Method and transmitter for transmitting data block in wireless communication system

Abstract

To provide a method and a device for transmitting a data block in a wireless communication system.SOLUTION: The method for transmitting a data block in a wireless communication system comprises the steps of: determining the number of bits (s) and the number of encoders (NES) to be allocated to one axis of a signal constellation; encoding an information bit on the basis of the s and the NES and generating a coded block; parsing the coded block on the basis of the s and the NES and generating a plurality of frequency sub-blocks; and transmitting the plurality of frequency sub-blocks to a receiver.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to wireless communication, and more particularly to a method for transmitting data blocks in a wireless communication system and a transmitter using the same. [Background technology]

[0002] Recently, various wireless communication technologies have been developed with the development of information and communication technology. Among them, WLAN (Wireless Local Area Network) is a technology based on radio frequency technology that enables wireless connection to the Internet in homes, businesses, or specific service areas using portable terminals such as personal digital assistants (PDAs), laptop computers, and portable multimedia players (PMPs).

[0003] IEEE (Institute of Electrical and Electronics Engineering) 802.11n is a relatively recent technical standard that was established to overcome the limitations of communication speed, which has been pointed out as a weakness of WLAN. IEEE 802.11n aims to increase the speed and reliability of the network and extend the operating distance of the wireless network. More specifically, IEEE 802.11n supports High Throughput (HT), which is a maximum data processing speed of 540 Mbps or more, and is based on MIMO (Multiple Inputs and Multiple Outputs) technology that uses multiple antennas on both the transmitter and receiver to minimize transmission errors and optimize data speed. This standard also uses a coding method that transmits multiple overlapping copies to increase data reliability, and can also use OFDM (Orthogonal Frequency Division Multiplex) to increase speed.

[0004] Generally, in a wireless communication system, a codeword is interleaved over the entire frequency band in order to obtain a frequency diversity gain and maximize an interleaving effect. When the size of the frequency band used increases, the codeword and the interleaver are increased by the size of the frequency band to obtain a coding gain and a diversity gain.

[0005] However, increasing the size of the interleaver as the size of the frequency band increases may increase the burden of modifying the existing structure and may increase complexity. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a data block transmission method supporting a wide band in a wireless LAN system and a transmitter using the same. [Means for solving the problem]

[0007] In one aspect, a method for transmitting data blocks in a wireless communication system is provided, the method comprising: determining a number of bits (s) allocated to one axis of a signal constellation and a number of encoders (N ES ) determining said s and N ES generating a coded block by encoding information bits based on s and N ES and transmitting the plurality of frequency sub-blocks to a receiver.

[0008]

number

[0009] The step of encoding the information bits includes: ES encoding the information bits using forward error correction (FEC) encoders; ES to rearrange the encoded information bits based on the coded information bits to generate the coded block.

[0010] The signal constellation is used for at least one of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (16-QAM), 64-QAM, and 256-QAM.

[0011] The frequency sub-blocks correspond to a plurality of frequency bands, respectively.

[0012] Each frequency band has a bandwidth of 80 MHz.

[0013] The number of the frequency subblocks is two.

[0014] The coded block is parsed in a round robin manner to generate the plurality of frequency sub-blocks.

[0015] In another aspect, a transmitter for transmitting a data block in a wireless communication system is provided, the transmitter comprising: a number of bits (s) allocated to one axis of a signal constellation and a number of encoders (N ES ) and determining s and N ES a coding unit for generating a coded block by encoding information bits based on s and N ES a parsing unit for parsing the coded block based on the first factor to generate a plurality of frequency sub-blocks, and a transmitting unit for transmitting the plurality of frequency sub-blocks to a receiver.

[0016] In another aspect, a method for transmitting data blocks in a wireless communication system is provided, the method comprising: a number s of bits allocated to one axis of a signal constellation and a number N of encoders. ES determining the coded block; generating the coded block; ES The method includes the steps of: parsing the coded block bit-wise to generate a plurality of frequency sub-blocks; and transmitting the plurality of frequency sub-blocks to a receiver. Effect of the Invention

[0017] Adjacent bits of an encoding block are prevented from consecutively having the same reliability on the signal constellation, and the decoding performance of the receiver is prevented from being degraded. [Brief description of the drawings]

[0018] [Figure 1] 1 is a diagram showing the architecture of IEEE802.11. [Diagram 2] A block diagram showing an example of a PPDU format. [Diagram 3] 2 is a block diagram illustrating an example of a transmitter in which an embodiment of the present invention is implemented in adjacent bands. [Figure 4] 2 is a block diagram illustrating an example of a transmitter in which an embodiment of the present invention is implemented in non-contiguous bands. [Diagram 5] An example of segment parsing is shown below. [Figure 6] An example of applying the segment parsing in FIG. 5 is shown below. [Figure 7] Another example of application of the segment parsing of FIG. 5 will be described. [Figure 8] 1 illustrates an example of segment parsing according to an embodiment of the present invention. [Figure 9] 13 illustrates another example of segment parsing according to an embodiment of the present invention. [Figure 10]4 illustrates segment parsing according to one embodiment of the present invention. [Figure 11] 13 illustrates segment parsing according to another embodiment of the present invention. [Figure 12] The simulation results are shown. [Figure 13] The simulation results are shown. [Figure 14] The simulation results are shown. [Figure 15] 4 is a flowchart illustrating a data transmission method according to an embodiment of the present invention. [Figure 16] 10 is a flowchart illustrating a data transmission method according to another embodiment of the present invention. [Figure 17] 1 is a block diagram showing a transmitter in which an embodiment of the present invention is implemented; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A Wireless Local Area Network (WLAN) system in which an embodiment of the present invention is implemented includes at least one Basic Service Set (BSS). A BSS is a set of stations (STAs) that are successfully synchronized to communicate with each other. BSSs can be classified into Independent BSSs (IBSSs) and Infrastructure BSSs.

[0020] A BSS may include at least one STA and an AP (Access Point). The STA may be an AP or a non-AP STA. The AP is a functional medium that provides a connection over a wireless medium for each of the STAs in the BSS. The AP may also be called by other names such as a centralized controller, a Base Station (BS), a scheduler, etc.

[0021] FIG. 1 is a diagram showing the architecture of IEEE802.11.

[0022] The IEEE 802.11 wireless-medium physical layer (PHY) architecture includes a PHY Layer Management Entity (PLME), a Physical Layer Convergence Procedure (PLCP) sublayer 110, and a Physical Medium Dependent (PMD) sublayer 100.

[0023] The PLME provides PHY management functions in cooperation with the MLME (MAC (Medium Access Control) Layer Management Entity).

[0024] The PLCP sublayer 110 transfers MPDUs (MAC Protocol Data Units) received from the MAC sublayer 120 to the sublayer at the instruction of the MAC layer between the MAC sublayer 120 and the PMD sublayer 100, and transfers frames coming from the PMD sublayer 100 to the MAC sublayer 120.

[0025] The PMD sublayer 100 is a sublayer below the PLCP and enables transmission and reception of PHY entities between two STAs over a wireless medium.

[0026] The MPDU delivered by the MAC sublayer 120 is called a PSDU (Physical Service Data Unit) in the PLCP sublayer 110. The MPDU is similar to the PSDU, but when an aggregated MPDU (A-MPDU) that is an aggregation of multiple MPDUs is delivered, each MPDU and the PSDU are different from each other.

[0027] The PLCP sublayer 110 adds an additional field including information required by the physical layer transmitter / receiver in the process of receiving the PSDU from the MAC sublayer 120 and transmitting it to the PMD sublayer 100. The added fields are a PLCP preamble, a PLCP header, and tail bits required on the data field in the MPDU. The PLCP preamble allows the receiver to prepare a synchronization function and antenna diversity before transmitting the PSDU. The PLCP header includes a field including information about the frame.

[0028] The PLCP sublayer 110 adds the above-mentioned fields to the PSDU to generate a PPDU (PLCP Protocol Data Unit), which is then transmitted to the receiving station via the PMD sublayer. The receiving station receives the PPDU, and obtains information necessary for data recovery from the PLCP preamble and PLCP header to recover the data.

[0029] FIG. 2 is a block diagram showing an example of a PPDU format.

[0030] PPDU 600 may include a Legacy-Short Training Field (L-STF) 610, a Legacy-Long Training Field (L-LTF) 620, a Legacy-SIG (L-SIG) field 630, a Very High Throughput (VHT)-SIG A field 640, a VHT-STF 650, a VHT-LTF 660, a VHT-SIG B 670, and a data field 680.

[0031] The L-STF610 is used for frame timing acquisition, AGC (Automatic Gain Control), coarse frequency acquisition, etc.

[0032] The L-LTF 620 is used for channel estimation for demodulation of the L-SIG field 630 and the VHT-SIG A field 640 .

[0033] The L-SIG field 630 contains control information regarding the transmission time of the PPDU.

[0034] The VHT-SIG A field 640 includes common information required for STAs supporting multiple input multiple output (MIMO) transmission to receive spatial streams. The VHT-SIG A field 640 includes information on spatial streams for each STA, channel bandwidth information, group identifiers, information on STAs assigned with each group identifier, a short GI (Guard Interval), and beamforming information (including whether SU-MIMO or MU-MIMO).

[0035] The VHT-STF650 is used to improve the performance of AGC estimation in MIMO transmission.

[0036] The VHT-LTF660 is used by each STA to estimate the MIMO channel.

[0037] The VHT-SIG B field 670 includes individual control information for each STA. The VHT-SIG B field 670 includes Modulation and Coding Scheme (MCS) information. The size of the VHT-SIG B field 640 varies depending on the type of MIMO transmission (MU-MIMO or SU-MIMO) and the channel bandwidth used for PPDU transmission.

[0038] The data field 680 includes the PSDU passed down from the MAC layer, the service field, tail bits, and padding bits, if necessary.

[0039] To support higher data rates, WLAN systems can support a variety of bandwidths. For example, supported bandwidths can include at least one of 20 MHz, 40 MHz, 80 MHz, and 160 MHz. Also, because continuous bandwidth is not always available, non-contiguous bands can be used. For example, a 160 MHz bandwidth can be supported using two non-contiguous 80 MHz bands (referred to as 80+80Mhz).

[0040] Below, we will use a contiguous 160 MHz band and a non-contiguous 80+80 MHz band as examples. However, there is no limit to the size or number of bands.

[0041] The WLAN system can support MU-MIMO and / or SU-MIMO. In the following, SU-MIMO is described as an example, but those skilled in the art can easily apply it to MU-MIMO.

[0042] FIG. 3 is a block diagram illustrating an example of a transmitter in which an embodiment of the present invention may be implemented in adjacent bands.

[0043] The data unit is encoded by at least one forward error correction (FEC) encoder (S710). The data unit includes scrambled information bits with PHY padding bits added to the PDSU. The data unit is divided into bit sequences having a specific bit size by an encoder parser, and each bit sequence can be input to a respective FEC encoder.

[0044] The encoding method is BCC (Binary Convolution Code). However, the encoding methods shown are merely examples, and those skilled in the art can apply the technical concept of the present invention to well-known encoding methods such as LDPC (low-density parity-check) and turbo code.

[0045] The encoded data units are then split into N SS The pixels are rearranged into spatial blocks (S720). SS is the number of spatial streams.

[0046] The output bits of each stream parser are divided into two frequency sub-blocks (S730). One frequency sub-block can correspond to an 80 MHz bandwidth.

[0047] Each of the two frequency subblocks is independently interleaved by a BCC interleaver (S740). The interleaver may have a size corresponding to 20 MHz, 40 MHz, and 80 MHz. Since one frequency subblock corresponds to an 80 MHz band, the frequency subblocks may be interleaved by an interleaver corresponding to 80 MHz.

[0048] Each interleaved frequency subblock is independently mapped onto a signal constellation by a constellation mapper (S750). The signal constellation can correspond to various modulation methods such as BPSK (Binary Phase Shift Keying), QPSK (Quadrature phase-shift keying), 16-QAM (Quadrature amplitude modulation), 64-QAM, or 256-QAM, and there is no restriction on the modulation method.

[0049] The mapped sub-blocks are then spatially mapped using space-time block coding (STBC) and cyclic shift delay (CSD) (S760).

[0050] The two spatially mapped sub-blocks are subjected to an inverse discrete Fourier transform (IDFT) and then transmitted (S770).

[0051] FIG. 4 is a block diagram illustrating an example of a transmitter in which an embodiment of the present invention may be implemented in non-contiguous bands.

[0052] Compared with the transmitter of Fig. 3, each of the two frequency sub-blocks is independently subjected to IDFT. Since each frequency sub-block corresponds to an 80 MHz band, and the 80 MHz bandwidth is non-adjacent, the IDFT is independently performed.

[0053] The segment parser parses the encoded data unit into multiple frequency sub-blocks in order to support a larger bandwidth without increasing the size of the BCC interleaver.

[0054] For example, assume that an existing BCC interleaver supports a maximum of 80 MHz. In order to support a 160 MHz bandwidth, the BCC interleaver must be modified to support 160 MHz. However, by using a segment parser, the data stream is parsed into sub-blocks that have the size of the frequency bandwidth supported by the BCC interleaver. Therefore, a wider bandwidth can be supported without changing the size of the interleaver, and frequency diversity gain can also be obtained.

[0055] The following parameters are defined below.

[0056] N CBPS: number of coded bits per symbol

[0057] N CBPSS : Number of coded bits per symbol per spatial stream (numberofcodedbitspersymbolperspatialstream)

[0058] N BPSC : Number of coded bits per subcarrier over all spatial streams

[0059] N BPSCS : Number of coded bits per subcarrier per spatial stream

[0060] N SS : Number of spatial streams

[0061] N ES : The number of encoders for data fields. The number of encoders is the same as the number of codewords.

[0062] R: code rate

[0063] An example of segment parsing is shown in Figure 5. The simplest segment parsing proposed to date is to assign even bits to the first sub-block and odd bits to the second sub-block for each spatial stream.

[0064] Figure 6 shows an example of applying the segment parsing of Figure 5. ES =4, N SS= 6, R = 6 / 5, and bandwidth 80 MHz.

[0065] The number of bits corresponding to the Q-axis (or I-axis) of the 64-QAM signal constellation is 3. Therefore, the output of the encoder is allocated to each spatial stream in a round robin manner with 3 bits each. Each spatial stream is parsed by the stream parser to generate sub-blocks.

[0066] The parsed subblocks are interleaved by the interleaver. Interleaver input bits are assigned sequentially to 26 columns, and the 3j, 3j+1, and 3j+2 columns of the 3i-th column are directly mapped to the signal constellation, the 3j, 3j+1, and 3j+2 columns of the 3i+1-th column are mapped to the signal constellation by applying a cyclic shift one step below, and the 3j, 3j+1, and 3j+2 columns of the 3i+2-th column are mapped to the signal constellation by applying a cyclic shift two steps below.

[0067] It is shown that consecutive bits of a codeword are mapped to bits having different reliabilities on a signal constellation.

[0068] FIG. 7 shows another example of applying the segment parsing of FIG. ES = 1 or 2, N SS = 1, R = 6 / 5, and a bandwidth of 160 MHz. Unlike the example in Figure 6, this condition shows that consecutive bits of a codeword are consecutively mapped to positions on the signal constellation with the same reliability.

[0069] If the bits of a codeword continue to have the same reliability on a signal constellation, the decoding performance of the receiver may be significantly degraded, because errors may occur if the channel conditions degrade with respect to the reliability.

[0070] Therefore, in the present invention, a segment parsing is proposed that ensures that bits of a codeword do not consecutively have the same reliability on the signal constellation.

[0071] The proposed segment parsing takes into account the number of encoders and the number of bits allocated to one axis of the signal constellation.

[0072] Consider the number of bits s allocated to one axis of the signal constellation as follows:

[0073]

number

[0074] For example, s=1 for BPSK and QPSK, s=2 for 16-QAM, s=4 for 64-QAM, and s=4 for 256-QAM.

[0075] 8 illustrates an example of segment parsing according to an embodiment of the present invention, in which two frequency subblocks are allocated in units of s for each spatial stream according to each modulation scheme.

[0076] FIG. 9 shows another example of segment parsing according to an embodiment of the present invention. This is a case where the output of each encoder is bundled. That is, sN ES Parse into units.

[0077] Bits of adjacent codewords can be mapped to have different reliabilities on the signal constellation.

[0078] The example in FIG. 9 can be mathematically represented as follows:

[0079] Let the output bits of each spatial stream parser be N CBPSS Divide by blocks of bits. Each block is N CBPSS The signal is parsed into two frequency sub-blocks of 1 / 2 bits according to the following formula:

[0080]

number

number

[0081] Meanwhile, the number of bits of a coded block (i.e., the number of bits of the i-th spatial block) is 2sN ES If the number of bits in a coded block is not a multiple of 2sN, there may be residual bits that are not allocated to the frequency subblocks. ES If the bit is not divisible by 1, the problem arises as to how to allocate the extra bits. Typically, the following cases arise with a 160 MHz bandwidth: (1) 64-QAM, R=2 / 3, N SS =5, N ES =5 (2) 64-QAM, R=2 / 3, N SS =7, N ES =7 (3) 64-QAM, R=3 / 4, N SS =5, N ES =5 (4) 64-QAM, R=3 / 4, N SS =7, N ES =7

[0082] FIG. 10 illustrates segment parsing according to one embodiment of the present invention.

[0083]

number

[0084] That is, N CBPSS is 2sN ES If not divided by, each block is CBPSS The signal is parsed into two frequency sub-blocks of 1 / 2 bits according to the following formula:

[0085]

number

[0086] Equation 3 additionally shows the allocation of extra bits to Equation 2.

[0087] FIG. 11 illustrates segment parsing according to another embodiment of the present invention.

[0088]

number

[0089] 12 to 14 show the simulation results. SS = 3, 16-QAM, R = 1 / 2, and FIG. SS = 3, 16-QAM, R = 3 / 4, and FIG. SS=3, 256-QAM, R=3 / 4. 'Nseg=1' is using one interleaver over 60MHz bandwidth without segment parsing. 'Nseg=2, parser=0' is applying the existing segment parsing in Figure 5. 'Nseg=2, parser=1' is applying the proposed segment parsing in Figure 10.

[0090] We show that the existing segment parsing increases the packet error rate (PER) compared to when segment parsing is not performed, but the proposed segment parsing hardly increases the PER.

[0091] FIG. 15 is a flowchart illustrating a data transmission method according to an embodiment of the present invention.

[0092] The information bits are encoded to generate a coded block (S910). The encoding may include FEC encoding such as BCC or LDPC as well as spatial mapping by a stream parser. The number of bits in a coded block (per spatial stream) is N CBPSS It is.

[0093] The stream parser can parse based on s. The output bits of the FEC encoder are N CBPSS The s bits are rearranged into NSSS spatial blocks of s bits. Contiguous blocks of s bits can be assigned to other spatial streams in a round robin fashion.

[0094] Segment parsing is performed on the first segment unit (S920). The first segment unit is sN ES Each encoded block can have a value of N CBPSS The subblocks may be parsed into M frequency subblocks of / M bits each, where the subblocks may correspond to a bandwidth corresponding to the size of the interleaver.

[0095] When M=2, the block encoded as in Equation 2 can be parsed and divided into two sub-blocks.

[0096] It is determined whether there are any extra bits (S930).

[0097] N CBPSS If the number of segments is not divided into M × the first segment unit (i.e., N CBPSS (if M is not a multiple of M × the first segment unit), the second segment unit may be parsed into M frequency subblocks for the extra bits (S940). ES The second segment unit may have a value of s. When M=2, the block encoded as in Equation 3 may be parsed and divided into two sub-blocks.

[0098] Each subblock is transmitted to a receiver (S950). The parsed subblocks are independently interleaved by an interleaver, mapped onto a signal constellation, and transmitted.

[0099] FIG. 16 is a flowchart illustrating a data transmission method according to another embodiment of the present invention.

[0100] The information bits are encoded to generate a coded block (S1010). The encoding may include FEC encoding such as BCC or LDPC as well as spatial mapping by a stream parser. The number of bits in a coded block (per spatial stream) is N CBPSS It is.

[0101] The stream parser can parse based on s. The output bits of the FEC encoder are N CBPSSThe s bits are rearranged into NSSS spatial blocks of s bits. Contiguous blocks of s bits can be assigned to other spatial streams in a round robin fashion.

[0102] The size of the coded block, N CBPSS is divided into a reference value (S1020). The reference value is M times the first segment unit.

[0103] N CBPSS If the segment unit is divided into M×first segment units, segment parsing is performed on the first segment units (S1030). ES Each encoded block can have a value of N CBPSS A block encoded as in Equation 2 may be parsed into M frequency sub-blocks of M / M bits. The sub-blocks may correspond to a bandwidth corresponding to the size of the interleaver. When M=2, the block encoded as in Equation 2 may be parsed and divided into two sub-blocks.

[0104] N CBPSS If the frequency subblocks are not divided into M×first segment units, the frequency subblocks may be parsed into M frequency subblocks for the first segment unit and the second segment unit for the extra bits (S1040). ES The first segment unit is sN ES The first segment unit may have a value of m, and the second segment unit may have a value of s. First, segment parsing is performed on the first segment unit, and segment parsing is performed on the second segment unit for the extra bits. When M=2, the block encoded as in Equation 3 may be parsed and divided into two sub-blocks.

[0105] Each subblock is transmitted to a receiver (S1050). The parsed subblocks are independently interleaved by an interleaver, mapped onto a signal constellation, and transmitted.

[0106] 17 is a block diagram showing a transmitter in which an embodiment of the present invention is implemented. The embodiments of FIG. 15 to FIG. 16 can be implemented by a transmitter.

[0107] The transmitter 1000 includes a coding unit 1010, a parsing unit 1020, and a transmitting unit 1030. The coding unit 1010 may implement the functions of the FEC encoding and stream parser in Figs. 3 and 4. The parsing unit 1020 may implement the functions of the segment parser in Figs. 3 and 4. The transmitting unit 1030 may implement the functions of the interleaver and constellation mapper in Figs. 3 and 4.

[0108] The coding unit 1010 generates an encoded block. The parsing unit 1020 parses the encoded block into a plurality of frequency sub-blocks. The segment parsing of Equation 2 or Equation 3 can be implemented by the parsing unit 1020. The transmitting unit 1030 transmits the sub-blocks to a receiver.

[0109] The coding unit 1010, the parsing unit 1020, and the transmitting unit 1030 may be implemented by one or more processors. The processor may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The memory may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and / or other storage devices. When the embodiment is implemented in software, the techniques described above may be implemented with modules (processes, functions, etc.) that perform the functions described above. The modules may be stored in the memory and executed by the processor. The memory may be internal or external to the processor and may be coupled to the processor by various means known in the art.

[0110] In the exemplary system described above, the method is described based on a flowchart with a series of steps or blocks, but the present invention is not limited to the order of steps, and certain steps may occur in a different order or simultaneously with other steps than those described above. Furthermore, those skilled in the art will appreciate that the steps shown in the flowcharts are not exclusive, and other steps may be included, or one or more steps in the flowcharts may be omitted without affecting the scope of the present invention.

Claims

1. 1. A method for transmitting data in a wireless communication system, comprising: encoding the information bits to generate encoded data bits; stream parsing the coded data bits into a number of blocks, the number of blocks being a number of spatial streams; parsing each said block into two sub-blocks based on a predetermined value; mapping each of the sub-blocks to a constellation; transmitting said sub-blocks to a receiver; Including, 13. A method of transmitting data, wherein the predetermined value is determined based on a number of coded bits per subcarrier per spatial stream.

2. The predetermined value is and N ＢＰＳＣＳ 2. The method of claim 1, wherein x is the number of coded bits per subcarrier per spatial stream.

3. 2. The method of claim 1, wherein the predetermined value is a number of bits allocated to an axis of a signal constellation.

4. 2. The method of claim 1, wherein the encoding is a Forward Error Correction (FEC) encoding.

5. The method of claim 4, wherein the FEC coding is Low-Density Parity-check Coding (LDPC).

6. 1. A wireless communication station, comprising: encoding the information bits to generate encoded data bits; Stream parsing the encoded data bits into a number of blocks, the number of blocks being a number of spatial streams; parsing each said block into two sub-blocks based on a predetermined value; mapping each of said sub-blocks into a constellation; causing the station to transmit the sub-block to a receiver; A circuit configured as follows: The wireless communication station, wherein the predetermined value is determined based on a number of coded bits per subcarrier per spatial stream.

7. The predetermined value is and N ＢＰＳＣＳ 7. The wireless communication station of claim 6, wherein x is the number of coded bits per subcarrier per spatial stream.

8. 7. A radio communication station according to claim 6, characterized in that said predetermined value is the number of bits allocated to an axis of a signal constellation.

9. 7. The wireless communication station according to claim 6, wherein the encoding is FEC (Forward Error Correction) encoding.

10. 10. The wireless communication station according to claim 9, wherein the FEC coding is Low-Density Parity-check Coding (LDPC).

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