Communication device and communication method

Abstract

To achieve flexible frequency scheduling while suppressing increase in overhead for notifying a user of control signaling.SOLUTION: A communication device includes an antenna and a control circuit. The antenna receives an uplink single-user partial-band transmission packet containing an HE-SIG-B and a data field from a transmitting-side communication device. The HE-SIG-B includes RU allocation information indicating one of a plurality of RU allocations and a plurality of user fields. One of the plurality of RU allocations indicates a plurality of RUs each corresponding to a plurality of user fields. One RU of the plurality of RUs is allocated to the communication device, other RUs of the plurality of RUs are unallocated RUs, and a dummy AID is set in the user fields corresponding to the unallocated RUs. The HE-SIG-B is transmitted in a 20 MHz bandwidth, and the data field is transmitted with one RU to which 106 tones less than 20 MHz are allocated. The control circuit decodes the received uplink single-user partial-band transmission packet.SELECTED DRAWING: Figure 13

Description

[Technical field]

[0001] FIELD The present disclosure relates generally to wireless communications, and more particularly to a communication apparatus and method for receiving control signaling in a wireless communication system. [Background technology]

[0002] The IEEE (Institute of Electrical and Electronics Engineers) 802.11 working group is developing the 802.11ax HE (High Efficiency) WLAN (Wireless Local Area Network) air interface to enable users to achieve a very large increase in real-world throughput in high-density scenarios. OFDMA (Orthogonal Frequency Division Multiple Access) multi-user transmission is envisioned as one of the most important features of 802.11ax. OFDMA is a multiple access scheme that performs multiple operations of data streams to and from multiple users over the time and frequency resources of an OFDM system.

[0003] Research is being conducted into frequency scheduling for OFDMA multi-user transmission in 802.11ax. According to frequency scheduling, a wireless communication access point device (hereinafter simply referred to as "access point" or "AP") adaptively assigns subcarriers to multiple wireless communication station devices (hereinafter simply referred to as "terminal stations" or "STAs") based on the reception quality of the STA's frequency band. This makes it possible to obtain the maximum multi-user diversity effect and perform communication very efficiently.

[0004] Frequency scheduling is generally performed based on resource units (RUs). An RU includes multiple consecutive subcarriers. An RU is assigned by an AP to each of multiple STAs with which the AP communicates. The resource allocation result of frequency scheduling performed by an AP should be notified to the STAs as resource allocation information. In addition, the AP should also notify other control signaling, such as common control information and user-specific allocation information, to the STAs. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE802.11-15 / 0132r9, Specification Framework for TGax,September 2015 [Non-Patent Document 2] IEEE802.11-15 / 1066r0,HE-SIG-B Contents,September 2015 [Non-Patent Document 3] IEEE Std 802.11ac-2013 [Non-Patent Document 4] IEEE802.11-15 / 0132r15, Specification Framework for TGax,January 2016 [Non-Patent Document 5] IEEE802.11-16 / 0024r0, Proposed TGax Draft Specification, January 2016 [Non-Patent Document 6] IEEE802.11-15 / 0132r17,Specification Framework for TGax,May 2016 [Non-Patent Document 7] IEEE802.11-15 / 0574r0,SIG Structure for UL PPDU,May 2015 [Non-Patent Document 8] IEEE802.11-16 / 0613r1,HE-SIG-B Related Issues,May 2016 [Non-Patent Document 9] IEEE802.11-15 / 0805r2,SIG-B Field for HEW PPDU,July 2015 Summary of the Invention [Problem to be solved by the invention]

[0006] As the flexibility of frequency scheduling increases, more signaling bits are required to inform STAs of control signaling (i.e., common control information, resource allocation information, and user-specific allocation information). As a result, the overhead for informing control signaling increases. Therefore, there is a trade-off between the flexibility of frequency scheduling and the overhead for informing control signaling. The challenge is how to achieve flexible frequency scheduling while suppressing the increase in the overhead for informing control signaling. [Means for solving the problem]

[0007] In one general aspect, the techniques disclosed herein feature a communications device, the communications device having an antenna and control circuitry, the antenna receiving an uplink single-user partial-band transmission packet from a transmitting communications device, the uplink single-user partial-band transmission packet including a High Efficiency signaling B (HE-SIG-B) and a data field, the HE-SIG-B including RU allocation information indicating one of a plurality of resource unit (RU) allocations and a plurality of user fields, the one of the plurality of RU allocations indicating a plurality of RUs each corresponding to the plurality of user fields, one RU of the plurality of RUs being assigned to the communications device and another RU of the plurality of RUs being an unassigned RU, the user field corresponding to the unassigned RU being set to a dummy association ID (AID), the HE-SIG-B being transmitted in a bandwidth of 20 MHz, the data field being transmitted in one RU assigned with 106 tones less than 20 MHz, and the control circuitry decoding the received uplink single-user partial-band transmission packet.

[0008] It should be noted that the general or specific disclosure may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any combination thereof.

[0009] According to the transmitting device and transmitting method of the present disclosure, it is possible to achieve flexible frequency scheduling while suppressing an increase in overhead for notifying control signaling.

[0010] Further benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. Benefits and / or advantages may be obtained individually by various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and / or advantages. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 illustrates a format of an HE packet conforming to the IEEE 802.11ax specification framework document. [Diagram 2] FIG. 13 is a diagram showing an example of an OFDMA structure of an HE data field of an HE packet when CBW=40 MHz. [Diagram 3] A figure showing an example of the structure of HE-SIG-B of an HE packet when CBW=40 MHz. [Figure 4] FIG. 13 is a diagram showing an example of the format of HE-SIG-B of an HE packet when CBW=40 MHz. [Diagram 5] A figure showing another example of the format of HE-SIG-B of an HE packet when CBW=40 MHz. [Figure 6] FIG. 11 is a diagram illustrating an example of a format of an HE-SIG-B of an HE packet when CBW=40 MHz according to the first embodiment of the present disclosure. [Figure 7] FIG. 11 is a diagram illustrating an example of a format of an HE-SIG-B of an HE packet when CBW=40 MHz according to a second embodiment of the present disclosure. [Figure 8] FIG. 13 is a diagram illustrating an example of a format of an HE-SIG-B of an HE packet when CBW=40 MHz according to a third embodiment of the present disclosure. [Figure 9] FIG. 13 is a diagram illustrating an example of a format of an HE-SIG-B of an HE packet when CBW=40 MHz according to a fourth embodiment of the present disclosure. [Figure 10] FIG. 13 is a diagram illustrating an example of a format of an HE-SIG-B of an HE packet when CBW=40 MHz according to a fifth embodiment of the present disclosure. [Figure 11] FIG. 23 is a diagram showing an example of the format of an HE-SIG-B of an HE packet when CBW=40 MHz according to a sixth embodiment of the present disclosure. [Figure 12] 2 is a block diagram showing a configuration example of an AP according to the present disclosure. FIG. [Figure 13] 2 is a block diagram showing a configuration example of an STA according to the present disclosure. [Figure 14] A figure showing an example of the format of an HE packet used in SU partial band transmission in the present disclosure. [Figure 15]A figure showing an example of the format of HE-SIG-B of an HE packet used for SU partial band transmission relating to the twelfth embodiment of the present disclosure. [Figure 16] A figure showing an example of the format of HE-SIG-B of an HE packet used for SU partial band transmission in the thirteenth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Various embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. In the following description, detailed descriptions of known functions and configurations are omitted for clarity and conciseness.

[0013] 1 illustrates the format of a High Efficiency (HE) packet 100 that conforms to the IEEE 802.11ax specification framework document. The HE packet 100 includes a legacy preamble including a legacy short training field (L-STF) 102, a legacy long training field (L-LTF) 104, and a legacy signal field (L-SIG) 106, an HE preamble including a repetition L-SIG field (RL-SIG) 108, a first HE signal field (HE-SIG-A) 110, a second HE signal field (HE-SIG-B) 112, an HE short training field (HE-STF) 114, and an HE long training field (HE-LTF) 116, and an HE data field 120.

[0014] The legacy preamble (102, 104, 106) is used to facilitate backward compatibility with legacy 802.11a / g / n / ac standards. The L-STF 102 and L-LTF 104 are primarily used for packet detection, automatic gain control (AGC) settings, frequency offset estimation, time synchronization, and channel estimation. The L-SIG 106, along with the RL-SIG 108 in the HE preamble, is used to help distinguish the HE packet 100 from legacy 802.11a / g / n / ac packets.

[0015] The HE-SIG-A 110 in the HE preamble carries common control information required to interpret the remaining fields of the HE packet 100, such as the CBW (Channel Bandwidth), the number of HE-SIG-B symbols, and the MCS (Modulation and Coding Scheme) used for the HE-SIG-B 112.

[0016] The HE-SIG-B 112 in the HE preamble contains, among other things, resource allocation information and user-specific allocation information for the designated receiving STA for downlink (DL) multiuser (MU) transmission. The HE-SIG-B 112 is not present in the HE packet 100 if it is intended to be used for single user (SU) transmission or uplink (UL) MU transmission. For UL MU transmission, the resource allocation information and user-specific allocation information for the designated transmitting STA is pre-configured at the AP and transmitted by the AP in a trigger frame to the designated transmitting STA.

[0017] The HE-STF 114 in the HE preamble is used to reset the AGC and reduce the dynamic range requirements for the ADC (Analog to Digital Converter). The HE-LTF 116 in the HE preamble is provided for MIMO (Multiple Input Multiple Output) channel estimation to receive and equalize the HE data field 120.

[0018] The HE data field 120 carries the payload for one or more STAs. For a particular STA for SU transmission or a particular group of STAs for MU-MIMO transmission, the payload is carried on a specified resource in units of RUs across multiple OFDM symbols. RUs can have different types depending on the number of constituent subcarriers per RU. The OFDM symbols in the HE data field 120 should use a DFT (Discrete Fourier Transform) period of 12.8 μs and a subcarrier spacing of 78.125 kHz. The number of subcarriers per OFDM symbol depends on the value of the CBW. For example, if CBW=40 MHz, the number of subcarriers per OFDM symbol is 512. Therefore, for a particular type of RU, the maximum number of RUs per OFDM symbol also depends on the size of the CBW.

[0019] FIG. 2 shows an example of an OFDMA structure for the HE data field 120 of an HE packet 100 with CBW=40 MHz. A Type I RU contains 26 consecutive tones and has a bandwidth of about 2 MHz. A Type II RU contains 52 consecutive tones and has a bandwidth of about 4.1 MHz. A Type III RU contains 106 consecutive tones and has a bandwidth of about 8.3 MHz. A Type IV RU contains 242 consecutive tones and has a bandwidth of about 18.9 MHz. A Type V RU contains 484 consecutive tones and has a bandwidth of about 37.8 MHz. The maximum number of Type I, Type II, Type III, Type IV and Type V RUs that a 40 MHz OFDMA can support are 18, 8, 4, 2 and 1, respectively. A mix of different types of RUs can also be accommodated in a 40 MHz OFDMA.

[0020] Details of the transmission processing of the L-STF 102, L-LTF 104, L-SIG 106, RL-SIG 108, HE-SIG-A 110, HE-SIG-B 112, HE-STF 114, HE-LTF 116, and HE data field 120 can be found in the IEEE 802.11ax specification framework document.

[0021] In particular, HE-SIG-B 112 is coded per 20 MHz subband. For CBW=40 MHz, 80 MHz, 160 MHz or 80+80 MHz, the number of 20 MHz subbands carrying different content is 2. HE-SIG-B symbols should use a DFT period of 3.2 μs and a subcarrier spacing of 312.5 kHz. The number of data subcarriers per HE-SIG-B symbol is 52.

[0022] 3 shows an example of the structure of the HE-SIG-B 112 of the HE packet 100 for CBW=40 MHz. The HE-SIG-B 112 includes two channel fields that use different frequency sub-band channels: HE-SIG-B1 302 and HE-SIG-B2 304. The HE-SIG-B1 302 is transmitted over a first 20 MHz sub-band channel 322, while the HE-SIG-B2 304 is transmitted over a second 20 MHz sub-band channel 324.

[0023] Resource allocation information and user-specific allocation information for an allocation located entirely within a 20 MHz subband channel is carried in one of two HE-SIG-B channel fields and transmitted over the same 20 MHz subband channel. More specifically, HE-SIG-B1 302 carries resource allocation information and user-specific allocation information for an allocation (e.g., 312) located entirely within a first 20 MHz subband channel 322, while HE-SIG-B2 304 carries resource allocation information and user-specific allocation information for an allocation (e.g., 314) located entirely within a second 20 MHz subband channel 324. In this way, even if the control signaling in a 20 MHz subband channel (e.g., 322) is corrupted due to interference, the control signaling in the other 20 MHz subband channel (e.g., 324) can be properly decoded.

[0024] 4 shows an example of the format of the HE-SIG-B 112 of the HE packet 100 when CBW=40 MHz. Each of the two HE-SIG-B channel fields includes a common field 410 and a user-specific field 450. Each common field 410 includes a resource allocation subfield 412, a CRC (Cyclic Redundancy Check) subfield, and a tail bit subfield, each of which has a predetermined length.

[0025] With reference to HE-SIG-B1 302 in FIG. 3, the resource allocation subfield 412-1 in FIG. 4 includes an RU placement pattern index that indicates a particular RU placement pattern in the frequency domain (including MU-MIMO related information) for the first 20 MHz subband channel 322. The mapping between the RU placement pattern index and the corresponding RU placement pattern is predefined. An example of the mapping between the RU placement pattern index and the corresponding RU placement pattern is shown in Table 1. Note that the RUs are placed from lower to higher frequencies in the frequency domain within the 20 MHz subband channel, and Type-I and Type-II RUs can only be used for SU-MIMO transmissions.

[0026] [Table 1-1] [Table 1-2]

[0027] With reference to Table 1, for example, the resource allocation subfield 412-1 of Figure 4 included in the HE-SIG-B1 302 of Figure 3 may include 25 RU placement pattern indexes to indicate a particular RU placement pattern for the first 20 MHz subband channel, where five Type I RUs are followed by one Type III RU in the frequency domain, and each of the five Type I RUs is used for SU-MIMO transmission, while the Type III RU is used for MU-MIMO transmission in which two users are multiplexed. Similarly, in connection with the HE-SIG-B2 304 of Figure 3, the resource allocation subfield 412-2 of Figure 4 may include another RU placement pattern index and MU-MIMO related information to indicate a particular RU placement pattern in the frequency domain for the second 20 MHz subband channel 324.

[0028] Each user-specific field 450 in FIG. 4 includes multiple BCC (Binary Convolutional Coding) blocks. Each BCC block, except the last BCC block, includes a first user-specific subfield, a second user-specific subfield, a CRC subfield, and a tail bit subfield, each having a predetermined length. The last BCC block may include a single user-specific subfield. Each of the user-specific subfields in the user-specific field 450 carries user-specific allocation information (e.g., STA identifier for addressing, and user-specific transmission parameters such as number of spatial streams and MCS, etc.). For each RU assigned for SU-MIMO transmission, there is only one corresponding user-specific subfield. For each RU assigned for MU-MIMO transmission with K users multiplexed, there are K corresponding user-specific subfields. The order of the user-specific subfields in the user-specific field 450 of one HE-SIG-B channel field complies with the RU placement pattern signaled by the resource allocation subfield 412 of the same HE-SIG-B channel. The number of user-specific subfields in the user-specific field 450 of one HE-SIG-B channel may be derived from the resource allocation subfield 412 of the same HE-SIG-B channel.

[0029] Note that at the end of HE-SIG-B1 302 and / or HE-SIG-B2 304, padding bits may be added to align the last symbols between HE-SIG-B1 302 and HE-SIG-B2 304 and maintain the same duration.

[0030] However, there may be a significant load imbalance between the two HE-SIG-B channel fields 302 and 304 (i.e., one HE-SIG-B channel field may be much longer than the other HE-SIG-B channel field in length before adding padding bits). In the example of FIG. 5, there are three allocations across the first 20 MHz subband channel 322, used for MU-MIMO transmissions with 6 users multiplexed, SU-MIMO transmissions, and MU-MIMO transmissions with 7 users multiplexed, respectively. Here, each BCC block contains two user-specific subfields. Thus, the number of user-specific subfields N for HE-SIG-B1 302 is uss,1 and the number of BCC blocks, N blk,1 are 14 and 7, respectively. On the other hand, there are six allocations across the second 20 MHz subband channel 324, each of which is used for SU-MIMO transmission. Thus, the number of user-specific subfields N uss,2 and the number of BCC blocks, N blk,2 are 6 and 3, respectively. Each common field 510 is cf = 22 bits long, - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, and - The MCS used in HE-SIG-B 112 is the number of data bits per HE-SIG-B symbol N DBPS Assume that the device is a VHT-MCS1 (see IEEE802.11ac standard) with a QoS of 52.

[0031] Therefore, the number of HE-SIG-B symbols in this example, N sym is 8, which can be calculated using the following equation (1).

[0032]

number

[0033] During the ceremony,

number

[0034]

number

[0035] In this example, in order to maintain the same duration between HE-SIG-B1 302 and HE-SIG-B2 304, it is necessary to add some padding symbols to the end of HE-SIG-B2 304. It can be concluded that if one HE-SIG-B channel field is much longer than the other, a significant number of padding symbols will be required for the other HE-SIG-B channel field, resulting in a significant overhead for signaling control signaling and compromising channel efficiency.

[0036] Next, various embodiments of the format of the HE-SIG-B 112 will be described in more detail, which can reduce the overhead for reporting control signaling and greatly improve channel efficiency.

[0037] According to a first aspect of the present disclosure, a portion of a user-specific field of one HE-SIG-B channel field that is longer than the other HE-SIG-B channel field before padding bits are added is transferred to the other HE-SIG-B channel field so that the number of HE-SIG-B symbols is minimized. Thus, the overhead for reporting control signaling is reduced and channel efficiency is improved. The transferred portion of the user-specific field is placed at a predetermined position in the other HE-SIG-B channel field. The transferred portion of the user-specific field can be transmitted using a more robust transmission scheme than that used to transmit the other portion of the user-specific field. As a result, the STA can properly decode the transferred portion of the user-specific field even when the other HE-SIG-B channel field has poor channel quality due to interference.

[0038] <First embodiment> According to a first aspect of the present disclosure, one or more last BCC blocks of a user specific field of one HE-SIG-B channel field that is longer than the other HE-SIG-B channel field before adding padding bits are transferred to the other HE-SIG-B channel. This transfer minimizes the number of HE-SIG-B symbols. Thus, the overhead for reporting control signaling is reduced and channel efficiency is improved.

[0039] If the other HE-SIG-B channel field has poor channel quality due to interference, a STA whose corresponding BCC block is transferred to the other HE-SIG-B channel may not be able to properly decode the resource allocation signaling in the other HE-SIG-B channel field, and therefore cannot determine the number of original BCC blocks of the other HE-SIG-B channel field. In this case, if the transferred BCC block is located immediately after the original BCC block of the other HE-SIG-B channel field, the STA cannot determine the start of the transferred BCC block and properly decode it.

[0040] According to the first embodiment of the present disclosure, the relocated BCC block is placed at a predetermined position in the other HE-SIG-B channel field (e.g., at the end of the other HE-SIG-B channel field). The relocated BCC block may be duplicated one or more times in the other HE-SIG-B channel field. As a result, even if the other HE-SIG-B channel field has poor channel quality due to interference, the STA can still properly decode the relocated BCC block.

[0041] According to the first embodiment of the present disclosure, the number of transferred BCC blocks N rblk can be calculated using the following equation (3).

[0042]

number

[0043] where R is the repetition factor,

number

[0044] 6 shows an example of the format of the HE-SIG-B 112 of the HE packet 100 when CBW=40 MHz according to the first embodiment of the present disclosure. Each of the two HE-SIG-B channel fields includes a common field 610 and a user-specific field 650. Each common field 610 includes a resource allocation subfield, a rearrangement BCC block number subfield 614, a repetition subfield 616, a CRC subfield, and a tail bit subfield. The rearrangement BCC block number subfield 614 of one HE-SIG-B channel field has a predetermined length and indicates the number of BCC blocks rearranged from the one HE-SIG-B channel field to the other HE-SIG-B channel field. The repetition subfield 616 of one HE-SIG-B channel has a predetermined length and indicates how many times the rearrangement BCC block is replicated in the other HE-SIG-B channel field (i.e., indicates the value of the repetition factor R). Based on both the Number of Rearranged BCC Blocks subfield 614 and the Repetition subfield 616 of one HE-SIG-B channel field, the STA can determine the start of the rearranged BCC blocks in the other HE-SIG-B channel field and, if the repetition factor R is greater than 1, perform MRC (Maximum Ratio Combining) on ​​the rearranged BCC blocks and decode them properly.

[0045] Assuming that Figure 6 is based on the same resource allocation as Figure 5, the number of user-specific subfields in HE-SIG-B1 302, N uss,1 and the number of BCC blocks, N blk,1 are 14 and 7, respectively. Therefore, the number of user-specific subfields in HE-SIG-B2 304, N uss,2 and the number of BCC blocks, N blk,2 are 6 and 3, respectively. Each common field 610 is cf = 22 bits long, - Each user-specific subfield is ussEach BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, - The MCS used in HE-SIG-B 112 is N DBPS = 52, and - Assume that the repetition factor = 2.

[0046] From equation (3), N rblk It is easy to derive that =1. Therefore, the number of HE-SIG-B symbols N sym is 7, which can be calculated by:

[0047]

number

[0048] During the ceremony,

number

[0049] In other words, based on the same resource allocation, the first embodiment may require fewer HE-SIG-B symbols than the prior art.

[0050] Note that in the example of FIG. 6, the Number of Rearrangement BCC Blocks subfield 614-1 in HE-SIG-B1 302 should indicate a single rearrangement BCC block, the Repetition subfield 616-1 in HE-SIG-B1 302 should indicate that the rearrangement BCC block is replicated once (i.e., repetition factor R=2), while the Number of Rearrangement BCC Blocks subfield 614-2 in HE-SIG-B2 304 should indicate that no rearrangement BCC blocks are present.

[0051] According to a first embodiment of the present disclosure, instead of signaling the number of rearrangement BCC blocks and the repetition factor R value of HE-SIG-B1 302 and HE-SIG-B2 304 in the respective common fields 610, the number of rearrangement BCC blocks and the repetition factor R of HE-SIG-B1 302 and HE-SIG-B2 304 may be signaled in HE-SIG-A 110.

[0052] <Second embodiment> According to the second embodiment of the present disclosure, one or more last BCC blocks of a user-specific field of one HE-SIG-B channel field that is longer than the other HE-SIG-B channel field before adding padding bits are relocated to the other HE-SIG-B channel, such that the number of HE-SIG-B symbols is minimized, thus reducing the overhead for signaling control signaling and improving channel efficiency.

[0053] According to the second embodiment of the present disclosure, the rearrangement BCC block is placed at a predetermined position of the other HE-SIG-B channel field (e.g., at the end of the other HE-SIG-B channel field). The rearrangement BCC block can be transmitted by a more robust MCS than the MCS used for the other BCC block. As a result, even if the other HE-SIG-B channel field has poor channel quality due to interference, the STA can still properly decode the rearrangement BCC block.

[0054] According to the second embodiment of the present disclosure, the number of rearrangement BCC blocks N rblk can be calculated using the following equation (6).

[0055]

number

[0056] In the formula, N DBPS,rblkis the number of data bits per symbol in the rearrangement BCC block, and N DBPS,oblk is the number of data bits per symbol of the other BCC block.

[0057] 7 shows an example of the format of the HE-SIG-B 112 of the HE packet 100 when CBW=40 MHz according to the second embodiment of the present disclosure. Each of the two HE-SIG-B channel fields includes a common field 710 and a user-specific field 750. Each common field 710 includes a resource allocation subfield, a rearrangement BCC block number subfield 714, a rearrangement BCC block MCS subfield 716, a CRC subfield, and a tail bit subfield. The rearrangement BCC block number subfield 714 of one HE-SIG-B channel field has a predetermined length and indicates the number of BCC blocks rearranged from that HE-SIG-B channel field to the other HE-SIG-B channel field. The rearrangement BCC block MCS subfield 716 of one HE-SIG-B channel field has a predetermined length and indicates the MCS used for the rearrangement BCC block in the other HE-SIG-B channel. Note that the MCS used for BCC blocks in HE-SIG-B 112 other than the rearrangement BCC blocks may be indicated in HE-SIG-A 110. Based on both the Rearrangement BCC Block Number subfield 714 and the Rearrangement BCC Block MCS subfield 716 of one HE-SIG-B channel field, a STA can determine the start of the rearrangement BCC blocks in the other HE-SIG-B channel field and decode them appropriately.

[0058] Assuming that FIG. 7 is based on the same resource allocation as FIG. 5 and FIG. 6, the number of user-specific subfields in HE-SIG-B1 302, N uss,1 and the number of BCC blocks, N blk,1 are 14 and 7, respectively, while the number of user-specific subfields in HE-SIG-B2 304, N uss,2 and the number of BCC blocks, N blk,2are 6 and 3, respectively. Each common field 710 is cf = 22 bits long, - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, - The MCS used for the rearrangement BCC block is N DBPS, rblk= 26, VHT-MCS0, and - The MCS used for the other BCC block is N DBPS , oblk Assume that VHT-MCS1 has a metric of 1.0, metric of 2.0, and metric of 1.5 ... respectively.

[0059] From equation (6), N rblk It is easy to derive that =1. Therefore, the number of HE-SIG-B symbols N sym is 7, which can be calculated by:

[0060]

number

[0061] During the ceremony,

number

[0062] In other words, based on the same resource allocation, the second embodiment may require fewer HE-SIG-B symbols than the prior art.

[0063] Note that in the example of FIG. 7, the number of rearrangement BCC blocks subfield 714-1 in HE-SIG-B1 302 should indicate a single rearrangement BCC block and the number of rearrangement BCC blocks MCS subfield 716-1 in HE-SIG-B1 302 should indicate VHT-MCS0, while the number of rearrangement BCC blocks subfield 714-2 in HE-SIG-B2 304 should indicate that no rearrangement BCC blocks are present.

[0064] According to a second embodiment of the present disclosure, instead of signaling the number of rearrangement BCC blocks and the MCS of the rearrangement BCC blocks of HE-SIG-B1 302 and HE-SIG-B2 304 in the respective common fields 710, the number of rearrangement BCC blocks and the MCS of the rearrangement BCC blocks of HE-SIG-B1 302 and HE-SIG-B2 304 may be signaled in HE-SIG-A 110.

[0065] <Third embodiment> According to the third embodiment of the present disclosure, one or more last BCC blocks of a user-specific field of one HE-SIG-B channel field that is longer than the other HE-SIG-B channel field before adding padding bits are relocated to the other HE-SIG-B channel, such that the number of HE-SIG-B symbols is minimized. Thus, the overhead for signaling control signaling is reduced and the channel efficiency is improved.

[0066] According to the third embodiment of the present disclosure, the rearranged BCC block is placed at a predetermined position of the other HE-SIG-B channel field (e.g., at the end of the other HE-SIG-B channel field). The rearranged BCC block can be transmitted at a higher power than other BCC blocks. As a result, even if the other HE-SIG-B channel field has poor channel quality due to interference, the STA can still properly decode the rearranged BCC block. However, the power boost of the rearranged BCC block may result in a higher PAPR (Peak-to-Average Power Ratio).

[0067] According to the third embodiment of the present disclosure, the number of rearrangement BCC blocks N rblk can be calculated using the following equation (9).

[0068]

number

[0069] FIG. 8 illustrates an example of the format of the HE-SIG-B 112 of the HE packet 100 when CBW=40 MHz according to the third embodiment of the present disclosure. Each of the two HE-SIG-B channels includes a common field 810 and a user-specific field 850. Each common field 810 includes a resource allocation subfield, a rearrangement BCC block number subfield 814, a CRC subfield, and a tail bit subfield. The rearrangement BCC block number subfield 814 of one HE-SIG-B channel field has a predetermined length and indicates the number of BCC blocks rearranged from that HE-SIG-B channel field to the other HE-SIG-B channel field. Based on the rearrangement BCC block number subfield 814 of one HE-SIG-B channel field, the STA can determine the start of the rearrangement BCC blocks in the other HE-SIG-B channel field and decode them appropriately.

[0070] Assuming that Figure 8 is based on the same resource allocation as Figures 5 to 7, the number of user-specific subfields N uss,1 and the number of BCC blocks, N blk,1 are 14 and 7, respectively. Therefore, the number of user-specific subfields in HE-SIG-B2 304, N uss,2 and the number of BCC blocks, N blk,2 are 6 and 3, respectively. - Each common field 810 is cf = 22 bits long, - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, and - The MCS used in HE-SIG-B 112 is N DBPS Assume that VHT-MCS1 has a metric of 1.0, metric of 2.0, and metric of 1.5 ... respectively.

[0071] From equation (9), N rblk It is easy to derive that = 2. Therefore, the number of HE-SIG-B symbols N sym is 6, which can be calculated by:

[0072]

number

[0073] During the ceremony,

number

[0074] In other words, based on the same resource allocation, the third embodiment may require fewer HE-SIG-B symbols than the prior art, the first embodiment or the second embodiment.

[0075] Note that in the example of FIG. 8, the Number of Relocation BCC Blocks subfield 814-1 in HE-SIG-B1 302 should indicate a single relocation BCC block, while the Number of Relocation BCC Blocks subfield 814-2 in HE-SIG-B2 304 should indicate that there are no relocation BCC blocks.

[0076] According to a third embodiment of the present disclosure, instead of signaling the number of relocation BCC blocks of HE-SIG-B1 302 and HE-SIG-B2 304 in the respective common fields 810, the number of relocation BCC blocks of HE-SIG-B1 302 and HE-SIG-B2 304 may be signaled in HE-SIG-A 110.

[0077] According to the first three embodiments of the present disclosure, the two HE-SIG-B channel fields (except for the rearrangement BCC block in the second embodiment) utilize the same MCS signaled in the HE-SIG-A 110. This common MCS for the two HE-SIG-B channel fields should be determined such that all STAs scheduled in both the first 20 MHz sub-band channel 322 and the second 20 MHz sub-band channel 324 will successfully decode the HE-SIG-B 112 with an acceptable probability (e.g., 90%).

[0078] According to a second aspect of the present disclosure, the MCS of one HE-SIG-B channel field may be different from the MCS used for the other HE-SIG-B channel field. Furthermore, the MCS used for one HE-SIG-B channel field that is longer than the other HE-SIG-B channel field may be less robust than the MCS used for the other HE-SIG-B channel field, such that the number of HE-SIG-B symbols is minimized. Thus, the overhead for signaling control signaling is reduced and channel efficiency is improved.

[0079] <Fourth embodiment> According to a fourth embodiment of the present disclosure, a first MCS and a second MCS are used for HE-SIG-B1 302 and HE-SIG-B2 304, respectively. The first MCS for HE-SIG-B1 302 should be determined such that a STA scheduled in the first 20 MHz sub-band channel 322 has an acceptable (e.g., 90%) probability of successfully decoding HE-SIG-B1 302. Similarly, the second MCS for HE-SIG-B2 304 should be determined such that a STA scheduled in the second 20 MHz sub-band channel 324 has an acceptable (e.g., 90%) probability of successfully decoding HE-SIG-B2 304. One of the first MCS used for HE-SIG-B1 302 and the second MCS used for HE-SIG-B2 304 may be less robust than the common MCS used in the first three embodiments because the first MCS used for HE-SIG-B1 302 or the second MCS used for HE-SIG-B2 304 takes into account only a portion of the STAs scheduled in both the first 20 MHz sub-band channel 322 and the second 20 MHz sub-band channel 324. It should be noted that unlike the first three embodiments, according to the fourth embodiment of the present disclosure, there is no need to rearrange the BCC blocks of either HE-SIG-B1 302 or HE-SIG-B2 304.

[0080] According to the fourth embodiment of the present disclosure, in addition to the signaling indicating the number of HE-SIG-B symbols, the HE-SIG-A 110 needs signaling indicating the first MCS used for HE-SIG-B1 302 and the second MCS used for HE-SIG-B2 304. Based on such signaling, the STA can properly decode the two HE-SIG-B channel fields.

[0081] According to a fourth embodiment of the present disclosure, before adding padding bits, if HE-SIG-B1 302 is much longer than HE-SIG-B2 304 (i.e., HE-SIG-B1 302 includes much more user-specific subfields than HE-SIG-B2 304), the first MCS used for HE-SIG-B1 302 can be set to be less robust than the second MCS used for HE-SIG-B2 304, thereby minimizing the number of HE-SIG-B symbols. Thus, the overhead for signaling control signaling is reduced and channel efficiency is improved. If HE-SIG-B2 304 is much longer than HE-SIG-B1 302 before adding padding bits, the second MCS used for HE-SIG-B2 304 can be set to be less robust than the first MCS used for HE-SIG-B1 302, which minimizes the number of HE-SIG-B symbols and improves channel efficiency. If the length of HE-SIG-B2 304 is similar to that of HE-SIG-B1 302, the first MCS used for HE-SIG-B1 302 can be set to be the same as the second MCS used for HE-SIG-B2 304.

[0082] 9 shows an example of a format of the HE-SIG-B 112 when CBW=40 MHz according to the fourth embodiment of the present disclosure. Each of the two HE-SIG-B channels includes a common field 910 and a user-specific field 950.

[0083] Assuming that Figure 9 is based on the same resource allocation as Figures 5 to 8, the number of user-specific subfields N uss,1 and the number of BCC blocks, N blk,1 are 14 and 7, respectively. Therefore, the number of user-specific subfields in HE-SIG-B2 304, N uss,2 and the number of BCC blocks, N blk,2are 6 and 3, respectively. Because HE-SIG-B1 302 is much longer than HE-SIG-B2 304 in this example before adding padding bits, the first MCS used for HE-SIG-B1 302 is set to be less robust than the second MCS used for HE-SIG-B2 304, thereby minimizing the number of HE-SIG-B symbols. For example, the first MCS used for HE-SIG-B1 302 is set to VHT-MCS2, where N DBPS,1 = 78, and the second MCS used for HE-SIG-B2 304 is set to VHT-MCS1, where N DBPS,2 =52. Each common field 910 is cf = 22 bits long, - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits.

[0084] Therefore, the number of HE-SIG-B symbols, N sym is 6, which can be calculated by:

[0085]

number

[0086] During the ceremony,

number

[0087] In other words, based on the same resource allocation, the fourth embodiment may require fewer HE-SIG-B symbols than the prior art, the first embodiment or the second embodiment.

[0088] According to a third aspect of the present disclosure, for some specific resource allocations, the common fields (including resource allocation signaling) of each of the two HE-SIG-B channel fields can be ignored, which minimizes the number of HE-SIG-B symbols, thus reducing the overhead for reporting control signaling and improving channel efficiency.

[0089] <Fifth embodiment> According to the fifth embodiment of the present disclosure, when a single RU of a particular type (e.g., a Type IV RU) is allocated across each of the first 20 MHz subband channel 322 and the second 20 MHz subband channel 324, and the same number of users are scheduled in each of the first 20 MHz subband channel 322 and the second 20 MHz subband channel 324, each of the two HE-SIG-B channel fields may include only user-specific fields, which minimizes the number of HE-SIG-B symbols. Thus, the overhead for reporting control signaling is reduced and channel efficiency is improved.

[0090] 10 shows an example of the format of the HE-SIG-B 112 of the HE packet 100 for CBW=40 MHz according to the fifth embodiment of the present disclosure. In this example, a single Type IV RU used for MU-MIMO transmission with 6 users multiplexed is allocated across each of the first 20 MHz sub-band channel 322 and the second 20 MHz sub-band channel 324. Thus, each of the HE-SIG-B1 302 and the HE-SIG-B2 304 includes only a user-specific field 1050. The number of user-specific sub-fields N uss and the number of BCC blocks per HE-SIG-B channel field, N blk are 6 and 3, respectively. - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, and - The MCS used in HE-SIG-B 112 is N DBPS Assume that VHT-MCS1 has a metric of 1.0, metric of 2.0, and metric of 1.5 ... respectively.

[0091] Therefore, the number of HE-SIG-B symbols, N sym is 4, which can be calculated by:

[0092]

number

[0093] During the ceremony,

number

[0094] According to a fifth embodiment of the present disclosure, in addition to signaling indicating the number of HE-SIG-B symbols and the MCS used for HE-SIG-B 112, signaling is needed within HE-SIG-A 110 to indicate the presence of a specific resource allocation in which a single RU of a particular type is allocated across each of the first 20 MHz subband channel 322 and the second 20 MHz subband channel 324, and a like number of users are scheduled in each of the first 20 MHz subband channel 322 and the second 20 MHz subband channel 324. Based on such signaling, STAs can properly decode HE-SIG-B 112.

[0095] According to the fifth embodiment of the present disclosure, since there is no resource allocation signaling in the two HE-SIG-B channels, the STA can select the number of user-specific subfields per HE-SIG-B channel field, N uss It may not be possible to determine the HE-SIG-B symbol N sym Given the number of MCSs, the MCS used for HE-SIG-B 112, and the value of α, the number of user-specific subfields per HE-SIG-B channel field can be determined by:

[0096]

number

[0097] During the ceremony,

number

[0098] In other words, the STA selects the number of user-specific subfields per HE-SIG-B channel field, N uss In order to help determine i (i.e., whether there is an even number of user-specific subfields per HE-SIG-B channel field, or equivalently, whether an even number of users are scheduled in each of the first 20 MHz subband channel 322 and the second 20 MHz subband channel 324).

[0099] Sixth embodiment According to the sixth embodiment of the present disclosure, when the entire 40 MHz bandwidth covering the first 20 MHz sub-band channel 322 and the second 20 MHz sub-band channel 324 is allocated to MU-MIMO transmission, each of the two HE-SIG-B channel fields may contain only user-specific fields. Furthermore, the user-specific sub-fields are divided fairly between the two HE-SIG-B channel fields for efficient load balancing. More specifically, for MU-MIMO transmission with K users multiplexed, the first

number

number

[0100] 11 shows an example of the format of the HE-SIG-B 112 of the HE packet 100 when CBW=40 MHz according to the sixth embodiment of the present disclosure. In this example, the entire 40 MHz bandwidth covering both the first 20 MHz sub-band channel 322 and the second 20 MHz sub-band channel 324 is allocated for MU-MIMO transmission with 7 users multiplexed. Therefore, each of the HE-SIG-B1 322 and the HE-SIG-B2 304 includes only the user-specific field 1150. The number of user-specific sub-fields N of the HE-SIG-B1 302 is uss,1 and the number of BCC blocks, N blk,1 are 4 and 2, respectively. The number of user-specific subfields in HE-SIG-B2 304, N uss,2 and the number of BCC blocks, N blk,2 are 3 and 2, respectively. - Each user-specific subfield is uss Each BCC block has a length of L = 22 bits and contains two user-specific subfields. blk = 54 bits long, and - The MCS used in HE-SIG-B 112 is N DBPS Assume that VHT-MCS1 has a metric of 1.0, metric of 2.0, and metric of 1.5 ... respectively.

[0101] Therefore, the number of HE-SIG-B symbols, N sym is 3, which can be calculated by:

[0102]

number

[0103] During the ceremony,

number

[0104] According to a sixth embodiment of the present disclosure, in addition to the signaling indicating the number of HE-SIG-B symbols and the MCS used for HE-SIG-B 112, signaling is required in HE-SIG-A 110 indicating the presence of a specific resource allocation in which the entire channel bandwidth is allocated for MU-MIMO transmission. Based on such signaling, STAs can properly decode HE-SIG-B 112.

[0105] According to the sixth embodiment of the present disclosure, since there is no resource allocation signaling in the two HE-SIG-B channels, the STA can select the number of user-specific subfields N in HE-SIG-B1 302. uss,1 and the number of user-specific subfields in HE-SIG-B2 304, N uss,2 It may not be possible to determine the number of HE-SIG-B symbols N sym Given the number of,MCS used in HE-SIG-B 112, and the value of,α, the user-specific subfield,N,in,HE-SIG-B1 302, uss,1 The number of can be determined by the following equation (20).

[0106]

number

[0107] During the ceremony,

number

[0108] The number of user-specific subfields in HE-SIG-B2 304, N uss,2 can be determined by the following equation (22):

[0109]

number

[0110] wherein

Number

[0111] In other words, for the purpose of assisting the STA in determining the number N of user-specific subfields within HE-SIG-B1 302 uss,1 and the number N of user-specific subfields within HE-SIG-B2 304 uss,2 in HE-SIG-A 110, signaling may be required to indicate the value of α (i.e., to indicate whether there are an even number of user-specific subfields within HE-SIG-B1 302) and to indicate the value of β (i.e., to indicate whether there are an equal number of user-specific subfields in both HE-SIG-B1 302 and HE-SIG-B2 304). Alternatively, in HE-SIG-A 110, signaling may be required to indicate the remainder when the number of users multiplexed in MU-MIMO transmission is divided by 4. A remainder equal to 0 means α = 0 and β = 0. A remainder equal to 1 means α = 1 and β = 1. A remainder equal to 2 means α = 1 and β = 0. A remainder equal to 3 means α = 0 and β = 1.

[0112] <HE-SIG-B related signaling field in HE-SIG-A> According to the proposed IEEE802.11ax draft specification [see Non-Patent Document 5], the signaling field within HE-SIG-A 110 shown in Table 2 provides the necessary information regarding HE-SIG-B112.

[0113]

Table 2

[0114] According to the proposed IEEE 802.11ax provisional specification [5], DCM (Dual sub-Carrier Modulation) is only applicable to MCS0, MCS1, MCS3 and MCS4.

[0115] According to the proposed IEEE 802.11ax provisional specification [see non-patent document 5], the number of spatially multiplexed users in full-band MU-MIMO transmission is up to eight.

[0116] According to the proposed IEEE 802.11ax provisional specification [5], the bit length of each user-specific subfield in HE-SIG-B112 is 21, the bit length of each BCC block containing a single user-specific subfield in HE-SIG-B112 is 31, and the bit length of a BCC block containing two user-specific subfields in HE-SIG-B112 is 52, which is exactly the same as the number of data subcarriers per HE-SIG-B symbol.

[0117] <Seventh embodiment> The seventh embodiment of the present disclosure employs exactly the same compressed HE-SIG-B structure as the sixth embodiment for full-bandwidth MU-MIMO transmissions. However, the seventh embodiment specifies different signaling support in the HE-SIG-A 110 for the compressed HE-SIG-B 112 than the sixth embodiment.

[0118] As shown in Table 3, for a compressed HE-SIG-B112, the number of HE-SIG-B symbols depends on the MCS used for the HE-SIG-B112 and the number of user-specific subfields in the HE-SIG-B112, N SSS,1It should be noted that the maximum number of HE-SIG-B symbols in the compressed HE-SIG-B 112 is eight. From Table 3, it can be seen that three bits of the four-bit SIGB symbol number field in the HE-SIG-A 110 are sufficient to indicate the number of HE-SIG-B symbols in the compressed HE-SIG-B 112, and thus the remaining one bit of the four-bit SIGB symbol number field in the HE-SIG-A 110 can be used for other purposes. It can also be seen from Table 3 that MCS2, MCS4 and MCS5 may not be required for the compressed HE-SIG-B 112. This is because, for the same number of spatially multiplexed users in a full-bandwidth MU-MIMO transmission, MCS4 with DCM applied requires the same number of HE-SIG-B symbols as MCS3 with DCM applied, MCS4 or MCS5 without DCM applied requires the same number of HE-SIG-B symbols as MCS3 without DCM applied, and MCS2 requires the same number of HE-SIG-B symbols as MCS1 without DCM applied. As a result, two bits of the 3-bit SIGB MCS field in HE-SIG-A 110 are sufficient to indicate the MCS used for compressed HE-SIG-B 112, and therefore the remaining bit of the 3-bit SIGB MCS field in HE-SIG-A 110 may also be used for other purposes.

[0119] [Table 3]

[0120] According to the seventh embodiment of the present disclosure, when the SIGB compression field of HE-SIG-A 110 is set to 1, 3-bit signaling is carried within HE-SIG-A 110 to indicate the number of spatial multiplexing users in a full bandwidth MU-MIMO transmission.

[0121] In one embodiment, one of the three signaling bits reuses a predetermined bit, e.g., the MSB (Most Significant Bit), of the 4-bit SIGB Symbol Number field in the HE-SIG-A 110. In one embodiment, one of the three signaling bits reuses a predetermined bit, e.g., the MSB, of the 3-bit SIGB MCS field in the HE-SIG-A 110. In either case, only two additional signaling bits are required in the HE-SIG-A 110. This saves one signaling bit compared to directly signaling the number of spatially multiplexed users in a full bandwidth MU-MIMO transmission in the HE-SIG-A 110. For example, as shown in Table 4, the MSB of the 4-bit SIGB Symbol Number field in the HE-SIG-A 110 is reused to indicate whether there is an equal number of user-specific subfields in both the HE-SIG-B1 302 and the HE-SIG-B2 304. Two additional signaling bits indicate the number of user-specific subfields in the HE-SIG-B1 302 (i.e., N uss,1 ) is used to denote the number of spatially multiplexed users in full-bandwidth MU-MIMO transmission. The receiver can determine the number of spatially multiplexed users in full-bandwidth MU-MIMO transmission by the following equation (24):

[0122]

number

[0123] Here, if both HE-SIG-B1 302 and HE-SIG-B2 304 have the same number of user-specific subfields, then β is equal to zero; otherwise, β is equal to one.

[0124] [Table 4]

[0125] In one embodiment, two of the three signaling bits reuse both a predetermined bit, e.g., the MSB, of the 4-bit SIGB symbol number field in the HE-SIG-A 110 and a predetermined bit, e.g., the MSB, of the 3-bit SIGB MCS field in the HE-SIG-A 110. In this case, only one additional signaling bit is needed in the HE-SIG-A 110 to indicate the number of spatially multiplexed users in the full-bandwidth MU-MIMO transmission. This saves two signaling bits compared to signaling the number of spatially multiplexed users in the full-bandwidth MU-MIMO transmission directly in the HE-SIG-A 110. For example, the MSB of the 4-bit SIGB symbol number field in the HE-SIG-A 110 is reused to indicate whether there is an equal number of user-specific subfields in both the HE-SIG-B1 302 and the HE-SIG-B2 304. The MSB of the 3-bit SIGB MCS field in HE-SIG-A110 is the number N of BCC blocks in HE-SIG-B1 302. blk,1 is reused to indicate whether is 1 or 2. One additional signaling bit is used to indicate whether the last BCC block in HE-SIG-B1 302 contains a single user-specific subfield or two user-specific subfields. The receiver can determine the number of spatial multiplexing users in a full-bandwidth MU-MIMO transmission by the following equation (24):

[0126]

number

[0127] Here, if the last BCC block of HE-SIG-B1 302 contains two user-specific subfields, then α is equal to zero; otherwise, α is equal to 1. If both HE-SIG-B1 302 and HE-SIG-B2 304 have the same number of user-specific subfields, then β is equal to zero; otherwise, β is equal to 1.

[0128] <Eighth embodiment> The eighth embodiment of the present disclosure employs exactly the same compressed HE-SIG-B structure as the sixth embodiment for full-bandwidth MU-MIMO transmissions. However, the eighth embodiment specifies different signaling support in the HE-SIG-A 110 for the compressed HE-SIG-B 112 than the sixth embodiment.

[0129] According to the eighth embodiment of the present disclosure, the bit length of the SIGB compressed field in the HE-SIG-A 110 is extended from 1 bit to 3 bits to indicate both the HE-SIG-B mode (i.e., whether the HE-SIG-B 112 is compressed or not) and the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission. An example of the signaling coding is shown in Table 5. As a result, only two additional signaling bits are needed in the HE-SIG-A 110 to indicate the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission. This saves one signaling bit compared to signaling the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission directly in the HE-SIG-A 110.

[0130] [Table 5]

[0131] <Ninth embodiment> The ninth embodiment of the present disclosure employs exactly the same compressed HE-SIG-B structure as the sixth embodiment for full-bandwidth MU-MIMO transmissions. However, the ninth embodiment specifies different signaling support in the HE-SIG-A 110 for the compressed HE-SIG-B 112 than the sixth embodiment.

[0132] From Table 3, the number of HE-SIG-B symbols (i.e., N sym ) and the number of spatially multiplexed users in full-bandwidth MU-MIMO transmission (i.e., N uss ) are possible. ussFor N = 2, the possible number of HE-SIG-B symbols is 1, 2 or 3. uss For N = 3 or 4, the possible number of HE-SIG-B symbols is 1, 2 or 4. uss For N = 5 or 6, the possible number of HE-SIG-B symbols is 1, 2, 4 or 7. uss For ,=7 or 8, the possible number of HE-SIG-B symbols is 1, 2, 4 or 8. In summary, there are a total of 25 possible combinations between the number of HE-SIG-B symbols and the number of spatially multiplexed users in a full-bandwidth MU-MIMO transmission. In other words, 5 bits are sufficient to signal the 25 possible combinations between the number of HE-SIG-B symbols and the number of spatially multiplexed users in a full-bandwidth MU-MIMO transmission.

[0133] According to the ninth embodiment of the present disclosure, when the SIGB compression field in the HE-SIG-A 110 is set to 1, the bit length of the SIGB symbol number field in the HE-SIG-A 110 is extended from 4 bits to 5 bits to jointly signal the number of HE-SIG-B symbols and the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission. An example of signaling coding is shown in Table 6. As a result, only one additional signaling bit is needed in the HE-SIG-A 110 to indicate the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission. This saves two signaling bits compared to signaling the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission directly in the HE-SIG-A 110.

[0134] [Table 6-1] [Table 6-2] [Table 6-3]

[0135] <Tenth embodiment> The tenth embodiment of the present disclosure employs exactly the same compressed HE-SIG-B structure as the sixth embodiment for full-bandwidth MU-MIMO transmissions. However, the tenth embodiment specifies different signaling support in the HE-SIG-A 110 for the compressed HE-SIG-B 112 than the sixth embodiment.

[0136] From Table 3, since MCS2, MCS4, MCS5 may not be required for compressed HE-SIG-B112, the total number of combinations between whether DCM is applied to HE-SIG-B112, the MCS of HE-SIG-B112, the number of HE-SIG-B symbols, and the number of spatially multiplexed users in full-bandwidth MU-MIMO transmission is 42. In other words, for compressed HE-SIG-B112, 6 bits are sufficient to indicate whether DCM is applied to HE-SIG-B112, the MCS of HE-SIG-B112, the number of HE-SIG-B symbols, and the number of spatially multiplexed users in full-bandwidth MU-MIMO transmission.

[0137] According to the tenth embodiment of the present disclosure, the applicability of DCM to HE-SIG-B 112, the MCS of HE-SIG-B 112, the number of HE-SIG-B symbols and the number of spatial multiplexing users in full bandwidth MU-MIMO transmission are jointly indicated using 8-bit signaling in HE-SIG-A 110. When the SIGB compression field of HE-SIG-A 110 is set to 0, the first 3 bits of the 8-bit signaling are used to indicate the MCS of HE-SIG-B 12, the next 1 bit of the 8-bit signaling is used to indicate whether DCM is applied to HE-SIG-B 112, and the last 4 bits of the 8-bit signaling are used to indicate the number of HE-SIG-B symbols, as shown in Table 2. When the SIGB compression field in HE-SIG-A 110 is set to 1, 8-bit signaling is used to jointly indicate the application or non-application of DCM for HE-SIG-B 112, the MCS of HE-SIG-B 112, the number of HE-SIG-B symbols, and the number of spatially multiplexed users in the full-bandwidth MU-MIMO transmission. In this case, no additional signaling bits are needed in HE-SIG-A 110 to indicate the number of spatially multiplexed users in the full-bandwidth MU-MIMO transmission.

[0138] In accordance with the present disclosure, for full-bandwidth MU-MIMO compressed HE-SIG-B112, by utilizing a limited number of spatially multiplexed users (i.e., up to 8) in a full-bandwidth MU-MIMO transmission and by utilizing that the user-specific subfields are fairly distributed between HE-SIG-B1 302 and HE-SIG-B2 304, one or more of HE-SIG-B related signaling such as the HE-SIG-B mode, whether DCM is applied for HE-SIG-B112, the MCS of HE-SIG-B112 and the number of HE-SIG-B symbols can be signaled along with the number of spatially multiplexed users in the full-bandwidth MU-MIMO transmission in order to reduce the additional signaling bits required to indicate the number of spatially multiplexed users in the compressed HE-SIG-B112 full-bandwidth MU-MIMO transmission.

[0139] <Eleventh embodiment> The eleventh embodiment of the present disclosure employs exactly the same compressed HE-SIG-B structure as the sixth embodiment for full-bandwidth MU-MIMO transmissions. However, the eleventh embodiment specifies different signaling support in the HE-SIG-A 110 for the compressed HE-SIG-B 112 than the sixth embodiment.

[0140] According to the eleventh embodiment of the present disclosure, when the SIGB compression field in the HE-SIG-A110 is set to 1, the SIGB symbol number field in the HE-SIG-A110 is used to signal the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission instead of the number of HE-SIG-B symbols. An example of signaling coding is shown in Table 7. As a result, no additional signaling bits are needed in the HE-SIG-A110 to indicate the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission. This saves three signaling bits compared to signaling the number of spatial multiplexing users in the full-bandwidth MU-MIMO transmission directly in the HE-SIG-A110.

[0141] [Table 7]

[0142] According to the eleventh embodiment of the present disclosure, when the SIGB compression field in the HE-SIG-A 110 is set to 1, the number of HE-SIG-B symbols can be calculated according to the values ​​of the SIGB MCS field, the SIGB DCM field and the SIGB symbol count field in the HE-SIG-A 110, as shown in Table 3.

[0143] <HE-SIG-AシグナリングフィールドおよびHE-SIG-Bシグナリングフィールド> According to the IEEE 802.11ax specification framework document [see non-patent document 6], in addition to the HE-SIG-B related signaling fields as shown in Table 7, the HE-SIG-A110 includes a UL / DL field indicating whether the HE packet is intended for DL ​​or UL.

[0144] According to the IEEE 802.11ax specification framework document [see non-patent document 6], as shown in Table 8, the common block field of HE-SIG-B includes one or more 8-bit RU allocation signaling subfields, each of which indicates RU allocation information per 20 MHz packet bandwidth, such as RU configuration in the frequency domain, RUs allocated to MU-MIMO, and the number of users in the MU-MIMO allocation. For example, the RU allocation index "00101000" indicates a specific RU configuration in the frequency domain, including the following five RUs allocated for SU-MIMO transmission: - The first 26-tone RU (i.e., Type I RU). - A second 26-tone RU (i.e., a Type I RU). - A 52-tone RU covering the third and fourth 26-tone RUs (i.e., Type II RU). - The fifth 26-tone RU (i.e., Type I RU) - 106-tone RU covering the 6th, 7th, 8th and 9th 26-tone RUs (i.e., Type III RU).

[0145] [Table 8-1] [Table 8-2]

[0146] In addition to DL MU transmissions, HE packets may also be used for DL ​​or UL SU sub-band transmissions according to the present disclosure. FIG. 14 illustrates an example of a format of an HE packet used for SU sub-band transmission according to the present disclosure. For SU sub-band transmissions, the pre-HE-STF portion of the HE packet, including L-STF 102, L-LTF 104, L-SIG 106, RL-SIG 108, HE-SIG-A 110, and HE-SIG-B 112, is transmitted over a 20 MHz bandwidth, while the HE-STF 114, HE-LTF 116, and HE data field 120 are transmitted within a single 26-tone, 52-tone, or 106-tone RU with a bandwidth less than 20 MHz. If the SU sub-band transmission using the HE packet of FIG. 14 is not in a primary 20 MHz channel, carrier sensing may not be performed on the non-primary 20 MHz channel, so additional transmission rules are needed to protect such SU sub-band transmissions. For example, a SU sub-band transmission using an HE packet that is not in the primary 20 MHz channel is preceded by a RTS / CTS message exchange.

[0147] <Twelfth embodiment> According to the twelfth embodiment of the present disclosure, for DL ​​or UL SU sub-band transmission in a single 26-tone, 52-tone or 106-tone RU, the RU allocation index in the HE-SIG-B 112 of the HE packet in Figure 14 should be assigned such that the number of user-specific subfields in the HE-SIG-B 112 corresponding to the RU configuration specified by the RU allocation index is as small as possible, so that the HE-SIG-B overhead of the SU sub-band transmission is minimized.

[0148] Table 9 shows how RU allocation indexes are assigned when a single 26-tone RU, 52-tone RU, or 106-tone RU is assigned for SU subband transmission according to the twelfth embodiment of the present disclosure. For example, for SU subband transmission in the first or second 26-tone RU, only five user-specific subfields are required, which is the minimum among all possible RU configurations, so the RU allocation index should be set to "00101000". Similarly, for SU subband transmission in the fifth 26-tone RU, only three user-specific subfields are required, which is the minimum among all possible RU configurations, so the RU allocation index should be set to "10000000".

[0149] [Table 9]

[0150] Figure 15 shows an example of the format of the HE-SIG-B 112 of the HE packet of Figure 14 used for SU partial band transmission in the first 26-tone RU according to the twelfth embodiment of the present disclosure. In this case, the RU allocation index is set to "00101000" and only the first user-specific subfield is meaningful, while the other four user-specific subfields are dummy with AID (i.e., STA identifier) ​​= 2046. Table 10 shows the number of HE-SIG-B symbols of the HE packet of Figure 14 used for SU partial band transmission in the first 26-tone RU according to the twelfth embodiment of the present disclosure.

[0151] [Table 10]

[0152] <Thirteenth embodiment> According to a thirteenth embodiment of the present disclosure, each of the 15 reserved entries in the RU allocation signaling table shown in Table 8 is used to indicate a particular 26-tone RU, 52-tone RU or 106-tone RU assigned to a SU partial band transmission.

[0153] Table 11 shows RU allocation signaling in the HE-SIG-B 112 of the HE packet 100 according to the thirteenth embodiment of the present disclosure. In particular, RU allocation indexes 11100000 to 11101110 are used to indicate a specific 26-tone RU, 52-tone RU, or 106-tone RU assigned to SU partial band transmission. For example, RU allocation index "11100000" is used to indicate the first 26-tone RU assigned to SU partial band transmission, and RU allocation index "11101001" is used to indicate the first 52-tone RU covering the first and second 26-tone RUs assigned to SU partial band transmission.

[0154] According to a thirteenth embodiment of the present disclosure, as shown in Table 11, the 8-bit RU allocation signaling subfield in HE-SIG-B112 can specify not only two or more 26-tone RUs, 52-tone RUs and / or 106-tone RUs, but also a single 26-tone RU, 52-tone RU, or 106-tone RU.

[0155] [Table 11-1] [Table 11-2]

[0156] FIG. 16 shows an example of the format of the HE-SIG-B 112 of the HE packet of FIG. 14 used for SU partial band transmission in the first 26-tone RU according to the thirteenth embodiment of the present disclosure. Since the 8-bit RU allocation signaling subfield of the HE-SIG-B 112 shown in Table 11 can indicate a specific 26-tone RU, 52-tone RU or 106-tone RU, only a single user-specific subfield is required in the HE-SIG-B 112, and there is no dummy user-specific subfield in the HE-SIG-B 112. Table 12 shows the number of HE-SIG-B symbols of the HE packet 100 used for SU partial band transmission in the first 26-tone RU according to the thirteenth embodiment of the present disclosure. Compared with the twelfth embodiment, the HE-SIG-B overhead of the thirteenth embodiment is significantly reduced, especially when MCS0, MCS1, MCS2 or MCS3 is applied to the HE-SIG-B 112.

[0157] [Table 12]

[0158] <Fourteenth embodiment> According to the fourteenth embodiment of the present disclosure, for SU partial band transmission, the RU allocation signaling in the HE-SIG-B 112 of the HE packet in FIG. 14 is used to indicate a single 26-tone RU, 52-tone RU, or 106-tone RU, instead of a RU configuration including two or more 26-tone RUs, 52-tone RUs, and / or 106-tone RUs. As a result, similar to the thirteenth embodiment of the present disclosure, only a single user-specific subfield is required in the HE-SIG-B 112. As shown in Table 12, compared with the twelfth embodiment, the HE-SIG-B overhead of the fourteenth embodiment is significantly reduced, especially when MCS0, MCS1, MCS2, or MCS3 is applied to the HE-SIG-B 112.

[0159] According to a fourteenth embodiment of the present disclosure, the existing 8-bit RU allocation signaling subfield in the Per User Info field of the trigger frame (see Non-Patent Document 6) can be used to indicate a single 26-tone RU, 52-tone RU, or 106-tone RU. The first bit of the 8-bit RU allocation signaling indicates that the assigned RU is located in a primary or non-primary 80 MHz channel. The mapping of the subsequent 7-bit RU allocation index to the assigned RU is shown in Table 13. For example, the RU allocation index "00000000" indicates that the first 26-tone RU of the primary 80 MHz channel is assigned for SU sub-band transmission.

[0160] [Table 13]

[0161] It should be noted that trigger-based UL MU transmission is an optional feature of IEEE 802.11ax (see Non-Patent Document 6). If a STA intends to implement trigger-based UL MU transmission, the use of 8-bit RU allocation signaling in the Per User Info field of the trigger frame does not add additional implementation complexity. However, if a STA does not intend to implement trigger-based UL MU transmission, the use of 8-bit RU allocation signaling in the Per User Info field of the trigger frame adds additional implementation complexity.

[0162] According to a fourteenth embodiment of the present disclosure, alternative 4-bit RU allocation signaling can be used to indicate a single 26-tone RU, 52-tone RU, or 106-tone RU. The mapping of 4-bit RU allocation index to RU allocation is defined in Table 14. For example, RU allocation index "0000" indicates that the first 26-tone RU in 20 MHz is allocated for SU subband transmission.

[0163] [Table 14]

[0164] If a STA does not intend to implement trigger-based UL MU transmission, the alternative 4-bit RU allocation signaling subfield shown in Table 14 is less complex to implement than the 8-bit RU allocation signaling shown in Table 13, because the former requires a smaller lookup table than the latter.

[0165] According to the fourteenth embodiment of the present disclosure, when a transmitting STA is going to engage in SU partial band transmission in a single 26-tone RU, 52-tone RU, or 106-tone RU with a receiving STA using an HE packet, the transmitting STA can determine whether to use 8-bit RU allocation signaling as shown in Table 13 or an alternative 4-bit RU allocation signaling subfield as shown in Table 14 in the HE-SIG-B112 of the HE packet based on the capability of the receiving STA. If the receiving STA supports trigger-based UL MU transmission, the transmitting STA uses 8-bit RU allocation signaling as shown in Table 13. Otherwise, the transmitting STA uses the alternative 4-bit RU allocation signaling subfield as shown in Table 14. As a result, the implementation complexity is minimized.

[0166] According to the fourteenth embodiment of the present disclosure, when a transmitting STA intends to engage in SU partial band transmission in a single 26-tone RU, 52-tone RU, or 106-tone RU with a receiving STA using an HE packet, an 8-bit RU allocation signaling subfield as shown in Table 13 or an alternative 4-bit RU allocation signaling subfield as shown in Table 14 is used in the HE-SIG-B 112 of the HE packet. Otherwise, an 8-bit RU allocation signaling subfield as shown in Table 8 may be used. As a result, additional signaling support in the HE-SIG-A 110 of the HE packet is needed for the receiving STA to know which RU allocation signaling subfield is used in the HE-SIG-B 112 of the HE packet.

[0167] Table 15 shows the HE-SIG-B related signaling fields in the HE-SIG-A 110 of the HE packet according to the fourteenth embodiment of the present disclosure. The SIGB compression field in the HE-SIG-A is reused to indicate whether HE-SIG-B compression is enabled. If HE-SIG-B compression is enabled, the last bit of the SIGB symbol count field in the HE-SIG-A 110 is used to indicate whether HE-SIG-B compression for full bandwidth MU-MIMO or HE-SIG-B compression for SU partial band transmission is enabled. If both the SIGB compression field and the SIGB symbol count field in the HE-SIG-A 110 indicate that HE-SIG-B compression for SU partial band transmission is enabled, the 8-bit RU allocation signaling subfield as shown in Table 13 or the alternative 4-bit RU allocation signaling subfield as shown in Table 14 is used in the HE-SIG-B 112. If both the SIGB compression field and the SIGB symbol number field of the HE-SIG-A 110 indicate that HE-SIG-B compression for full bandwidth MU-MIMO is enabled, there is no RU allocation signaling subfield in the HE-SIG-B 112 according to the sixth to eleventh embodiments of the present disclosure. Otherwise, 8-bit RU allocation signaling as shown in Table 8 may be used in the HE-SIG-B 112. As a result, the receiving STA can know which RU allocation signaling is used in the HE-SIG-B 112 of the HE packet based on the SIGB symbol number field and the SIGB compression field of the HE-SIG-A 110 of the HE packet. Furthermore, compared with the HE-SIG-B related signaling field in the HE-SIG-A of Table 7 according to the eleventh embodiment of the present disclosure, no additional HE-SIG-A signaling bits are required in the fourteenth embodiment of the present disclosure.

[0168] [Table 15]

[0169] Table 16 shows HE-SIG-B related signaling fields in HE-SIG-A 110 of an HE packet according to the fourteenth embodiment of the present disclosure when only UL SU partial band transmission is supported. The SIGB compression field in HE-SIG-A 110 is used together with the UL / DL field in HE-SIG-A 110 to indicate whether HE-SIG-B compression for full bandwidth MU-MIMO or HE-SIG-B compression for SU partial band transmission is enabled. If both the UL / DL field and the SIGB compression field in HE-SIG-A 110 indicate that HE-SIG-B compression for SU partial band transmission is enabled, 8-bit RU allocation signaling as shown in Table 13 or alternative 4-bit RU allocation signaling as shown in Table 14 is used in HE-SIG-B 112. If both the UL / DL field and the SIGB compression field of the HE-SIG-A 110 indicate that the HE-SIG-B compression for full bandwidth MU-MIMO is enabled, there is no RU allocation signaling in the HE-SIG-B 112 according to the sixth to eleventh embodiments of the present disclosure. Otherwise, 8-bit RU allocation signaling as shown in Table 8 may be used in the HE-SIG-B 112. As a result, the receiving STA can know which RU allocation signaling is used in the HE-SIG-B 112 of the HE packet 100 based on the UL / DL field and the SIGB compression field of the HE-SIG-A 110 of the HE packet 100. Furthermore, compared with the HE-SIG-B related signaling fields in the HE-SIG-A in Table 7 according to the eleventh embodiment of the present disclosure, no additional HE-SIG-A signaling bits are required in the fourteenth embodiment of the present disclosure when only UL SU partial band transmission is supported.

[0170] [Table 16]

[0171] <Access point configuration> FIG. 12 is a block diagram showing a configuration example of an AP according to the present disclosure. The AP includes a controller 1202, a scheduler 1204, a message generation unit 1208, a message processor 1206, a PHY processor 1210, and an antenna 1212. The antenna 1212 can be configured by one antenna port or a combination of a plurality of antenna ports. The controller 1202 is a MAC protocol controller and controls general MAC protocol operations. In the case of DL transmission, the scheduler 1204 performs frequency scheduling under the control of the controller 1202 based on the channel quality indicator (CQI) from the STA, and allocates the STA's data to the RU. Further, the scheduler 1204 outputs the resource allocation result to the message generation unit 1208. The message generation unit 1208 generates corresponding control signaling (i.e., common control information, resource allocation information, and user-specific allocation information) and the scheduled STA data, which are formed into HE packets by the PHY processor 1210 and transmitted via the antenna 1212. The control signaling can be configured according to the above-described embodiment. On the other hand, the message processor 1206 analyzes the CQI received from the STA through the antenna 1212 under the control of the controller 1202 and provides it to the scheduler 1204 and the controller 1202. These CQIs are the reception quality information notified from the STA. The CQI may also be referred to as "CSI" (Channel State Information).

[0172] <Configuration of STA> FIG. 13 is a block diagram showing a configuration example of a STA according to the present disclosure. The STA includes a controller 1302, a message generator 1304, a message processor 1306, a PHY processor 1308, and an antenna 1310. The controller 1302 is a MAC protocol controller and controls general MAC protocol operations. The antenna 1310 can be configured with one antenna port or a combination of multiple antenna ports. In the case of DL transmission, the antenna 1310 receives a downlink signal including an HE packet, and the message processor 1306 identifies the designated RU and its specific allocation information from the control signaling included in the received HE packet, and decodes the specific data from the received HE packet in the designated RU according to the specific allocation information. The control signaling included in the HE packet can be configured according to the above-mentioned embodiment. The message processor 1306 estimates a channel quality from the HE packet received via the antenna 1310 and provides it to the controller 1302. The message generator 1304 generates a CQI message, which is formed by a PHY processor 1308 and transmitted via an antenna 1310 .

[0173] In the above embodiment, the present invention is illustratively configured by hardware, but the present invention may also be provided by software cooperating with hardware.

[0174] In addition, the functional blocks used in the description of this embodiment are generally realized as LSI devices, which are integrated circuits. The functional blocks may be formed as individual chips, or some or all of the functional blocks may be integrated into a single chip. Although the term "LSI" is used here, the terms "IC", "system LSI", "super LSI" or "ultra LSI" may also be used depending on the degree of integration.

[0175] In addition, the circuit integration is not limited to LSI, but may be realized by a dedicated circuit other than LSI or a general-purpose processor. A field programmable gate array (FPGA), which is programmable after the LSI is manufactured, or a reconfigurable processor that allows the reconfiguration of the connections and settings of circuit cells in the LSI may be used.

[0176] If an integrated circuit technology that replaces LSI appears as a result of advances in semiconductor technology or other technologies derived from it, the functional blocks may be integrated using such technology. Another possibility is applications such as biotechnology. [Industrial Applicability]

[0177] The present disclosure may be applied to a method for formatting and transmitting resource allocation information in a wireless communication system. [Explanation of symbols]

[0178] 1202 Controller 1204 Scheduler 1206 Message Processor 1208 Message Creation Unit 1210 PHY Processor 1212 Antenna 1302 Controller 1304 Message Creation Unit 1306 Message Processor 1308 PHY Processor 1310 Antenna

Claims

1. A communication device comprising an antenna and a control circuit, The antenna receives a High Efficiency (HE) packet including a High Efficiency signaling B (HE-SIG-B) and a data field from a transmitting communication device; When the HE packet is used for single-user subband transmission, The HE-SIG-B includes resource unit (RU) allocation information indicating one of a plurality of RU allocations and a plurality of user fields; one of the plurality of RU assignments indicates a plurality of RUs each corresponding to the plurality of user fields; One RU of the plurality of RUs is assigned to the communication device, and another RU of the plurality of RUs is an unassigned RU; A dummy association ID (AID) is set in the user field corresponding to the unallocated RU, The HE-SIG-B is transmitted in a bandwidth of 20 MHz, and the data field is transmitted in the assigned one RU of 106 tones less than 20 MHz; When the HE packet is used for single-user full-bandwidth transmission, The HE-SIG-B includes RU allocation information indicating one RU across the entire 20 MHz bandwidth and a user field corresponding to the one RU, and the HE-SIG-B and the data field are transmitted in the 20 MHz bandwidth; The control circuitry decodes the received HE packet. Communications equipment.

2. The RU allocation information is used for multiple-input multiple-output (MIMO) transmission. The communication device according to claim 1 .

3. The RU allocation information is used for orthogonal frequency division multiplexing transmission; The communication device according to claim 1 .

4. 1. A communication method for a communication device, comprising: receiving a High Efficiency (HE) packet including an HE-SIG-B and a data field from a transmitting communication device; When the HE packet is used for single-user subband transmission, The HE-SIG-B includes resource unit (RU) allocation information indicating one of a plurality of RU allocations and a plurality of user fields; one of the plurality of RU assignments indicates a plurality of RUs each corresponding to the plurality of user fields; One RU of the plurality of RUs is assigned to the communication device, and another RU of the plurality of RUs is an unassigned RU; A dummy association ID (AID) is set in the user field corresponding to the unallocated RU, The HE-SIG-B is transmitted in a bandwidth of 20 MHz, and the data field is transmitted in the assigned one RU of 106 tones less than 20 MHz; When the HE packet is used for single-user full-bandwidth transmission, the HE-SIG-B includes RU allocation information indicating one RU across the entire 20 MHz bandwidth and a user field corresponding to the one RU, and the HE-SIG-B and the data field are transmitted in the 20 MHz bandwidth; and decoding the received HE packet. Communication methods.

Images