Receiving method, station and integrated circuit for receiving

Abstract

The present disclosure discloses a receiving method, a station and an integrated circuit for receiving. The station includes: a receiving unit, receiving a signal including a non-traditional preamble and a data field, the non-traditional preamble including a first field for indicating the number of spatial streams NSS in the data field and a second field for indicating one of a plurality of modulation and coding modes MCS, wherein two or more diversity transmission modes are supported and one of the two or more diversity transmission modes is applied based on the value of the NSS; and a circuit, decoding the signal.

Description

[0001] This application is a divisional application of an invention patent application with an application date of March 13, 2017, application number: 201780020956.X, and invention name: "Device and method for diversity transmission in a wireless communication system". Technical Field

[0002] The present disclosure relates generally to wireless communications, and more particularly to apparatus and methods for diversity transmission in wireless communication systems. Background Art

[0003] 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 achieve a substantial increase in the actual throughput achieved by users in high-density scenarios. OFDMA (Orthogonal Frequency Division Multiple Access) multi-user transmission has been envisioned as one of the most important features in 802.11ax. OFDMA is a multiple access method that performs multiple operations on data streams to and from multiple users on the time and frequency resources of an OFDM (Orthogonal Frequency Division Multiplexing) system.

[0004] Frequency scheduling is usually performed for OFDMA multi-user transmission in 802.11ax. According to frequency scheduling, a radio communication access point device (hereinafter referred to as "access point" or "AP") adaptively allocates subcarriers to multiple radio communication station devices (hereinafter referred to as "terminal stations" or "STA") 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 quite efficiently.

[0005] Frequency scheduling is usually performed based on resource units (RUs). RUs include multiple consecutive subcarriers. Depending on the number of constituent subcarriers per RU, RUs can be of different types. RUs are allocated by the AP to each of the multiple STAs with which the AP communicates. The RU allocation results of the frequency scheduling performed by the AP should be reported to the STA as RU allocation information. In addition, the AP should also report other control signaling to the STA, such as common control information and per-user allocation information.

[0006] Citation List

[0007] Patent Literature

[0008] [PTL 1]US 9,160,492 B2

[0009] Non-patent literature

[0010] [NPL 1] IEEE 802.11-16 / 0024r1, Proposed TGax draft specification, March 2016

[0011] [NPL 2] IEEE 802.11-16 / 0056r0, On QPSK DCM Modulation and LDPC ToneMapper for DCM, January 2016

[0012] [NPL 3] IEEE 802.11-15 / 1068r1, Reliable Dual Sub-Carrier Modulations (DCM) for HE-SIG-B and Data, September 2015

[0013] [NPL 4] A Novel SFBC-OFDM Scheme for Doubly Selective Channels, IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL.58, NO.5, June 2009, p2573-2578

[0014] [NPL 5]IEEE Std 802.11ad TM -2012 Summary of the invention

[0015] In 802.11ax, a STA can send the data field of a HE packet in one RU with a bandwidth of about 2 MHz in uplink OFDMA, while sending the preamble of the HE packet with a bandwidth of 20 MHz. Therefore, the power spectral density of the data field of the HE packet is 9 dB higher than that of the preamble. Therefore, one STA may experience severe narrowband interference. In addition, it is also necessary to enhance the PER (packet error rate) performance of the HE packet in order to extend the transmission range for outdoor scenarios. Research is underway to perform efficient diversity transmission in 802.11ax to mitigate narrowband interference and improve PER performance.

[0016] In one general aspect, the technology disclosed herein is characterized by: a transmitting device, comprising: a transmission signal generating unit, generating a transmission signal including a traditional preamble, a non-traditional preamble, and a data field, the non-traditional preamble including a signal field, which carries a number N indicating the number of spatial streams in the data field SS and a second control signaling indicating a modulation mode used in the data field; when diversity transmission in the data field is enabled and two or more diversity transmission modes are applicable to the modulation mode used in the data field, according to N SS The value of determines two or more diversity transmission modes to be used in the data field; and a transmitting unit transmits the generated transmission signal.

[0017] In one general aspect, the technology disclosed herein is characterized by: a station comprising: a receiving unit that receives a signal including a non-legacy preamble code and a data field, the non-legacy preamble code including a first field for indicating the number of spatial streams NSS in the data field and a second field for indicating one of a plurality of modulation and coding schemes MCS, wherein two or more diversity transmission schemes are supported and one of the two or more diversity transmission schemes is applied based on the value of the NSS; and a circuit that decodes the signal.

[0018] In one general aspect, the technology disclosed herein is characterized by: a station comprising: a receiving unit, receiving a signal including a non-traditional preamble code and a data field, the non-traditional preamble code including a first field for indicating the number of spatial streams NSS in the data field and a second field for indicating one of multiple modulation and coding modes MCS, wherein two or more diversity transmission modes are supported; and a circuit, decoding the signal, a first mode of the two or more diversity transmission modes is a dual subcarrier modulation DCM, and a second mode of the two or more diversity transmission modes is a space frequency diversity mode, and if the non-traditional preamble code indicates that at least one of the two or more diversity transmission modes is applied to the data field and the value of the Nss is an odd number, then the first mode is applied to at least one spatial stream.

[0019] In one general aspect, the technology disclosed herein is characterized by: a receiving method comprising: receiving a signal including a non-traditional preamble code and a data field, the non-traditional preamble code including a first field for indicating the number of spatial streams Nss in the data field and a second field for indicating one of a plurality of modulation and coding modes MCS, wherein two or more diversity transmission modes are supported and one of the two or more diversity transmission modes is applied based on the value of the NSS; and decoding the signal.

[0020] In one general aspect, the technology disclosed herein is characterized by: an integrated circuit for controlling a method, the method comprising: receiving a signal including a non-legacy preamble and a data field, the non-legacy preamble including a first field for indicating the number of spatial streams Nss in the data field and a second field for indicating one of a plurality of modulation and coding schemes MCS, wherein two or more diversity transmission schemes are supported and one of the two or more diversity transmission schemes is applied based on a value of the NSS; and decoding the signal.

[0021] It should be noted that the general or specific disclosure may be embodied as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination thereof.

[0022] By utilizing the diversity transmission of the present disclosure, narrowband interference can be mitigated and PER performance can be improved.

[0023] Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and / or advantages may be obtained individually by the various embodiments and features of the specification and drawings, and the various embodiments and features do not need to be provided in full to obtain one or more of these benefits and / or advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A diagram illustrating the format of a HE (High Efficiency) packet compliant with the proposed 802.11ax draft specification is shown.

[0025] Figure 2 An example configuration of a transmitting unit for generating the HE data field of an HE packet for single-user transmission in a RU (resource unit) using DCM (dual subcarrier modulation) and BCC (binary convolutional coding) according to the proposed 802.11ax draft specification is shown.

[0026] Figure 3 A diagram illustrating an example operation of a DCM in the case of QPSK (Quadrature Phase Shift Keying) modulation according to the prior art is shown.

[0027] Figure 4 A diagram illustrating an example operation of SFBC (Space Frequency Block Coding) as a type of SFDS (Space Frequency Diversity Scheme) according to the related art is shown.

[0028] Figure 5 A flow chart illustrating an example method for performing diversity transmission according to a first embodiment of the present disclosure is shown.

[0029] Fig. 6AA diagram illustrating example pairings of spatial streams in the case of OL (Open Loop) MIMO (Multiple Input Multiple Output) transmission with direct mapping and four spatial streams according to the first embodiment of the present disclosure is shown, where the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0030] Figure 6B A diagram illustrating another example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and six spatial streams according to the first embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0031] Figure 6C A diagram illustrating another example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and eight spatial streams according to the first embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0032] Fig.6D A diagram illustrating another example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the first embodiment of the present disclosure is shown, where the stream indices assigned to the spatial streams are not aligned with the physical antenna configuration.

[0033] Figure 7 An example configuration of a transmission unit for generating a HE data field of an HE packet for single-user transmission in an RU using diversity transmission and BCC according to the first embodiment of the present disclosure is shown.

[0034] Figure 8 A flow chart illustrating an example method for performing diversity transmission according to a second embodiment of the present disclosure is shown.

[0035] Fig.9A A diagram illustrating an example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0036] Fig. 9B A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and five spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0037] Fig. 9C A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and six spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0038] Fig.9D A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and seven spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0039] Fig.9E A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and eight spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are aligned with the physical antenna configuration.

[0040] Fig.9F A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are not aligned with the physical antenna configuration.

[0041] Figure 9G A diagram illustrating another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and five spatial streams according to the second embodiment of the present disclosure is shown, wherein the stream indices assigned to the spatial streams are not aligned with the physical antenna configuration.

[0042] Fig.10 A diagram illustrating an example operation of e-SFDS (enhanced SFDS) in case of QPSK modulation according to the second embodiment of the present disclosure is shown.

[0043] Fig.11 An example configuration of a transmission unit for generating a HE data field of an HE packet for single-user transmission in an RU using diversity transmission and BCC according to the second embodiment of the present disclosure is shown.

[0044] Fig.12 An example configuration of a wireless communication device according to the present disclosure is shown. DETAILED DESCRIPTION

[0045] 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 have been omitted for clarity and conciseness.

[0046] Figure 1The format of a HE (High Efficiency) packet 100 in accordance with the proposed 802.11ax draft specification [see NPL 1] is shown. 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; a HE preamble including a repeated L-SIG field (RL-SIG) 108, a first HE signal field (HE-SIG-A) 110, a second HE signal field (HE-SIG-B) 112, a HE short training field (HE-STF) 114, and a HE long training field (HE-LTF) 116; a HE data field 120; and a packet extension (PE) field 122.

[0047] The legacy preamble (102, 104, 106) is used to facilitate backward compatibility with the legacy 802.11a / g / n / ac standards. The L-STF 102 and L-LTF 104 are primarily used for packet detection, AGC (automatic gain control) setting, frequency offset estimation, time synchronization, and channel estimation. The L-SIG 106 is used together with the RL-SIG 108 copied from the L-SIG 106 in the HE preamble to help distinguish the HE packet 100 from the legacy 802.11a / g / n / ac packet. In addition, the L-SIG 106 includes a length field indicating the transmission time of the HE packet 100.

[0048] The HE-SIG-A 110 in the HE preamble carries common control information required to interpret the remaining fields of the HE packet 100. In the case of an HE packet 100 for single-user transmission, the HE-SIG-A 110 includes fields such as bandwidth, MCS (modulation and coding scheme), N ss The MCS field indicates the modulation scheme and coding rate used in the HE data field 120. The modulation scheme may be BPSK (binary phase shift keying), QPSK (quadrature phase shift keying), 16-QAM (16-quadrature amplitude modulation), 64-QAM, etc. N ss The HE-SIG-A field indicates the number of spatial streams in the HE data field 120, the coding field indicates whether LDPC (Low Density Parity Check Coding) or BCC (Binary Convolutional Coding) is used in the HE data field 120, and the DCM field indicates whether DCM is used in the HE data field 120. In the case of the HE packet 100 for downlink multi-user transmission, the HE-SIG-A 110 includes signaling fields such as a bandwidth field, a SIGB MCS field, a SIGB DCM field, and a SIGB symbol number field.

[0049] The HE-SIG-B 112 in the HE preamble includes a common field 122, followed by a user-specific field 124. The common field 122 contains RU allocation information (e.g., RU arrangement in the frequency domain and the number of users multiplexed in each RU). If the RU is designated for single-user transmission, the number of users multiplexed in the RU is one. If the RU is designated for MU-MIMO (multi-user multiple-input multiple-output) transmission, the number of users multiplexed in the RU is two or more. The user-specific field 124 includes multiple user-specific subfields. Each user-specific subfield carries per-user allocation information. For each RU designated for single-user transmission, there is only a single corresponding user-specific subfield, which contains information such as STA identifier, N ss , MCS, DCM, and coding, etc. For each RU designated for MU-MIMO transmission with K multiplexed users, there are K corresponding user-specific subfields, each of which includes signaling fields such as STA identifier, spatial configuration, MCS, DCM, and coding. The ordering of the user-specific subfields in the user-specific field conforms to the RU arrangement signaled by the common field 122. If the HE packet 100 is intended for single-user transmission or for multi-user transmission based on uplink triggering, the HE-SIG-B 112 is not present in the HE packet 100. For multi-user transmission based on uplink triggering, the RU allocation information and per-user allocation information for the designated transmitting STA are preset at the AP and sent by the AP to the designated transmitting STA in the trigger frame.

[0050] The HE-STF 114 in the HE preamble is used to reset the AGC and reduce the dynamic range requirements of the ADC (Analog-to-Digital Converter). The HE-LTF 116 in the HE preamble is provided for MIMO channel estimation for receiving and equalizing the HE data field 120. The HE data field 120 for the STA includes a PSDU (Physical Layer Service Data Unit), which is sent on its designated RU spanning all OFDM symbols in the HE data field 120. The PE field 122 carries null data, which is purely used to allow the receiving unit to have enough time to process the last OFDM symbol of the HE data field 120.

[0051] Details of the transmission process for 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, HE data field 120, and PE field 122 may be found in the proposed 802.11ax draft specification [see NPL 1].

[0052] Figure 2 FIG. 1 illustrates a HE data field 120 (see FIG. 1 ) for generating HE data for single-user transmission in a RU using DCM and BCC according to the proposed 802.11ax draft specification [see NPL 1]. Figure 1 ) of the example configuration of the sending unit 200. The sending unit 200 includes a pre-FEC PHY padding block 202, a scrambling unit 204, a BCC encoding unit 206, a post-FEC PHY padding block 208, a stream parsing unit 210, an N ss BCC interleaving units 212, N ss constellation mapping units 214, N ss DCM tone mapping unit 216, (N ss -1) CSD (Cyclic Shift Diversity) block 218, spatial and frequency mapping block 220, N TX IDFT (Inverse Discrete Fourier Transform) blocks 222, N TX GI (guard interval) insertion and windowing blocks 224 and N TX Analog and RF (radio frequency) blocks 226, where N ss is the number of spatial streams and N TX is the number of sending chains.

[0053] The pre-FEC PHY padding block 202, the scrambling unit 204, the BCC encoding unit 206, and the post-FEC PHY padding block 208 convert the PSDU into a sequence of coded data bits. The stream parsing unit 210 rearranges the sequence of coded data bits into N ss data blocks, each of which corresponds to a specific spatial stream. ss For each of the spatial streams, the corresponding BCC interleaving unit 212 interleaves the coded bits in the data block. The corresponding constellation mapping unit 214 maps the coded and interleaved bits in the data block to modulation constellation points. The corresponding DCM tone mapping unit 216 operates DCM on the modulation constellation points, followed by cyclic shift insertion by the corresponding CSD block 218, except for the first spatial stream. The space and frequency mapping block 220 maps the N for single-user transmission in the RU to ss The modulation constellation points of the spatial streams are mapped to N TX For N TX For each of the transmit chains, the IDFT block 222 converts the modulation constellation points into multiple time-domain OFDM symbols. The GI insertion and windowing block 224 adds its own circular extension in front of each OFDM symbol and optionally smoothes the edge of each OFDM symbol to increase spectral attenuation. The analog and RF block 226 converts multiple time-domain OFDM symbols into analog signals that are sent through the antenna.

[0054] Figure 3 The diagram illustrates an example operation of DCM (dual subcarrier modulation) in the case of QPSK modulation according to the prior art [see NPL1, NPL2, NPL3, NPL5]. DCM is performed per spatial stream. The coded and interleaved bits in the data block corresponding to the first spatial stream SS1 are modulated by QPSK and mapped to the lower half ( Figure 3 ), that is, {d 1,k ,k=0,1,...,N SD / 2-1}, where N SD is the number of data subcarriers in the RU. The modulated symbols of the lower half of the data subcarriers corresponding to the first spatial stream SS1 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the first spatial stream in the RU ( Figure 3 ), that is,

[0055]

[0056] Where P(k) is a function of the subcarrier index k, for example, P(k)=k+N SD / 2. Similarly, the coded and interleaved bits in the data block corresponding to the second spatial stream SS2 are modulated by QPSK and mapped to the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU, that is, {d 2,k ,k=0,1,...,N SD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the second spatial stream SS2 in the RU, that is,

[0057]

[0058] In this way, frequency diversity gain can be obtained. Therefore, narrowband interference can be mitigated and PER performance can be improved.

[0059] Figure 4 The diagram illustrates an example operation of SFBC (space frequency block coding) as a SFDS (space frequency diversity scheme) according to the prior art [see PL1, NPL4]. SFBC is performed across two spatial streams. The coded and interleaved bits in the data block corresponding to the first spatial stream SS1 are modulated and mapped to the lower half ( ) of the data subcarriers corresponding to the first spatial stream SS1 in the RU. Figure 4 ), that is, {d 1,k ,k=0,1,...,N SD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the first spatial stream SS1 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the second spatial stream SS2 in the RU ( Figure 4 ), that is,

[0060]

[0061] On the other hand, the coded and interleaved bits in the data block corresponding to the second spatial stream SS2 are modulated and mapped to the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU, that is, {d2,k,k=0,1,...,N SD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU are repeated, conjugated, inverted, and then mapped to the upper half of the data subcarriers corresponding to the first spatial stream SS1 in the RU, that is,

[0062]

[0063] In this way, in addition to the frequency diversity gain, a spatial diversity gain can also be obtained.

[0064] Note that Figure 3 The DCM shown and Figure 4 The SFDS shown may not be used in the case of higher order modulation (eg, 64-QAM) because they may reduce the data rate for higher order modulation at the expense of achieving better PER performance.

[0065] like Figure 3 The DCM shown is applicable to diversity transmission with any number of spatial streams. Figure 3 The DCM shown does not bring spatial diversity gain. On the other hand, Figure 4 The SFDS shown has both spatial diversity gain and frequency diversity gain for diversity transmission with two spatial streams. However, it is not clear how to combine Figure 4 The SFDS shown is extended to diversity transmission with more than two spatial streams. Next, according to the present disclosure, various embodiments of an apparatus and method for performing diversity transmission with any number of spatial streams in such a manner as to obtain both spatial diversity gain and frequency diversity gain as much as possible will be described in more detail.

[0066] <First Embodiment>

[0067] Figure 5 An example method 500 for performing diversity transmission with any number of spatial streams according to a first embodiment of the present disclosure is illustrated. The method 500 starts at step 502. At step 504, Nss The spatial streams are paired into N p Yes, among them

[0068] [Mathematical formula.1]

[0069] Np ＝ floor(N ss / twenty one)

[0070] Note that if N ss is an odd number, then one of the spatial streams is unpaired.

[0071] According to the first embodiment of the present disclosure, the method for pairing spatial streams may be configurable or predetermined. In the case where there are several configurable methods for pairing spatial streams, additional signaling is required in the user-specific subfield of HE-SIG-A 110, HE-SIG-B 112 or the trigger frame to indicate the method actually used to pair the used spatial streams.

[0072] According to the first embodiment of the present disclosure, for open-loop (OL) MIMO transmission, spatial stream pairing can be performed based on the physical antenna configuration and the mapping of spatial streams to antennas, so that the correlation between the paired spatial streams is as weak as possible. To achieve this, it is preferred to avoid pairing of spatial streams to be transmitted through adjacent antennas and maximize the minimum physical distance between the antennas through which the paired spatial streams are transmitted. In the case where the stream index assigned to the spatial stream is aligned with the physical antenna configuration, the spatial stream pairing method is used to pair the spatial streams into N P An example method for the pair includes: starting from the stream space with the smallest stream index, separating the streams by N in terms of stream index. P Every two spatial streams of N are paired together. ss If is an odd number, the spatial stream with the largest stream index is not paired. As a result, the spatial diversity gain of each paired spatial stream can be improved, especially for OL MIMO transmission with direct mapping.

[0073] Fig. 6A An example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the first embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the third spatial stream SS3 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, but is similar to the correlation between the second spatial stream SS2 and the fourth spatial stream SS4. Therefore, it is better to pair SS1 with SS3 and SS2 with SS4 so that each of the four spatial streams can achieve similar and better spatial diversity gain.

[0074] Figure 6BAnother example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and six spatial streams according to the first embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the fourth spatial stream SS4 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2 or between the first spatial stream SS1 and the third spatial stream SS3, but is similar to the correlation between the second spatial stream SS2 and the fifth spatial stream SS5 or between the third spatial stream SS3 and the sixth spatial stream SS6. Therefore, it is better to pair SS1 with SS4, SS2 with SS5, and SS3 with SS6, so that each of the six spatial streams can achieve similar and better spatial diversity gain.

[0075] Figure 6C Another example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and eight spatial streams according to the first embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the fifth spatial stream SS5 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, between the first spatial stream SS1 and the third spatial stream SS3, or between the first spatial stream SS1 and the fourth spatial stream SS4, but is similar to the correlation between the second spatial stream SS2 and the sixth spatial stream SS6, between the third spatial stream SS3 and the seventh spatial stream SS7, or between the fourth spatial stream SS4 and the eighth spatial stream SS8. Therefore, it is better to pair SS1 with SS5, SS2 with SS6, SS3 with SS7, and SS4 with SS8, so that each of SS1 to SS8 can achieve similar and better spatial diversity gain.

[0076] Fig.6D Another example pairing of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the first embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is not aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the second spatial stream SS2 is generally weaker than the correlation between the first spatial stream SS1 and the third spatial stream SS3, but is similar to the correlation between the third spatial stream SS3 and the fourth spatial stream SS4. Therefore, it is better to pair SS1 with SS2 and SS3 with SS4 so that SS1, SS2, SS3, SS4 can achieve similar and better spatial diversity gain.

[0077] exist Figure 5 Step 506 in Figure 4 The SFDS shown in FIG. 1 is applied to each spatial stream pair. If Nss is an odd number, then Figure 3The DCM shown is applied to unpaired spatial streams. The method 500 stops at step 508 .

[0078] According to the first embodiment of the present disclosure, diversity transmission is enabled for single-user transmission in RU, and two diversity transmission modes including DCM and SFDS are applicable to the modulation mode used in RU. The diversity transmission mode used in RU depends only on the number N of spatial streams to be transmitted in RU. ss To determine, as follows:

[0079] -If N ss is an even number, then SFDS is applied to N P For example, in N ss =2, SFDS is applied to a single spatial stream pair.

[0080] -If N ss is an odd number, then SFDS is applied to N P For each of the N spatial stream pairs, DCM is applied to the unpaired spatial streams. ss = 1, DCM is applied to a single spatial stream. ss =3, SFDS is applied to a single spatial stream pair, and DCM is applied to the remaining unpaired spatial streams.

[0081] According to the first embodiment of the present disclosure, HE-SIG-A110, Figure 1 The user-specific subfield of the HE-SIG-B 112 of the HE packet 100 in the HE packet or the DCM field in the trigger frame can be reused to indicate whether diversity transmission is enabled. In the case of enabling diversity transmission, the receiving unit can ss Determine which diversity transmission mode is used for single-user transmission in the RU.

[0082] According to the above configuration, by using SFDS as the diversity transmission mode for each paired spatial stream, if two or more spatial streams are transmitted in the RU, both frequency diversity and spatial diversity gain can be obtained for each paired spatial stream. Therefore, the narrowband interference experienced by the HE packet 100 is alleviated, and the PER performance of the HE packet 100 is improved. In addition, since the transmitting unit determines which diversity transmission mode to use for which spatial stream based on the number of spatial streams, the receiving unit is able to know which diversity transmission mode is used for which spatial stream without receiving additional signaling bits for reporting which diversity transmission mode is actually used for which spatial stream, even when two or more spatial streams are transmitted in the RU. Therefore, no additional signaling bits are required to support the above configuration. This is very important because the HE-SIG-A field, or the user-specific subfield of the HE-SIG-B field, may not have enough signaling bits to indicate which diversity transmission mode is used for which spatial stream.

[0083] According to the first embodiment of the present disclosure, if N SS If is an odd number, the unpaired spatial streams to which DCM is applied do not enjoy spatial diversity gain.

[0084] According to the first embodiment of the present disclosure, before decoding the HE data field 120 of the HE packet 100 transmitted by a single user in the RU, the receiving unit should be able to decode the HE data field 120 according to the number of spatial streams N. ss Know how the spatial streams are paired. For example, if N ss =4, the first spatial stream pair includes the first spatial stream SS1 and the third spatial stream SS3, and the second spatial stream pair includes the second spatial stream SS2 and the fourth spatial stream SS4.

[0085] According to a first embodiment of the present disclosure, for ss The method of decoding the HE data field 120 of the HE packet 100 for a single user transmission in the RU at the receiving unit when the number is even includes decoding the HE data field 120 from N P The information bits of the first spatial stream and the second spatial stream in each of the spatial stream pairs, and deparsing N ss spatial streams to obtain a sequence of decoded information bits.

[0086] According to a first embodiment of the present disclosure, for ss The method of decoding the HE data field 120 of the HE packet 100 for a single user transmission in the RU at the receiving unit when the number is an odd number includes decoding the HE data field 120 from N P information bits of the first spatial stream and the second spatial stream in each of the spatial stream pairs, decoding the information bits from the unpaired spatial streams, and inverse parsing N ssspatial streams to obtain a sequence of decoded information bits.

[0087] According to the first embodiment of the present disclosure, in order to decode the information bits from the first spatial stream in the spatial stream pair, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the first spatial stream in the pair. SD / 2-1) and the second data subcarrier P(k) (N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1), and then combine the two LLRs. To decode the information bits from the second spatial stream in the spatial stream pair, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the second spatial stream in the pair. SD / 2-1) and the LLR corresponding to the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1) and then combine the two LLRs.

[0088] According to the first embodiment of the present disclosure, in order to decode information bits from an unpaired spatial stream, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the unpaired spatial stream. SD / 2-1) and the LLR at the second data subcarrier P(k) (N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1) and then combine the two LLRs.

[0089] Figure 7 FIG. 1 illustrates a method for generating a HE packet 100 for single-user transmission in a RU using diversity transmission and BCC according to a first embodiment of the present disclosure (see FIG. Figure 1 ) of the HE data field 120. The transmitting unit 700 includes a pre-FEC PHY padding block 702, a scrambling unit 704, a BCC encoding unit 706, a post-FEC PHY padding block 708, a stream parsing unit 710, an N ss BCC interleaving units 712, N ss constellation mapping unit 714, DCM / SFDS tone mapping unit 716, (N ss -1) CSD block 718, spatial and frequency mapping block 720, N TXIDFT blocks 722, N TX GI insertion and windowing blocks 724 and N TX The transmitting unit 700 also includes a spatial stream pairing block 732 and a diversity mode selection block 734.

[0090] Pre-FEC PHY padding block 702, scrambling unit 704, BCC encoding unit 706, post-FEC PHY padding block 708, stream parsing unit 710, BCC interleaving unit 712, constellation mapping unit 714, CSD block 718, space and frequency mapping block 720, IDFT block 722, GI insertion and windowing block 724, and analog and RF block 726 have the same functions as they do in FIG. Figure 2 The corresponding parts in the sending unit 200 shown have exactly the same functions.

[0091] The spatial stream pairing block 732 converts N ss The spatial streams are paired into N P Yes. If N ss is an odd number, then N ss One of the spatial streams is not paired. The diversity mode selection block 734 selects the number of spatial streams according to N ss The value of determines the diversity mode to be used. ss If is an odd number, the DCM / SFDS tone mapping unit 716 performs the following for the unpaired spatial streams: Figure 3 The DCM shown, and for N P Each of the spatial stream pairs performs Figure 4 SFDS shown.

[0092] According to the configuration of the first embodiment of the present disclosure, by using SFDS as the diversity transmission mode for each paired spatial stream, if two or more spatial streams are transmitted in the RU, both frequency diversity and spatial diversity gain can be obtained for each paired spatial stream. Therefore, narrowband interference experienced by the HE packet 100 is mitigated, and the PER performance of the HE packet 100 is improved. In addition, no additional signaling bits are required to report to the receiving unit which diversity transmission mode is used for which spatial stream.

[0093] <Second Embodiment>

[0094] Figure 8 An example method 800 for performing diversity transmission according to a second embodiment of the present disclosure is illustrated. The method 800 starts at step 802. At step 804, if the number of spatial streams N ss If 1 is equal to 1, the method 800 proceeds to step 806. Otherwise, the method 800 proceeds to step 808.

[0095] In step 806, Figure 3The DCM shown is applied to a single spatial stream. Method 800 stops at step 818. At step 808, if the number of spatial streams N ss If , then the method 800 proceeds to step 810. Otherwise, the method 800 proceeds to step 814.

[0096] In step 810, N ss The spatial streams are grouped into N g groups, of which

[0097] [Mathematical formula.2]

[0098] N g =floor(N ss / twenty two)

[0099] Each group includes two spatial streams. Figure 4 The SFDS shown is applied to N g Method 800 stops at step 818 .

[0100] In step 814, the Nss spatial streams are grouped into N g groups, where N g One of the groups includes three spatial streams, and the remaining (N g -1) groups each including two spatial streams. In step 816, Figure 4 The conventional SFDS shown is applied to (N g -1) each of the two spatial stream groups, and applying enhanced SFDS (e-SFDS) to the three spatial stream groups. The operation of e-SFDS will be described in detail later. The method 800 stops at step 818.

[0101] According to the second embodiment of the present disclosure, the method for grouping spatial streams may be configurable or predetermined. In the case where multiple methods for grouping spatial streams are configurable, additional signaling is required in the user-specific subfield of HE-SIG-A 110, HE-SIG-B 112 or the trigger frame to indicate the method actually used to group the spatial streams.

[0102] According to the second embodiment of the present disclosure, for OL MIMO, spatial streams can be grouped based on physical antenna configuration and mapping of spatial streams to antennas so that the correlation between the grouped spatial streams is as weak as possible. To achieve this, it is preferred to avoid grouping spatial streams to be transmitted through adjacent antennas into the same group and to maximize the minimum physical distance between antennas through which spatial streams in the same group are transmitted.

[0103] In the case where the stream indices assigned to the spatial streams are aligned with the physical antenna configuration, if Nss If it is an even number, it is used to group the spatial streams into N g An example method for creating spatial stream groups includes: starting with the spatial stream with the smallest stream index, dividing the spatial stream groups by N in terms of stream index. g Every two spatial streams of N are grouped together. ss is an odd number and greater than 1, it is used to group spatial streams into N g An example method for generating a spatial stream group includes: starting from the spatial stream with the second smallest stream index, for (N g -1) Each of the two spatial stream groups will be separated by N in terms of stream index. g Every two spatial streams are grouped together. The remaining three spatial streams are grouped into three spatial stream groups. As a result, the spatial diversity gain of each spatial stream can be improved, especially for OL MIMO transmission with direct mapping.

[0104] Fig.9A An example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the third spatial stream SS3 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, but is similar to the correlation between the second spatial stream SS2 and the fourth spatial stream SS4. Therefore, it is better to group SS1 with SS3 and SS2 with SS4 so that each of the four spatial streams can achieve similar and better spatial diversity gain.

[0105] Fig. 9B Another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and five spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the third spatial stream SS3 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, but is similar to the correlation between the second spatial stream SS2 and the fourth spatial stream SS4, or between the third spatial stream SS3 and the fifth spatial stream SS5. Therefore, it is better to group SS1, SS3 with SS5 and group SS2 with SS4 so that each of SS1 to SS5 can achieve similar and better spatial diversity gain.

[0106] Fig. 9CAnother example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and six spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the fourth spatial stream SS4 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, or between the first spatial stream SS1 and the third spatial stream SS3, but is similar to the correlation between the second spatial stream SS2 and the fifth spatial stream SS5, or between the third spatial stream SS3 and the sixth spatial stream SS6. Therefore, it is better to pair SS1 with SS4, SS2 with SS5, and SS3 with SS6, so that each of SS1 to SS6 can achieve similar and better spatial diversity gain.

[0107] Fig.9D Another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and seven spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the fourth spatial stream SS4 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, or the correlation between the first spatial stream SS1 and the third spatial stream SS3, but is similar to the correlation between the second spatial stream SS2 and the fifth spatial stream SS5, the third spatial stream SS3 and the sixth spatial stream SS6, or the fourth spatial stream SS4 and the seventh spatial stream SS7. Therefore, it is better to group SS1, SS4 with SS7, SS2 with SS5, and SS3 with SS6, so that each of SS1 to SS7 can achieve similar and better spatial diversity gain.

[0108] Fig.9E Another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and eight spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the fifth spatial stream SS5 is generally weaker than the correlation between the first spatial stream SS1 and the second spatial stream SS2, between the first spatial stream SS1 and the third spatial stream SS3, or between the first spatial stream SS3 and the fourth spatial stream SS4, but is similar to the correlation between the second spatial stream SS2 and the sixth spatial stream SS6, between the third spatial stream SS3 and the seventh spatial stream SS7, or between the fourth spatial stream SS4 and the eighth spatial stream SS8. Therefore, it is better to pair SS1 with SS5, SS2 with SS6, SS3 with SS7, and SS4 with SS8, so that each of SS1 to SS8 can achieve similar and better spatial diversity gain.

[0109] Fig.9F Another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and four spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is not aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the second spatial stream SS2 is generally weaker than the correlation between the first spatial stream SS1 and the third spatial stream SS3, but is similar to the correlation between the third spatial stream SS3 and the fourth spatial stream SS4. Therefore, it is better to group SS1 with SS2 and SS3 with SS4 so that SS1, SS2, SS3, SS4 can achieve similar and better spatial diversity gain.

[0110] Figure 9G Another example grouping of spatial streams in the case of OL MIMO transmission with direct mapping and five spatial streams according to the second embodiment of the present disclosure is illustrated. Here, the stream index assigned to the spatial stream is not aligned with the physical antenna configuration. Note that the correlation between the first spatial stream SS1 and the second spatial stream SS2 is generally weaker than the correlation between the first spatial stream SS1 and the fourth spatial stream SS4, but is similar to the correlation between the fourth spatial stream SS4 and the fifth spatial stream SS5, or between the second spatial stream SS2 and the third spatial stream SS3. Therefore, it is better to group SS1, SS2 with SS3 and SS4 with SS5 so that each of SS1 to SS5 can achieve similar and better spatial diversity gain.

[0111] Fig.10 FIG. 1 illustrates an example operation of e-SFDS in the case of using QPSK modulation according to the second embodiment of the present disclosure. e-SFDS is performed across three spatial streams. The coded and interleaved bits in the data block corresponding to the first spatial stream SS1 are modulated by QPSK and mapped to the lower half ( 10 ) of the data subcarriers corresponding to the first spatial stream SS1 in the RU. Fig.10 ), that is, {d 1,k ,k=0,1,...,N SD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the first spatial stream SS1 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the second spatial stream SS2 in the RU ( Fig.10 ), that is,

[0112]

[0113] The coded and interleaved bits in the data block corresponding to the second spatial stream SS2 are modulated by QPSK and mapped to the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU, that is, {d 2,k ,k=0,1,...,NSD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the second spatial stream SS2 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the third spatial stream SS3 in the RU, that is,

[0114]

[0115] The coded and interleaved bits in the data block corresponding to the third spatial stream SS3 are modulated by QPSK and mapped to the lower half of the data subcarriers corresponding to the third spatial stream SS3 in the RU, that is, {d 3,k ,k=0,1,...,N SD / 2-1}. The modulated symbols of the lower half of the data subcarriers corresponding to the third spatial stream SS3 in the RU are repeated, conjugated, and then mapped to the upper half of the data subcarriers corresponding to the first spatial stream SS1 in the RU, that is,

[0116]

[0117] According to the second embodiment of the present disclosure, the e-SFDS has an advantage in that both frequency diversity and spatial diversity gains can be obtained for each of three spatial streams in one three-spatial stream group.

[0118] Note that the e-SFDS as shown in FIG. 9 may not be used in the case of higher order modulation (eg, 64-QAM) because it may reduce the data rate for higher order modulation at the expense of achieving higher error performance.

[0119] According to the second embodiment of the present disclosure, diversity transmission is enabled for single-user transmission in the RU, and three diversity transmission modes including DCM, traditional SFDS and e-SFDS are applicable to the modulation mode used in the RU. The diversity transmission mode used in the RU depends only on the number N of spatial streams to be transmitted in the RU. ss To determine, as follows:

[0120] -If N ss =1, DCM is applied to a single spatial stream.

[0121] -If N ss is an even number, then the traditional SFDS is applied to N g For example, in N ss =2, conventional SFDS is applied to a single two-spatial stream group.

[0122] -If N ss is an odd number and greater than 1, then there exists N g Applying the traditional SFDS to (Ng -1) two-spatial-stream groups, and e-SFDS is applied to three-spatial-stream groups. ss =3, e-SFDS is applied to a single three-spatial stream group. In the case of Nss=5, conventional SFDS is applied to a two-spatial stream group, and e-SFDS is applied to a three-spatial stream group.

[0123] According to the second embodiment of the present disclosure, HE-SIG-A 110, Figure 1 The user-specific subfield of the HE-SIG-B 112 of the HE packet 100 in the HE packet or the DCM field in the trigger frame can be reused to indicate whether diversity transmission is enabled. In the case of enabling diversity transmission, the receiving unit should be able to ss Determine which diversity transmission mode(s) to use.

[0124] According to the above configuration, by using SFDS as the diversity transmission method for each of the two spatial stream groups and using e-SFDS as the diversity transmission method for the three spatial stream groups, if two or more spatial streams are transmitted in RU, it is possible to transmit N ss Both frequency diversity and spatial diversity gain are obtained by transmitting each of the plurality of spatial streams. Therefore, narrowband interference experienced by the HE packet 100 is mitigated, and the PER performance of the HE packet 100 is improved. In addition, since the transmitting unit determines which diversity transmission mode to be used for which spatial stream based on the number of spatial streams, the receiving unit is able to know which diversity transmission mode is used for which spatial stream without receiving additional signaling bits for reporting which diversity transmission mode is actually used for which spatial stream, even when two or more spatial streams are transmitted in the RU. Therefore, no additional signaling bits are required to support the above configuration. This is very important because the HE-SIG-A field or the user-specific subfield of the HE-SIG-B field may not have enough signaling bits to indicate which diversity transmission mode is used for which spatial stream.

[0125] According to the second embodiment of the present disclosure, before decoding the HE data field 120 of the HE packet 100 transmitted by a single user in the RU, the receiving unit should be able to decode the HE data field 120 according to the number of spaces N. ss Know how to group spatial streams. For example, if N ss =4, then the first two spatial stream groups include SS1 and SS3, and the second two spatial stream groups include SS2 and SS4.

[0126] According to a second embodiment of the present disclosure, for ss is an even number, the decoded at the receiving unit for the single user transmission in the RU Figure 1The method of decoding the HE data field 120 of the HE packet 100 in the HE data field 120 includes decoding the HE data field 120 of the HE packet 100 from the N ss / 2 information bits of the first spatial stream and the second spatial stream in each of the two spatial stream groups and the inverse analysis N ss spatial streams to obtain a sequence of decoded information bits.

[0127] According to a second embodiment of the present disclosure, for ss is an odd number and greater than 1, the received signal is decoded at the receiving unit for a single user transmission in the RU. Figure 1 The method of decoding the HE data field 120 of the HE packet 100 in (N g -1) information bits of the first spatial stream and the second spatial stream in each of the two spatial stream groups, decoding the information bits of the first spatial stream, the second spatial stream, and the third spatial stream in the three spatial stream group, and inverse parsing N ss spatial streams to obtain a sequence of decoded information bits.

[0128] According to the second embodiment of the present disclosure, in order to decode the information bits from the first spatial stream in the two-spatial stream group, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the first spatial stream in the group. SD / 2-1) and the LLR at the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1), and then combine the two LLRs. To decode the information bits from the second spatial stream in the two-spatial stream group, the receiving unit calculates the first data subcarrier k (k = 0, 1, ..., N) corresponding to the second spatial stream in the group. SD / 2-1) and the LLR at the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1) and then combine the two LLRs.

[0129] According to the second embodiment of the present disclosure, in order to decode the information bits from the first spatial stream in the three-spatial stream group, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the first spatial stream in the group. SD / 2-1) and the LLR at the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k=0,1...,N SD / 2-1), and then combine the two LLRs. In order to decode the information bits from the second spatial stream in the group, the receiving unit calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the second spatial stream in the group. SD / 2-1) and the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1), and then combine the two LLRs. To decode the information bits from the third spatial stream in the group, the receiving unit only calculates the first data subcarrier k (k=0, 1, ..., N) corresponding to the third spatial stream in the group. SD / 2-1) and the LLR at the second data subcarrier P(k)(N SD / 2≤P(k)≤N SD -1 and k = 0, 1, ..., N SD / 2-1) and then combine the two LLRs.

[0130] Fig.11 FIG. 1 illustrates a method for generating a single-user transmission in a RU using diversity transmission and BCC according to a second embodiment of the present disclosure. Figure 1 100 of the HE data field 120 of the HE packet 100 in FIG. The transmitting unit 1100 includes a pre-FEC PHY padding block 1102, a scrambling unit 1104, a BCC encoding unit 1106, a post-FEC PHY padding block 1108, a stream parsing unit 1110, and an N ss BCC interleaving units 1112, N ss constellation mapping unit 1114, DCM / SFDS / e-SFDS tone mapping unit 1116, (N ss -1) CSD block 1118, spatial and frequency mapping block 1120, N TX IDFT blocks 1122, N TX GI insertion and windowing blocks 1124 and N TX Analog and RF blocks 1126, where N ss is the number of spatial streams, and N TX The transmitting unit 1100 further includes a spatial stream grouping block 1132 and a diversity mode selection block 1134 .

[0131] Pre-FEC PHY padding block 1102, scrambling unit 1104, BCC encoding unit 1106, post-FEC PHY padding block 1108, stream parsing unit 1110, BCC interleaving unit 1112, constellation mapping unit 1114, CSD block 1118, space and frequency mapping block 1120, IDFT block 1122, GI insertion and windowing block 1124, and analog and RF block 1126 have the same functions as they do in FIG. Figure 2 The respective corresponding parts in the sending unit 200 shown have exactly the same functions.

[0132] If N ss is greater than 1, the spatial stream grouping block 1132 will N ss The spatial streams are grouped into N g groups. If N ss is an even number, then all N g Each group is a two-spatial-stream group. ss is an odd number, then N g One of the groups is a three-spatial-stream group, and the remaining (N g Each of the N-1) groups is a two-spatial stream group. ss The value of determines the diversity mode to be used for each group. ss = 1, the DCM / SFDS / e-SFDS tone mapping unit 1116 performs the following for a single spatial stream: Figure 3 The DCM shown. ss When N is an even number, the DCM / SFDS / e-SFDS tone mapping unit 1116 g Each of the two spatial stream groups performs Figure 4 The conventional SFDS shown. ss Greater than 1 and N ss When the number is an odd number, the DCM / SFDS / e-SFDS tone mapping unit 1116 performs the following for the three spatial stream groups: Fig.10 The e-SFDS shown, and for the remaining (N g -1) Each of the two spatial stream groups performs as follows Figure 4 The traditional SFDS shown.

[0133] According to the configuration of the second embodiment of the present disclosure, by using SFDS as the diversity transmission method for each of the two spatial stream groups and using e-SFDS as the diversity transmission method for the three spatial stream groups, if two or more spatial streams are transmitted in RU, it is possible to transmit N ssBoth frequency diversity and spatial diversity gain are obtained by transmitting each of the 100 spatial streams. Therefore, the narrowband interference experienced by the HE packet 100 is mitigated and the PER performance of the HE packet 100 is improved. In addition, no additional signaling bits are required to report to the receiving unit which diversity transmission mode is used for which spatial stream.

[0134] <Configuration of Wireless Communication Device>

[0135] Fig.12 An example configuration of a wireless communication device 1200 according to the first and second embodiments of the present disclosure is shown. The wireless communication device 1200 may be an AP in a centralized wireless network, an STA in a centralized wireless network, or a node in a point-to-point wireless network. The wireless communication device 1200 includes a control unit 1210, a transmitting unit 1220, a receiving unit 1230, and a plurality of antennas 1240. The control unit 1210 includes a packet generating unit 1212. The packet generating unit 1212 creates packets, such as Figure 1 After the transmission process of the transmission unit 1220 according to one of the various embodiments of the present disclosure, the created packet is transmitted through the antenna 1240. On the other hand, the control unit 1210 analyzes and processes the packet received through the antenna 1240 after the reception process of the reception unit 1230.

[0136] According to the embodiments of the present disclosure, at least the following sending devices and sending methods are disclosed.

[0137] A sending device according to an embodiment of the present disclosure includes:

[0138] a transmission signal generating unit, which generates a transmission signal including a traditional preamble, a non-traditional preamble and a data field, wherein the non-traditional preamble includes a signal field, which carries a first control signaling indicating the number of spatial streams NSS in the data field and a second control signaling indicating a modulation mode used in the data field, and when diversity transmission in the data field is enabled and two or more diversity transmission modes are applicable to the modulation mode used in the data field, the two or more diversity transmission modes to be used in the data field are determined according to the value of NSS; and a transmitting unit, which transmits the generated transmission signal.

[0139] According to the transmitting device of an embodiment of the present disclosure, the signal field in the non-traditional preamble carries a third control signaling indicating whether the diversity transmission in the data field is enabled.

[0140] According to the transmitting apparatus of an embodiment of the present disclosure, if NSS is an odd number, NSS spatial streams are paired into Np=floor(NSS / 2) spatial stream pairs, and one of the NSS spatial streams is not paired.

[0141] According to the transmitting apparatus of the embodiment of the present disclosure, if NSS is an odd number, the first diversity transmission mode is applied to the unpaired spatial stream, and the second diversity transmission mode is applied to each of the Np spatial stream pairs.

[0142] According to the transmitting device of the embodiment of the present disclosure, it is possible to pair spatial streams based on the physical antenna configuration and the mapping of spatial streams to antennas.

[0143] According to the transmitting device of an embodiment of the present disclosure, when NSS is an odd number and greater than 1, NSS spatial streams are grouped into Ng=floor(NSS / 2) spatial stream groups, one of the Ng groups includes three spatial streams, and each of the remaining (Ng-1) groups includes two spatial streams.

[0144] According to the transmitting device of the embodiment of the present disclosure, the third diversity transmission mode is applied to the three-spatial stream group, and the second diversity transmission mode is applied to each of the remaining (Ng-1) two-spatial stream groups.

[0145] According to the transmitting device of the embodiment of the present disclosure, it is possible to group spatial streams based on the physical antenna configuration and the mapping of spatial streams to antennas.

[0146] According to the transmitting device of the embodiment of the present disclosure, the first diversity transmission mode is dual subcarrier modulation DCM.

[0147] According to the transmitting device of the embodiment of the present disclosure, the second diversity transmission mode is a space frequency diversity mode SFDS.

[0148] According to the transmitting device of the embodiment of the present disclosure, the third diversity transmission mode is enhanced SFDS e-SFDS.

[0149] The sending method according to an embodiment of the present disclosure includes:

[0150] Generate a transmission signal including a traditional preamble, a non-traditional preamble, and a data field, the non-traditional preamble including a signal field carrying a first control signaling indicating the number of spatial streams NSS in the data field and a second control signaling indicating a modulation mode used in the data field, and when diversity transmission in the data field is enabled and two or more diversity transmission modes are applicable to the modulation mode used in the data field, the two or more diversity transmission modes to be used in the data field are determined according to the value of NSS; and transmit the generated transmission signal.

[0151] In the aforementioned embodiments, the present invention is configured in hardware through the above examples, but the present invention can also be provided by the cooperation of software and hardware.

[0152] In addition, the functional blocks used in the description of the embodiments are generally implemented as LSI devices as integrated circuits. The functional blocks may be formed as separate chips, or a portion or all of the functional blocks may be integrated into a single chip. The term "LSI" is used herein, but the terms "IC", "system LSI", "super LSI" or "ultra LSI" may also be used depending on the level of integration.

[0153] In addition, circuit integration is not limited to LSI and can be realized by a dedicated circuit or a general-purpose processor other than LSI. After the manufacture of LSI, a programmable field programmable gate array (FPGA) or a reconfigurable processor that allows the connection and setting of the circuit unit in LSI to be reconfigured can be used.

[0154] If a circuit integration technology that replaces LSI emerges due to the advancement of semiconductor technology or other technology derived from semiconductor technology, such technology can be used to integrate functional blocks. Another possibility is to apply biotechnology or the like.

[0155] Industrial Applicability

[0156] The present disclosure may be applied to a method for diversity transmission in a wireless communication system.

[0157] Reference Mark List

[0158] 1210 Control Unit

[0159] 1212 Packet Generation Unit

[0160] 1220 Sending Unit

[0161] 1230 Receiving Unit

[0162] 1240 Antenna

Claims

1. A station comprising: A receiving unit receives a signal including a non-traditional preamble and a data field, wherein the non-traditional preamble includes a signal indicating the number N of spatial streams in the data field. SS and a first field for indicating one of a plurality of modulation and coding modes MCS, wherein two or more diversity transmission modes are supported and one of the two or more diversity transmission modes is based on the N SS The value of is applied; as well as A circuit is provided for decoding the signal. 2 . The station according to claim 1 , wherein the non-legacy preamble includes a third field for indicating whether at least one of the two or more diversity transmission modes is applied to the data field. 3 . The station according to claim 1 , wherein the two or more diversity transmission modes include a first mode, and the first mode is dual subcarrier modulation (DCM).

4. The station according to claim 3, wherein if the value of the Nss is equal to an odd number and the non-legacy preamble indicates that diversity transmission is applied to the data field, the first mode is applied to one of the spatial streams.

5. The station according to claim 3, wherein the two or more diversity transmission modes include a second mode which is a space frequency diversity mode SFDS.

6. The station of claim 5, wherein if the value of Nss is an odd number and greater than 3, more than two spatial streams are paired into N p =floor(N SS / 2) spatial stream pairs, and one of the spatial streams is unpaired, and wherein the first manner is applied to the unpaired spatial stream, and the second manner is applied to the N p Each of the spatial stream pairs.

7. The station of claim 6, wherein the spatial streams can be paired based on a physical antenna configuration and a mapping of spatial streams to antennas.

8. The station of claim 1, wherein if the N SS If the value of is an odd number, the spatial streams are grouped into N g =floor(N SS / 2) spatial stream groups, the N g One of the groups includes three spatial streams, and the remaining (N g -1) Each of the groups includes two spatial streams.

9. The station according to claim 8, wherein an enhanced spatial frequency diversity scheme (e-SFDS) is applied to the three spatial stream groups, and SFDS is applied to the remaining (N g -1) for each of the two spatial stream groups.

10. The station of claim 8, wherein the spatial streams can be grouped based on a physical antenna configuration and a mapping of spatial streams to antennas.

11. The station according to claim 5, wherein if the value of Nss is an even number, the second manner is applied to the data field.

12. A station comprising: A receiving unit receives a signal including a non-traditional preamble and a data field, wherein the non-traditional preamble includes a signal indicating the number N of spatial streams in the data field. SS and a second field for indicating one of a plurality of modulation and coding schemes MCS, wherein two or more diversity transmission schemes are supported; and circuitry, decoding the signal, The first mode of the two or more diversity transmission modes is dual subcarrier modulation DCM, and The second mode of the two or more diversity transmission modes is a space frequency diversity mode, and If the non-legacy preamble indicates that at least one of the two or more diversity transmission modes is applied to the data field and the value of Nss is an odd number, the first mode is applied to at least one spatial stream.

13. A receiving method, comprising: A signal including a non-legacy preamble and a data field is received, the non-legacy preamble including a first field for indicating the number Nss of spatial streams in the data field and a second field for indicating one of a plurality of modulation and coding schemes MCS, wherein two or more diversity transmission schemes are supported and one of the two or more diversity transmission schemes is based on the Nss. SS The value of is applied; as well as The signal is decoded. 14 . The receiving method according to claim 13 , wherein the non-legacy preamble includes a third field for indicating whether at least one of the two or more diversity transmission modes is applied to the data field. 15 . The receiving method according to claim 13 , wherein the two or more diversity transmission modes include a first mode, and the first mode is dual subcarrier modulation (DCM).

16. The receiving method according to claim 15, wherein if the value of the Nss is equal to an odd number and the non-legacy preamble code indicates that diversity transmission is applied to the data field, the first mode is applied to one of the spatial streams.

17. An integrated circuit for a control method, the method comprising: A signal including a non-legacy preamble and a data field is received, the non-legacy preamble including a first field for indicating the number Nss of spatial streams in the data field and a second field for indicating one of a plurality of modulation and coding schemes MCS, wherein two or more diversity transmission schemes are supported and one of the two or more diversity transmission schemes is based on the Nss. SS The value of is applied; as well as The signal is decoded.

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