TWI566562B - Hew communication station and method for communicating longer duration ofdm symbols using minimum bandwidth units having tone allocations - Google Patents

Description

High performance wireless local area network (HEW) communication station and method for transmitting longer delay orthogonal frequency division multiplexing (OFDM) symbols using a minimum bandwidth unit having a tone configuration Priority claim

The US corresponding application in this application claims the priority rights of the following US provisional patent applications: No. 61/906,059, filed on November 19, 2013, No. 61/973,376, filed on April 1, 2014, 2014 Application No. 61/976,951, filed on the 8th of the month, No. 61/986,256, filed on April 30, 2014, No. 61/986,250, filed on April 30, 2014, No. 61/ on May 12, 2014 991, 730, filed on Jun. 18, 2014, the disclosure of which is incorporated herein by reference.

Field of invention

Embodiments relate to wireless networks. Some embodiments relate to wireless local area networks (WLANs) and Wi-Fi networks including networks operating in accordance with the IEEE 802.11 family of standards. Some embodiments relate to the High Performance WLAN Research Group (HEW SG) (named DensiFi and is referred to as IEEE 802.11ax SG). Some embodiments relate to high performance wireless communication or high performance WLAN (HEW) communication.

Background of the invention

Wireless communication has evolved towards increasing data rates (eg, from IEEE 802.11a/g to IEEE 802.11n to IEEE 802.11ac). In high-density deployment scenarios, overall system performance can become more important than higher data rates. For example, in high density hotspots and cellular offload scenarios, many devices competing for wireless media may have low to medium data rate requirements (relative to the extremely high data rate of IEEE 802.11ac). The framework for the well-known and very old-fashioned IEEE 802.11 communications, including very high-throughput (VHT) communications, is less suitable for such high-density deployment scenarios. A recently formed research group for Wi-Fi evolution, known as IEEE 802.11 HEW SG (ie, IEEE 802.11ax), is addressing these high-density deployment scenarios.

One problem with HEW is to define an efficient communication structure that can reuse at least some of the 802.11ac hardware, such as block interleavers. Another problem with HEW is to define an efficient communication structure suitable for use with longer OFDM symbol delays.

Therefore, there is a general need for an apparatus and method for improving overall system performance in a wireless network, particularly for high density deployment scenarios. also There is a general need for devices and methods suitable for HEW communication. There is also a general need for an apparatus and method suitable for HEW communication that can communicate in accordance with an effective communication structure and that can reuse at least some of the conventional hardware. There is also a general need for an apparatus and method suitable for HEW communication that can communicate in accordance with an efficient communication structure for OFDM symbols using longer delays.

According to an embodiment of the present invention, a high performance WLAN (HEW) communication station (STA) is specifically proposed, which comprises a physical layer circuit system and a medium access control layer circuit system: according to an orthogonal frequency division multiple access ( OFDMA) techniques for passing longer delay orthogonal frequency division multiplexing (OFDM) symbols on channel resources, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data subcarriers; Configuring the minimum bandwidth units for transmitting the longer delay OFDM symbols according to one of a plurality of subcarrier configurations for one of a plurality of interleaver combinations, wherein the longer delay OFDM signals The symbol has a symbol delay of 2 or 4 times the delay of a standard OFDM symbol.

100‧‧‧HEW Network

102‧‧‧Master Station (STA)

104‧‧‧HEW platform/HEW device

106‧‧‧Old platform/old version

200‧‧‧ PHY layer circuit system

208‧‧‧Encoder

214‧‧‧block interleaver

216‧‧‧Cluster Mapper

300‧‧‧HEW device

301‧‧‧Antenna

302‧‧‧Physical Layer (PHY) circuitry

304‧‧‧Media Access Control Layer Circuit System (MAC)

306‧‧‧Other processing circuitry

308‧‧‧ memory

400‧‧‧Program

402, 404, 406‧‧‧ operations

1 illustrates a HEW network in accordance with some embodiments; FIG. 2 is a block diagram of a physical layer of a HEW communication station in accordance with some embodiments; FIG. 3 illustrates a HEW device in accordance with some embodiments; and FIG. 4 is used in accordance with some embodiments. A program that communicates using a minimum bandwidth unit.

Detailed description of the preferred embodiment

The description and drawings are to be considered as illustrative of the embodiments Other embodiments may incorporate structural changes, logic changes, electrical changes, process changes, and other changes. Portions and features of some embodiments may be included in or substituted for parts and features of other embodiments. The embodiments set forth in the claims are intended to cover all available equivalents of the claims.

Some embodiments disclosed herein provide systems and methods for tone configuration in a HEW network. In some embodiments, the master station can configure the tone to the HEW to provide a minimum orthogonal frequency division multiple access (OFDMA) bandwidth unit (ie, a minimum bandwidth unit). In some embodiments, the HEW communication station can be configured to deliver longer delay orthogonal frequency division multiplexing (OFDM) symbols on channel resources that include one or more minimum bandwidth units. Each of the minimum bandwidth units can have a predetermined bandwidth, and the minimum bandwidth units can be assembled according to one of a plurality of subcarrier (ie, tone) configurations for one of the plurality of interleaver combinations . In some embodiments, an optimal subcarrier configuration and interleaver size combination is provided for use by the OFDMA minimum bandwidth unit for communication using longer delay OFDM symbols. These embodiments are discussed in more detail below. Some embodiments disclosed herein are suitable for communication using longer delay OFDM symbols (eg, larger FFT sizes).

FIG. 1 illustrates a HEW network in accordance with some embodiments. The HEW network 100 can include a master station (STA) 102, a plurality of HEW stations 104 (HEW devices), and a plurality of legacy stations 106 (legacy devices). The master station 102 can be arranged to communicate with the HEW station 104 in accordance with one or more of the IEEE 802.11 standards. Communication with the old platform 106. According to some HEW embodiments, the master station 102 can be arranged to contend for wireless media (e.g., during a contention period) to receive the exclusive control duration of the media for a HEW control period (i.e., a transmission opportunity). TXOP)). The master station 102 can transmit master synchronization or control transmissions, for example, at the beginning of the HEW control period to specifically indicate which HEW stations 104 are scheduled for communication during the HEW control period. During the HEW control period, the scheduled HEW station 104 can communicate with the master station 102 in accordance with a non-contention based multiple access technique. This communication is different from conventional Wi-Fi communication in which the device communicates based on contention-based communication technology rather than non-contention-based multiple access technology. During the HEW control period, the master station 102 can communicate with the HEW station 104 (eg, using one or more HEW frames). The legacy station 106 can suppress communication during the HEW control period. In some embodiments, the master synchronous transmission may be referred to as a control and schedule transmission.

In some embodiments, the multiple access technology used during the HEW control period may be a scheduled OFDMA technique, but this is not a requirement. In some embodiments, the multiple access technology may be a Time Division Multiple Access (TDMA) technology or a Frequency Division Multiple Access (FDMA) technology that may be combined with OFDMA. In some embodiments, the multiple access technology may be a sub-space multiple access (SDMA) technology including multi-user (MU) multiple input multiple output (MIMO) (MU-MIMO) technology that may be combined with OFDMA. These multiple access techniques used during the HEW control period can be configured for uplink data communication or downlink data communication.

The master station 102 can also communicate with the legacy station 106 (outside the control period) in accordance with the legacy IEEE 802.11 communication technology. In some embodiments The master station 102 may also be configurable to communicate with the HEW station 104 outside of the HEW control period in accordance with the legacy IEEE 802.11 communication technology, but this is not a requirement.

In some embodiments, the HEW communication during the control period can be a bandwidth that can be configured to have one of 20 MHz, 40 MHz, or 80 MHz contiguous bandwidth or 80+80 MHz (160 MHz) non-contiguous bandwidth. In some embodiments, a 320 MHz channel width can be used. In some embodiments, a subchannel bandwidth of less than 20 MHz can also be used. In these embodiments, each channel or subchannel of the HEW communication can be configured to transmit a plurality of spatial streams. The HEW communication during the control period can be uplink communication or downlink communication.

According to an embodiment, an HEW station (e.g., master station 102 or HEW station 104) may be configured to pass longer delay orthogonal frequency division multiplexing (OFDM) symbols on channel resources in accordance with OFDMA techniques. The channel resources may include one or more minimum bandwidth units, and each minimum bandwidth unit may have a predetermined number of data subcarriers. Longer delay OFDM symbols may have a symbol delay that is 2 or 4 times the standard OFDM symbol delay (ie, symbol time (eg, T _symbol )). The minimum bandwidth unit may be assembled according to one of a plurality of subcarrier configurations for one of the plurality of interleaver combinations. These embodiments are discussed in more detail below. Some embodiments disclosed herein are applicable to IEEE 802.11ax and HEW networks operating with longer OFDM symbol delays (eg, twice (2 times) and four times (4 times) the standard symbol delay).

As discussed in more detail below, an HEW station can include physical layer (PHY) circuitry and media access control (MAC) layer circuitry. In some embodiments, the PHY circuitry can include a depth of one OFDM symbol Block interleaver. The block interleaver can be a block that can be configured to interleave encoded data according to any of a plurality of interleaver combinations. The interleaver combination can include the number of rows and the number of columns.

2 is a block diagram of a physical layer of a HEW communication station in accordance with some embodiments. The PHY layer circuitry 200 can be adapted for use as part of a physical layer of a HEW communication station, such as the master station 102 (FIG. 1) and/or the HEW communication station 104 (FIG. 1). As illustrated in FIG. 2, PHY layer circuitry 200 may include, in particular, one or more encoders 208, one or more block interleavers 214, and one or more cluster mappers 216. Each of the encoders 208 can be configured to encode input data prior to interleaving by the interleaver 214. Each of the cluster mappers 216 can be configured to map the interleaved data to a cluster (eg, a QAM cluster) after interleaving. Each interleaver 214 can be configured to interleave blocks of encoded data according to any of a plurality of interleaver combinations. In some embodiments, encoder 208 can be a binary convolutional code (BCC) encoder. An FFT can be performed on the clustered mapped symbols provided by the cluster mapper to generate a time domain signal for transmission.

According to an embodiment, encoder 208 and mapper 216 operate in accordance with one of a plurality of predetermined modulation and coding scheme (MCS) combinations for a particular subcarrier configuration (ie, tone configuration). . The plurality of predetermined MCS combinations for the subcarrier configuration may be limited to integers (Ncbps) of coded bits per OFDM symbol and integers (Ndbps) of data bits per OFDM symbol. In these embodiments, the number of coded bits per OFDM symbol (Ncbps) is an integer, and the number of data bits per OFDM symbol (Ndbps) is an integer. The predetermined MCS combination and subcarrier configuration that can be used may include BPSK, QPSK, 16-QAM, 64-QAM, and 256-QAM. The modulation order and the code rate of 1/2, 3/4, 2/3, and 5/6 are limited to Ncbps and Ndbps, both of which are integers. Non-integer Ndbps may cause a non-integer number of padding bits or a number of encoded bits that exceed the number of OFDM symbols, which may result in a minimum of one additional OFDM symbol consisting of only padding bits. The integer Ndbps guarantees that all data lengths work with the equation (20 to 32) of 11n "Number of OFDM Symbols" in the 802.11 2012 specification without additional padding. Thus, embodiments disclosed herein may be limited to certain MCS combinations and subcarrier configurations. In these embodiments, the interleaver hardware architecture is tied within the boundaries of the IEEE 802.11 interleaver, allowing legacy 802.11 hardware blocks to be reused for HEW.

In such embodiments, prior to interleaving, the communication station is configured to encode the input data based on the write rate, and after interleaving, the communication station can be configured to map the interleaved bit cluster based on the modulation level To the QAM cluster point. The code rate and modulation level may be based on one of a predetermined MCS combination for a particular subcarrier configuration. These embodiments are described in more detail below.

In some embodiments, each minimum bandwidth unit can be configurable for communication between one spatial stream and four bit streams. In such embodiments, SDMA or MIMO techniques may be used during the control period to deliver spatial streams.

Embodiments disclosed herein provide the number of subcarriers, the number of pilot subcarriers, and the size of the block interleaver for the condition of binary coded (BCC) code writing. In some embodiments, the structure of an OFDMA waveform for 802.11ax described in U.S. Provisional Patent Application Serial No. 61/976,951 It is suitable for use, but this is not required. Some embodiments disclosed herein describe a minimum bandwidth unit for an OFDMA waveform and describe the architecture of the subcarrier configuration. In some embodiments, the subcarrier configuration can be assembled to re-use IEEE 802.11ac hardware to establish a new OFDMA structure.

As outlined above, various embodiments disclosed herein provide for the design of a minimum OFDMA bandwidth unit suitable for an IEEE 802.11ax teamed network with longer symbol delays (eg, 11n/ac OFDM symbol delay) 2x, 4x) (eg, larger FFT size) operates. These embodiments provide the number of data subcarriers, the number of pilot subcarriers, and the size of the block interleaver for the status of BCC code writing. Possible configurations consistent with IEEE 802.11ac interleaving are disclosed herein. Some of the better configurations provide reduced add-ons and provide ease of implementation, especially when considering the reuse of the IEEE 802.11ac architecture.

Longer symbol delays can be specifically addressed for use in outdoor environments where a more efficient cycle first code (CP) can be used to overcome longer delay spreads. Other benefits may include reduced CP additions and looser timing timing accuracy than in an indoor environment.

A better combination for the block interleaver can be based on the channel model, MCS, and other parameters, and can be determined by system simulation. Since the intent of the embodiments disclosed herein is to define a subcarrier configuration, an exhaustive search within the boundaries is performed to achieve a reasonable subcarrier configuration.

The embodiments disclosed herein provide, to a large extent, the reuse of existing system parameters and system blocks. This situation is made less re-use and less expensive, and therefore less expensive, via reuse of existing system blocks and thus via hardware reuse. Accordingly, embodiments disclosed herein provide The currently defined interleaver structure (with extensions for narrower bandwidths), the current write rate (the ability to modify the rate), and the modulation type (with the ability to modify the modulation size) are reused.

In an OFDMA system, the total number of subcarriers used in the minimum bandwidth unit can be a system design parameter. From this total subcarrier count, the OFDMA system has subcarriers assigned to data (for data), pilots (usually used for time/frequency and channel tracking), protection (to conform to spectral masks), and at DC Subcarriers around DC (to simplify direct conversion (DC) receiver design). For example, in 20 MHz 802.11ac, the fixed subcarrier spacing is 312.5 kHz, and therefore, the total number of subcarriers is 64. Among these 64 subcarriers, 52 subcarriers are used for data, 1 subcarrier is used for DC (that is, null is given), 4 subcarriers are used for pilot, and the remaining 7 subcarriers are used. Protected (ie, given null values).

Embodiments disclosed herein provide subcarrier configurations based on a set of modulation types used in prior systems (i.e., BPSK, QPSK, 16-QAM, 64 QAM, and 256 QAM). The code rate (r) used in previous systems includes the following sets r = 1/2, 3/4, 2/3, and 5/6. This collection is not used for all modulation types in the previous system, but this collection does include all current rates used throughout the entire modulation set. To determine the effective subcarrier configuration, the same modulation and code assignments as those performed in previous systems (eg, IEEE 802.11a/.11n/.11ac) can be used. As outlined above, embodiments disclosed herein may utilize existing channel interleavers for use in previous 802.11 systems. The channel interleaver is defined in IEEE Standard 802.11ac-2013 section 22.3.10.8 "IEEE Information Technology Standards - Telecommunications and Intersystem Information Exchange - Area Networks and Metropolitan Area Networks - Part 11: Wireless LAN Media Access Control (MAC) and Physical Layer (PHY) Specifications, Amendment 4: Enhancements to the extremely high throughput of operating in bands below 6 GHz (IEEE Standard for Information Technology - Telecommunications and information exchange between systems - Local and metropolitan Area networks-Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications, Amendment 4: Enhancements for Very High Throughput for Operation in Bands below 6 GHz). In the text, the interleaver parameters are outlined in "Number of Rows and columns in the interleaver" in Table 22-17. This table is provided here for the sake of integrity for 1 to 4 spatial streams.

In IEEE 802.11n, the introduction of a 40 MHz bandwidth channel reuses the existing interleaver algorithm, where modifications to the matrix size are defined to write and read data. In IEEE 802.11ac, the same interleaver algorithm is utilized with the introduction of an 80 MHz bandwidth channel. These parameters define the number of coded symbols stored in the interleaver. Some embodiments disclosed herein may also reuse existing interleaver algorithms where new values are used to define N _COL and N _ROW for the smallest bandwidth unit. The N _ROT operation defines the rotation of the value when more than one spatial stream is present, but does not define the interleaver size and therefore will not affect the subcarrier configuration.

As can be seen in the above table, N _ROW is a constant multiple of the number of coded bits per subcarrier per stream. Therefore, the interleaver entity size is a function of the MCS. Embodiments disclosed herein may define a constant (y) used to calculate N _ROW .

In the case of using the above constraints, a set of subcarrier configurations can be achieved. As mentioned above, some of these embodiments are applicable to longer symbol delays for minimum bandwidth units, which allows up to four users to work within a 20 MHz channel bandwidth. Such embodiments can be extended to more than four users by dividing the configuration evenly into smaller configurations. For example, if the multiplex of eight users is concerned, the pitch counts found for the situation of the four users can be evenly divided among the two users in each configuration to provide for four uses. The tone count is 2 times, which assumes that the tone count can be divided by two. However, if the pitch count cannot be divisible by 2, but the pitch count can be divided by 3, then 3 times the multiplex of four users will be possible.

As mentioned above in 20 MHz 802.11ac, the fixed (i.e., standard)* subcarrier spacing is 312.5 kHz, and therefore, the total number of subcarriers is 64. Of these 64 subcarriers, 52 subcarriers are used for data, 1 subcarrier is used for DC (assumed to be null), 4 subcarriers are used for pilot, and the remaining 7 subcarriers are used. For protection (presumed to give null values). According to an embodiment, for 2x and 4x symbol delays, the FFT sizes may be 128 and 256, respectively. Embodiments disclosed herein may provide 24 to 32 subcarriers for each of four users for data subcarriers, which will then be allowed for 4 users for a 128 point FFT, respectively. To zero null subcarriers; and embodiments disclosed herein may provide 48 to 64 subcarriers for each of four users for data subcarriers, which will then be followed by a 256 point FFT Allow 16 to 0 null subcarriers for 4 users, respectively. To determine if a fit is suitable for use, an equation set can be used based on the following set of variables defined below:

Assuming all modulations can be 3/4 and 5/6 of the code rate as supported by IEEE 802.11ac including 64QAM and 256QAM (introduced in 802.11ac), the appropriate for 256-point FFT is allowed. The configuration is shown in Table I below and may include:

Table I shows three possibilities for the number of tone tones: 48, 54 and 60, which will leave a total of 64, 40 and 16 additional subcarriers within 20 MHz. These additional subcarriers can be used for pilot tones per subchannel, null at DC, and null subcarriers used as guard bands, for example, for a total of 4 x (54 + 3) + 3 + 13 + 12 = 256 subcarriers. In the 20 MHz channel, 54 data subcarriers and 3 pilot tones can be assigned to each of the four users plus three null values at the DC and on the left side protection. 13 null values and 12 null values on the right side of the protection. This example configuration is within the current interleaver and supports all MCSs that are caused by the use of several interleaver sizes to be selected. Among the choices for the size of the interleaver, a size closer to the square shape may be preferred (for example, N _COL = 6 and N _ROW = 9), but other interleaver sizes are also suitable.

In such embodiments, the master station 102 can be configured to process the longer delay OFDM symbols using a Fast Fourier Transform (FFT). In order to process a longer delay OFDM symbol using a 256-point FFT without code rate exclusion, a predetermined number of data subcarriers for the minimum bandwidth unit may be limited to one of 48, 54 and 60 data subcarriers. By. The interleaver combinations of these embodiments are shown in Table I.

The appropriate configuration for the 128-point FFT is shown in Table II below:

In these embodiments, in order to process longer delay OFDM symbols using a 128-point FFT without code rate exclusion, the number of data subcarriers for the smallest bandwidth unit may be limited to 28 and 30 data subcarriers. One of them. The interleaver combinations used in these embodiments are shown in Table II.

A suitable configuration for a 256-point FFT without using 256 QAM to support a write rate of 5/6 is shown in Table III below (eg, for 802.11ac for 20 MHz exclusion):

In such embodiments, in order to process longer delay OFDM symbols with a 256 point FFT with 5/6 code rate exclusion for 256-QAM, the number of data subcarriers for the smallest bandwidth unit may be Limited to one of 48, 50, 54, 52, 54, 56, 60 and 62 data subcarriers. The interleaver combinations used in these embodiments are shown in Table III.

A suitable configuration for a 128-point FFT without using 256 QAM to support a write rate of 5/6 is shown in Table IV below (eg, for 802.11ac for 20 MHz exclusion):

In such embodiments, in order to process a longer delay OFDM symbol with a 128 point FFT with 5/6 code rate exclusion for 256-QAM, the number of data subcarriers for the minimum bandwidth unit may be Limited to one of 24, 26, 28 and 30 data subcarriers. The interleaver combinations used in these embodiments are shown in Table IV.

In some embodiments, the master station 102 can be configured to communicate in parallel using up to four of the minimum bandwidth units on a 20 MHz or 40 MHz channel during a control period in accordance with OFDMA techniques. In such embodiments, when four minimum bandwidth units are used for communication over a single channel bandwidth, the master station 102 can communicate in parallel with up to four HEW stations 104 during the control period in accordance with OFDMA techniques. In such embodiments, when 2 times longer symbol delay is used, for example, in a 20 MHz channel bandwidth, the subcarrier spacing can be reduced by a factor of two (eg, one and a half of 312.5 KHz), when 4 times When the longer symbol delay is used in the 20MHz channel bandwidth, the subcarrier spacing can be reduced by a factor of four. In such embodiments, the subcarrier configuration with more guard subcarriers can be used for tighter subcarrier spacing. In some embodiments, the station 102 can be configured to communicate in parallel using up to four of the minimum bandwidth units of each of the 20 MHz portions of the 40 MHz channel, the 80 MHz channel, and the 160 MHz channel.

In some embodiments, for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, one instance of the subcarrier configuration includes a total of 256 subcarriers, including: for use at 20 MHz or 54 data subcarriers and 3 pilot subcarriers for each of the four minimum bandwidth units communicated in any of the 40 MHz channels, 2 to 4 null subcarriers at the DC, and at each 12 to 13 guard subcarriers at the edge of the band. For this example subcarrier configuration, the interleaver combinations shown in Table I may be suitable and support all current MCS combinations (i.e., without any write rate limiting).

In some embodiments, for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, an instance of a subcarrier configuration comprising a total of 256 subcarriers may be for a total of 256 subcarriers (ie, 4 ×(54+3)+3+12+13=256) includes 54 data subcarriers and 3 pilot pairs for each of the four minimum bandwidth units used for communication within the 20MHz or 40MHz channel bandwidth The carrier, 3 null subcarriers at the DC, 12 guard subcarriers at one band edge, and 13 guard subcarriers at the edge of the other band (eg, left and right). For this example subcarrier configuration, the interleaver combinations shown in Table I may be suitable and support all current MCS combinations (i.e., without any write rate limiting). Other subcarrier configurations may also be suitable for use.

In some embodiments, block interleaver 214 can have a depth of one OFDM symbol and can be a block that can be configured to interleave encoded data. The interleaver combination may include the number of rows (NCol) and the number of columns (Nrow), and the number of columns may be based on the number of coded bits per subcarrier per carrier (N _BPSCS ).

In some embodiments, for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, the instance interleaver group has 9 rows and the number is equal to the number of coded bits per single subcarrier. _(N BPSCS) the column three times (nrow) (i.e., 9 × 3 interleaver ligand group). In these embodiments, the number of subcarriers (Nsd) multipliers (1-BPSK, 2-QPSK, etc.) is the number of coded bits per symbol. The number of coded bits per single carrier can be calculated by multiplying by the number of streams (N _ROW * N _COL ) that are then set to the interleaver size, where N _ROW is y*N _BPSCS .

In some embodiments, longer delayed OFDM symbols may be selected for larger delay extended environments (eg, outdoor), and standard delayed OFDM symbols may be selected for use in smaller delay extended environments (eg, indoors). In such embodiments, a more efficient cyclic first code (CP) can be used to overcome large delay spreads, and other benefits such as reduced CP additions and loose clock timing accuracy can be provided. The standard delayed OFDM symbol may have a symbol delay ranging from 3.6 microseconds (us) including a 400 nanosecond (ns) short guard interval (eg, for a 40 MHz channel) to 4 us including a 800 ns guard interval (eg, for a 20 MHz channel). The longer delay OFDM symbol may have a symbol delay that is one of 2 or 4 times the delay of the standard delayed OFDM symbol.

FIG. 3 illustrates a HEW device in accordance with some embodiments. The HEW device 300 can be a HEW compatible device that can be arranged to communicate with one or more other HEW devices, such as an HEW station and/or a master station, and with legacy devices. The HEW device 300 can be adapted to operate as a master station or an HEW station. According to an embodiment, HEW device 300 may include, in particular, physical layer (PHY) circuitry 302 and media access control layer circuitry (MAC) 304. PHY 302 and MAC 304 may be HEW compatible layers and may also be compatible with one or more legacy IEEE 802.11 standards. PHY 302 can be arranged to transmit HEW frame. HEW device 300 may also include other processing circuitry 306 and memory 308 that are assembled to perform the various operations described herein.

According to some embodiments, the MAC 304 may be arranged to contend for the wireless medium during the contention period to receive the control duration HEW control period of the medium and to group the HEW frames. PHY 302 can be arranged to transmit HEW frames as discussed above. The PHY 302 can also be arranged to receive HEW frames from the HEW station. The MAC 304 may also be arranged to perform transmission and reception operations via the PHY 302. PHY 302 may include circuitry for modulation/demodulation, upconversion, and/or down conversion, filtering, amplification, and the like. In some embodiments, processing circuitry 306 can include one or more processors. In some embodiments, two or more antennas may be coupled to physical layer circuitry arranged to transmit and receive signals, including transmissions of HEW frames. Memory 308 can store information for assembling processing circuitry 306 to perform operations for assembling and transmitting HEW frames and performing various operations described herein.

In some embodiments, HEW device 300 can be configured to communicate via a multi-carrier communication channel using OFDM communication signals. In some embodiments, HEW device 300 can be configured to conform to a particular communication standard (such as the Institute of Electrical and Electronics Engineers (IEEE) standards including the IEEE 802.11-2012, 802.11n-2009, and/or 802.11ac-2013 standards and/or Or including the proposed specification for the WLAN of the proposed HEW standard), but the scope of the invention is not limited in this respect, as it may also be adapted to be transmitted and/or according to other technologies and standards. Receive communications. In some other embodiments, HEW device 300 can be assembled to receive usage such as the following Signals transmitted by one or more other modulation techniques: spread spectrum modulation (eg, direct sequence code division multiple access (DS-CDMA) and/or frequency hopping code division multiple access (FH-CDMA)), points Time multiplex (TDM) modulation, and/or frequency division multiplexing (FDM) modulation, but the scope of the embodiments is not limited in this respect.

In some embodiments, the HEW device 300 can be part of a portable wireless communication device, such as a personal digital assistant (PDA), a wireless communication capable laptop or laptop, a web tablet, a wireless telephone, or Smart phones, wireless headsets, pagers, instant messaging devices, digital cameras, access points, televisions, medical devices (eg, heart rate monitors, blood pressure monitors, etc.), or wirelessly receive and/or transmit information Other devices. In some embodiments, HEW device 300 can include one or more of the following: a keyboard, a display, a non-electric memory cartridge, multiple antennas, a graphics processor, an application processor, a speaker, and other actions. Device component. The display can be an LCD screen including a touch screen.

The antenna 301 of the HEW device 300 can include one or more unidirectional or omnidirectional antennas including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other suitable for transmitting RF signals. Type of antenna. In some multiple input multiple output (MIMO) embodiments, antenna 301 can be effectively separated to take advantage of the spatial diversity and different channel characteristics that can be induced between each of the antennas and the antenna of the transmission station.

Although the HEW device 300 is illustrated as having a number of separate functional elements, one or more of the functional elements can be combined and can be a software-associated component (such as a processing component including a digital signal processor (DSP)) And/or a combination of other hardware components. For example, some components can Includes one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), special application integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and various hard functions for performing at least the functions described herein A combination of physical and logical circuitry. In some embodiments, the functional elements of HEW device 300 may refer to operating one or more processing programs on one or more processing elements.

Embodiments can be practiced in one or a combination of hardware, firmware, and software. Embodiments can also be implemented as instructions stored on a computer readable storage device, which can be read and executed by at least one processor to perform the operations described herein. The computer readable storage device can include any non-transitory mechanism for storing information in a form readable by a machine (eg, a computer). For example, computer readable storage devices may include read only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be associated with instructions stored on a computer readable storage device.

4 is a process for transmitting a longer delayed OFDM symbol using a minimum bandwidth unit, in accordance with some embodiments. Program 400 may be performed by a HEW device, such as HEW station 104 or HEW master device or station 102.

Operation 402 includes assembling a block interleaver to interleave blocks of encoded input data according to one of a plurality of interleaver combinations determined for a subcarrier configuration for a minimum bandwidth unit of a longer delay OFDM symbol.

Operation 404 includes processing the symbols using a 128-point FFT or a 256-point FFT to generate a time domain OFDMA waveform. For processing longer-delay OFDM symbols with a 256-point FFT without code rate exclusion, for minimum The predetermined number of data subcarriers of the bandwidth unit may be limited to one of 48, 54 and 60 data subcarriers. In order to process a longer delay OFDM symbol with a 128 point FFT without code rate exclusion, the number of data subcarriers for the smallest bandwidth unit may be limited to one of 28 and 30 data subcarriers. In order to process a longer delay OFDM symbol with a 256-point FFT with 5/6 code rate exclusion for 256-QAM, the number of data subcarriers for the minimum bandwidth unit can be limited to 48, 50, One of 54, 52, 54, 56, 60, and 62 data subcarriers. In order to process a longer delay OFDM symbol with a 128-point FFT with 5/6 code rate exclusion for 256-QAM, the number of data subcarriers for the minimum bandwidth unit can be limited to 24, 26, One of 28 and 30 data subcarriers

Operation 406 includes transmitting a longer delay OFDM symbol (in the form of a time domain OFDMA waveform) over channel resources comprising one or more minimum bandwidth units in accordance with a non-contention based communication technique. In some embodiments, longer delay OFDM symbols may be delivered during a control period (eg, TXOP) according to MU-MIMO techniques.

In an example, a high performance WLAN (HEW) communication station (STA) including a physical layer circuitry and a medium access control layer circuitry is configured to: according to an orthogonal frequency division multiple access (OFDMA) technique Transmitting a longer delay orthogonal frequency division multiplexing (OFDM) symbol on a channel resource, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data subcarriers; One of a plurality of subcarrier configurations of one of the interleaver combinations to match the minimum bandwidth Units are used to pass the longer delay OFDM symbols. The longer delay OFDM symbols have a symbol delay of 2 or 4 times the delay of a standard OFDM symbol.

In another example, the station is configured to process the longer delay OFDM symbols using a Fast Fourier Transform (FFT). In order to process the longer delay OFDM symbols using a 256-point FFT without code rate exclusion, the predetermined number of data subcarriers for the minimum bandwidth unit are 48, 54 or 60 data. Subcarrier. In order to process the longer delay OFDM symbols with a 128-point FFT without code rate exclusion, the number of data subcarriers for the minimum bandwidth unit is 28 or 30 data subcarriers. In order to process the longer delay OFDM symbols with the 256-point FFT with 5/6 one code rate exclusion for 256-QAM, the number of data subcarriers for the minimum bandwidth unit is 48. , 50, 54, 52, 54, 56, 60 or 62 data subcarriers. In order to process the longer delay OFDM symbols with the one-point write rate of 5/6 for 256-QAM, the number of data subcarriers for the minimum bandwidth unit is 24 , 26, 28 or 30 data subcarriers.

In another example, the station is further configured to communicate in parallel using up to four of the minimum bandwidth units on a 20 MHz or 40 MHz channel during a control period in accordance with the OFDMA technique.

In another example, for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, the subcarrier configuration includes a total of 256 subcarriers, including: for use at 20 MHz or 40 MHz 54 data subcarriers and 3 pilot subcarriers for each of the four minimum bandwidth units communicated in any channel, 2 to 4 null subcarriers at the DC, and in each frequency band 12 to 13 guard subcarriers at the edge.

In another example, the PHY circuitry includes a block interleaver having a depth of one of the OFDM symbols. The block interleaver can be a block that can be configured to interleave encoded data, and the interleaver combinations can include the number of rows and the number of columns, the number of which is based on each subcarrier per stream The number of one of the coded bits.

In another example, for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, the interleaver combination has 9 rows, and a number equal to the coded bits per single subcarrier. One of the three times the number of columns.

In another example, the communication station further includes: an encoder configured to encode the input data prior to interleaving according to one of a plurality of write code rates; and a cluster mapper for The encoded data is mapped to a QAM cluster after interleaving. The encoder and the mapper operate in accordance with one of a plurality of predetermined modulation and write code scheme (MCS) combinations for the subcarrier configuration. The plurality of predetermined MCS combinations for the subcarrier configuration are limited to one integer (Ncbps) of coded bits per OFDM symbol and one integer (Ndbps) of data bits per OFDM symbol.

In another example, the longer delay OFDM symbols are selected for a larger delay spread environment and the standard delayed OFDM symbols are selected for a smaller delay spread environment.

In another example, the standard delayed OFDM symbols have a van Surrounded by a symbol delay of 3.6 microseconds (us) including a 400 nanosecond (ns) short guard interval to 4 us including an 800 ns guard interval, and the longer delay OFDM symbols have the same standard delay OFDM symbol A symbol delay of one of 2 or 4 times the delay.

In another example, the communication station further includes one or more processors and memory, and the physical layer circuitry includes a transceiver.

In another example, the communication station further includes two antennas coupled to the transceiver.

In another example, a method performed by a high performance WLAN (HEW) communication station (STA) includes transmitting a longer delay orthogonal segment on a channel resource according to an orthogonal frequency division multiple access (OFDMA) technique Frequency multiplexed (OFDM) symbols, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data subcarriers; and according to one of a plurality of interleaver combinations One of the subcarrier configurations to assemble the minimum bandwidth units for communicating the longer delay OFDM symbols. The longer delay OFDM symbols have a symbol delay of 2 or 4 times the delay of a standard OFDM symbol.

In another example, the method further includes processing the longer delay OFDM symbols using a fast Fourier transform (FFT). In order to process the longer delay OFDM symbols using a 256-point FFT without code rate exclusion, the predetermined number of data subcarriers for the minimum bandwidth unit are 48, 54 or 60 data. Subcarrier. In order to process the longer delay OFDM symbols using a 128-point FFT without code rate exclusion, the number of data subcarriers for the minimum bandwidth unit is There are 28 or 30 data subcarriers.

In another example, to process the longer delay OFDM symbols using the 256 point FFT with 5/6 one code rate exclusion for 256-QAM, the data for the minimum bandwidth unit The number of subcarriers is 48, 50, 54, 52, 54, 56, 60, or 62 data subcarriers, and is excluded in order to have a write rate of 5/6 for 256-QAM. The 128-point FFT is used to process the longer-delay OFDM symbols, and the number of data subcarriers used for the minimum bandwidth unit is 24, 26, 28, or 30 data subcarriers.

In another example, the method includes selecting the longer delay OFDM symbols for a larger delay spread environment, and selecting the standard delayed OFDM symbols for a smaller delay spread environment.

In another example, a non-transitory computer readable storage medium stores instructions for execution by one or more processors to perform operations to assemble a high performance WLAN (HEW) communication station (STA) to: An orthogonal frequency division multiple access (OFDMA) technique for transmitting longer delay orthogonal frequency division multiplexing (OFDM) symbols on channel resources, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit Having a predetermined number of data subcarriers; and assembling the minimum bandwidth units for delivering the longer delay OFDM according to one of a plurality of subcarrier configurations for one of the plurality of interleaver combinations symbol. The longer delay OFDM symbols have a symbol delay of 2 or 4 times the delay of a standard OFDM symbol.

The Abstract of the Invention is provided to comply with the requirements of the 37 C.F.R. section of the abstract of the invention that will allow the reader to ascertain the nature and essentials of the technical disclosure. 1.72(b). It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claim. The following claims are hereby incorporated into the embodiments, each of which is a separate embodiment in its entirety.

400‧‧‧Program

402, 404, 406‧‧‧ operations

Claims (20)

A high-performance WLAN (HEW) communication station (STA) comprising a physical layer circuit system and a medium access control layer circuit system for transmitting a long delay on a channel resource according to an orthogonal frequency division multiple access (OFDMA) technique Time orthogonal frequency division multiplexing (OFDM) symbols, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data subcarriers; and being used in a plurality of interleaver combinations One of a plurality of subcarrier configurations of one of the plurality of subcarrier configurations for communicating the longer delay OFDM symbols, wherein the longer delay OFDM symbols have a delay of 2 as a standard delayed OFDM symbol Double or 4 times the symbol delay. A communication station as claimed in claim 1, wherein the communication station is configured to process the longer delay OFDM symbols using a Fast Fourier Transform (FFT), wherein the processing is performed using a 256-point FFT for no code rate exclusion. The longer delay OFDM symbols, the predetermined number of data subcarriers for the minimum bandwidth unit are 48, 54 or 60 data subcarriers, and wherein one is used in order to eliminate the code rate without A 128-point FFT is used to process the longer delay OFDM symbols, and the number of data subcarriers used for the minimum bandwidth unit is 28 or 30 data subcarriers. The communication station of claim 2, wherein the 256-point FFT is used in order to eliminate the code rate of one of 5/6 for 256-QAM. For the longer delay OFDM symbols, the number of data subcarriers used for the minimum bandwidth unit is 48, 50, 54, 52, 54, 56, 60 or 62 data subcarriers. And wherein in order to process the longer delay OFDM symbols using the 128-point FFT with 5/6 one code rate exclusion for 256-QAM, the number of data subcarriers for the minimum bandwidth unit is There are 24, 26, 28 or 30 data subcarriers. The communication station of claim 3, wherein the communication station is further configured to communicate in parallel using up to four of the minimum bandwidth units on a 20 MHz or 40 MHz channel during a control period in accordance with the OFDMA technique. The communication station of claim 4, wherein for a minimum bandwidth unit having 54 data subcarriers for 256 point FFT processing, the subcarrier configuration comprises a total of 256 subcarriers, including: for use at 20 MHz or 40 MHz 54 data subcarriers and 3 pilot subcarriers of each of the four minimum bandwidth units communicated in any one of the channels, 2 to 4 null subcarriers at the DC, and at each 12 to 13 guard subcarriers at the edge of the band. The communication station of claim 4, wherein the physical layer circuitry comprises a block interleaver having a depth of one OFDM symbol, the block interleaver being a block that can be configured to interleave encoded data, and Wherein the interleaver combinations include the number of rows and the number of columns, the number of columns being based on one of the number of coded bits per subcarrier per stream Head. A communication station as claimed in claim 6, wherein for a minimum bandwidth unit having 54 data subcarriers for 256-point FFT processing, the interleaver combination has 9 rows, and a number equal to the writing of each single subcarrier A column that is 3 times the number of code bits. The communication station of claim 6, wherein the communication station further comprises: an encoder for encoding the input data prior to interleaving according to one of the plurality of write rates; and a cluster mapper for The interleaving then maps the encoded data to a QAM cluster, wherein the encoder and the mapper operate according to one of a plurality of predetermined modulation and write code scheme (MCS) combinations for the subcarrier configuration, The plurality of predetermined MCS combinations for the subcarrier configuration are limited to one integer (Ncbps) of coded bits per OFDM symbol and one integer (Ndbps) of data bits per OFDM symbol. A communication station as claimed in claim 1, wherein the longer delay OFDM symbols are selected for a larger delay spread environment, and wherein the standard delayed OFDM symbols are selected for use in a smaller delay spread environment. The communication station of claim 9, wherein the standard delayed OFDM symbols have a symbol delay ranging from 3.6 microseconds (us) of a 400 nanosecond (ns) short guard interval to 4 us including an 800 ns guard interval, and Where the longer delay OFDM symbols have such standard delays A symbol delay of one of 2 or 4 times the delay of the OFDM symbol. The communication station of claim 1, further comprising one or more processors and memory, and wherein the physical layer circuitry comprises a transceiver. The communication station of claim 11, further comprising two antennas coupled to the transceiver. A method performed by a high performance WLAN (HEW) communication station (STA), the method comprising: transmitting a longer delay orthogonal frequency division multiplexing on a channel resource according to an orthogonal frequency division multiple access (OFDMA) technique (OFDM) symbols, the equal channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data subcarriers; and a plurality of subcarriers according to one of a plurality of interleaver combinations One of the configurations to assemble the minimum bandwidth units for communicating the longer delay OFDM symbols, wherein the longer delay OFDM symbols have a symbol delay of 2 or 4 times the delay of the standard delayed OFDM symbol . The method of claim 13, further comprising processing the longer delay OFDM symbols using a fast Fourier transform (FFT), wherein the longer delay is processed using a 256-point FFT in the absence of write rate exclusion. OFDM symbol, the predetermined number of data subcarriers for the minimum bandwidth unit being 48, 54 or 60 data subcarriers, and In order to process the longer delay OFDM symbols by using a 128-point FFT without the erasure of the code rate, the number of data subcarriers used for the minimum bandwidth unit is 28 or 30 data subcarriers. The method of claim 14, wherein the longer-latency OFDM symbols are processed for use in the minimum bandwidth unit in order to process the 256-point FFT with a 5/6 write rate penalty exclusion for 256-QAM The number of subcarriers of the data is 48, 50, 54, 52, 54, 56, 60 or 62 data subcarriers, and wherein in order to write in one of 5/6 for 256-QAM The 128-point FFT is used to process the longer-delay OFDM symbols in the case of code rate exclusion, and the number of data subcarriers used for the minimum bandwidth unit is 24, 26, 28, or 30 data subcarriers. The method of claim 13, further comprising: selecting the longer delay OFDM symbols for use in a larger delay spread environment; and selecting the standard delayed OFDM symbols for use in a smaller delay spread environment. A non-transitory computer readable storage medium storing instructions for execution by one or more processors to perform operations to assemble a high performance WLAN (HEW) communication station (STA) to: according to an orthogonal frequency division Multiple Access (OFDMA) technology to pass longer delay orthogonal frequency division multiplexing (OFDM) symbols on channel resources, the channel resources comprising one or more minimum bandwidth units, each minimum bandwidth unit having a predetermined number of data Subcarrier; Configuring the minimum bandwidth units for transmitting the longer delay OFDM symbols according to one of a plurality of subcarrier configurations for one of a plurality of interleaver combinations, wherein the longer delay OFDM signals The symbol has a symbol delay of 2 or 4 times the delay of the standard delayed OFDM symbol. The non-transitory computer readable storage medium of claim 17, wherein the longer delay OFDM symbols are processed using a Fast Fourier Transform (FFT), wherein a 256-point FFT is used in order to eliminate the code rate without erasure. Processing the longer delay OFDM symbols, the predetermined number of data subcarriers for the minimum bandwidth unit being 48, 54 or 60 data subcarriers, and wherein in the case of no code rate exclusion The 128-point FFT is used to process the longer delay OFDM symbols, and the number of data subcarriers used for the minimum bandwidth unit is 28 or 30 data subcarriers. The non-transitory computer readable storage medium of claim 18, wherein the longer delay OFDM symbols are processed for use in the case of having a 5/6 one code rate exclusion for 256-QAM, The number of data subcarriers used for the minimum bandwidth unit is 48, 50, 54, 52, 54, 56, 60 or 62 data subcarriers, and wherein there is for 256-QAM The 128-point FFT is used to process the longer-delay OFDM symbols when the 5/6 code rate is excluded. The number of data subcarriers used for the minimum bandwidth unit is 24, 26, and 28 Or 30 data subcarriers. The non-transitory computer readable storage medium of claim 17, wherein the longer delay OFDM symbols are selected for a larger delay spread environment, and the standard delayed OFDM symbols are selected for use in a smaller delay extended environment.