KR20160008453A - Operation method of device in wireless local area network - Google Patents

Abstract

Disclosed is an operation method of a station in a wireless local area network (WLAN). A method for transmitting data which is performed in a first station comprises the following steps: mapping a data stream to at least one spatial stream; dividing each of the at least one spatial stream into three or more sub-blocks; and transmitting the sub-blocks through frequency bands. Therefore, the performance of the WLAN can be improved.

Description

[0001] OPERATION METHOD OF DEVICE IN WIRELESS LOCAL AREA NETWORK [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless LAN technology, and more particularly, to a method of transmitting and receiving data.

With the development of information and communication technology, various wireless communication technologies are being developed. Among them, a wireless local area network (WLAN) may be a personal digital assistant (PDA), a laptop computer, a portable multimedia player (PMP), a smart phone A smart phone, a tablet PC, or the like, to wirelessly connect to the Internet in a home, an enterprise, or a specific service providing area.

The standard for wireless LAN technology is being developed as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. As the spread of wireless LANs is activated and applications using the wireless LANs are diversified, there is a growing need for new wireless LAN technologies that support higher throughput than existing wireless LAN technologies. Very high throughput (VHT) Wireless LAN technology is a proposed technology to support data rates of over 1Gbps. Among them, the wireless LAN technology according to the IEEE 802.11ac standard is a technology for providing an ultra high throughput in a band below 6 GHz, and the wireless LAN technology according to the IEEE 802.11ad standard is a technology for providing an ultra high throughput in a 60 GHz band.

In addition, standards for various wireless LAN technologies have been defined and technology development is under way. Typically, the wireless LAN technology according to the IEEE 802.11af standard is a technology defined for operation of a wireless LAN in a TV idle band, and the wireless LAN technology according to the IEEE 802.11ah standard operates at a low power in a band below 1 GHz The wireless LAN technology according to the IEEE 802.11ai standard is a technology defined for fast initial link setup (FILS) in a wireless LAN system. Recently, IEEE 802.11ax standardization for the purpose of improving frequency efficiency in a dense environment in which a plurality of base stations and terminals exist is proceeding.

In a system based on this WLAN technology, the unit of interleaving may be limited to a bandwidth that includes 256 subcarriers (e.g., 80 MHz for IEEE 802.11 ac). Thus, if transmission over a contiguous 160 MHz or non-contiguous 80 + 80 MHz band is performed, the segment parser of the station may be located in a space that is received from the station ' s stream parser, A spatial stream may be divided into two subblocks (e.g., a first subblock transmitted over the first 80 MHz band, a second subblock transmitted over the second 80 MHz band) Each sub-block may be transmitted to an interleaver or mapper of the station.

However, the station's segment parser can not split the spatial stream into three or more subblocks. In addition, the station's segment parser may support transmission over adjacent 160 MHz and non-contiguous 80 + 80 MHz bands, but may also use other frequency band combinations (e.g., adjacent 80 + 60 MHz bands, non- + 40MHz band, etc.). As a result, the efficiency of the wireless LAN deteriorates.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for transmitting and receiving data in a wireless LAN.

According to an aspect of the present invention, there is provided a method of transmitting data in a station, the method comprising: mapping a data stream to at least one spatial stream; , And transmitting each of the subblocks through the allocated frequency bands.

Here, the minimum number of sub-carriers included in each of the frequency bands may be 32. [

At least two of the frequency bands may include a different number of subcarriers.

Here, the frequency bands may be contiguous or non-contiguous.

Here, the number of frequency bands may be equal to the number of subblocks.

Here, the step of dividing into the sub-blocks may be performed in the segment parser of the station.

Here, the data stream is included in the PPDU, and the signal field of the preamble of the PPDU may include information related to the frequency bands.

According to another aspect of the present invention, there is provided a method of receiving data in a station, the method comprising: receiving subblocks through non-adjacent frequency bands; Reconstructing the blocks into a spatial stream, and reconstructing the plurality of spatial streams into a data stream.

Here, the minimum number of sub-carriers included in each of the frequency bands may be 32. [

At least two of the frequency bands may include a different number of subcarriers.

Here, reconstructing into the spatial stream may be performed in a segment multi-parser of the station.

Here, the data stream is included in the PPDU, and the signal field of the preamble of the PPDU may include information related to the frequency bands.

According to another aspect of the present invention, there is provided a method of receiving data in a station, the method including dividing a source block received through adjacent frequency bands into a plurality of subblocks, Reconstructing a plurality of spatial streams into a data stream, and reconstructing the plurality of spatial streams into a data stream.

Here, the step of dividing into the plurality of subblocks may be performed in the segment parser of the station.

Here, reconstructing into the spatial stream may be performed in a segment multi-parser of the station.

According to the present invention, a station's segment parser may divide a spatial stream into three or more sub-blocks. In addition, the station's segment parser can support transmission over various frequency band combinations as well as transmission over adjacent 160 MHz and non-adjacent 80 + 80 MHz bands. Accordingly, the frequency resources can be efficiently used in the wireless LAN, and the performance of the wireless LAN can be improved.

1 is a block diagram showing the structure of a wireless LAN device.
2 is a schematic block diagram illustrating a transmission signal processing unit in a wireless LAN.
3 is a schematic block diagram illustrating a received signal processing unit in a wireless LAN.
FIG. 4 is a diagram showing a relationship between frames. FIG.
5 is a conceptual diagram for explaining a frame transmission procedure according to the CSMA / CA scheme for avoiding collision between frames in a channel.
6 is a block diagram illustrating an embodiment of a transmit signal processor for transmission over an adjacent 160 MHz band.
7 is a block diagram illustrating an embodiment of a transmit signal processor for transmission over a non-adjacent 80 + 80 MHz band.
8 is a flowchart illustrating an operation method of a station according to an embodiment of the present invention.
9 is a conceptual diagram illustrating the operation of a segment parser of a station that generates sub-blocks of the same size when N _SS = 1, N _ES = 1, and S = 1 (BPSK, QPSK).
10 is a conceptual diagram illustrating an operation of a segment parser of a station that generates sub-blocks of the same size when N _SS = 1, N _ES = 1, and S = 2 (16-QAM).
11 is a conceptual diagram illustrating the operation of a segment parser of a station that generates sub-blocks of the same size when N _SS = 1, N _ES = 1, and S = 3 (64-QAM).
12 is a conceptual diagram illustrating an operation of a segment parser of a station generating sub-blocks of the same size when N _SS = 1, N _ES = 1, and S = 4 (256-QAM).

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and like parts are denoted by similar reference numerals throughout the specification.

A basic service set (BSS) in a wireless local area network (WLAN) (hereinafter referred to as "wireless LAN") includes a plurality of wireless LAN devices. The WLAN device may include a medium access control (MAC) layer and a physical (PHY) layer according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. At least one of the plurality of wireless LAN devices may be an access point (AP), and the remaining wireless LAN device may be a non-AP station (non-AP STA). Or ad-hoc networking, a plurality of wireless LAN devices may all be non-AP stations. In general, a station (STA) is also used when collectively referred to as an access point (AP) and a non-AP station, but for simplicity, the non-AP station is also abbreviated as a station (STA).

1 is a block diagram showing the structure of a wireless LAN device.

1, a wireless LAN device 1 includes a baseband processor 10, a radio frequency (RF) transceiver 20, an antenna unit 30, a memory 40, an input interface unit 50, An output interface unit 60, and a bus 70, The baseband processor 10 performs the baseband related signal processing described herein, and may include a MAC processor 11, a PHY processor 15, and the like.

In one embodiment, the MAC processor 11 may include a MAC software processing unit 12 and a MAC hardware processing unit 13. At this time, the memory 40 includes software (hereinafter referred to as "MAC software") including some functions of the MAC layer, and the MAC software processing unit 12 implements some functions of the MAC by driving the MAC software , The MAC hardware processing unit 13 may implement the remaining functions of the MAC layer as hardware (MAC hardware), but the present invention is not limited thereto. The PHY processor 15 may include a transmission signal processing unit 100 and a reception signal processing unit 200.

The baseband processor 10, the memory 40, the input interface unit 50 and the output interface unit 60 can communicate with each other via the bus 70. [ The RF transceiver 20 may include an RF transmitter 21 and an RF receiver 22. In addition to the MAC software, the memory 40 may store an operating system, an application, etc., and the input interface unit 50 acquires information from the user, and the output interface unit 60 acquires information from the user Output.

The antenna unit 30 may include one or more antennas. When using multiple-input multiple-output (MIMO) or multi-user MIMO (MU-MIMO), the antenna unit 30 may include a plurality of antennas.

2 is a schematic block diagram illustrating a transmission signal processing unit in a wireless LAN.

2, the transmission signal processing unit 100 includes an encoder 110, an interleaver 120, a mapper 130, an inverse Fourier transformer 140, and a guard interval (GI) inserter 150 can do.

Encoder 110 encodes the input data and may be, for example, a forward error correction (FEC) encoder. The FEC encoder may include a binary convolutional code (BCC) encoder, in which case a puncturing device may be included. Alternatively, the FEC encoder may include a low-density parity-check (LDPC) encoder.

The transmission signal processing unit 100 may further include a scrambler scrambling the input data before encoding the input data to reduce the probability that a long same sequence of 0's or 1's occurs. If a plurality of BCC encoders are used as the encoder 110, the transmission signal processing unit 100 may further include an encoder parser for demultiplexing the scrambled bits into a plurality of BCC encoders. When an LDPC encoder is used as the encoder 110, the transmission signal processing unit 100 may not use the encoder parser.

The interleaver 120 interleaves the bits of the stream output from the encoder 110 to change the order. Interleaving may be applied only when a BCC encoder is used as the encoder 110. [ The mapper 130 maps the bit stream output from the interleaver 120 to constellation points. When an LDPC encoder is used as the encoder 110, the mapper 130 may perform LDPC tone mapping in addition to the property store mapping.

When MIMO or MU-MIMO is used, the transmission signal processing unit 100 may use a plurality of interleavers 120 and a plurality of mappers 130 corresponding to the number of spatial streams N _SS . The transmission signal processing unit 100 may further include a stream parser that divides outputs of a plurality of BCC encoders or LDPC encoders into a plurality of blocks to be provided to different interleavers 120 or a mapper 130. In addition, the transmission signal processing unit 100 includes a space-time block code (STBC) encoder for spreading a property point from N _SS spatial streams to N _STS space-time streams, and a spatial mapper for mapping the received signals to transmit chains. The spatial mapper can use direct mapping, spatial expansion, beamforming, or the like.

The inverse Fourier transformer 140 transforms a sex store block output from the mapper 130 or the spatial mapper into an inverse discrete Fourier transform (IDFT) or an inverse fast Fourier transform (IFFT) Domain block, that is, a symbol. When the STBC encoder and the spatial mapper are used, the inverse Fourier transformer 140 may be provided for each transmission chain.

When MIMO or MU-MIMO is used, the transmission signal processing unit 100 may insert a cyclic shift diversity (CSD) before or after the inverse Fourier transform to prevent unintended beamforming. The CSD may be specified for each transport chain or for each space-time stream. Or CSD may be applied as part of a spatial mapper. Further, when using MU-MIMO, some blocks before the space mapper may be provided for each user.

The GI inserter 150 inserts a GI in front of the symbol. The transmission signal processing unit 100 can smoothly window the edge of the symbol after inserting the GI. The RF transmitter 21 converts the symbol into an RF signal and transmits it via the antenna. When MIMO or MU-MIMO is used, the GI inserter 150 and the RF transmitter 21 can be provided for each transmission chain.

3 is a schematic block diagram illustrating a received signal processing unit in a wireless LAN.

3, the received signal processing unit 200 may include a GI eliminator 220, a Fourier transformer 230, a demapper 240, a deinterleaver 250, and a decoder 260. The RF receiver 22 receives the RF signal through the antenna and converts it into a symbol, and the GI remover 220 removes the GI from the symbol. When using MIMO or MU-MIMO, the RF receiver 22 and the GI remover 220 may be provided for each receive chain.

The Fourier transformer 230 transforms symbols, i.e., time domain blocks, into discrete Fourier transforms (DFTs) or fast Fourier transforms (FFTs) into frequency domain ghost points. Fourier transformer 230 may be provided for each receive chain. If MIMO or MU-MIMO is used, it may include a spatial demapper that transforms the Fourier transformed reception chain into a spatiotemporal stream, and an STBC decoder that despreads the span stream from the space-time stream to the spatial stream. have.

The dem mapper 240 demaps the block of the sex store output from the Fourier transformer 230 or the STBC decoder into a bit stream. If the received signal is LDPC encoded, demapper 240 may perform further LDPC tone demapping before property demapping. The deinterleaver 250 deinterleaves the bits of the stream output from the demapper 240. Deinterleaving can be applied only when the received signal is BCC encoded.

In case of using MIMO or MU-MIMO, the received signal processing unit 200 may use a plurality of demapper 240 and a plurality of deinterleavers 250 corresponding to the number of spatial streams. At this time, the received signal processing unit 200 may further include a stream deparser that combines the streams output from the plurality of deinterleavers 250.

The decoder 260 decodes the stream output from the deinterleaver 250 or the stream decoder, and may be, for example, an FEC decoder. The FEC decoder may include a BCC decoder or an LDPC decoder. The received signal processing unit 200 may further include a descrambler for descrambling the decoded data by the decoder 260. When a plurality of BCC decoders are used as the decoder 260, the received signal processing unit 200 may further include an encoder deparser for multiplexing the decoded data. When the LDPC decoder is used as the decoder 260, the received signal processing unit 200 may not use the encoder de-parser.

FIG. 4 is a diagram showing an interframe space (IFS) relationship. FIG.

Referring to FIG. 4, a data frame, a control frame, and a management frame may be exchanged between the wireless LAN devices. A data frame is a frame used for transmission of data forwarded to an upper layer. The data frame is transmitted after performing a backoff after a distributed coordination function IFS (DIFS) from when the medium becomes idle.

The management frame is used for exchange of management information that is not forwarded to the upper layer, and is transmitted after backoff after IFS such as DIFS or PIFS (point coordination function IFS). The subtype frame of the management frame includes Beacon, Association request / response, probe request / response, and authentication request / response. A control frame is a frame used for controlling access to a medium. Subtype frames of the control frame include RTS, CTS, and ACK. The control frame is transmitted after backoff after DIFS elapses when it is not a response frame of another frame, and is transmitted without backoff after SIFS (short IFS) if it is a response frame of another frame. The type and subtype of the frame can be identified by a type field and a subtype field in the frame control field.

Meanwhile, the QoS (Quality of Service) STA can transmit an arbitration IFS (AIFS) for an access category (AC) to which a frame belongs, i.e., a frame after the backoff after the AIFS [AC] elapses. At this time, a frame in which AIFS [AC] can be used may be a control frame, not a data frame, a management frame, and a response frame.

5 is a conceptual diagram for explaining a frame transmission procedure according to a carrier sense multiple access (CSMA) / collision avoidance (CA) scheme for avoiding collision between frames in a channel.

Referring to FIG. 5, a first station STA1 denotes a transmitting station to which data is to be transmitted, and a second station STA2 denotes a receiving station that receives data transmitted from the first station STA1. The third station STA3 may be located in an area capable of receiving a frame transmitted from the first station STA1 and / or a frame transmitted from the second station STA2.

The first station STA1 can determine whether a channel is being used through carrier sensing. The first station STA1 can determine the occupation state of the channel based on the magnitude of the energy existing in the channel or the correlation of the signal or can use the NAV (network allocation vector) The occupied state can be judged.

The first station STA1 transmits a request to send (RTS) frame to the second station after performing the backoff if it is determined that the channel is not used by another station during DIFS (i.e., when the channel is idle) (STA2). When receiving the RTS frame, the second station STA2 may transmit a clear to send (CTS) frame, which is a response to the RTS frame, to the first station STA1 after SIFS.

On the other hand, when receiving the RTS frame, the third station STA3 transmits the frame transmission period (for example, SIFS + CTS frame + SIFS + data) continuously transmitted subsequently using duration information included in the RTS frame Frame + SIFS + ACK frame). Alternatively, when receiving the CTS frame, the third station STA3 may use the duration information included in the CTS frame to transmit a frame transmission period (for example, SIFS + data frame + SIFS + ACK frame) You can set the NAV timer for. The third station STA3 can update the NAV timer using the duration information included in the new frame when the new frame is received before the expiration of the NAV timer. The third station STA3 does not attempt to access the channel until the NAV timer expires.

When receiving the CTS frame from the second station STA2, the first station STA1 may transmit the data frame to the second station STA2 after SIFS from the completion of reception of the CTS frame. When the second station STA2 successfully receives the data frame, the second station STA2 can transmit an ACK frame, which is a response to the data frame, to the first station STA1 after SIFS.

The third station STA3 can determine whether the channel is being used through carrier sensing when the NAV timer expires. If the third station STA3 determines that the channel has not been used by another station during the DIFS since the expiration of the NAV timer, the third station STA3 may attempt to access the channel after the contention window CW due to the random backoff has passed.

Meanwhile, a station may support transmission over a contiguous 160 MHz or non-contiguous 80 + 80 MHz band. In this case, the transmission signal processing unit 100 included in the station may have the following configuration.

6 is a block diagram illustrating an embodiment of a transmit signal processor for transmission over an adjacent 160 MHz band.

Referring to FIG. 6, the transmission signal processing unit 100-1 of the station basically includes the configuration of the transmission signal processing unit 100 described with reference to FIG. 2, and may further include an additional configuration. The transmission signal processing unit 100-1 of the station includes the encoders 110-1 to 110-L, the stream parser 112, the segment parsers 114-1 to 114-L, The interleavers 120-1 to 120-M, the mappers 130-1 to 130-M, the segment de-multiplexers 132-1 to 132-L, the STBC encoder 134, CSD inserter 136, spatial mapper 138, inverse Fourier transformers 140-1 to 140-N and GI inserters 150-1 to 150-N. Here, L, M, and N denote integers of 2 or more, and they may have the same value or different values.

 The encoders 110-1, ..., 110-L may refer to the encoder 110 described with reference to FIG. The stream parser 112 may generate a plurality of spatial streams by rearranging the data streams received from the encoders 110-1, ..., 110-L and send each of the plurality of spatial streams to the segment parsers 114-1, ..., 114-L. The segment parsers 114-1 to 114-L may divide the spatial stream into two subblocks and divide each of the two subblocks into interleavers 120-1 to 120- Lt; / RTI > The interleavers 120-1, ..., and 120-M may refer to the interleaver 120 described with reference to FIG. The mappers 130-1, ..., and 130-M may refer to the mappers 130 described with reference to FIG. The mappers 130-1, ..., 130-M may send the processed sub-blocks to the segment de-parsers 132-1, ..., 132-L. The segment multi-parsers 132-1, ..., and 132-L may perform operations opposite to those of the segment parsers 114-1, ..., and 114-L. That is, the segment multiplexers 132-1, ..., 132-L can reconstruct the two sub-blocks received from the mappers 130-1, ..., and 130-M into one spatial stream, And transmit the stream to the STBC encoder 134. The STBC encoder 134 may spread the spatial stream received from the segment multiplexer 132-1, ..., 132-L into a space-time stream, and transmit the space-time stream to the spatial mapper 138 and the CSD insertion Gt; 136 < / RTI > The CSD inserter 136 may insert the CSD into the space-time stream and may transmit the CSD-inserted space-time stream to the space mapper 138. Space mapper 138 may map the space-time stream received from STBC encoder 134 and CSD inserter 136 to a transport chain. The inverse Fourier transformers 140-1 to 140-N may denote the inverse Fourier transformers 140 described with reference to FIG. The GI inserters 150-1,..., 150-N may refer to the GI inserter 150 described with reference to FIG. The reception signal processing unit (not shown) of the station corresponding to the transmission signal processing unit 100-1 of the station may include a configuration corresponding to each configuration of the transmission signal processing unit 100-1.

7 is a block diagram illustrating an embodiment of a transmit signal processor for transmission over a non-adjacent 80 + 80 MHz band.

Referring to FIG. 7, the transmission signal processing unit 100-2 of the station may have a configuration similar to that of the transmission signal processing unit 100-1 described with reference to FIG. The transmission signal processing unit 100-2 of the station does not include the segment multiplexers 132-1, ..., 132-L, unlike the transmission signal processing unit 100-1. Therefore, the transmission signal processing unit 100-2 of the station has the same configuration as that of the transmission signal processing unit 100-1 from the encoders 110-1 to 110-L to the mappers 130-1 to 130- The configuration from the STBC encoders 134-1 and 134-2 to the GI inserters 150-1 to 150-N / 2 may be different from that of the transmission signal processor 100-1. A reception signal processing unit (not shown) of the station corresponding to the transmission signal processing unit 100-2 of the station may include a configuration corresponding to each configuration of the transmission signal processing unit 100-2.

The segment parsers 114-1 to 114-L included in the transmission signal processing units 100-1 and 100-2 of the station described above can divide one spatial stream into only two sub-blocks. Thus, a station may support transmission over a frequency band combination that includes up to two frequency bands (e.g., adjacent 160 MHz band, non-adjacent 80 + 80 MHz band), but three or more It can not support transmission over a frequency band combination that includes frequency bands (e.g., non-contiguous 80 + 80 + 80 MHz bands). The station may also support transmission over a frequency band combination that includes frequency bands having a bandwidth of at least 80 MHz (e.g., 256 subcarriers), but may have a bandwidth less than 80 MHz (e.g., 2.5 MHz, 5 MHz, 10 MHz, 20 MHz, 40 MHz, 60 MHz bandwidth, etc.).

Next, a frequency band combination including at least one frequency band (in particular, three or more frequency bands) having a bandwidth of 2.5 MHz or more (for example, 2.5 MHz, 5 MHz, 10 MHz, 20 MHz, 40 MHz, 60 MHz bandwidth, A station that transmits and receives data via the network will be described. The bandwidth applied to the present invention is not limited to the above-described size, but may have various sizes (e.g., 1.25 MHz, etc.). In addition, the number of subcarriers included in the same bandwidth may be different. For example, the 20 MHz bandwidth is composed of 256 subcarriers (in this case, 2.5 MHz bandwidth is composed of 32 subcarriers, 5 MHz bandwidth is composed of 64 subcarriers, 10 MHz bandwidth is composed of 128 subcarriers), or 64 subcarriers Configuration (in this case, the 80 MHz bandwidth can be composed of 256 subcarriers). That is, the number of subcarriers included in a specific bandwidth can be variously set. In the following, a frequency band is described as being divided into specific bandwidth units, which may mean that a frequency band is divided into sub-carrier units constituting a specific bandwidth. For example, if the frequency bands are 20 + 80 MHz, the first frequency band may include 64 subcarriers, and the second frequency band may include 256 subcarriers. In another example, when the frequency bands are 2.5 + 10 MHz, the first frequency band may include 32 subcarriers, and the second frequency band may include 128 subcarriers.

First, the frequency band combinations used in the embodiments of the present invention may be as shown in Table 1 below. Table 1 below illustrates one embodiment of a frequency band combination comprising adjacent or non-adjacent frequency bands. The frequency band combination may include at least one frequency band, and the bandwidth of the frequency band may be 2.5 MHz, 5 MHz, 10 MHz, 20 MHz, 40 MHz, 60 MHz, 80 MHz, and the like. The order of magnitude of the center frequency of each frequency band may be "A ₀ <B ₀ <C ₀ <D ₀ ". Frequency bands having the same index (e.g., A ₀ , A ₁ , A ₂ , A ₃ ) may be adjacent to each other. One of the "A ₀ to A ₃ bands" may be a B ₀ band and a neighboring or non-adjacent band. "B ₀ to B _3-band" is a band of the non-contiguous or C ₀ and the band may be in adjacent bands. "C ₀ to C ₃ band" one of the band or the band of the non-adjacent and D ₀ may be in adjacent bands. The frequency band combinations are not limited to the embodiment shown in Table 1, and can be variously set.

8 is a flowchart illustrating an operation method of a station according to an embodiment of the present invention. Here, the transmission signal processing unit and the reception signal processing unit of the station according to an embodiment of the present invention may be similar to the transmission signal processing unit and the reception signal processing unit described with reference to FIGS. However, the operation of the segment parser and the de-parser of the station according to an embodiment of the present invention may be different from the operations of the segment parser and the de-parser described with reference to Figs.

Referring to FIG. 8, the first station STA1 may obtain frequency band combination information including at least one frequency band (S800). When the frequency band combination includes a plurality of frequency bands, the plurality of frequency bands may not be adjacent to each other or adjacent to each other. At least two of the frequency bands may have different bandwidths (i.e., different numbers of subcarriers). The first station STA1 may acquire the frequency band combination information from the second station STA2. For example, the second station STA2 may transmit a frame including frequency band combination information (e.g., a management frame (i.e., a beacon frame, a probe response frame, A frame, an association response frame, a control frame, and a data frame), and the first station STA1 can acquire frequency band combination information. The frequency band combination information may be included in a signal field (e.g., HE (high efficiency) -SIGA, HE-SIGB, etc.) of the preamble of the frame. Here, the frequency band combination information can be expressed in an index form. Alternatively, the first station STA1 may determine whether the frequency band is busy or idle by performing a carrier sensing operation, and generate a frequency band combination including at least one frequency band determined as an idle state can do.

The first station STA1 may generate a data stream, map the data stream to at least one spatial stream (S810), and may map the spatial stream to at least one sub-block (S820). Step S810 may be performed by the stream parser 112 of the first station STA1 and step S820 may be performed by the segment parser 114-1, ..., 114-L of the first station STA1 have. Specifically, the stream parser 112 of the first station STA1 may map the data stream (i.e., the encoded data stream) into at least one spatial stream, and may map each of the at least one spatial stream to the first station STA1 To the segment parsers 114-1,. The segment parsers 114-1, ..., 114-L of the first station STA1 may map one spatial stream to at least one sub-block based on the number of frequency bands included in the frequency band combination. Here, the number of subblocks may be equal to the number of frequency bands included in the frequency band combination. For example, if the frequency band combination is a contiguous or non-contiguous 40 + 40 + 80 MHz band, the spatial stream is transmitted via three subblocks (i.e., the first 40 MHz band (or 128 subcarriers) (I.e., a third sub-block transmitted through a second sub-block, a second sub-block transmitted through a second sub-block, a second sub-block transmitted through a second 40 MHz band (or 128 sub- Divided). In another example, if the frequency band combination is a contiguous or non-contiguous 2.5 + 5 + 20 MHz band, the spatial stream is transmitted in three subblocks (i.e., the first 2.5 MHz band (or 32 subcarriers) A first sub-block, a second sub-block transmitted through a second 5-MHz band (or 64 sub-carriers), and a third sub-block transmitted via a third 20-MHz band (or 256 sub-carriers) .

The segment parsers 114-1 to 114-L of the first station STA1 generate a plurality of subblocks containing the same number of bits or each of the plurality of subblocks has a bandwidth Or a number of subcarriers) according to the number of subblocks. For example, the number of bits included in a sub-block transmitted through an 80 MHz bandwidth (or 256 sub-carriers) may be greater than the number of bits included in a sub-block transmitted through a 40 MHz bandwidth (or 128 sub-carriers) have.

Here, the segment parsers 114-1, ..., 114-L of the first station can generate at least one sub-block through Equation (1) below.

는 Z 이하의 가장 큰 정수를 의미한다. z mod t는 z를 t로 나눈 나머지 값을 의미한다. x_m은 N_CBPSS를 포함한 블록(즉, 공간 스트림)에서 m번째 비트를 의미하고, m은 0 내지 N_CBPSS-1의 값을 가진다. N_CBPSS는 공간 스트림 별 부호화된 비트들(coded bits per original spatial stream)의 수를 의미한다. N_SB는 서브 블록들의 수를 의미한다. l은 서브 블록의 인덱스를 의미하고, 0 내지 N_SB-1의 값을 가진다. y_k,l은 서브 블록 l의 비트 k를 의미한다. s는 N_BPSCS가 1인 경우 1이고, 그외의 경우에 N_BPSCS/2이다. N_BPSCS는 각 공간 스트림의 단일 부반송파당 부호화된 비트들(coded bits per single subcarrier for each original spatial stream)의 수를 의미한다. N_ES는 인코더(예를 들어, BCC 인코더)들의 수를 의미한다. N_CBPSS가 N_SB·s·N_ES로 나누어지지 않는 경우, 제1 스테이션(STA1)의 세그먼트 파서(114-1, …, 114-L)는 아래 수학식 2를 통해 적어도 하나의 서브 블록을 생성할 수 있다.

Means the largest integer less than or equal to Z. z mod t means the remainder of z divided by t. x _m denotes an m-th bit in a block including N _CBPSS (i.e., a spatial stream), and m has a value of 0 to N _CBPSS- 1. N _CBPSS means the number of coded bits per original spatial stream. N _SB means the number of subblocks. 1 denotes an index of a sub-block, and has a value of 0 to N _SB -1. y _{k, l} means bit k of sub-block l. s is 1 when N _BPSCS is 1, and N _BPSCS / 2 _otherwise . N _BPSCS denotes the number of coded bits per single subcarrier for each original spatial stream of each spatial stream. N _ES means the number of encoders (e.g., BCC encoders). If N _CBPSS is not divided into N _SB · s · N _ES , the segment parsers 114-1 through 114-L of the first station STA1 generate at least one sub-block through the following equation (2) can do.

Operations of the segment parsers 114-1, ..., 114-L of the first station STA1 according to the above-described methods are as follows.

FIG. 9 illustrates a segment parser 114-N of a station generating sub-blocks of the same size in the case of N _SS = 1, N _ES = 1, S = 1 (binary phase shift keying (BPSK), quadrature phase shift keying (QPSK) 10 is a conceptual diagram illustrating the operation of subblocks of the same size in the case of N _SS = 1, N _ES = 1, S = 2 (16-QAM (quadrature amplitude modulation) 11 is a conceptual diagram showing the operation of the segment parsers 114-1 to 114-L of the generating station. FIG. 11 is a conceptual diagram showing the operation of the segment parsers 114-1 to 114-L of the same station when N _SS = 1, N _ES = 1, S = (N- _SS = 1, N _ES = 1, S = 4 (256-QAM), and so on). FIG. 12 is a conceptual diagram showing the operation of the segment parsers 114-1, (114-1, ..., 114-L) of the station that generates sub-blocks of the same size in the case of the sub-blocks of the same size. Here, N _SS means the number of spatial streams.

9 to 12, the segment parsers 114-1, ..., 114-L of the first station can generate as many subblocks as N _SB , and consecutive bits of S are allocated to each subblock Can be assigned.

Referring again to FIG. 8, the segment parsers 114-1, ..., 114-L of the first station STA1 send at least one sub-block to the interleavers 120-1, ..., 120 -M) or mappers 130-1 ... 130-M. Here, the same modulation scheme may be applied to each sub-block, or a different demodulation scheme may be applied. On the other hand, when the frequency band combination includes one frequency band, the segment parsers 114-1, ..., 114-L of the first station STA1 receive (receive) the stream parser 112 of the first station STA1 (120-1, ..., 120-M) of the first station (STA1) without segmentation processing. Thereafter, at least one sub-block may be processed through the interleaver 120-1, ..., 120-M of the first station STA1 through the RF transmitter 21 of the first station STA1. That is, the first station STA1 may transmit the corresponding sub-block through the frequency band corresponding to the sub-block (S830). For example, when three subblocks are generated by one spatial stream, the first station STA1 may transmit three subblocks through three different frequency bands. Meanwhile, the frequency band combination information including the frequency band in which the subblock is transmitted may be included in the signal field of the preamble of the PPDU (physical layer convergence procedure (PLCP) protocol data unit) including the corresponding data stream.

Meanwhile, the second station STA2 may obtain frequency band combination information including frequency bands through which subblocks constituting the frame of the first station STA1 are transmitted. For example, the second station STA2 may acquire frequency band combination information by receiving a frame (for example, a management frame, a control frame, a data frame, and the like) including the frequency band combination information from the first station STA1 . The frequency band combination information may be included in the signal field of the preamble of the data frame.

If the frequency bands are non-adjacent, the second station STA2 may receive at least one sub-block through at least one frequency band and may reconstruct at least one sub-block into a spatial stream (S840) . Step S840 may be performed by a segment multiplexer (not shown) of the second station STA2. For example, when subblocks are received through a plurality of frequency bands, the segment multi-parser of the second station STA2 may reconstruct subblocks received through different frequency bands into a spatial stream. Here, the bandwidth of each of the frequency bands may be 2.5 MHz, 5 MHz, 10 MHz, 20 MHz, 40 MHz, 60 MHz, 80 MHz, etc. and may have different bandwidths (i.e., different numbers of subcarriers). The second station STA2 may reconstruct a plurality of spatial streams into a data stream (S850).

The operation of the second station STA2 may be different from the operation of the second station STA2 if the frequency bands are non-adjacent. That is, when the frequency bands are adjacent to each other, the second station STA2 can further perform a sub-block parsing operation as compared with the case where the frequency bands are non-adjacent. When the frequency bands are adjacent to each other, the second station STA2 can receive the original block through at least one frequency band, and can map the raw block to at least one subblock. The step of mapping the raw block to at least one sub-block may be performed in a segment parser (not shown) of the second station STA2. The subsequent steps may be the same as steps S840 and S850 described above.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (15)

A data transmission method performed at a station,
Mapping a data stream to at least one spatial stream;
Dividing each of the at least one spatial stream into three or more subblocks; And
And transmitting each of the subblocks over allocated frequency bands. The method according to claim 1,
And a minimum number of subcarriers included in each of the frequency bands is 32. The method of claim 1, The method according to claim 1,
Wherein at least two of the frequency bands comprise a different number of subcarriers. The method according to claim 1,
Wherein the frequency bands are contiguous or non-contiguous. The method according to claim 1,
Wherein the number of frequency bands is equal to the number of subblocks. The method according to claim 1,
Wherein the dividing into the subblocks is performed in a segment parser of the station. The method according to claim 1,
Wherein the data stream is included in a PPDU (physical layer convergence procedure (PLCP) protocol data unit), and a signal field of a preamble of the PPDU includes information related to the frequency bands. . A method of receiving data performed at a station,
Receiving subblocks through non-contiguous frequency bands;
Reconstructing at least three subblocks received through different frequency bands into a spatial stream; And
And reconstructing the plurality of spatial streams into a data stream. The method of claim 8,
And a minimum number of subcarriers included in each of the frequency bands is 32. The method of claim 1, The method of claim 8,
Wherein at least two of the frequency bands comprise a different number of subcarriers. The method of claim 8,
Wherein reconfiguring into the spatial stream is performed in a segment &lt; RTI ID = 0.0 &gt; deparser &lt; / RTI &gt; of the station. The method of claim 8,
Wherein the data stream is included in a PPDU (physical layer convergence procedure (PLCP) protocol data unit), and a signal field of a preamble of the PPDU includes information related to the frequency bands. . A method of receiving data performed at a station,
Dividing an original block received through contiguous frequency bands into a plurality of subblocks;
Reconstructing at least three subblocks received through different frequency bands into a spatial stream; And
And reconstructing the plurality of spatial streams into a data stream. 14. The method of claim 13,
Wherein the dividing into the plurality of subblocks is performed in a segment parser of the station. 14. The method of claim 13,
Wherein reconfiguring into the spatial stream is performed in a segment &lt; RTI ID = 0.0 &gt; deparser &lt; / RTI &gt; of the station.

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