively passed 802.16d OFDM modulation and 802.16e OFDMA modulation; Finally, a transmit antenna is selected for each tributary signal by a permutation matrix.
  • the branch is transmitted at 802.16d, assuming that the permutation matrix is the 802.16d transmit branch select transmit antennas 1 and 2.
  • the space-time encoder inputs a pair of symbols (Si, S i+ i ), that is, at time i, symbols Si and Si+1 are transmitted from antenna 1 and antenna 2, respectively; at time i + 1 , the symbol (-S i+1 * And (Si*) are transmitted from antenna 1 and antenna 2, respectively.
  • (*) denotes a complex conjugate. This ensures that the symbol to be transmitted has an orthogonal space-time structure, which constitutes full time domain diversity. This structure has been adopted by mobile communication standards such as IS-136, WCDMA and CDMA2000.
  • the 802.16e transmit branch process is the same as the 802.16d transmit branch process.
  • the receiver is just the opposite.
  • a receive beam is selected for each branch by a spatial beamforming or selection unit; then, the two signals are respectively demodulated by 802.16d OFDM and 802.16e OFDMA; the output OFDM signal or OFDMA signal is Symbol-level simple space-time decoding and horizontal layered spatial multiplexing decoding, and then 802.16d or 802.16e channel decoding/symbol de-mapping respectively; Finally, 802.16d signals and 802.16e signal outputs are obtained.
  • the receiver estimates the transmitted signal according to the following formula to obtain Ti x Ri order diversity, in this example Ti 1.
  • the formula is as follows:
  • the symbol is the signal received by the receiving antenna 1 at the time i; the symbol +1 is the signal received by the receiving antenna 1 at time i + 1; the time domain response of the multipath fading channel of the transmitting antenna 1 to the receiving antenna 1; i+1 is the time domain response of the multipath fading channel of the transmitting antenna 2 to the receiving antenna 1.
  • the same processing is used for the 802.16e receive branch.
  • the second space time code application implementation is as shown in FIG. 26, and specifically includes:
  • a 3G and 802.16e (referred to as 16e) OFDMA dual-mode coexistence system based on dual-antenna transmit diversity, dual-antenna reception, and single-space-time code technology, as shown in Figure 26.
  • 16e OFDMA dual-mode coexistence system based on dual-antenna transmit diversity, dual-antenna reception, and single-space-time code technology, as shown in Figure 26.
  • For each mode there are 2 transmit antennas on the transmit end and 2 receive antennas on the receive side.
  • This scheme requires a short space-time decoder that requires multiple input multiple output (MIMO) channel estimation.
  • MIMO multiple input multiple output
  • the 3G source and the 16e source pass 3G channel coding/symbol mapping and 16e channel coding/symbol mapping, respectively. Then the two signals are sent for symbol level space time coding. In this case, 3G and 16e OFDMA uses space-time trellis coding and space-time block coding, respectively. The output four signals are then subjected to 3G spread spectrum modulation and 16e OFDMA modulation, respectively. Finally, a transmissive matrix is selected for each tributary signal by the permutation matrix.
  • the branch is transmitted at 16e, and the replacement matrix is assumed to be a 16e transmission branch selecting transmitting antennas 1 and 2.
  • the space-time encoder inputs a pair of symbols (Si 5 S i+ i ), that is, at time i, symbols Si and Si+1 are transmitted from antenna 1 and antenna 2, respectively; at time i + 1 , the symbol (-S i+1 * ) and (Si*) are transmitted from antenna 1 and antenna 2, respectively.
  • (*) denotes a complex conjugate. The same is true for the 3G spread spectrum transmission branch.
  • the receiver is just the opposite, with a spatial beamforming or selection unit selecting a receive antenna for each branch. Then, the two signals are respectively subjected to 3G spread spectrum demodulation and 16e OFDMA demodulation.
  • the output 3G despread signal or OFDMA signal is decoded by symbol level space-time decoding, and then decoded by 3G or 16e channel decoding/symbol de-mapping and horizontal layered spatial multiplexing, respectively.
  • the 3G signal and the 16e signal output are obtained.
  • the 16e OFDMA subscriber station is shown in Figure 11, and the 16e OFDMA portion of Figure 11 is changed to 3G to obtain the 3G subscriber station system.
  • the branch is received at 16e, assuming that the spatial beamforming or selection unit selects the receiving antennas 1 and 2 for the 16e receiving branch.
  • the 3G spread spectrum receiving branch is the same.
  • the present invention will be described below by taking a space frequency code as an example and two specific embodiments.
  • the first specific implementation as shown in FIG. 27, specifically includes:
  • the root transmit antennas should be at least spaced apart so that the process of transmitting signals in different paths can be approximated as independent attenuation processes.
  • MISO single output
  • the 16d source and the 16e source are respectively mapped through 16d channel coding/symbol mapping and 16e channel coding/symbol mapping. Then the two transmit signals are respectively subjected to symbol level simple space frequency coding. The output four signals are then subjected to 16d OFDM modulation and 16e OFDMA modulation, respectively. Finally, a transmitting antenna is selected for each branch signal by the permutation matrix.
  • the branch is transmitted at 16d, and the replacement matrix is assumed to be a 16d transmission branch to select the transmitting antennas 1 and 2.
  • the space frequency encoder encodes the pair of symbols (Si, S i+1 ), that is, on subcarrier i, symbols Si and S i+1 are transmitted from antenna 1 and antenna 2, respectively; in subcarrier i + 1 , symbol (- S i+1 * ) and (S ⁇ ) are transmitted from the antenna 1 and the antenna 2, respectively.
  • (*) denotes a complex conjugate. This ensures that the symbol to be transmitted has an orthogonal space-frequency structure, which constitutes complete frequency domain diversity. 16e sends the same branch.
  • the receiver is just the opposite, with a spatial beamforming or selection unit selecting a receive antenna for each branch. Then, the two signals are subjected to 16d OFDM demodulation and 16e OFDMA demodulation, respectively.
  • the output OFDM signal or OFDMA signal is decoded by symbol-level single-space-frequency decoding and horizontal layered spatial multiplexing, and then decoded by 16d or 16e channel/symbol respectively. Finally, the 16d signal and the 16e signal output are obtained.
  • the branch is received, assuming that the spatial beamforming or selection unit selects the receive antenna 1 for the 16d receive branch.
  • the receiver estimates the transmitted signal as follows:
  • the symbol is the signal received by the receiving antenna 1 on the subcarrier i; the symbol R i+I is the signal received by the receiving antenna 1 subcarrier i + 1; when the transmitting antenna 1 is the multipath fading channel of the receiving antenna 1 The domain response; h i+1 is the time domain response of the multipath fading channel of the transmitting antenna 2 to the receiving antenna 1.
  • the second specific implementation as shown in FIG. 28, specifically includes:
  • FIG. 802.11 OFDM and 802.16e OFDMA dual-mode coexistence system based on dual-antenna transmit diversity, dual-antenna receive simple space-frequency code technology, is shown in FIG.
  • This scheme requires a multi-input multiple-output (MIMO) channel estimate to receive a short space-frequency decoder.
  • MIMO multi-input multiple-output
  • the 802.11 source and the 802.16e source pass 802.11 channel coding/symbol mapping and 802.16e channel coding/symbol mapping, respectively. Then two signals are sent for symbol level space frequency coding.
  • 802.11 OFDM and 802.16e OFDMA use space-frequency trellis coding and space-frequency block coding, respectively.
  • the output four signals are then 802.11 OFDM modulated and 802.16e OFDMA modulated respectively.
  • a transmissive matrix is selected for each tributary signal by the permutation matrix.
  • the branch is transmitted at 802.16e, assuming that the permutation matrix is the 802.16e transmit branch select transmit antennas 1 and 2.
  • the space frequency encoder encodes the pair of symbols (Si, S i+1 ), that is, on subcarrier i, symbols Si and S i+1 are transmitted from antenna 1 and antenna 2, respectively; in the subcarrier symbol (-S i+1) *) and (Si*) are transmitted from antenna 1 and antenna 2, respectively.
  • (*) denotes a complex conjugate. The same is true for 802.11 sending branches.
  • the receiver is just the opposite, with a spatial beamforming or selection unit selecting a receive antenna for each branch. Then, the two signals are demodulated by 802.11 OFDM and 802.16e OFDMA, respectively.
  • the output 802.11 OFDM signal or 802.16e OFDMA signal is decoded by symbol level air frequency decoding and horizontal layer space multiplexing, and then decoded/symbol mapped by 802.11 or 802.16e channel respectively. Finally, the 802.11 signal and the 802.16e signal output are obtained.
  • the 802.16e receive branch assuming that the spatial beamforming or selection unit selects receive antennas 1 and 2 for the 802.16e receive branch.
  • the receiver estimates the transmitted signal as follows:
  • the 802.11 receiving branch is the same.
  • the present invention is further described by taking a space-time-frequency code as an example.
  • the corresponding specific implementation, as shown in FIG. 29 and FIG. 30, specifically includes:
  • 16d OFDM and 16e OFDMA dual-mode coexistence systems based on simple antenna time-frequency code technology for four-antenna transmit diversity and single-antenna reception, as shown in Figure 30.
  • For each mode there are 4 transmit antennas at the receiving end, and the distance should be at least such that the process of transmitting signals in different paths can be approximated as independent attenuation processes.
  • the scheme receiving a short space-time decoder requires multi-input single-output (MISO) channel estimation.
  • MISO multi-input single-output
  • the 16d source and the 16e source are respectively mapped through 16d channel coding/symbol mapping and 16e channel coding/symbol mapping. Then the two transmit signals are respectively subjected to symbol level simple space time frequency coding. The output four signals are then subjected to 16d OFDM modulation and 16e OFDMA modulation, respectively. Finally, a transmissive matrix is selected for each tributary signal by the permutation matrix.
  • the branch is transmitted at 16e, assuming that the permutation matrix is a 16e transmission branch selecting transmit antennas 1, 2, 3 and 4.
  • the space time frequency encoder encodes the paired symbols (S 1 ; S 2 , S 3 , S 4 ) in the following orthogonal matrix A3, as shown in FIG.
  • the 16e 4 transmit antenna space-time frequency coder is composed of a space time block coding unit and a mapping unit.
  • the 16e OFDMA modulator consists of an IFFT processing unit and a serial to parallel conversion unit.
  • the space time block coding unit first pairs the symbols ( The different column symbols according to the orthogonal matrix A3 are transmitted in chronological order by different transmitting antennas. For example, the first column symbol (S l5 0, 0, S 2 ) of the orthogonal matrix A3 is transmitted by the transmitting antenna 1 in chronological order; the second column symbol of the orthogonal matrix A3 (-S ⁇ AS!*) Transmitted by transmit antenna 2 in chronological order; and so on.
  • the mapping unit further performs code mapping on the output of the space time block coding unit in the frequency domain.
  • the space time block coding unit and the mapping unit together perform space time-frequency coding. Then after IFFT processing and serial-to-parallel conversion, It is sent out by the corresponding transmit antenna.
  • the receiver is just the opposite, with a spatial beamforming or selection unit selecting a receive antenna for each branch. Then, the two signals are subjected to 16d OFDM demodulation and 16e OFDMA demodulation, respectively.
  • the output OFDM signal or OFDMA signal is decoded by symbol-level simple space-time-frequency decoding and horizontal layered spatial multiplexing, and then decoded by 16d or 16e channel/symbol respectively. Finally, the 16d signal and the 16e signal output are obtained.
  • a set of transmitting antennas is employed on the transmitter side.
  • the space-time/space-frequency/space-time-frequency coding is performed on the signal, so that the same-frequency signals of different modes can be layer-multiplexed in space, as in the original frequency band.
  • space-time coding can be applied to multi-mode network systems in which different modes of signals use heterogeneous modulation types, while space-frequency coding and space-time coding are generally applicable to signals in which different modes adopt the same modulation type (OFDM). Modular network system.
  • the base station of the present invention can access the user station in the N mode simultaneously with the same frequency or time-sharing, and the user station can simultaneously access the same frequency or the same frequency in the N mode.
  • Base stations, heterogeneous networks can coexist, and subscriber stations can switch between heterogeneous networks in a soft handover manner.
  • Multi-mode or hetero-mode base stations can be co-located to avoid renting land and building a computer room for each base station of different modes or heterogeneous networks. It can multiply the spectrum utilization without increasing the bandwidth and antenna transmit power, thereby multiplying the wireless channel capacity, system capacity, and data communication rate. Therefore, in the present invention, space/space frequency/space time-frequency coding can obtain a higher coding gain without sacrificing bandwidth, thereby improving the anti-interference and anti-noise capability.

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Description

实现多模网络共存的系统及方法、 多模发射机及接收机 技术领域 本发明涉及网络通信技术领域， 尤其涉及一种实现多模网络共存的 系统及方法、 多模发射机及接收机。
背景技术
在无线通信系统中， 采用多个发射天线能把无线信道分割成多个并 行的窄带信道， 可以有效提高信道比特传输率， 且研究结果显示， 信道 容量随天线数量增加而线性增大。 与接收分集和智能天线相比， MIMO ( Multiple Input Multiple Output, 多输入多输出） 系统不但能够提供分集 增益和阵列增益， 而且可以采用 SDM ( Space Division Multiplex, 空间复 用） 的方式提高系统容量。
由于发射机还有接收机的天线数有限， 因此增加分集增益和提高发 射速率是一对矛盾。 STC ( Space-Time Code, 空时码） 和 SFC ( Space- Frequency Code , 空频码） 能较好地解决这一矛盾。
所述的空时码利用多天线系统所能提供的空间分集， 其性能取决于 系统的天线数和信号在空间和时间上的编码， 所述的空时码主要包括 STTC ( Space-Time Trellis Code, 空时网格码 )和 STBC ( Space-Time Block Code, 空时分组码）。 空时码的设计假设非多径信道条件， 属于窄带码， 最大可获得的分集增益等于发射天线数和接收天线数的乘积。 由于空时 码只利用空间分集， 而未能利用多径提供的信道频率分集， 因此， 在宽 带多径信道条件下， 空时码的性能并不是最佳的。
所述的空频码是在多径环境下， 基于 OFDM ( Orthogonal Frequency Division Multiplex, 正交频分复用）的多天线系统的编码问题提出的编码 方案，主要包括 SFTC( Space- Frequency Trellis Code,空频网格码 )^SFBC ( Space- Frequency Block Code, 空频分组码） 。 空频码潜在能实现的分 集增益是发射天线数、 接收天线数和信道冲击响应长度（信道多径数） 的乘积。
从衰落信道的相干时间和相干带宽来看， 空时码要求在跨越几个 OFDM字符的一个码块周期内信道衰落时间响应保持近似不变，即相干时 间越大越好； 而空频码要求跨越几个子载波的一个码块的信道衰落频率 响应保持近似不变， 即相干带宽越大越好。
从约束条件上看， 空时码在平坦衰落信道中具有较好性能， 而空频 码在快衰落信道中具有较好性能。
然而， 实际上发射机是无法预知信道状态信息的， 为此可以整合空 时码和空频码的优势， 又提出 STFC ( Space-Time- Frequency Code, 空时 频码）方案， 在空间域、 时间域和频率域上联合考虑， 从而实现多天线 衰落信道下的最大分集增益。
所述的空时频码主要包括： STFTC ( Space-Time- Frequency Trellis
Code, 空时频网格码）和 STFBC ( Space-Time- Frequency Block Code, 空 时频分组码） 。
目前， 802.16标准的宽带固定无线接入版本（简称 "16d，， ) 中有三 种实现模式， 具体为： SC ( Single Carrier, 单载波）调制模式、 256 FFT ( Fast Fourier Transform, 快速傅立叶变换） OFDM调制模式和 2048 FFT OFDMA ( Orthogonal Frequency Division Multiplex Access, 正交频分复用 接入）调制模式。 802.16标准的宽带移动无线接入版本（简称 "16e" ) 中有两种实现模式， 具体为： 128/512/1024 FFT SOFDMA ( Scalable Orthogonal Frequency Division Multiplex Access, 可扩展的正交频分复用 接入）调制模式和 2048 FFT OFDMA调制模式。 802.11标准采用的则是 64 FFT OFDM调制技术。 DAB ( Digital Audio Broadcasting,数字音频广播）、 DVB ( Digital video broadcasting , 数字视频广播） 和 Hiperlan ( High Perfomace Radio Local Area Network, 高性能无线局域网） /II标准也采用 OFDM调制技术。 3G ( 3rf Generation, 第三代移动通信系统）标准采用的 则是扩频调制技术。
若一个多模网络系统需要同时支持 16d和 16e的各种模式的用户站的 接入， 或一个异模网络系统要同时支持 802.16和 802.11等 OFDM终端的接 入， 或几个异模网络系统要共存， 则不同模式的网络系统很可能采用相 同频段工作， 在这种情况下， 将出现如图 1至图 8的 8种情况的相互干扰。 其中， 模 i TX表示模式 i的发送模块， 模 i RX表示模式 i的接收模块； BS为 基站， SS为用户站， 因此， 在现有技术中， 不同模式的网络系统共存时 为避免相互干扰必须采用不同工作频段。
一般来说， 所谓的多模网络系统指的是其中存在多种模式完全不同 的网络的系统，'例如， 3G和 WLAN共存的网络系统； 所谓的异模网絡系 统指的是其中存在多种模式原理基本相同 , 但模式参数有所差异的网络 的系统， 例如， 802.16d和 802.16e共存的网络系统。 但是， 不论是多模网 络系统， 还是异模网络系统， 其中的不同模式的网络之间不能相互通讯。 本文将多模网络系统和异模网络系统通称为多模网络共存的系统。
由上述描述不难看出， 在现有技术对频谱需求较宽。 而频谱恰恰是 运营商稀缺的资源； 另外， 有几种模式的用户站就需要有几个频段， 假 设各种模式的频宽要求相同， 若某一种模式的用户站数量多， 而其它的 用户站数量很少， 由于用户站数量少的模式相应的频段并无法调整给用 户站数量多的模式用， 频谱资源浪费较大。
另外， 由于各种模式网络要分别占用不同的频段， 用户站无法以软 切换的方式在异种网絡间移动切换。
发明内容
本发明提供一种实现多模网络共存的系统及方法、 多模发射机及接 收机， 从而能够以较少的频率资源实现通信可靠的多模网络的共存。
本发明提供一种实现多模网络共存的多模发射机， 包括：
一组编码单元， 分别用于对各个网络模式的发送信号进行空间复用 编码， 各网络模式均形成多条发送支路信号；
一组发射天线， 分别用于将各网络模式下的多条发送支路信号进行 发送处理。
所述的编码单元包括：
空时 /空频 /空时频编码单元： 用于对各个网络模式的发送信号进行空 时 /空频 /空时频编码处理。
所述发射机还包括： 一组信号发送处理单元， 各信号发送处理单元对应相应的编码单元 , 分别用于对发送的信号迸行信道编码、 符号映射及调制处理。
所述的信号发送处理单元包括信道编码模块、 符号映射模块和调制 器， 且所述的空时 /空频 /空时频编码单元用于对经信道编码模块、 符号映 射模块或调制器处理前或处理后的信号进行编码处理。
所述的发射机还包括：
置换矩阵单元： 与所述的一组发射天线连接， 用于对发送信号进行 同时或分时发送处理， 并根据处理结果将发送信号发送给各个发射天线。
本发明还提供了一种实现多模网络共存的多模接收机， 包括： 一組接收天线， 用于接收各个网络模式的信号；
一組解码单元， 用于对接收的各个网络模式的信号进行解码， 形成 多条接收支路信号；
水平分层空间复用解码单元， 用于对所述多条接收信号进行水平空 间解复用。
所述解码单元包括：
空时 /空频 /空时频解码单元： 用于对各个网络模式的接收信号进行空 时 /空频 /空时频解码处理。
所述的接收机还包括：
一组信号接收处理单元， 分别用于对各个网络模式下的接收信号进 行处理。
所述的信号接收处理单元包括信道解码模块、 符号解映射模块和解 调器， 且所述的空时 /空频 /空时频解码单元用于对信道解码模块、 符号解 映射模块或解调器处理前或处理后的信号进行解码处理。
所述的接收机还包括：
空间波束成形或选择单元： 与所述的一组接收天线连接， 用于对接 收信号进行同时或分时接收处理。 本发明还提供一种实现多模网络共存的系统， 包括： 多模发射机： 用于将各个网络模式中的分别经过空间复用编码形成 的多条发送支路信号通过一组发射天线同时或分时进行发送；
多模接收机： 用于接收多模发射机发送的信号， 进行解码形成多条 接收支路信号后进行水平分层空间复用解码处理， 获得各网络模式下的 接收信号。
其中， 所述的多模发射机包括空时 /空频 /空时频编码单元： 用于对发 送信号进行空时 /空频 /空时频编码处理；
所述的多模接收机包括空时 /空频 /空时频解码单元： 用于对接收信号 进行空时 /空频 /空时频解码处理。
所述的多模接收机还包括水平分层空间复用解码单元， 用于对所述 多条接收信号统一进行水平空间解复用。
所述系统中还包括：
单模发射机： 将某一网络模式下的信号进行信道编码、 符号映射及 调制处理， 并通过发射天线发送；
单模接收机： 接收发射机发送来的信号， 进行解调、 符号解映射和 信道解码处理获得一种网络模式下的接收信号。
所述系统中需要共址设置的各个模式的基站采用多模发射机和多模 接收机实现。
所述系统中需要同时同频接入同一用户站或基站时， 则所述同时同 频接入的同一用户站或基站中需要采用多模接收机实现。
本发明所述的系统包括基站和用户站， 并且，
所述的基站和用户站采用多模发射机和多模接收机；
或者，
所述基站采用多模发射机和多模接收机， 所述用户站采用多模接收 机和单模发射机； 或者，
所述基站采用多模发射机和多模接收机， 所述用户站采用单模接收 机和单模发射机； 或者，
所述基站采用单模发射机和多模接收机， 所述用户站采用多模接收 机和单模发射机；
或者，
所述基站采用单模发射机和多模接收机， 所述用户站采用单模接收 机和单模发射机。
本发明中 , ·在多模接收机侧， 可从接收到的各种不同模式的信号中 选择出一种或多种模式的信号作为接收信号。
本发明还提供一种实现多模网络共存的方法， 包括：
将各个网络模式中的分别经过空间复用编码形成的多条发送支路信 号通过一组发射天线同时或分时进行发送；
接收多个网络模式的信号后， 进行解码形成多条接收支路信号后进 行水平分层空间复用解码处理， 获得各网络模式下的接收信号。
其中， 所述形成多条发送支路信号的空间复用编码包括： 对发送信 号进行空时 /空频 /空时频编码处理； 所述形成多条接收支路信号的解码包 括： 对接收信号进行空时 /空频 /空时频解码处理。
该方法还包括：
对多个网絡模式的发送信号进行信道编码、 符号映射及调制处理； 且所述的空时 /空频 /空时频编码在信道编码、 符号映射或调制处理前或处 理后进行；
对多个网络模式的接收信号进行解调、 符号解映射和信道解码处理； 且所述的空时 /空频 /空时频解码在信道解码、 符号解映射或解调处理前或 处理后的进行。
该方法还包括： 从接收到的各种不同模式的信号中选择出一种或多 种模式的信号作为接收信号。 由上述本发明提供的技术方案可以看出， 本发明中， 发射机和接收 机使用多个天线进行数据传输的多输入多输出技术， 并通过空间复用， 如同在原有频段上建立了多个互不干扰、 并行的子信道， 避免不同模式 或异种网絡的每种基站都要申请不同的频段。 因此， 本发明可以在不增 加带宽和天线发送功率的情况下， 成倍地提高频谱利用率， 进而成倍地 提高无线信道容量、 系统容量和数据通信速率。
本发明能够有效克服现有技术中描述的 8种情况的相互干扰。 所述基 站可同时同频或分时同频以多种模式接入所述用户站， 用户站亦可同时 同频或分时同频以多种模式接入所述基站， 异种网絡可以共存， 用户站 可以软切换的方式在异种网络间移动切换。 多模或异模基站可以共址， 避免不同模式或异种网络的每种基站都要租用土地、 建设机房。
本发明的实现是采用 MIMO构成多路信道可以在一定程度上对抗信 道衰落， 因为多个信道同时处于深衰落的可能性较小， 从而改善链路可 靠性。
另外， 本发明中采用的空时 /空频 /空时频编码将编码技术和天线阵技 术结合在一起， 实现了空分多址， 提高了系统的抗衰落性能， 且能通过 发射分集增益和接收分集增益提供高速率、 高盾量的数据传输。 与不使 用空时 /空频 /空时频编码的编码系统相比， 空时 /空频 /空时频编码可以在 不牺牲带宽的情况下获得较高的编码增益， 进而提高了抗干扰和抗噪声 的能力。
附图说明 图 1至图 8为现有技术中多模网络中存在干扰的场景；
图 9为本发明所述的收发系统的第一实施例的结构示意图； 图 10为本发明所述的收发系统的第二实施例的结构示意图； 图 11为本发明所述的收发系统的第三实施例的结构示意图； 图 12为本发明所述的收发系统的第四实施例的结构示意图； 图 13为本发明所述的收发系统的第五实施例的结构示意图； 图 14为本发明的系统中应用的现有单模收发系统的结构示意图； 图 15为本发明所述的多模通信系统的第一实施例的结构示意图； 图 16为本发明所述的多模通信系统的第二实施例的结构示意图； 图 17为本发明所述的多模通信系统的第三实施例的结构示意图； 图 18为本发明所述的多模通信系统的第四实施例的结构示意图； 图 19为本发明所述的多模通信系统的第五实施例的结构示意图； 图 20为本发明所述的多模通信系统的第六实施例的结构示意图； 图 21为本发明所述的多模通信系统的第七实施例的结构示意图； 图 22为本发明所述的多模通信系统的第八实施例的结构示意图； 图 23为本发明所述的多模通信系统的第九实施例的结构示意图； 图 24为本发明所述的多模通信系统的第十实施例的结构示意图； 图 25为基于空时码的汉模收发系统的第一实施例的结构示意图； 图 26为基于空时码的双模收发系统的第二实施例的示意图； 图 27为基于空频码的双模收发系统的第一实施例的结构示意图； 图 28为基于空频码的双模收发系统的第二实施例的示意图； 图 29为基于空时频码的双模收发系统的第一实施例的示意图； 图 30为图 29中的 16e模式下的发射机具体实现方式示意图。
具体实施方式 本发明的核心是采用空时 /空频 /空时频编码技术使得在多模无线通 信系统中的基站和用户站之间可以同时同频或分时同频以多种模式进行 通信。
本发明所述的系统中包括多模共存的发射机和接收机， 下面将结合 附图分别进行说明。
如图 9至图 13所示， 本发明所述的系统中的多模共存发射机 100， 主 要包括以下各组成单元：
( 1 )信号发送处理单元
该单元具体包括以下各个模块：
信道编码模块 111 : 每种模式通信系统对应一个信道编码模块， 用于 基于本系统的传输模式进行编码处理；
符号映射模块 112: 用于对各个模式下的信号进行符号映射处理； 调制模块 113: 用于对各个模式下的信号进行调制处理。
相应 N种不同模式的信源信号的 T条发送支路， 具体可以采用不同模 式的信道编码方式、 符号映射方式和调制方式， 例如， SC调制、 OFDM 调制、 OFDMA调制和扩频调制， 可以分别用于不同的支路；
( 2 ) 空时 /空频 /空时频编码单元 120
用于对来源于 N种不同模式信源的发送信号进行编码处理，具体为对 N个不同模式的信源信号分别进行空时 /空频 /空时频编码形成丁= ( Tr T2+...+Tq )条发送支路， 其中 q=N; 所述的空时 /空频 /空时频编码包 括：空时 /空频 /空时频编码网格编码和 /或空时 /空频 /空时频编码分组编码， 即可以为所有模式的信源信号都采用一种空时 /空频 /空时频编码， 也可以 是某几种模式的信源信号采用空时 /空频 /空时频编码网格编码， 而另几种 模式的信源信号采用空时 /空频 /空时频编码分组编码；
所述的空时 /空频 /空时频编码单元 120可以设置于不同的位置， 用于 对信道编码、 符号映射及调制处理前或处理后的信号进行处理； 根据该 单元设置的位置的不同， 多模发射机可以分为：
基于比特级空时 /空频 /空时频码的多模发射机， 如图 9或图 10、 基于 符号级空时 /空频 /空时频码的多模发射机， 如图 11或图 12、 基于信源比特 级和信道比特级混合、 基于信源符号级和信道符号级混合及基于比特级 (信源或信号）和符号级（信源或信号） 混合的多模或异模发射机， 如 图 13; 比特级空时 /空频 /空时频编码器的编码最小单位为比特， 而符号级 空时 /空频 /空时频编码器的编码最小单位为符号， 例如， 图 11中编码最小 单位可以为经 QAM符号映射后的符号； 图 12中编码最小单位可以为经 OFDM调制后的 OFDM符号。
( 3 )加权置换矩阵单元 130
N种模式发射机同时工作时， 从 T个发射天线中， 为每个每种模式的 信号选择 Ti ( i=l,..,q )个发射天线； 当有信道状态信息反馈回路存在时， 加权置换矩阵单元 130还可以做发射波束成形器。 该矩阵单元并非是系统 必须的。
N种模式发射机分时发送时， 通过加权置换矩阵单元 130作为切换开 关使 N种模式发送支路共享同一组发射天线，可以使发射天线数量极大减 少。
( 4 )一组发射天线 140
加权置换矩阵单元 130处理后的信号通过各个发射天线进行发送。 本发明所述的系统中的多模共存接收机的结构仍如图 9至图 12所示， 具体包括：
( 1 ) 空间波束成形或选择单元 210
N种模式接收机同时工作时， 一是接收波束成形； 二是， 可以用于从 R= ( ¾+¾+... +Rq ) 个接收天线中为每种模式的信号选择 Ri ( i=l,...,q ) 个接收天线，或是从 R个接收天线所形成的若干个波束中为每个支路选择 一个接收波束； 该单元并非是系统必须的；
N种模式接收机分时接收时， 通过空间波束成形或选择单元 210作为 切换开关使 N种模式接收支路共享同一组接收天线，可以使接收天线数量 极大减少。
( 2 )信号接收处理单元
该单元具体包括：
解调器 221 : 用于对各个模式下的信号进行解调制处理；
符号解映射模块 222: 用于对各个模式下的信道符号进行解映射处 理；
信道解码模块 223: 用于对各个模式下的信道信号进行解码处理； 相应 N种不同模式的接收信号的 R条接收支路釆用 N种不同模式的信 道解码方式、 符号解映射方式和解调方式， 例如， SC解调、 OFDM解调、 OFDMA解调和扩频解调， 可以分别用于不同的支路；
( 3 ) 空时 /空频 /空时频解码单元 230
对 N个不同模式的接收信号分别进行空时 /空频 /空时频解码形成 R条 接收支路， 具体可以为空时 /空频 /空时频网格解码和 /或空时 /空频 /空时频 分组解码）； 可以是所有模式的信源信号都采用一种空时 /空频 /空时频解 码， 也可以是某几种模式的信源信号采用空时 /空频 /空时频网格解码， 而 另几种模式的信源信号采用空时 /空频 /空时频分组解码；当解码第 i模式的 接收信号时， 第 1、 2 ( i-1 ) 、 ( i+1 ) N模式的支路信号被 看作干扰信号处理， 即除第 i模式外的其他支路信号当作干扰信号；
与发射机侧对应， 按空时 /空频 /空时频解码器 230放置的位置的不同， 可以有基于比特級空时码的多模或异模接收机， 如图 9或图 10, 基于符号 级空时码的多模或异模接收机， 如图 11或图 12, 基于信源比特级和信道 比特级混合、 基于信源符号级和信道符号级混合及基于比特级（信源或 信号）和符号级（信源或信号） 混合的多模或异模接收机， 如图 13; 比 特级空时 /空频 /空时频解码器的编码最小单位为比特，而符号级空时 /空频 /空时频解码器的解码最小单位为符号， 例如， 图 11中解码最小单位可以 为经 QAM符号解映射之前的符号； 图 12中解码最小单位可以为经 OFDM 解调之前的 OFDM符号。
( 4 ) 水平分层空间复用解码单元 240
水平分层空间复用解码单元 240位于空时 /空频 /空时频解码器 230之 后， 但不一定紧随其后， 用于对 N个信号接收支路统一进行水平分层空间 复用解码， 例如可以采用水平分层空间复用解码进行各路信号的提取和 干扰抑制或抵消； 当解码第 i模式的支路信号时， 第 1、 2 ( i-1 ) ,
( i+1 ) N模式的支路信号被看作干扰信号处理。
经上述接收机各单元处理后， 便可以获得 N种不同模式的信号， 并可 以从接收到的 N种不同模式的信号中选择出一种或多种模式的信号作为 有用接收信号， 具体的选择方式本发明中不作限定。
在接收机中的水平分层空间复用解码单元 240进行水平分层空间复 用解码过程中， 理论上， 可采用 ML (最大似然）译码能得到最大的空间 分集度（为 ) , 但其译码复杂度大； 也可采用次最佳的算法： 包括线 性算法 {如迫零 ( ZF )算法和最小均方误差 （MMSE )算法等 } 和非线 性算法 {包括 SUC ( Successive Cancellation,一种逐次抵消算法）， OSUC ( Ordered Successive Cancellation , 另一种逐次抵消算法） ， 即 ZF V-BLAST (迫零贝尔实验室分层空时结构） ， 等} ； 其中的线性算法译 码复杂度低， 但由于没有充分利用接收信号中的有用信息， 能得到的分 集度只有 RrTi+1 , 远低于 ML方法， 空时特性较差 （虽然 MMSE的性能较 ZF好） ； 非线性方法的特性虽不如 ML方法， 但其译码复杂度大大低于 ML方法， 在性能和复杂度之间做了很好的折中； 在非线性方法中， SUC 的性能只比线性方法略好， 而 OSUC却远远优于线性方法。
由于本发明提供的多模发射机或接收机在实际应用中可能需要与现 有的单模发射机或接收机同时组网应用， 例如， 在用户侧采用单模发射 机， 在网络侧采用多模接收机， 或者， 在用户侧采用单模接收机， 而在 网络侧采用多模发射机， 等等， 因此， 下面将对单模发射机和接收机的 结构进行说明。
现有的单模发射机或接收机的结构如图 14所示， 本质上即为普通的 空时 /空频 /空时频码发射机或接收机。 同样， 根据空时 /空频 /空时频编码 器 120和空时 /空频 /空时频编码器 230放置的位置的不同， 可以有基于比特 级（信源或信号） 空时 /空频 /空时频码和基于符号级（信源或信号）空时 /空频 /空时频码的第 j模发射机和接收机。 为对本发明有进一步理解， 将对本发明在具体组网应用中的实现方 式进行说明， 下面将对本发明应用于基站和用户站中为例进行说明。 本发明的第一种应用方案如图 15所示：
该方案适用于 TDD (时分双工模式）和 FDD (频分汉工模式）方式； 对于 TDD方式， 基于各模式网络收发同步的假设。
在图 15中， 基站发射机和接收机为多模发射机和多模接收机， 基站 有 N模同时工作， 而用户站发射机和接收机也为多模发射机和多模接收 机， 即用户站也有 N模同时工作， 在这种情况下， N模网络可以同时同频 共存， 即所述基站可同时同频以 N种模式接入所述用户站， 用户站可以软 切换的方式在异种网络间移动切换， 不同模式的所述基站可共址。
以 TDD为例， 仍参见图 15, 为克服图 1至图 4所示干扰的系统示意图。 其中， 各幅附图中的 t。、 t! tr、 tk和 tk+1表示不同的时刻； 模 i TX^示模式 i 的发送模块， 模 i RX表示模式 i的接收模块； BS为基站， SS为用户站； 其 中， 为模式 i的下行帧， 1¾为模式 i的上行帧。
BS1和 BS2按无线网络规划置于不同的蜂窝做频率复用， 基站间干扰 可忽略不计； 由于各模式网络收发同步， 基站的不同模式收发器间、 用 户站间都不会引入图 4所示的干扰。 本发明的第二种应用方案如图 16所示：
同样， 该方案也适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模 式网络收发同步的假设。
如果基站发射机和接收机为多模发射机和多模接收机，即基站 N模同 时工作； 而用户站发射机采用如图 14的单模发射机， 用户站接收机则采 用多模接收机， 即用户站发射机单模工作， 用户站接收机 N模同时工作， 但一次只选择一种模式作为当前的有效工作模式； 则 N模网絡可以同时同 频共存， 即所述基站可同时同频以 N种模式接入所述用户站， 用户站可以 每次一种或多种模式接入所述基站， 用户站可以软切换的方式在异种网 络间移动切换。 该方式用户站发射天线数量较少， 不同模式的所述基站 可共址。
以 TDD为例， 参见图 16, 为克服图 1到图 4所示干扰的系统示意图。 BS1和 BS2按无线网络规划置于不同的蜂窝做频率复用， 基站间干扰可忽 略不计。 由于各模式网络收发同步， 基站的不同模式收发器间、 用户站 间都不会引入图 4所示干扰。 本发明的第三种应用方案如图 17所示：
该方案适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模式网络收 发同步的假设。
在图 17中， 基站发射机和接收机为多模发射机和多模接收机， 即基 站发射机 N模分时工作， 基站接收机 N模同时工作； 用户站可采用单模发 射机和单模接收机； 这种情况下， 所述基站可同时同频接收来自不同种 模式的所述用户站信号， 所述基站可分时同频发送不同种模式信号到不 同种模式的所述用户站。 该方式用户站最筒单， 基站发射天线数量较少， 不同模式的所述基站可共址。
以 TDD为例， 参见图 17, 为克服图 1至图 4所示的干扰的系统示意图。 BS1和 BS2按无线网络规划置于不同的蜂窝做频率复用 , 基站间干扰可忽 略不计。 由于各模式网络收发同步， 基站的不同模式收发器间、 用户站 ― i4—
间都不会引入图 4所示干扰。 本发明的第四种应用方案如图 18所示：
该方案适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模式网络收 发同步的假设。
图 18中， 基站发射机和接收机为多模发射机和多模接收机， 即基站 发射机 N模分时工作， 基站接收机 N模分时工作； 而用户站可采用单模发 射机和单模接收机， 则所述基站可分时同频接收来自不同种模式的所述 用户站信号 , 所述基站可分时同频发送不同种模式信号到不同种模式的 所述用户站。 该方式用户站最简单， 基站发射和接收天线数量都较少， 不同模式的所述基站可共址。
以 TDD为例， 参见图 18, 为克服图 1至图 4所示干扰的系统示意图。 BS1和 BS2按无线网絡规划置于不同的蜂窝做频率复用， 基站间干扰可忽 略不计。 由于各模式网络收发同步， 基站的不同模式收发器间、 用户站 间都不会引入图 4所示的干扰。 本发明的第五种应用方案如图 19和图 20所示：
该方案适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模式网络发 送同步的假设。
如果基站发射机采用如图 15的单模发射机， 且基站接收机采用多模 接收机， 即基站发射机单模工作， 基站接收机 N模同时工作， 但一次只选 择一种模式作为当前的有效工作模式； 用户站发射机采用如图 14的单模 发射机， 且用户站接收机采用多模接收机， 即用户站发射机单模工作， 用户站接收机 N模同时工作，但一次只选择一种模式作为当前的有效工作 模式； 则 N种不同模式的用户站可同时同频以 N种模式接入 N种不同模式 的所述基站， 用户站可以软切换的方式在异种网络间移动切换。 该方式 基站发射机最简单， 不同模式的所述基站不能共址， 但覆盖范围可部分 叠加。
以 TDD为例， 参见图 19和图 20, 在 FDD下不存在图 19的情况。 图 19 为克服图 5和图 6所示的干扰的系统示意图， 图 20为克服图 7和图 8所示干 扰的系统示意图。 本发明的第六种应用方案如图 21所示：
该方案基于各模式网络发送同步的假设， 适用于 TDD方式。
如果基站发射机采用如图 14的单模发射机， 且基站接收机采用多模 接收机， 即基站发射机单模工作， 基站接收机 N模同时工作， 但一次只选 择一种模式作为当前的有效工作模式，且 N种不同模式的所述基站分时发 送； 用户站发射机采用如图 14所示的单模发射机， 且用户站接收机釆用 多模接收机， 即用户站发射机单模工作， 用户站接收机 N模同时工作， 但 一次只选择一种模式作为当前的有效工作模式；则 N种不同模式的所述基 站可同时同频接收来自 N种不同种模式的所述用户站信号， N种不同模式 的所述基站可分时同频发送 N种不同模式的信号到 N种模式的所述用户 站。 该方式基站发射机最简单， 基站发射天线数量较少， 不同模式的所 述基站不能共址， 但覆盖范围可部分叠加。
参见图 21和图 22。 图 21为克服图 5和图 6所示干扰的系统示意图， 图 22为克服图 7和图 8所示干扰的系统示意图。 本发明的第七种应用方案如图 23所示：
该方案适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模式网络收 发同步的假设。
如果基站采用如图 14所示的单模发射机， 且基站接收机采用多模接 收机， 即基站发射机单模工作， 基站接收机 N模同时工作， 但一次只选择 一种模式作为当前的有效工作模式， 且 N种不同模式的所述基站分时发 送； 用户站采用如图 14所示的单模发射机和单模接收机； 则 N种不同模式 的所述基站可同时同频接收来自 N种不同种模式的所述用户站信号， N种 不同模式的所述基站可分时同频发送 N种不同模式的信号到 N种模式的所 述用户站。 该方式基站发射机和用户站都最简单， 且基站发射天线数量 较少， 不同模式的所述基站不能共址， 但覆盖范围可部分叠加。
以 TDD为例， 参见图 23, 为克服所述干扰 e和干扰 f的系统示意图。 由 于各模式网络收发同步， 不会引入干扰 g和干扰 h。 本发明的第八种应用方案如图 24所示：
该方案适用于 TDD和 FDD方式； 对于 TDD方式， 基于各模式网络收 发同步的假设。
如果基站和用户站皆采用单模发射机和单模接收机，且 N种不同模式 的所述基站分时发送并分时接收，则 N种不同模式的所述基站可分时同频 接收来自 N种不同种模式的所述用户站信号， N种不同模式的所述基站可 分时同频发送 N种不同模式的信号到 N种模式的所述用户站。 该方式基站 和用户站都最简单， 不同模式的所述基站不能共址， 但覆盖范围可部分 叠加。
以 TDD为例， 参见图 24, 为克服图 5和图 6所示干扰的系统示意图。 而且， 由于各模式网络收发同步， 因此， 在此情况下， 不会引入图 7和图 8所示的干扰。 下面再以空时码为例， 以两个具体的实例说明本发明的具体实现方 式。
第一个实施例如图 25所示， 具体包括：
空时码主要针对平坦衰落信道， 而在实际高速数据传输系统中信道 特性通常为频率选择性衰落。 OFDM (正交频分复用）技术能把频率选择 性衰落信道划分为多个并行的相关的平坦衰落信道， 因而各载波上呈现 非频率选择性衰落。 802.16将空时码与正交频分复用技术组合运用。
该实施例将空时码与正交频分复用技术的组合用于 802.16d OFDM系 统和 802.16e OFDMA系统的双模共存上。
基于双天线发射分集、 单天线接收的简单空时码技术的 802.16d
OFDM和 802.16e OFDMA双模共存系统， 如图 25所示。对于每种模式， 在 发射端有 2根发射天线， 相距至少为 λ /2 ( λ为波长）， 即发送信号在不 同路径种传播的过程应能够被近似认为是相互独立的衰减过程， 在接收 端有 1根接收天线， 这种方案接收短的空时解码器需要 MISO (多输入单 输出） 的信道估计。
802.16d信源和 802.16e信源分别通过 802.16d信道编码 /符号映射和 802.16e信道编码 /符号映射； 然后， 两路发送信号分别进行符号級简单空 时编码； 输出的四路信号再分别经过 802.16d OFDM调制和 802.16e OFDMA调制； 最后， 由置换矩阵为每个支路信号选择一个发射天线。 在 802.16d发送支路， 假设置换矩阵为 802.16d发送支路选择发射天线 1和 2。 空时编码器输入成对符号（Si, Si+i ) ， 即在时刻 i, 符号 Si和 Si+1 分别从天线 1和天线 2发射； 在时刻 i + 1 , 符号 （- Si+1* ) 和（Si* )分别 从天线 1和天线 2发射。 其中 （* ) 表示复共轭。 这样可保证欲发射符号 具有正交空时结构， 构成完全时域分集。 该结构已经被 IS-136、 WCDMA 和 CDMA2000等移动通信标准所釆纳。
802.16e发送支路处理过程与 802.16d发送支路处理过程相同。
接收机则正好相反， 由空间波束成形或选择单元为每个支路选择一 个接收天线； 然后， 两路信号分别经过 802.16d OFDM解调和 802.16e OFDMA解调； 输出的 OFDM信号或 OFDMA信号经符号级简单空时解码 和水平分层空间复用解码，再分别经 802.16d或 802.16e信道解码 /符号解映 射； 最后， 得到 802.16d信号和 802.16e信号输出。
在 802.16d接收支路， 假设空间波束成形或选择单元为 802.16d接收支 路选择接收天线 1 ;
接收机按下述公式估计发送的信号， 获得 Ti x Ri阶分集， 本例中 Ti
Figure imgf000019_0001
1 , 所述公式如下：
SAi = hi* x Ri* + hi+i* x Ri+i*;
Figure imgf000019_0002
其中， 符号 为接收天线 1在时刻 i接收到的信号； 符号 +1为接收天 线 1时刻 i + 1接收到的信号； 为发射天线 1到接收天线 1的多径衰落信道 的时域响应； hi+1 为发射天线 2到接收天线 1的多径衰落信道的时域响应。
802.16e接收支路采用同样的处理。 第二个空时码应用实施例如图 26所示， 具体包括：
基于双天线发射分集、 双天线接收的筒单空时码技术的 3G和 802.16e (简称 16e ) OFDMA双模共存系统， 如图 26所示。 对于每种模式， 在发 射端有 2根发射天线， 在接收端有 2根接收天线， 这种方案接收短的空时 解码器需要多输入多输出 （MIMO ) 的信道估计。
3G信源和 16e信源分别通过 3G信道编码 /符号映射和 16e信道编码 /符 号映射。 然后两路发送信号分别进行符号级空时编码。 在本例中， 3G和 16e OFDMA分别采用空时格状编码和空时分组编码。 输出的四路信号再 分别经过 3G扩频调制和 16e OFDMA调制。 最后由置换矩阵为每个支路 信号选择一个发射天线。
在 16e发送支路，假设置换矩阵为 16e发送支路选择发射天线 1和 2。 空 时编码器输入成对符号 ( Si 5Si+i ) , 即在时刻 i, 符号 Si和 Si+1 分别从天 线 1和天线 2发射； 在时刻 i + 1 , 符号 （- Si+1* ) 和（Si* )分别从天线 1 和天线 2发射。 其中 （* ) 表示复共轭。 3G扩频发送支路同理。
接收机则正好相反， 由空间波束成形或选择单元为每个支路选择一 个接收天线。 然后， 两路信号分别经过 3G扩频解调和 16e OFDMA解调。 输出的 3G解扩信号或 OFDMA信号经符号级空时解码， 再分别经 3G或 16e信道解码 /符号解映射和水平分层空间复用解码。 最后得到 3G信号和 16e信号输出。相应， 16e OFDMA用户站如图 11所示， 图 11的 16e OFDMA 部分换为 3G即得到 3G用户站系统。
在 16e接收支路，假设空间波束成形或选择单元为 16e接收支路选择接 收天线 1和 2。 接收机按下式估计发送的信号， 获得 (本例中 η = 2, Ri = 2 ) 阶分集:
SAi = hi* Ri* + hi+i* x Ri+1* + hi+2* x Ri+2* + hi+3* x Ri+3*;
SA i+i = hi+1* x - x Ri+1* + hi+3* x Ri+2* - i+2* x Ri+3*; 其中， 符号 为接收天线 1在时刻 i接收到的信号； 符号 接收天 线 1时刻 i + 1接收到的信号； 符号 Ri+2 为接收天线 2在时刻 i接收到的信号； 符号 Ri+3为接收天线 2时刻 i + 1接收到的信号； 为发射天线 1到接收天线 1 的多径衰落信道的时域响应； hi+1 为发射天线 2到接收天线 1的多径衰落信 道的时域响应； hi+2 为发射天线 1到接收天线 2的多径衰落信道的时域响 应； hi+3 为发射天线 2到接收天线 2的多径衰落信道的时域响应。
3G扩频接收支路同理。 下面再以空频码为例， 以两个具体实施例对本发明进行说明。
第一个具体实施例如图 27所示， 具体包括：
基于双天线发射分集、单天线接收的简单空频码技术的 16d OFDM和 16e OFDMA双模共存系统， 如图 27所示。 对于每种模式， 在发射端有 2 根发射天线， 相距至少应能使发送信号在不同路径种传播的过程能够被 近似认为是相互独立的衰减过程， 在接收端有 1根接收天线， 这种方案接 收短的空频解码器需要多输入单输出 (MISO)的信道估计。
16d信源和 16e信源分别通过 16d信道编码 /符号映射和 16e信道编码 / 符号映射。 然后两路发送信号分别进行符号级简单空频编码。 输出的四 路信号再分别经过 16d OFDM调制和 16e OFDMA调制。最后由置换矩阵为 每个支路信号选择一个发射天线。
在 16d发送支路， 假设置换矩阵为 16d发送支路选择发射天线 1和 2。 空频编码器将成对符号（Si, Si+1 )进行编码， 即在子载波 i， 符号 Si和 Si+1 分别从天线 1和天线 2发射； 在子载波 i + 1 , 符号 (- Si+1* )和 (S^)分别从天 线 1和天线 2发射。 其中 (*)表示复共轭。 这样可保证欲发射符号具有正交 空频结构， 构成完全频域分集。 16e发送支路同理。
接收机则正好相反， 由空间波束成形或选择单元为每个支路选择一 个接收天线。然后 ,两路信号分别经过 16d OFDM解调和 16e OFDMA解调。 输出的 OFDM信号或 OFDMA信号经符号级筒单空频解码和水平分层空 间复用解码， 再分别经 16d或 16e信道解码 /符号解映射。 最后得到 16d信号 和 16e信号输出。
在 16d接收支路， 假设空间波束成形或选择单元为 16d接收支路选择 接收天线 1。 接收机按下式估计发送的信号：
SAi = h;* x Ri* + hi+i* x Ri+i*;
SA i+i = hi+i* x Ri* - hi* x Ri+1*;
其中， 符号 为接收天线 1在子载波 i接收到的信号； 符号 Ri+I为接收 天线 1子载波 i + 1接收到的信号； 为发射天线 1到接收天线 1的多径衰落 信道的时域响应； hi+1 为发射天线 2到接收天线 1的多径衰落信道的时域响 应。
16e接收支路同理。 第二个具体实施例如图 28所示， 具体包括：
基于双天线发射分集、双天线接收的简单空频码技术的 802.11 OFDM 和 802.16e OFDMA双模共存系统， 如图 28所示。 对于每种模式， 在发射 端有 2根发射天线， 在接收端有 2根接收天线， 这种方案接收短的空频解 码器需要多输入多输出 (MIMO)的信道估计。
802.11信源和 802.16e信源分别通过 802.11信道编码 /符号映射和 802.16e信道编码 /符号映射。 然后两路发送信号分别进行符号级空频编 码。在本例中， 802.11 OFDM和 802.16e OFDMA分别采用空频格状编码和 空频分组编码。 输出的四路信号再分别经过 802.11 OFDM调制和 802.16e OFDMA调制。 最后由置换矩阵为每个支路信号选择一个发射天线。
在 802.16e发送支路,假设置换矩阵为 802.16e发送支路选择发射天线 1 和 2。 空频编码器将成对符号 （Si, Si+1 )进行编码， 即在子载波 i, 符号 Si和 Si+1 分别从天线 1和天线 2发射； 在子载波 符号 (- Si+1* )和 (Si*) 分别从天线 1和天线 2发射。 其中（*)表示复共轭。 802.11发送支路同理。
接收机则正好相反， 由空间波束成形或选择单元为每个支路选择一 个接收天线。 然后， 两路信号分别经过 802.11 OFDM解调和 802.16e OFDMA解调。 输出的 802.11 OFDM信号或 802.16e OFDMA信号经符号级 空频解码和水平分层空间复用解码， 再分别经 802.11或 802.16e信道解码 / 符号解映射。 最后得到 802.11信号和 802.16e信号输出。
在 802.16e接收支路， 假设空间波束成形或选择单元为 802.16e接收支 路选择接收天线 1和 2。
接收机按下式估计发送的信号：
SAi = ¾* x Ri* + hi+1* x Ri+i* + hi+2* Ri+2* + hi+3* x Ri+3*
SA i+i = hi+i* x - Ri+i* + hi+3* x Ri+2* - hi+2* Ri+3* 其中， 符号 为接收天线 1在子载波 i接收到的信号； 符号 Ri+1为接收 天线 1子载波 i + 1接收到的信号； 符号 Ri+2 为接收天线 2在子载波 i接收到 的信号； 符号 Ri+3为接收天线 2在子载波 i + 1接收到的信号； hi 为发射天 线 1到接收天线 1的多径衰落信道的时域响应； hi+1 为发射天线 2到接收天 线 1的多径衰落信道的时域响应； hi+2 为发射天线 1到接收天线 2的多径衰 落信道的时域响应； hi+3 为发射天线 2到接收天线 2的多径衰落信道的时域 响应。
802.11接收支路同理。 下面再以空时频码为例对本发明进行说明， 相应的具体实施例如图 29和图 30所示， 具体包括：
基于四天线发射分集、单天线接收的简单空时频码技术的 16d OFDM 和 16e OFDMA双模共存系统， 如图 30所示。 对于每种模式， 在接收端有 4 根发射天线， 相距至少应能使发送信号在不同路径种传播的过程能够被 近似认为是相互独立的衰减过程， 在接收端有 1根接收天线， 这种方案接 收短的空时频解码器需要多输入单输出 (MISO)的信道估计。
16d信源和 16e信源分别通过 16d信道编码 /符号映射和 16e信道编码 / 符号映射。 然后两路发送信号分别进行符号级简单空时频编码。 输出的 四路信号再分别经过 16d OFDM调制和 16e OFDMA调制。最后由置换矩阵 为每个支路信号选择一个发射天线。
在 16e发送支路， 假设置换矩阵为 16e发送支路选择发射天线 1、 2、 3 和 4。 空时频编码器将成对符号（S1 ; S2, S3, S4 )按以下正交矩阵 A3进 行编码， 如图 16所示。
Figure imgf000023_0001
16e 4发射天线空时频编码器由空时分组编码单元和映射单元组成，
16e OFDMA调制器由 IFFT处理单元和串并转换单元组成。 空时分组编码 单元先将成对符号 （
Figure imgf000023_0002
按正交矩阵 A3的不同列码元按时间顺序 由不同的发射天线发送。 例如,正交矩阵 A3的第 1列码元（Sl50，0,S2 )按时 间顺序由发射天线 1发送； 正交矩阵 A3的第 2列码元（ -S^^AS!* )按时 间顺序由发射天线 2发送； 以此类推。 然后， 映射单元将空时分组编码单 元的输出进一步在频率域进行编码映射。 例如,空时分组编码单元的输出 ( Sl50,05S2 )经映射单元， （Sl50 )映射到 16e OFDMA调制器 1的子载波 1 , ( 0,S2 )映射到 16e OFDMA调制器 1的子载波 2, 以此类推。 空时分组编码 单元和映射单元共同完成空时频编码。 然后经 IFFT处理和串并转换后， 由相应的发射天线发送出去。
16d发送支路同理。
接收机则正好相反， 由空间波束成形或选择单元为每个支路选择一 个接收天线。然后，两路信号分别经过 16d OFDM解调和 16e OFDMA解调。 输出的 OFDM信号或 OFDMA信号经符号级简单空时频解码和水平分层 空间复用解码， 再分别经 16d或 16e信道解码 /符号解映射。 最后得到 16d 信号和 16e信号输出。
本发明的上述实施例中， 在发射机侧， 采用一组发射天线。 结合采 用空时或空频或空时频编码的方式对信号进行空时 /空频 /空时频编码， 使 得不同模式的同频信号可以在空间分层复用， 如同在原有频段上建立多 个互不干扰、 并行的子信道， 从而可避免不同模式或异种网络的每种基 站都要申请不同的频段， 在不增加带宽和天线发送功率的情况下， 成倍 地提高频谱利用率， 进而成倍地提高无线信道容量、 系统容量和数据通 信速率。
此外， 空时编码可以适用于其中不同模式的信号采用异种调制类型 的多模网络系统， 而空频编码和空时频编码一般适用于其中不同模式的 信号采用同种调制类型 （OFDM ) 的多模网络系统。
综上所述，本发明所述基站可同时同频或分时同频以 N种模式接入所 述用户站， 用户站亦可同时同频或分时同频以 N种模式接入所述基站， 异 种网络可以共存， 用户站可以软切换的方式在异种网絡间移动切换。 多 模或异模基站可以共址， 避免不同模式或异种网络的每种基站都要租用 土地、 建设机房。 并可以在不增加带宽和天线发送功率的情况下， 成倍 地提高频谱利用率， 进而成倍地提高无线信道容量、 系统容量和数据通 信速率。 因此， 本发明中， 空时 /空频 /空时频编码可以在不牺牲带宽的情 况下获得较高的编码增益， 进而提高了抗干扰和抗噪声的能力。
以上所述， 仅为本发明较佳的具体实施方式， 但本发明的保护范围 并不局限于此， 任何熟悉本技术领域的技术人员在本发明揭露的技术范 围内， 可轻易想到的变化或替换， 都应涵盖在本发明的保护范围之内。 因此， 本发明的保护范围应该以权利要求的保护范围为准。

Claims

权 利 要 求
1、 一种实现多模网络共存的多模发射机， 其特征在于， 包括： 一组编码单元， 分别用于对各个网络模式的发送信号进行空间复用 编码， 各网络模式均形成多条发送支路信号；
一组发射天线， 分别用于将各网络模式下的多条发送支路信号进行 发送处理。
2、 根据权利要求 1所述的实现多模网络共存的多模发射机， 其特征 在于， 所述编码单元包括：
空时 /空频 /空时频编码单元， 用于对各个网络模式的发送信号进行空 时 /空频 /空时频编码处理。
3、 根据权利要求 2所述的实现多模网络共存的多模发射机， 其特征 在于， 还包括：
一组信号发送处理单元， 分别用于对发送的信号进行信道编码、 符 号映射及调制处理。
4、 根据权利要求 3所述的实现多模网络共存的多模发射机， 其特征 在于， 所述的信号发送处理单元包括信道编码模块、 符号映射模块和调 制器； 且所述的空时 /空频 /空时频编码单元用于对经信道编码模块、 符号 映射模块或调制器处理前或处理后的信号进行编码处理。
5、根据权利要求 1、 2、 3或 4所述的实现多模网络共存的多模发射机， 其特征在于， 还包括：
置换矩阵单元， 与所述的一组发射天线连接， 用于对发送信号进行 同时或分时发送处理， 并根据处理结果将发送信号发送给各个发射天线。
6、 一种实现多模网络共存的多模接收机， 其特征在于， 包括： 一组接收天线， 用于接收各个网络模式的信号；
一组解码单元， 用于对接收的各个网络模式的信号进行解码， 形成 多条接收支路信号；
水平分层空间复用解码单元， 用于对所述多条接收信号统一进行水 平空间解复用。
7、 根据权利要求 6所述的实现多模网络共存的多模接收机， 其特征 在于， 所述解码单元包括：
空时 /空频 /空时频解码单元， 用于对各个网络模式的接收信号进行空 时 /空频 /空时频解码处理。
8、 根据权利要求 7所述的实现多模网络共存的多模接收机， 其特征 在于， 还包括：
一组信号接收处理单元， 分别用于对各个网络模式下的接收信号进 行处理。
9、 根据权利要求 8所述的实现多模网络共存的多模接收机， 其特征 在于， 所述的信号接收处理单元包括信道解码模块、 符号解映射模块和 解调器； 且所述的空时 /空频 /空时频解码单元对信道解码模块、 符号解映 射模块或解调器处理前或处理后的信号进行解码处理。
10、 根据权利要求 6、 7、 8或 9所述的实现多模网络共存的多模接收 机， 其特征在于， 还包括：
空间波束成形或选择单元， 与所述的一组接收天线连接， 用于对接 收信号进行同时或分时接收处理。
11、 一种实现多模网絡共存的系统， 其特征在于， 包括：
多模发射机， 用于将各个网络模式中的分别经过空间复用编码形成 的多条发送支路信号通过一组发射天线同时或分时进行发送；
多模接收机， 用于接收多模发射机发送的信号， 进行解码形成多条 接收支路信号后进行水平分层空间复用解码处理， 获得各网络模式下的 接收信号。
12、 根据权利要求 9所述的实现多模网络共存的系统， 其特征在于： 所述的多模发射机包括空时 /空频 /空时频编码单元， 用于对发送信号 进行空时 /空频 /空时频编码处理；
所述的多模接收机包括空时 /空频 /空时频解码单元， 用于对接收信号 进行空时 /空频 /空时频解码处理。
13、 根据权利要求 12所述的实现多模网络共存的系统， 其特征在于： 所述的多模接收机还包括水平分层空间复用解码单元， 用于对所述多条 接收信号统一进行水平空间解复用。
14、 根据权利要求 11、 12或 13所述的实现多模网络共存的系统， 其 特征在于， 还包括：
单模发射机， 将某一网络模式下的信号进行信道编码、 符号映射及 调制处理， 并通过发射天线发送；
单模接收机， 接收发射机发送来的信号， 进行解调、 符号解映射和 信道解码处理获得一种网络模式下的接收信号。
15、 根据权利要求 14所述的实现多模网络共存的系统， 其特征在于， 所述多模发射机和多模接收机设置在在系统中需要共址设置的各个模式 的基站中。
16、 根据权利要求 14所述的实现多模网络共存的系统， 其特征在于， 所述多模接收机设置在系统中需要同频接入同一用户站或基站中包括。
17、 根据权利要求 14所述的实现多模网络共存的系统， 其特征在于， 包括基站和用户站， 并且，
所述的基站和用户站采用多模发射机和多模接收机；
或者，
所述基站采用多模发射机和多模接收机， 所述用户站采用多模接收 机和单模发射机；
或者，
所述基站采用多模发射机和多模接收机， 所述用户站采用单模接收 机和单模发射机；
或者，
所述基站采用单模发射机和多模接收机， 所述用户站采用多模接收 机和单模发射机；
或者,
所述基站采用单模发射机和多模接收机， 所述用户站采用单模接收 机和单模发射机。
18、 根据权利要求 10、 11、 12、 13或 14所述的实现多模网络共存 的系统， 其特征在于， 所述多模接收机从接收到的各种不同模式的信号 中选择出一种或多种模式的信号作为接收信号。
19、 一种实现多模网络共存的方法， 其特征在于， 包括：
将各个网络模式中的分别经过空间复用编码形成的多条发送支路信 号通过一组发射天线同时或分时进行发送；
接收多个网络模式的信号后， 进行解码形成多条接收支路信号后进 行水平分层空间复用解码处理， 获得各网络模式下的接收信号。
20、 根据权利要求 19所述的实现多模网络共存的方法， 其特征在于， 所述形成多条发送支路信号的空间复用编码包括： 对发送信号进行空时 / 空频 /空时频编码处理； 所述形成多条接收支路信号的解码包括： 对接收 信号进行空时 /空频 /空时频解码处理。
21、 根据权利要求 20所述的实现多模网络共存的方法， 其特征在于， 还包括：
对多个网络模式的发送信号进行信道编码、 符号映射及调制处理； 且所述的空时 /空频 /空时频编码在信道编码、 符号映射或调制处理前或处 理后进行；
对多个网络模式的接收信号进行解调、 符号解映射和信道解码处理； 且所述的空时 /空频 /空时频解码在信道解码、 符号解映射或解调处理前或 处理后的进行。
22、 根据权利要求 19至 21任一项所述的实现多模网络共存的方法， 其特征在于， 还包括： 从接收到的各种不同模式的信号中选择出一种或 多种模式的信号作为接收信号。
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