CN117529951A

CN117529951A - Wireless communication device and method

Info

Publication number: CN117529951A
Application number: CN202180099193.9A
Authority: CN
Inventors: 根纳季·特所迪克; 希米·西隆; 奥德·里德里; 阿里克·克莱因; 多伦·埃兹里
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-07-09
Filing date: 2021-07-09
Publication date: 2024-02-06
Also published as: WO2023280417A1; EP4353023A1

Abstract

A wireless communication device (110, 120) for OFDMA communication with another wireless communication device is provided. The wireless communication device 5 comprises processing circuitry (111, 121) for (i) obtaining a plurality of subcarriers of a first Resource Unit (RU) within a channel bandwidth; (ii) Permuting the plurality of data subcarriers of the second RU based on an LDPC subcarrier mapping formula, wherein the LDPC subcarrier mapping formula depends on a number of the plurality of data subcarriers of the second RU that is greater than a number of subcarriers of the first RU; (iii) Mapping subcarriers of the first RU to a subset of permuted data subcarriers of the second RU 10 to obtain a rearranged plurality of subcarriers of the first RU distributed over permuted data subcarriers of the second RU; (iv) The method further includes communicating with the other wireless communication device based on the rearranged plurality of subcarriers of the first RU.

Description

Wireless communication device and method

Technical Field

The present disclosure relates to wireless communications. More particularly, the present disclosure relates to a wireless communication apparatus and method that uses Resource Units (RUs) having a plurality of subcarriers and distributes the subcarriers of the RUs over a channel bandwidth.

Background

Wireless local area networks (wireless local area network, WLAN) based on the institute of electrical and electronics engineers (Institute of Electrical and Electronics Engineers, IEEE) standard set 802.11 have been popular at an unprecedented rate. Such wireless networks (also referred to as Wi-Fi networks) support various modes of data transmission including, but not limited to, file transfer, email, web browsing, and real-time applications, such as audio and video applications. To efficiently support high throughput, the next generation Wi-Fi networks may operate using frequencies in the 6GHz band. For this new operating band, the maximum transmit power of the wireless device will be limited, i.e. with respect to the maximum total power (called effective isotropic radiated power, EIRP) and maximum power spectral density (power spectral density, PSD) within the bandwidth of use (BW). Several device classes have been defined, with each class having a different upper bound for EIRP and PSD. The low power access point (LPI) class defines very strict EIRP and PSD limitations for access points and clients to which they are connected. This presents new challenges for Wi-Fi networks to achieve the same link-level performance under tighter constraints, particularly for LPI device classes.

Disclosure of Invention

It is an object of the present disclosure to provide an improved wireless communication device and method.

The above and other objects are achieved by the subject matter as claimed in the independent claims. Other implementations are apparent in the dependent claims, the description and the drawings.

According to a first aspect, a wireless communication apparatus, e.g. a wireless station, is provided for orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) communication with another wireless communication apparatus, e.g. a wireless station, over a channel. The wireless communication device may be implemented as a wireless station according to IEEE 802.11. The wireless communication device includes processing circuitry to: obtaining a plurality of subcarriers (tone/subcarrier) of a first Resource Unit (RU) within a channel bandwidth of the channel; permuting (permula) at least a subset of the plurality of data subcarriers of a second RU based on a low-density parity-check (low-density parity check, LDPC) subcarrier mapping formula, wherein the LDPC subcarrier mapping formula depends on a number of the plurality of data subcarriers of the second RU that is greater than a number of the plurality of subcarriers of the first RU; mapping the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over the plurality of permuted data subcarriers of the second RU; the method further includes communicating with the other wireless communication device based on the rearranged plurality of subcarriers of the first RU.

In another possible implementation, the second RU is the largest RU within the channel bandwidth, i.e., includes the largest number of data subcarriers within the channel bandwidth.

In another possible implementation, the processing circuit is configured to permute at least a subset of the plurality of data subcarrier indexes of the second RU based on the following LDPC subcarrier mapping formula:

wherein N is _SD Representing the number of data subcarriers of the second RU, D _TM Representing parameters dependent on the channel bandwidth, k represents the subcarrier index.

In another possible implementation, the channel bandwidth is 20MHz, N _Sd ＝234，D _TM =9, the first RU includes 26, 52, or 106 subcarriers.

In another possible implementation, the channel bandwidth is 40mhz, n _SD ＝468，D _TM =12, the first RU includes 26, 52, 106, or 242 subcarriers.

In another possible implementation, the channel bandwidth is 80mhz, n _SD ＝980，D _TM =20, the first RU includes 26, 52, 106, 242 or 484 subcarriers.

In another possible implementation, the channel bandwidth is 160mhz, n _SD ＝2·980＝1960，D _TM =20, the first RU includes 26, 52, 106, 242, 484, or 996 subcarriers.

In another possible implementation, the channel bandwidth is 320mhz, n _SD ＝4·980＝3920，D _TM =20, the first RU includes 26, 52, 106, 242, 484, or 996 subcarriers.

In another possible implementation, the processing circuit is further configured to divide the channel bandwidth into a plurality of channel bandwidth segments of 80MHz size and to process each of the plurality of channel bandwidth segments independently. In other words, in one implementation, the processing circuitry is configured to process each 80MHz segment, as if the channel bandwidth was 80 MHz.

In another possible implementation, the processing circuit is configured to permute at least a subset of the plurality of data subcarrier indices of the second RU based on the LDPC subcarrier mapping formula by mapping an index k of the plurality of subcarriers of the first RU to an index t (k) of the plurality of data subcarriers of the second RU. In other words, in the present implementation, the processing circuit is configured to permute at least a subset of the plurality of data subcarriers of the second RU based on the following LDPC subcarrier mapping formula t (k):

r ₁ (t(k))＝x(k)，

wherein x (k) represents a plurality of data subcarrier indexes of the second RU, r ₁ (t (k)) represents a sequence of a plurality of permutation data subcarriers of the second RU.

In another possible implementation, the processing circuit is configured to permute at least a subset of the plurality of data subcarrier indices of the second RU based on the LDPC subcarrier mapping formula by mapping an index t (k) of the plurality of subcarriers of the first RU to an index k of the plurality of data subcarriers of the second RU. In other words, in the present implementation, the processing circuit is configured to permute at least a subset of the plurality of data subcarriers of the second RU based on the following LDPC subcarrier mapping formula t (k):

r ₂ (k)＝x(t(k))

wherein x (t (k)) represents a plurality of data subcarrier indexes of the second RU, r ₂ (k) A sequence representing a plurality of permuted data subcarriers of the second RU.

In another possible implementation, the channel bandwidth is 20MHz and N _SD =234, the processing circuitry is to permute at least a subset of the plurality of data subcarrier indices of the second RU by: rearranging odd data subcarriers of the plurality of permuted data subcarriers of the second RU into a first subsequence of the plurality of permuted data subcarriers of the second RU, and rearranging even data subcarriers of the second RU into a second subsequence of the plurality of permuted data subcarriers of the second RU. For example, the processing circuitry may be to rearrange the sequence of the plurality of permuted data sub-carriers of the second RU using first the odd data sub-carriers and then the even data sub-carriers. In other words, in one implementation, the processing circuitry is to rearrange the sequence of the plurality of permuted data subcarriers of the second RU by:

r _{3_20MHz} ＝{r ₁ ,r ₃ ,…,r ₂₃₃ ,r ₂ ,r ₄ ,…,r ₂₃₄ }。

In another possible implementation, the channel bandwidth is an integer multiple of 20MHz, and the processing circuit is configured to permute at least a subset of the plurality of data subcarrier indexes of the second RU by generating a sequence of permuted data subcarriers of the second RU, as follows:

r _{i_20MHz} ＝{r ₁ ,r ₃ ,…,r ₂₃₃ ,r ₂ ,r ₄ ,…,r ₂₃₄ }，

wherein BW represents at least a portion of the channel bandwidth.

In another possible implementation, the plurality of subcarriers of the first RU includes N subcarriers, and the processing circuitry is to map the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU by mapping the plurality of subcarriers of the first RU to a first N data subcarriers of the plurality of permuted data subcarriers of the second RU.

In another possible implementation, the processing circuit is to map a plurality of subcarriers of another RU to another subset of the plurality of permuted data subcarriers of the second RU, wherein the another subset includes next N data subcarriers of the plurality of permuted data subcarriers of the second RU.

In another possible implementation, the processing circuit is configured to add one or more padding subcarriers.

According to a second aspect, a method of operating a wireless communication device, e.g. a wireless station, for orthogonal frequency division multiple access (orthogonal frequency division multiple access, OFDMA) communication with another wireless communication device, e.g. a wireless station, over a channel is provided. The method comprises the following steps: obtaining a plurality of subcarriers (tone/subcarrier) of a first Resource Unit (RU) within a channel bandwidth of the channel; permuting at least a subset of the plurality of data subcarriers of the second RU based on a low-density parity-check (low-density parity check, LDPC) subcarrier mapping formula, wherein the LDPC subcarrier mapping formula depends on a number of the plurality of data subcarriers of the second RU that is greater than a number of the plurality of subcarriers of the first RU; mapping the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over the plurality of permuted data subcarriers of the second RU; the method further includes communicating with the other wireless communication device based on the rearranged plurality of subcarriers of the first RU.

The method provided by the second aspect of the present disclosure may be performed by the wireless communication apparatus provided by the first aspect of the present disclosure. Thus, other features of the method provided by the second aspect of the present disclosure are directly derived from the functionality of the wireless communication device provided by the first aspect of the present disclosure and the different implementations described above and below.

According to a third aspect, there is provided a computer program product comprising program code which, when executed by a computer or processor, causes the computer or processor to perform the method provided in the second aspect.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

Drawings

Embodiments of the present disclosure are described in detail below with reference to the attached drawing figures. In the drawings:

FIG. 1 illustrates the concept of duplicating a signal to achieve the same processing gain as an increased PSD;

fig. 2 illustrates a concept of distributing Resource Units (RUs) over a larger channel bandwidth for OFDMA communication;

FIG. 3 shows a schematic diagram of a wireless communication network including a wireless communication device according to an embodiment in communication with another wireless communication device;

fig. 4a to 4d illustrate corresponding permuted subcarrier sequences for subcarrier distribution for 20MHz, 40MHz, 80MHz and 160MHz channel bandwidths, respectively, of a wireless communication device provided by an embodiment;

fig. 5 is a flow chart of a method of operating a wireless communication device provided by an embodiment.

In the following, like reference numerals refer to like or at least functionally equivalent features.

Detailed Description

In the following description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific aspects of embodiments of the disclosure or in which the embodiments of the disclosure may be practiced. It is to be understood that embodiments of the present disclosure may be used in other aspects and may include structural or logical changes not depicted in the drawings. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims.

For example, it should be understood that the disclosure related to describing a method may be equally applicable to a corresponding device or system for performing the method, and vice versa. For example, if one or more specific method steps are described, the corresponding apparatus may comprise one or more units (e.g., functional units) to perform the described one or more method steps (e.g., one unit performing one or more steps, or multiple units performing one or more of the multiple steps, respectively), even if the one or more units are not explicitly described or illustrated in the figures. On the other hand, for example, if a specific apparatus is described based on one or more units (e.g., functional units), a corresponding method may include one step to perform the function of the one or more units (e.g., one step to perform the function of the one or more units, or a plurality of steps to each perform the function of one or more units of the plurality of units), even if the one or more steps are not explicitly described or shown in the drawings. Furthermore, it should be understood that features of the various exemplary embodiments and/or aspects described herein may be combined with one another, unless otherwise indicated.

Before describing the various embodiments in more detail, some technical background and terms related to wireless networks and devices according to the IEEE 802.11 WLAN standard will be introduced below using one or more of the following abbreviations or acronyms:

ACK acknowledgement

AP access point

BA block acknowledgement-in 802.11, it is generally expected that the receiver responds to the data transmission by responding with an ACK; if multiple frames are transmitted in a single PPDU, each frame must be acknowledged

BFR beamforming feedback reporting

BFRP beamforming feedback report polling

BSS basic service set

DoF degree of freedom

DL downlink

LDPC low density parity check

MAC medium access control

MIMO multiple input multiple output

MPDU MAC protocol data unit

MUI multi-user interference

MU-MIMO multi-user MIMO

NDP null data packet;

NDPA null packet advertisement

OBSS overlapping basic service set

OFDMA multiple access

PHY physical layer

PPDU PHY protocol data unit

Rx reception

SINR signal-to-interference-and-noise ratio

SNR signal to noise ratio

STA station (in general, may be AP STA or non-AP STA)

SVD singular value decomposition

TF trigger frame-in 802.11ax, a trigger frame is introduced as a means of triggering STA or STAs to send and synchronize to the trigger AP simultaneously

Tx transmission

UL uplink

As noted above, particularly for LPI class wireless devices operating in the new 6GHz band, it may be desirable to reduce the PSD while still providing substantially similar link-level performance.

It should be appreciated that the wireless communication device may reduce the BW used to transmit the signal in order to increase the PSD and improve the signal-to-noise ratio (SNR). Therefore, when the link SNR between an Access Point (AP) and a Station (STA) is low and the transmit power cannot be increased, selecting a smaller transmission BW is one possible method. However, as LPI restrictions become more stringent, for example, reducing the transmission BW of wireless devices may result in an increase in PSD that exceeds the maximum PSD allowed by such devices.

This problem can be solved by single user (non-OFDMA) transmissions, where the entire BW is allocated to the same user or group of users. In this case the signal is replicated over the whole BW, for example 2 or 4 times, as shown in fig. 1. This approach is called dual carrier modulation (dual carrier modulation, DCM) or DCM + replication (DUP). Duplicating the same signal across the entire BW may increase processing gain by combining duplicated portions, which may increase overall post-processing SNR.

In the case of OFDMA (when there are multiple allocations across the entire bandwidth), simple replication cannot be applied, requiring more complex methods. Each allocation may be a different size Resource Unit (RU), i.e. a different number of consecutive subcarriers (tone/subcarrier), wherein each subcarrier is associated with a specific frequency. Thus, this approach may be applicable to various valid combinations of RUs defined by the 802.11be Wi-Fi standard. One approach is to distribute the subcarriers of each RU over the entire BW or a portion of the entire BW. For example, as shown in fig. 6, 26 subcarrier RUs may be distributed over a BW of 20MHz, such that all subcarriers are uniformly distributed over the entire BW.

Accurate channel estimation is critical to achieving better link-level performance. One of the known techniques that can significantly improve the accuracy of the estimated channel is smoothing over the allocated BW. In general, an RU is defined as a sequence of consecutive subcarriers so that an estimated channel can be filtered (smoothed) in the frequency domain. The larger the RU size, the better the filter characteristics and thus the higher the channel estimation accuracy. When the number of consecutive subcarriers is too small (typically less than about 3 to 5 subcarriers), the efficiency of channel smoothing is significantly reduced.

The first approach to RU distribution is based on the following idea: pairs of RUs of the same size or four RUs are defined and then subcarriers are uniformly distributed over the entire RU set. For example, if a pair of RUs is selected, a first RU and a second RU may be assigned to odd and even subcarriers of the selected pair, respectively.

Another approach to RU distribution is based on the idea of dividing the entire BW into a set of subcarrier groups, where each subcarrier group comprises several subcarriers distributed over the entire BW. Each RU consists of a plurality of subcarrier groups in a defined set, and the number of groups allocated to an RU depends on the RU size.

Another approach for RU distribution is based on the idea of mapping the subcarriers of each RU to their physical locations in the whole BW using a general interleaving function. An interleaving function may be defined as a matrix with a certain number of rows and columns. The input indexes are written in row order, and the output indexes are read in column order. In this case, the index sequence is permuted, so the output sequence can be used for RU distribution. The specific mapping depends on the size of the interleaving matrix. For example, if there are two 26 sub-carrier RUs, the number of columns in the interleaving matrix is 26, then the index of the first RU is written to the first row and the index of the second RU is written to the second row. When the indexes are read column by column, all odd indexes allocated to the first RU and all even indexes allocated to the second RU are obtained.

Fig. 3 shows a schematic diagram of a wireless communication network 100, the wireless communication network 100 comprising a wireless communication device 110 provided by an embodiment in communication with another wireless communication device 120. In the embodiment shown in fig. 3, the wireless communication device 110 is a wireless access point 110 that communicates with a plurality of wireless stations 120. In one embodiment, wireless access point 110 and a plurality of wireless stations may be used to communicate in accordance with one or more of the IEEE 802.11 family of standards. Although in the following embodiments will be described in more detail in the context of wireless access point 110, it should be understood that embodiments disclosed herein may also be implemented in one or more wireless stations 120.

As shown in fig. 3, a wireless communication device 110 (e.g., wireless AP 110) includes processing circuitry 111 (e.g., a processor 111 for processing data) and a communication interface 113 for transmitting and receiving data. In one embodiment, communication interface 113 may include one or more antennas for wireless communication with one or more wireless stations 120. The processing circuitry 111 may be implemented in hardware and/or software. The hardware may include digital circuits, or both analog and digital circuits. The digital circuitry may include components such as application-specific integrated circuits (ASIC), field-programmable arrays (FPGA), digital signal processors (digital signal processor, DSP), or general-purpose processors. The wireless communication device 110 (e.g., wireless AP 110) may also include a memory 115, the memory 115 for storing executable program code that, when executed by the processing circuitry 111, causes the wireless communication device 110 (e.g., wireless AP 110) to perform the functions and operations described herein.

Similarly, one or more wireless stations 120 shown in fig. 3 include processing circuitry 121 (e.g., a processor 121 for processing data) and a communication interface 123 for receiving and transmitting data. In one embodiment, communication interface 123 may include one or more antennas for wireless communication with wireless AP 110. The processing circuit 121 may be implemented by hardware and/or software. The hardware may include digital circuits, or both analog and digital circuits. The digital circuitry may include components such as application-specific integrated circuits (ASIC), field-programmable arrays (FPGA), digital signal processors (digital signal processor, DSP), or general-purpose processors. The one or more wireless stations 120 may also include a memory 125, the memory 125 for storing executable program code that, when executed by the processing circuitry 121, causes the one or more wireless stations 120 to perform the functions and operations described herein.

The wireless AP 110 shown in fig. 3 is configured to communicate OFDMA with one or more wireless stations 120 using a selected channel bandwidth (e.g., 20MHz, 40MHz, 80MHz, 160MHz, or 320 MHz). As will be described in more detail below, the processing circuitry 111 of the wireless AP 110 is configured to obtain a plurality of consecutive subcarriers (tone/subcarrier) of a first Resource Unit (RU) within a selected channel bandwidth. For example, the first RU may include 26 subcarriers (also referred to herein as 26 subcarrier RUs) within a selected channel bandwidth of 20 MHz. It should be appreciated that each successive subcarrier of the first RU may be identified by a "logical" index.

The processing circuit 111 of the wireless AP 110 is further configured to permute at least a subset of the plurality of indexes of the plurality of consecutive data subcarriers of the second RU based on the LDPC subcarrier mapping formula t (k), to obtain a plurality of permuted data subcarriers of the second RU, where k represents the original index, t (k) represents the permuted index, and where the number of the plurality of data subcarriers of the second RU is greater than the number of the plurality of subcarriers of the first RU. In one embodiment, the second RU is the largest RU within the channel bandwidth, i.e., includes the largest number of data subcarriers within the channel bandwidth. For example, for a selected channel bandwidth of 20MHz, the second RU may have a total of 242 subcarriers, including 234 data subcarriers. The LDPC subcarrier mapping formula t (k) for permuting the second data subcarriers depends on the number of the plurality of data subcarriers of the second RU. In other words, the number of the plurality of data subcarriers of the second RU, denoted herein as N _SD Is a parameter of the LDPC subcarrier mapping formula t (k), depending on the selectionIs used for the channel bandwidth of the mobile station.

In one embodiment, processing circuitry 111 of wireless AP 110 is to permute the plurality of data subcarriers of the second RU based on the following LDPC subcarrier mapping formula:

Wherein D is _TM Representing parameters that depend on the channel bandwidth, k represents the subcarrier index. Essentially, parameter D _TM The distance between two consecutive subcarrier indexes of the output sequence is defined. It should be appreciated that the above LDPC subcarrier mapping formula (also referred to as an LPDC subcarrier mapper) has been used for wireless devices according to the IEEE 802.11be standard implementing an LDPC encoder. In this context, an LDPC subcarrier mapping formula is used to map a plurality of consecutive communication symbols, e.g., QAM symbols, to a plurality of non-consecutive OFDMA data subcarriers of an RU.

To spread the plurality of subcarriers of the first RU, processing circuitry 111 of wireless AP 110 is further to map the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over the plurality of permuted data subcarriers of the second RU. Based on the rearranged plurality of subcarriers of the first RU, processing circuitry 111 and communication interface 113 of wireless AP 110 are used to communicate with one or more wireless stations 120.

Using the already available LDPC subcarrier mapper t (k) to permute the data subcarriers of the second RU and distributing the plurality of subcarriers of the first RU over the permuted data subcarriers of the second RU has the following advantages, among others. It is not necessary to design and store a new interleaving sequence. The LDPC subcarrier mapper implemented by processing circuitry 111 of wireless AP 100 is a specific mapping function that produces a continuous subcarrier pattern and thus may smooth the channel estimation (CHEST) gain for data and carrier frequency offset (carrier frequency offset, CFO) pilots. Furthermore, the LDPC sub-carrier mapper implemented by processing circuitry 111 of wireless AP 100 may be used for any BW including multiple RUs (MRU/puncturing) because it is implemented by N _SD And D _TM And (5) parameterizing.

Hereinafter, some other embodiments of the wireless AP 110 implementing the LDPC subcarrier mapper t (k) will be further described with reference to fig. 4a to 4d, fig. 4a to 4d showing respective sequences of permuted subcarriers of a second RU of the wireless AP 110 for subcarrier distribution of 20MHz, 40MHz, 80MHz and 160MHz channel bandwidths, respectively, according to an embodiment. In fig. 4a to 4d, the corresponding sequence of permuted data subcarriers of the second RU advances line by line until the corresponding line ends, then the next line is continued, with the first index on the left. For example, in fig. 4a, the sequence of permuted data subcarriers of the second RU starts with indices 1, 27, 53, 79, 105, etc.

As described above, the embodiments disclosed herein are based on the general idea of using an LDPC subcarrier mapper defined for the largest RU within a selected transmission BW to distribute one or more smaller RUs. For example, if processing circuitry 111 of wireless AP 110 intends to transmit 26 a first RU of subcarriers on 20MHz channel BW, it may use an LDPC subcarrier mapper defined for 242 a second RU of subcarriers (since this is the largest RU of 20MHz selected channel BW). As shown in fig. 4a, the LDPC subcarrier mapper of the 242 subcarrier second RU is a sequence defining 234 index permutations. In this embodiment, in case that the channel bandwidth is 20MHz, the parameters of the LDPC subcarrier mapper have the following values: n (N) _SD =234 and D _TM =9. For the first 26 sub-carriers RU, processing circuit 111 may use the first 26 indices of the permutation sequence shown in fig. 4a, i.e. 1, 27, 53, 79, 105, … …, 159, 185. For another first 26 sub-carriers RU, processing circuitry 111 may use the next 26 indices of the permutation sequence shown in fig. 4a (i.e. the next row index), and so on. In this way, processing circuitry 111 may map a plurality (i.e., up to 9) of first 26-subcarrier RUs to the permuted subcarrier sequence of the second RU shown in fig. 4a, thereby distributing the subcarriers of the plurality of first 26-subcarrier RUs over the permuted sequence. Instead of 26 subcarriers, for example, one or more first RUs of the permuted subcarrier sequence mapped to the second RU shown in fig. 4a may have 52 or 106 subcarriers.

In the above embodiment, the processing circuit 111 of the wireless AP 110 distributes the one or more first RUs over the 242-subcarrier second RUs of the 20MHz transmission bandwidth directly using the LDPC subcarrier mapper t (k). In one embodiment, processing circuitry 111 of wireless AP 110 may directly use LDPC subcarrier mapper t (k) for distributing one or more first RUs over a second RU having a maximum number of subcarriers for a transmission bandwidth of 40MHz, 80MHz, 160MHz, or 320 MHz. For example, processing circuitry 111 may use the LDPC subcarrier mapper sequence t (k) defined by IEEE 802.11be for a 484 subcarrier second RU, 484+242 second MRU, or 996 subcarrier second RU. For a channel bandwidth of 40MHz, the permuted subcarrier sequence of the 484-subcarrier second RU is shown in fig. 4 b. The permuted subcarrier sequence of the 242+ 484-subcarrier second RU is shown in fig. 4 c. For a channel bandwidth of 80MHz, the permuted subcarrier sequence of the 996 subcarrier second RU is shown in fig. 4 b.

Thus, in one embodiment, for a channel bandwidth of 40MHz, the parameters of LDPC subcarrier mapper t (k) may have the following values: n (N) _SD =468 and D _TM =12, wherein the first RU comprises 26, 52, 106 or 242 subcarriers. In one embodiment, for a channel bandwidth of 80MHz, the parameters of LDPC subcarrier mapper t (k) may have the following values: n (N) _SD =980 and D _TM =20, wherein the first RU comprises 26, 52, 106, 242 or 484 subcarriers. In one embodiment, for a channel bandwidth of 160MHz, the parameters of LDPC subcarrier mapper t (k) may have the following values: n (N) _SD =2.980=1960 (i.e. the value becomes twice as large as the channel bandwidth of 80 MHz) and D _TM =20, wherein the first RU comprises 26, 52, 106, 242, 484 or 996 subcarriers. In one embodiment, for a channel bandwidth of 320MHz, the parameters of LDPC subcarrier mapper t (k) may have the following values: n (N) _SD =4.980=3920 (i.e. the value is four times compared to the channel bandwidth of 80 MHz) and D _TM =20, wherein the first RU comprises 26, 52, 106, 242, 484 or 996 subcarriers.

As already described in the context of a 20MHz channel bandwidth, the mapping sequence is determined based on the LDPC subcarrier mapper t (k), which can be described mathematically in the following way:

r ₁ (t(k))＝x(k)，

Where x (k) represents a plurality of data subcarriers, r ₁ (t (k)) represents a plurality of permutation data subcarriers of the second RU.

For the first RUs occupying half of the entire transmission BW, e.g., the 242-subcarrier first RU for 40MHz BW and the 484-subcarrier first RU for 80MHz bandwidth, two of these first RUs may be used per scene. To distribute the subcarriers of these first RUs, processing circuitry 111 of wireless AP 110 may use the following method: one of the first 242 subcarrier RUs (484 subcarrier RUs) in the 40MHz (80 MHz) BW is mapped to an odd subcarrier of the second RU, and the other of the first 242 subcarrier RUs (484 subcarrier RU) is mapped to an even subcarrier of the second RU, i.e., sequence y (t (k)).

According to another embodiment, processing circuitry 111 of wireless AP 110 may be configured to permute the plurality of subcarriers of the second RU using inverse mapping of the LDPC subcarrier mapper. In other words, in one embodiment, processing circuit 111 is configured to permute the plurality of data subcarriers of the second RU based on LDPC subcarrier mapping formula t (k), as follows:

r ₂ (k)＝x(t(k))

where x (t (k)) represents a plurality of data subcarriers, r ₂ (k) A plurality of permutation data subcarriers of the second RU is represented.

In another embodiment, processing circuitry 111 may be used to reassemble the permutation sequence of the second subcarriers provided by the LDPC subcarrier mapper, as this may provide a better subcarrier distribution and unification scheme for all RU sizes. More specifically, in the first stage, processing circuit 111 may use LDPC subcarrier mapper t (k) for a bandwidth of 20MHz, where N _SD =234 and D _TM =9. Then, the processing circuit 111 may further permute the sequence provided by the LDPC subcarrier mapper t (k) by first using odd subcarriers and then using even subcarriers, such that the further permuted sequence is given by:

in one embodiment, processing circuit 111 may be configured to process the replica r of the further permutation sequence by multiplying the replica r by 20MHz _i Concatenation expands the previous embodiment to bandwidths greater than 20MHz, where the number of concatenated copies is given by BW/20. Thus, in one embodiment, processing circuitry 111 may be configured to determine a permutation sequence for any Bandwidth (BW) greater than 20MHz, as follows:

in one embodiment, the 26-subcarrier RU may be the smallest first RU, i.e., the first RU having the smallest number of subcarriers. In one embodiment, processing circuitry 111 may be to obtain a mapping of subcarrier indexes of one or more first RUs of such size (i.e., one or more 26-subcarrier first RUs) and then generate a mapping of one or more larger first RUs based on the mapping of the one or more 26-subcarrier first RUs.

In one embodiment, processing circuitry 111 may be to reuse the original subcarriers of 26 subcarrier RU by:

1. For the upcoming IEEE standard 802.11be (information technology standard-telecommunication and information exchange between system local area network and metropolitan area network, month 5 of 2021), the proposed N x 26 subcarrier sequence x for 26 subcarrier RU is obtained ₂₆ (n=9 for bw=20 mhz, n=18 for bw=40 mhz, n=36 for bw=80 mhz).

2. If bw=80 MHz, the sequence is padded with 980-936=44 subcarrier indexes (it may be any index out of 980 subcarrier indexes that is not allocated to 26 subcarrier RU).

3. Permuting the sequence according to the permuting sequence r (as defined in one of the above embodiments) to obtain a mapped subcarrier index:

y ₂₆ ＝x ₂₆ (r)

4. for bw=20 MHz and 40MHz: the i 26 th subcarrier RU will be mapped to subcarrier y ₂₆ ((i-1) 26+1:i 26)

5. For bw=80 MHz, the i 26 th subcarrier RU will map onto subcarriers:

in another embodiment, processing circuitry 111 may be to reuse the original subcarriers of the largest RU within the bandwidth by:

1. the N sequence x defined for the maximum RU of the selected BW is obtained (n=234 for bw=20 mhz, n=468 for bw=40 mhz, n=980 for bw=80 mhz).

y ₂₆ ＝x ₂₆ (r)

5. For bw=80 MHz, the i 26 th subcarrier RU will map onto subcarriers:

in one embodiment, to map one or more first 52 subcarrier RUs based on the mapping of one or more first 26 subcarrier RUs, processing circuitry 111 may be to map one or more 52 subcarrier first RUs based on a rule that an i-th 52 subcarrier RU maps on subcarriers allocated to 2 (i-1) +1,2i 26 subcarrier RUs.

In one embodiment, to map one or more first 106 subcarrier RUs, processing circuitry 111 may be to map one or more 106 subcarrier first RUs by mapping an i 106 subcarrier RU on a subcarrier allocated to 2 (i-1) +1,2i 52 subcarrier RUs. Additional subcarriers completing 106 subcarriers may be defined as follows:

in one embodiment, to map one or more first 242 subcarrier RUs, processing circuitry 111 may be configured to map one or more 242 subcarrier first RUs by mapping 234 data subcarriers of an i-th 242 subcarrier RU onto subcarriers allocated to 26 subcarrier RUs from 9 (i-1) +1 to 9 i. In one embodiment, the additional subcarriers completing 242 subcarriers may be pilot subcarriers of the original 242 subcarrier RU. In another embodiment, the additional subcarriers completing 242 subcarriers may be every ith pilot subcarrier of all 242 subcarriers RU across BW.

In one embodiment, to map one or more first 484-subcarrier RUs, the processing circuitry may be to map one or more 484-subcarrier first RUs based on a rule that maps an i 484-subcarrier RU on subcarriers allocated to 2 (i-1) +1,2i 242-subcarrier RUs.

Fig. 5 is a flow chart of a method 500 of operating a wireless communication device 110 (e.g., wireless AP 110) provided by an embodiment. The method 500 comprises a first step 501: a plurality of subcarriers of a first Resource Unit (RU) are obtained within a channel bandwidth. Furthermore, the method 500 comprises a step 503: based on the LDPC subcarrier mapping formula t (k), at least a subset of the plurality of consecutive data subcarrier indexes of the second RU are permuted to obtain a plurality of permuted data subcarriers of the second RU, where k represents an original index and t (k) represents a permutation index. As described above, the LDPC subcarrier mapping formula t (k) depends on the number of the plurality of data subcarriers of the second RU, wherein the number of the plurality of second data subcarriers of the second RU is greater than the number of the plurality of subcarriers of the first RU. In one embodiment, the second RU is the largest RU within the channel bandwidth, i.e., includes the largest number of data subcarriers within the channel bandwidth. The method 500 comprises a further step 505: the plurality of subcarriers of the first RU are mapped to a subset of the plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over the plurality of permuted data subcarriers of the second RU. Furthermore, the method 500 comprises a step 507: the plurality of subcarriers based on the rearrangement of the first RU communicates with one or more wireless stations 120.

As described above, in one embodiment, the plurality of data subcarriers of the second RU are permuted based on the following LDPC subcarrier mapping formula:

other features of the method 500 come directly from the functionality of the wireless communication device 110 (e.g., the wireless AP 110), as well as the various embodiments described above and below.

Those skilled in the art will appreciate that the "blocks" ("units") of the various figures (methods and apparatus) represent or describe the functions of the embodiments of the disclosure (rather than necessarily individual "units" in hardware or software), and thus equally describe the functions or features of the apparatus embodiments as well as the method embodiments (unit equivalent steps).

In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the described embodiments of the apparatus are merely exemplary. For example, the unit division is just one logic function division, and other division manners may be actually implemented. For example, multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or described may be implemented by some interfaces. The indirect coupling or communication connection between devices or units may be accomplished through electronic, mechanical, or other forms.

Units described as separate components may or may not be physically separated; the components shown as units may or may not be physical units, may be co-located, or may be distributed among multiple network elements. Some or all of the elements may be selected according to actual needs to achieve the objectives of the embodiment.

In addition, functional units in embodiments of the invention may be integrated into one processing unit, or each unit may physically exist alone, or two or more units may be integrated into one unit.

Claims

1. A wireless communication device (110, 120) for Orthogonal Frequency Division Multiple Access (OFDMA) communication over a channel with another wireless communication device (120, 110), wherein the wireless communication device (110, 120) comprises processing circuitry (111, 121), the processing circuitry (111, 121) for:

obtaining a plurality of subcarriers of a first Resource Unit (RU) within a channel bandwidth of the channel;

permuting at least a subset of a plurality of data subcarriers of a second RU based on a Low Density Parity Check (LDPC) subcarrier mapping formula, wherein the LDPC subcarrier mapping formula is dependent on a number of the plurality of data subcarriers of the second RU that is greater than a number of the plurality of subcarriers of the first RU;

Mapping the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over the plurality of permuted data subcarriers of the second RU;

a plurality of subcarriers based on the rearrangement of the first RU is communicated with the other wireless communication device (120, 110).

2. The wireless communication device (110, 120) of claim 1, wherein the second RU is a maximum RU within the channel bandwidth.

3. The wireless communication device (110, 120) according to claim 1 or 2, wherein the processing circuit (111, 121) is configured to permute at least a subset of the plurality of data subcarriers of the second RU based on the following LDPC subcarrier mapping formula t (k):

4. The wireless communication device (110, 120) of any one of claims 1-3, wherein the channel bandwidth is 20mhz, n _SD ＝234，D _TM =9, wherein the first RU comprises 26, 52 or 106 subcarriers.

5. The wireless communication device (110, 120) of any of claims 1-3, wherein the channel bandwidth is 40mhz, n _SD ＝468，D _TM =12, wherein the first RU comprises 26, 52, 106 or 242 subcarriers.

6. The wireless communication device (110, 120) of any one of claims 1-3, wherein the channel bandwidth is 80mhz, n _SD ＝980，D _TM =20, wherein the first RU comprises 26, 52, 106, 242 or 484 subcarriers.

7. The wireless communication device (110, 120) of any of claims 1-3, wherein the channel bandwidth is 160mhz, n _SD ＝1960，D _TM =20, wherein the first RU comprises 26, 52, 106, 242, 484 or 996 subcarriers.

8. The wireless communication device (110, 120) of any one of claims 1-3, wherein the channel bandwidth is 320mhz, n _SD ＝3920，D _TM =20, wherein the first RU comprises 26, 52, 106, 242, 484 or 996 subcarriers.

9. The wireless communication device (110, 120) of claim 7 or 8, wherein the processing circuitry (111, 121) is further configured to divide the channel bandwidth into a plurality of channel bandwidth segments of size 80MHz and to process each of the plurality of channel bandwidth segments independently.

10. The wireless communication device (110, 120) of any of claims 1-9, wherein the processing circuitry (111, 121) is configured to permute at least a subset of the plurality of data subcarriers of the second RU based on the LDPC subcarrier mapping formula by mapping an index k of the plurality of subcarriers of the first RU to an index t (k) of the plurality of data subcarriers of the second RU.

11. The wireless communication device (110, 120) of any of claims 1-9, wherein the processing circuitry (111, 121) is configured to permute at least the subset of the plurality of data subcarriers of the second RU based on the LDPC subcarrier mapping formula by mapping an index t (k) of the plurality of subcarriers of the first RU to an index k of the plurality of data subcarriers of the second RU.

12. The wireless communication device (110, 120) of claim 10 or 11, wherein the channel bandwidth is 20MHz, and N _SD =234, wherein the processing circuit (11 l, 121) is configured to permute at least a subset of the plurality of data subcarriers of the second RU by: rearranging odd data subcarriers of the plurality of permuted data subcarriers of the second RU into a first subsequence of the plurality of permuted data subcarriers of the second RU, and rearranging even data subcarriers of the second RU into a second subsequence of the plurality of permuted data subcarriers of the second RU.

13. The wireless communication device (110, 120) of claim 10 or 11, wherein the channel bandwidth is an integer multiple of 20MHz, wherein the processing circuitry (111, 121) is configured to permute at least the subset of the plurality of data subcarriers of the second RU by generating the plurality of permuted data subcarriers of the second RU, as follows:

r _{i_20MHz} ＝{r ₁ ，r ₃ ，...，r ₂₃₃ ，r ₂ ，r ₄ ，...，r ₂₃₄ }，

Wherein BW represents at least a portion of the channel bandwidth.

14. The wireless communication device (110, 120) of any of the preceding claims, wherein the plurality of subcarriers of the first RU comprises N subcarriers, wherein the processing circuitry (111, 121) is configured to map the plurality of subcarriers of the first RU to a subset of the plurality of permuted data subcarriers of the second RU by mapping the plurality of subcarriers of the first RU to the first N data subcarriers of the plurality of permuted data subcarriers of the second RU.

15. The wireless communication device (110, 120) of claim 14, wherein the processing circuitry (111, 121) is configured to map a plurality of subcarriers of another RU to another subset of the plurality of permuted data subcarriers of the second RU, wherein the another subset comprises a next N data subcarriers of the plurality of permuted data subcarriers of the second RU.

16. The wireless communication device (110, 120) of any of the preceding claims, wherein the processing circuitry (111, 121) is configured to add one or more filler subcarriers.

17. A method (500) of operating a wireless communication device (110, 120) for Orthogonal Frequency Division Multiple Access (OFDMA) communication with another wireless communication device (120, 110) over a channel, wherein the method (500) comprises:

Obtaining (501) a plurality of subcarriers of a first Resource Unit (RU) within a channel bandwidth of the channel;

permuting (503) at least a subset of a plurality of data subcarriers of a second RU based on a Low Density Parity Check (LDPC) subcarrier mapping formula, wherein the LDPC subcarrier mapping formula is dependent on a number of the plurality of data subcarriers of the second RU that is greater than a number of the plurality of subcarriers of the first RU;

mapping (505) a plurality of subcarriers of the first RU to a subset of a plurality of permuted data subcarriers of the second RU to obtain a rearranged plurality of subcarriers of the first RU distributed over a plurality of permuted data subcarriers of the second RU;

-communicating (505) with the other wireless communication device (120, 110) based on the rearranged plurality of subcarriers of the first RU.

18. The method (500) of claim 17, wherein the second RU is a maximum RU within the channel bandwidth.

19. A computer program product comprising a computer readable storage medium for storing program code which, when executed by a computer or a processor, causes the computer or the processor to perform the method (500) according to claim 17 or 18.