KR102272713B1 - Wireless communication method and wireless communication terminal using signaling field - Google Patents

Abstract

A wireless communication terminal that communicates wirelessly is disclosed. The wireless communication terminal includes a transceiver; and a processor. The processor transmits a legacy signaling field including information that the legacy wireless communication terminal can decode through the transceiver and a legacy training signal for setting reception of the legacy signaling field. When transmitting the legacy signaling field, the processor transmits a predetermined signal through at least one subcarrier among a plurality of subcarriers corresponding to a position of a guard carrier of the legacy training signal.

Description

Wireless communication method and wireless communication terminal using signaling field

The present invention relates to a wireless communication method using a signaling field and a wireless communication terminal.

Recently, as the spread of mobile devices has expanded, wireless LAN technology that can provide fast wireless Internet services to them has been in the spotlight. Wireless LAN technology is a technology that enables mobile devices such as smart phones, smart pads, laptop computers, portable multimedia players, and embedded devices to wirelessly access the Internet in a home, business, or specific service area based on wireless communication technology in a short distance. to be.

Since IEEE (Institute of Electrical and Electronics Engineers) 802.11 supported the initial wireless LAN technology using the 2.4 GHz frequency, standards for various technologies are being put into practice or being developed. First, IEEE 802.11b supports a communication speed of up to 11Mbps while using a frequency of the 2.4GHz band. IEEE 802.11a, commercialized after IEEE 802.11b, uses a frequency of 5 GHz band instead of 2.4 GHz band, thereby reducing the influence on interference compared to the fairly crowded 2.4 GHz band, and orthogonal frequency division multiplexing (orthogonal frequency division multiplexing, OFDM) technology is used to increase the communication speed up to 54 Mbps. However, IEEE 802.11a has a disadvantage in that the communication distance is shorter than that of IEEE 802.11b. Also, IEEE 802.11g, like IEEE 802.11b, uses a frequency of the 2.4GHz band to achieve a communication speed of up to 54Mbps and has received considerable attention as it satisfies backward compatibility. have the upper hand

In addition, IEEE 802.11n is a technical standard established to overcome the limit on communication speed, which has been pointed out as a weakness in wireless LAN. 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) with a data processing rate of up to 540 Mbps or higher, and uses multiple antennas at both ends of the transmitter and receiver to minimize transmission errors and optimize data rates. It is based on MIMO (Multiple Inputs and Multiple Outputs) technology. In addition, this standard may use a coding method that transmits multiple duplicate copies to increase data reliability.

As the spread of wireless LAN is activated and applications using it are diversified, the need for a new wireless LAN system to support a very high throughput (VHT) higher than the data processing speed supported by IEEE 802.11n has emerged. became Among them, IEEE 802.11ac supports a wide bandwidth (80 MHz to 160 MHz) at a frequency of 5 GHz. The IEEE 802.11ac standard is defined only in the 5GHz band, but for backward compatibility with the existing 2.4GHz band products, the initial 11ac chipsets will also support operation in the 2.4GHz band. Theoretically, according to this standard, the wireless LAN speed of multiple stations is at least 1 Gbps, and the maximum single link speed is at least 500 Mbps. This is achieved by extending the air interface concepts adopted in 802.11n, including wider radio frequency bandwidth (up to 160 MHz), more MIMO spatial streams (up to 8), multi-user MIMO, and high-density modulation (up to 256 QAM). In addition, there is IEEE 802.11ad as a method of transmitting data using the 60GHz band instead of the existing 2.4GHz/5GHz. IEEE 802.11ad is a transmission standard that provides a speed of up to 7 Gbps using beamforming technology, and is suitable for streaming large amounts of data or high bit rate video such as uncompressed HD video. However, the 60 GHz frequency band has a disadvantage that it is difficult to pass through obstacles and can only be used between devices in a short distance.

Meanwhile, in recent years, as a next-generation wireless LAN standard after 802.11ac and 802.11ad, discussions have been ongoing to provide a wireless LAN communication technology with high efficiency and high performance in a high-density environment. That is, in the next-generation wireless LAN environment, high-frequency-efficiency communication must be provided indoors and outdoors in the presence of high-density stations and access points (APs), and various technologies are required to implement it.

In particular, as the number of devices using a wireless LAN increases, it is necessary to efficiently use a predetermined channel. Therefore, there is a need for a technology capable of efficiently using a bandwidth by simultaneously transmitting data between a plurality of stations and an AP.

An embodiment of the present invention aims to provide an efficient wireless communication method and a wireless communication terminal using a signaling field.

In particular, an embodiment of the present invention aims to provide a wireless communication method and a wireless communication terminal supporting a plurality of signaling field formats.

A wireless communication terminal for wireless communication according to an embodiment of the present invention includes a transceiver; and a processor, wherein the processor transmits a legacy signaling field including information that a legacy wireless communication terminal can decode through the transceiver and a legacy training signal for setting reception of the legacy signaling field, and the legacy signaling field When transmitting, a predetermined first signal is transmitted through at least one subcarrier among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal.

When the processor transmits the legacy signaling field, the processor transmits data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. At least one continuous with a plurality of subcarriers. The first signal may be transmitted through a subcarrier of .

When the processor transmits the legacy signaling field, the two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal based on 0 in the frequency band and the position of the right guard carrier The first signal may be transmitted through two subcarriers having the lowest frequency among a plurality of corresponding subcarriers.

After transmitting the legacy signaling field, the processor transmits the repetitive legacy signaling field generated based on the legacy signaling field, and when transmitting the repetitive legacy signaling field, corresponding to the position of the guard carrier of the legacy training signal A predetermined second signal may be transmitted through at least one of the plurality of subcarriers.

The processor may generate the repeating legacy signaling field by repeating the legacy signaling field.

The processor may signal information other than the legacy signaling field through a combination of the first signal and the second signal.

The first signal and the second signal may be the same.

The legacy signaling field includes length information indicating the duration of the non-legacy physical layer frame after the legacy signaling field, and the processor transmits the length information to the data size that one OFDM symbol transmitting the legacy physical layer frame can transmit Information other than information indicating the duration of the non-legacy physical layer frame may be signaled through a residual value divided by .

The processor includes information other than the information indicating the duration of the non-legacy physical layer frame, indicating whether the non-legacy physical layer frame includes a first signaling field, and the first signaling field When data is transmitted to a wireless communication terminal, information about a plurality of wireless communication terminals may be signaled.

Information other than information indicating the duration of the non-legacy physical layer frame indicates whether a second signaling field included in the non-legacy physical layer frame includes a repeated field in the time domain, and any one of the second signaling fields is It can be commonly used when transmitting data to a wireless communication terminal and transmitting data to a plurality of wireless communication terminals.

The processor divides the length information by the data size that can be transmitted by one OFDM symbol for transmitting the legacy physical layer frame and through the modulation method of the second OFDM symbol for transmitting the second signaling field, the non- Information other than information indicating the duration of the legacy physical layer frame may be signaled.

The modulation method may be binary phase shift keying (BPSK) or quadrature binary phase shift keying (QBPSK).

A wireless communication terminal for wirelessly communicating according to an embodiment of the present invention includes a transceiver; and a processor, wherein the processor receives a legacy training signal for setting reception of a legacy signaling field through the transceiver, and a legacy signaling field including information that a legacy wireless communication terminal can decode based on the legacy training signal Receive, receive a predetermined first signal through at least one subcarrier of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal, based on the first signal - non-legacy wireless communication A non-legacy signaling field signaling information for a terminal may be received.

When the processor receives the legacy signaling field, the processor transmits data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. The first signal may be received through one subcarrier.

When the processor receives the legacy signaling field, the two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal based on 0 in the frequency band and the position of the right guard carrier The first signal may be received through two subcarriers having the lowest frequency among a plurality of subcarriers corresponding to .

After receiving the legacy signaling field, the processor receives the repetitive legacy signaling field generated based on the legacy signaling field through the transceiver, and when receiving the repetitive legacy signaling field, a guard carrier of the legacy training signal A predetermined second signal may be received through at least one subcarrier among a plurality of subcarriers corresponding to the position of .

The first signal and the second signal may be the same.

The legacy signaling field includes length information indicating the duration of the non-legacy physical layer frame after the legacy signaling field, and the processor transmits the length information to the data size that one OFDM symbol transmitting the legacy physical layer frame can transmit Information other than information indicating the duration of the non-legacy physical layer frame may be obtained through the residual value divided by .

The processor includes information other than the information indicating the duration of the non-legacy physical layer frame, indicating whether the non-legacy physical layer frame includes a first signaling field, and the first signaling field When data is transmitted to a wireless communication terminal, information about a plurality of wireless communication terminals may be signaled.

A method of operating a wireless communication terminal for wireless communication according to an embodiment of the present invention includes transmitting a legacy training signal for setting reception of a legacy signaling field including information that can be decoded by the legacy wireless communication terminal; and transmitting a legacy signaling field, wherein the transmitting of the legacy signaling field includes at least one of a plurality of subcarriers corresponding to a position of a guard carrier of the legacy training signal through a first predetermined subcarrier. transmitting a signal.

An embodiment of the present invention provides an efficient wireless communication method and a wireless communication terminal using a signaling field.

In particular, an embodiment of the present invention provides a wireless communication method and a wireless communication terminal supporting a plurality of signaling field formats.

1 shows a wireless LAN system according to an embodiment of the present invention.
2 shows a wireless LAN system according to another embodiment of the present invention.
3 is a block diagram showing the configuration of a station according to an embodiment of the present invention.
4 is a block diagram showing the configuration of an access point according to an embodiment of the present invention.
5 schematically shows a process in which a station establishes a link with an access point according to an embodiment of the present invention.
6 shows the structures of a physical layer frame and a legacy layer frame according to an embodiment of the present invention.
7 illustrates a method for a legacy wireless communication terminal to obtain a duration of a physical layer frame based on L_LENGTH and a method for setting L_LENGTH according to an embodiment of the present invention.
8 shows that the wireless communication terminal additionally transmits a subcarrier having a predetermined value in at least one of the L-LTF, L-SIG field, and RL-SIG field according to an embodiment of the present invention.
9 shows the structure of the HE-SIG-A field according to an embodiment of the present invention.
10 shows the structure of the HE-SIG-B field according to an embodiment of the present invention.
11 shows the structure of the HE-SIG-B field according to another embodiment of the present invention.
12 shows a SIG-B structure of a physical layer frame when a wireless communication terminal transmits a physical layer frame to a plurality of wireless communication terminals according to an embodiment of the present invention.
13 shows a method of signaling a discontinuous frequency band when a wireless communication terminal transmits data through a discontinuous frequency band within a frequency band having a 20 MHz bandwidth according to an embodiment of the present invention.
14 illustrates a data transmission method when a wireless communication terminal transmits data through a discontinuous frequency band according to an embodiment of the present invention.
15 shows the structure of HE-SIG-A when the wireless communication terminal repeatedly transmits HE-SIG-A according to an embodiment of the present invention.
16 shows an operation of a wireless communication terminal according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

In addition, when a part "includes" a certain component, this means that other components may be further included rather than excluding other components unless otherwise stated.

This application claims priority based on Korean Patent Application Nos. 10-2015-0108397 and 10-2015-0109759, and the examples and descriptions described in each of the above applications, which are the basis of the priority, are shall be included in the detailed description of

1 illustrates a wireless LAN system according to an embodiment of the present invention. The WLAN system includes one or more basic service sets (BSS), which indicate a set of devices that can communicate with each other by successfully synchronizing. In general, the BSS may be divided into an infrastructure BSS (infrastructure BSS) and an independent BSS (IBSS), and FIG. 1 shows the infrastructure BSS among them.

As shown in FIG. 1 , the infrastructure BSS (BSS1, BSS2) includes one or more stations (STA1, STA2, STA3, STA_4, STA5) and an access point (PCP/AP) that is a station providing a distribution service. -1, PCP/AP-2), and a Distribution System (DS) connecting a plurality of access points (PCP/AP-1, PCP/AP-2).

A station (Station, STA) is an arbitrary device including a medium access control (MAC) and a physical layer interface for a wireless medium that comply with the provisions of the IEEE 802.11 standard, and in a broad sense, a non-access point ( It includes both non-AP) stations as well as access points (APs). Also, in this specification, the term 'terminal' may be used as a concept including both a station and a wireless LAN communication device such as an AP. The station for wireless communication includes a processor and a transmit/receive unit, and may further include a user interface unit and a display unit according to an embodiment. The processor may generate a frame to be transmitted through the wireless network or process a frame received through the wireless network, and may perform various other processes for controlling the station. In addition, the transceiver is functionally connected to the processor and transmits and receives frames through a wireless network for the station.

An access point (AP) is an entity that provides access to a distribution system (DS) via a wireless medium for a station associated with the AP. In the infrastructure BSS, in principle, communication between non-AP stations is performed via the AP, but when a direct link is established, direct communication is also possible between non-AP stations. Meanwhile, in the present invention, the AP is used as a concept including a PCP (Personal BSS Coordination Point), and broadly, a centralized controller, a base station (BS), a Node-B, a BTS (Base Transceiver System), or a site. It may include all concepts such as a controller.

A plurality of infrastructure BSSs may be interconnected through a distribution system (DS). In this case, a plurality of BSSs connected through the distribution system are referred to as an extended service set (ESS).

2 illustrates an independent BSS that is a wireless LAN system according to another embodiment of the present invention. In the embodiment of Fig. 2, the same or corresponding parts to the embodiment of Fig. 1 will be omitted redundant description.

Since BSS3 shown in FIG. 2 is an independent BSS and does not include an AP, all stations STA6 and STA7 are not connected to the AP. The independent BSS is not allowed to access the distribution system and forms a self-contained network. In the independent BSS, each of the stations STA6 and STA7 may be directly connected to each other.

3 is a block diagram showing the configuration of the station 100 according to an embodiment of the present invention.

As shown, the station 100 according to an embodiment of the present invention may include a processor 110 , a transceiver 120 , a user interface unit 140 , a display unit 150 , and a memory 160 . .

First, the transceiver 120 transmits/receives a wireless signal such as a wireless LAN physical layer frame, and may be built into the station 100 or provided externally. According to an embodiment, the transceiver 120 may include at least one transceiver module using different frequency bands. For example, the transceiver 120 may include transceiver modules of different frequency bands, such as 2.4 GHz, 5 GHz, and 60 GHz. According to an embodiment, the station 100 may include a transmission/reception module using a frequency band of 6 GHz or higher and a transmission/reception module using a frequency band of 6 GHz or less. Each transmission/reception module may perform wireless communication with an AP or an external station according to a wireless LAN standard of a frequency band supported by the corresponding transmission/reception module. The transceiver 120 may operate only one transceiver module at a time or operate a plurality of transceiver modules simultaneously according to the performance and requirements of the station 100 . When the station 100 includes a plurality of transmit/receive modules, each transmit/receive module may be provided in an independent form, or a plurality of modules may be integrated into one chip.

Next, the user interface unit 140 includes various types of input/output means provided in the station 100 . That is, the user interface unit 140 may receive a user input using various input means, and the processor 110 may control the station 100 based on the received user input. Also, the user interface unit 140 may perform an output based on a command of the processor 110 using various output means.

Next, the display unit 150 outputs an image on the display screen. The display unit 150 may output various display objects such as content executed by the processor 110 or a user interface based on a control command of the processor 110 . In addition, the memory 160 stores a control program used in the station 100 and various data corresponding thereto. Such a control program may include an access program necessary for the station 100 to access an AP or an external station.

The processor 110 of the present invention may execute various commands or programs and process data inside the station 100 . In addition, the processor 110 may control each unit of the above-described station 100 , and may control data transmission/reception between the units. According to an embodiment of the present invention, the processor 110 may execute a program for accessing the AP stored in the memory 160 and receive a communication setting message transmitted by the AP. Also, the processor 110 may read information on the priority condition of the station 100 included in the communication setup message, and request access to the AP based on the information on the priority condition of the station 100 . The processor 110 of the present invention may refer to the main control unit of the station 100, and according to an embodiment, a control unit for individually controlling a part of the station 100, for example, the transceiver 120, etc. may point to That is, the processor 110 may be a modulator and/or demodulator that modulates a radio signal transmitted/received from the transceiver 120 . The processor 110 controls various operations of wireless signal transmission and reception of the station 100 according to an embodiment of the present invention. Specific examples thereof will be described later.

The station 100 shown in FIG. 3 is a block diagram according to an embodiment of the present invention, and the separated blocks are logically divided into device elements. Accordingly, the elements of the above-described device may be mounted as one chip or a plurality of chips according to the design of the device. For example, the processor 110 and the transceiver 120 may be integrated into one chip or implemented as a separate chip. Also, in an embodiment of the present invention, some components of the station 100 , such as the user interface unit 140 and the display unit 150 , may be selectively provided in the station 100 .

4 is a block diagram showing the configuration of the AP 200 according to an embodiment of the present invention.

As shown, the AP 200 according to an embodiment of the present invention may include a processor 210 , a transceiver 220 , and a memory 260 . Among the configurations of the AP 200 in FIG. 4 , redundant descriptions of parts identical to or corresponding to those of the station 100 of FIG. 3 will be omitted.

Referring to FIG. 4 , the AP 200 according to the present invention includes a transceiver 220 for operating a BSS in at least one frequency band. As described above in the embodiment of FIG. 3 , the transceiver 220 of the AP 200 may also include a plurality of transceiver modules using different frequency bands. That is, the AP 200 according to an embodiment of the present invention may include two or more transmission/reception modules in different frequency bands, for example, 2.4 GHz, 5 GHz, and 60 GHz. Preferably, the AP 200 may include a transmission/reception module using a frequency band of 6 GHz or higher and a transmission/reception module using a frequency band of 6 GHz or less. Each transmission/reception module may perform wireless communication with a station according to a wireless LAN standard of a frequency band supported by the corresponding transmission/reception module. The transceiver 220 may operate only one transceiver module at a time or operate a plurality of transceiver modules simultaneously according to the performance and requirements of the AP 200 .

Next, the memory 260 stores a control program used in the AP 200 and various data corresponding thereto. Such a control program may include an access program for managing access of stations. In addition, the processor 210 may control each unit of the AP 200 , and may control data transmission/reception between the units. According to an embodiment of the present invention, the processor 210 may execute a program for accessing a station stored in the memory 260 and transmit a communication setting message for one or more stations. In this case, the communication setting message may include information on the access priority condition of each station. In addition, the processor 210 performs connection establishment according to the connection request of the station. According to an embodiment, the processor 210 may be a modulator and/or demodulator that modulates a radio signal transmitted and received from the transceiver 220 . The processor 210 controls various operations of wireless signal transmission and reception of the AP 200 according to an embodiment of the present invention. A specific embodiment thereof will be described later.

5 schematically illustrates a process in which an STA establishes a link with an AP.

Referring to FIG. 5 , the link between the STA 100 and the AP 200 is largely established through three steps of scanning, authentication, and association. First, the scanning step is a step in which the STA 100 acquires access information of the BSS operated by the AP 200 . As a method for performing scanning, a passive scanning method in which information is obtained by using only a beacon message S101 periodically transmitted by the AP 200, and a probe request by the STA 100 to the AP There is an active scanning method for transmitting a probe request (S103) and receiving a probe response from the AP (S105) to obtain access information.

The STA 100 successfully receiving the radio access information in the scanning step transmits an authentication request (S107a), receives an authentication response from the AP 200 (S107b), and performs the authentication step do. After the authentication step is performed, the STA 100 transmits an association request (S109a) and receives an association response from the AP 200 (S109b) to perform the association step. In the present specification, association basically means wireless coupling, but the present invention is not limited thereto, and coupling in a broad sense may include both wireless coupling and wired coupling.

Meanwhile, an additional 802.1X-based authentication step (S111) and an IP address acquisition step (S113) through DHCP may be performed. In FIG. 5 , the authentication server 300 is a server that processes 802.1X-based authentication with the STA 100 , and may exist physically coupled to the AP 200 or exist as a separate server.

When data is transmitted using Orthogonal Frequency Division Multiple Access (OFDMA) or Multi Input Multi Output (MIMO), any one wireless communication terminal may simultaneously transmit data to a plurality of wireless communication terminals. In addition, any one wireless communication terminal may simultaneously receive data from a plurality of wireless communication terminals. When the wireless communication terminal transmits data to a plurality of wireless communication terminals, the wireless communication terminal must use a physical layer frame of a different type from the physical layer frame used when transmitting data to one wireless communication terminal. Specifically, the wireless communication terminal needs to signal information through a signaling field having a structure different from the signaling field structure of a physical layer frame used when data is transmitted to one wireless communication terminal.

In addition, when the wireless communication terminal performs long-range transmission, the wireless communication terminal must use a highly reliable physical layer frame structure.

In addition, in order to implement a new function and to signal information on a plurality of wireless communication terminals, the wireless communication terminal must use a structure of a signaling field capable of transmitting more information than a signaling field of a legacy physical layer frame.

A signaling field of a physical layer frame that can transmit more information than a signaling field of a legacy physical layer frame and a wireless communication method that selectively uses a physical layer frame structure according to various situations will be described with reference to FIGS. 6 to 16 .

6 shows the structures of a physical layer frame and a legacy physical layer frame according to an embodiment of the present invention.

6(a) is a structure of a legacy physical layer frame, and FIG. 6(b) is a structure of a non-legacy physical layer frame according to an embodiment of the present invention.

The physical layer frame according to an embodiment of the present invention includes a legacy signaling field (L-SIG) signaling information for a legacy wireless communication terminal. In addition, the physical layer frame according to an embodiment of the present invention includes a repeating legacy signaling field (RL-SIG) so that the wireless communication terminal can distinguish the non-legacy physical layer frame from the legacy physical layer frame. Specifically, the non-legacy wireless communication terminal determines that the received physical layer frame is a non-legacy physical layer frame without decoding specific data of the received physical layer frame when the received physical layer frame includes a repeating legacy signaling field. can do. In this case, the repeating legacy signaling field (RL-SIG) may be generated based on the value of the legacy signaling field (L-SIG). In more detail, the repeating legacy signaling field (RL-SIG) may be a signaling field having the same value as the legacy signaling field (L-SIG). In addition, the repeating legacy signaling field (RL-SIG) may be a modified legacy signaling field (L-SIG).

In addition, the physical layer frame according to an embodiment of the present invention is HE-SIG-A commonly used when a wireless communication terminal transmits data to any one wireless communication terminal and when transmitting data to a plurality of wireless communication terminals. contains fields. Specifically, the HE-SIG-A field includes the bandwidth (Bandwidth) of the physical layer frame, BSS Color, the number of HE-LTFs (Number_of_HE-LTF), and MCS (Modulation and Coding Scheme) used for HE-SIG-B field transmission. It may include at least any one of information about The wireless communication terminal transmits the HE-SIG-A field through two OFDM symbols based on 64 FFT. The wireless communication terminal may transmit the HE-SIG-A field including the repeated field in the time domain through four OFDM symbols based on 64 FFT. In particular, during long-distance transmission requiring high-reliability transmission, the wireless communication terminal may transmit the HE-SIG-A field including the repeated field in the time domain through four OFDM symbols based on 64 FFT.

The physical layer frame according to an embodiment of the present invention includes a HE-SIG-B field for signaling information about a plurality of wireless communication terminals. When the wireless communication terminal transmits data to any one wireless communication terminal, the wireless communication terminal may not transmit the HE-SIG-B field.

In a specific embodiment, the structures of the legacy signaling field (L-SIG) and the repeating legacy signaling field (RL-SIG) may be as shown in FIG. 6(c) . In this case, the legacy signaling field (L-SIG) may include information on a transmission method of the data field indicated by the MPDU in FIG. 6 and length information indicating the length of the physical layer frame. Specifically, the legacy signaling field (L-SIG) may include an L_RATE field and an L_LENGTH field.

The L_RATE field indicates information about a data field transmission method. Specifically, the L_RATE field indicates an MCS used for data field transmission. For example, the L_RATE field may indicate information obtained by combining a modulation method such as BPSK/QPSK/16-QAM/64-QAM and a code rate such as 1/2, 2/3, and 3/4. Specifically, the L_RATE field may indicate any one of 6/9/12/18/24/36/48/54 Mbps.

The L_LENGTH field signals the length of the physical layer frame. Specifically, the legacy wireless communication terminal may acquire the duration of the physical layer frame based on the L_LENGTH field. In a specific embodiment, the legacy wireless communication terminal may acquire the duration of the physical layer frame based on the L_LENGTH field and the L_RATE field. This will be described with reference to FIG. 7 .

7 illustrates a method for a legacy wireless communication terminal to obtain a duration of a physical layer frame based on L_LENGTH and a method for setting L_LENGTH according to an embodiment of the present invention.

A wireless communication terminal communicates in units of OFDM symbols (hereinafter, symbols). Therefore, when the legacy wireless communication terminal calculates the duration of the physical layer frame, it is calculated in units of the length of a symbol for transmitting the legacy physical layer frame. When the L_RATE field indicates 6 Mbps, the duration of one symbol modulated by 64 FFT is 4us. In this case, one symbol may transmit 3 bytes. The legacy wireless communication terminal divides the value of the L_LENGTH field into 3-byte units and converts the duration of the physical layer frame indicated by the L_LENGTH field into the number of symbols. The legacy wireless communication terminal adds the number of symbols corresponding to the duration of the Tail field and SVC (service) field excluded from the value of the L_LENGTH field to the number of symbols corresponding to the value of the L_LENGTH field. The duration of the Tail field and the SVC field may be treated as one symbol. The legacy wireless communication terminal multiplies the sum of the number of symbols obtained above by 4us, which is the duration of one symbol, and adds 20us, which is the transmission time of the L-SIG field and L-STF and L-LTF located before the L_LENGTH field, to the physical layer frame. Get full duration. Specifically, the legacy wireless communication terminal obtains the entire duration of the physical layer frame using the following equation

PPDU_DURATION = RXTIME = TXTIME = (1+[L_LENGTH/3])x4+20

In this case, [x] is a flooring operation representing the smallest natural number greater than x. Since the L_LENGTH field is a 12-bit field, the maximum value of the L_LENGTH field is 4095. According to the above equation, 5.484 ms is the maximum duration of the physical layer frame.

The wireless communication terminal may set L_LENGTH based on an equation for obtaining the duration of the physical layer frame. The wireless communication terminal subtracts the L-SIG field located before the L_LENGTH field and 20us, which is the transmission time of L-STF and L-LTF, from the duration (TXTIME) of the physical layer frame as the number of symbols for transmitting the legacy signaling field. can be converted In this case, since the wireless communication terminal has to transmit in symbol units, a value obtained by subtracting 20us, which is the transmission time of L-SIG field and L-STF and L-LTF, and the L-SIG field located before the L_LENGTH field, from the duration (TXTIME) of the physical layer frame is legacy signaling After dividing the field by the duration of the symbol to be transmitted, it is rounded up (flooring). The wireless communication terminal converts the obtained number of symbols into the size of data. Specifically, the wireless communication terminal multiplies the obtained number of symbols by the size of data that can be transmitted by a symbol transmitting the legacy signaling field. Since the legacy wireless communication terminal subtracts the transmission time corresponding to the Tail field and the SVC field from the duration indicated by L_LENGTH, the wireless communication terminal subtracts the data size corresponding to the Tail field and the SVC field from the converted data size.

As described above, the duration of a symbol transmitted at a rate of 6 Mbps and modulated by 64 FFT is 4us. The size of data that can be transmitted by a symbol transmitted at 6 Mbps and modulated by 64 FFT is 3 bytes. In addition, the data size corresponding to the Tail field and the SVC field is 3 bytes. Accordingly, the wireless communication terminal may set the value of the L_LENGTH field according to the following equation.

L_LENGTH = [(TXTIME-20)/4] x 3 - 3

In this case, [x] is a flooring operation representing the smallest natural number greater than x.

As described above, the wireless communication terminal transmits data in symbol units. Therefore, the legacy wireless communication terminal converts the value of the L_LENGTH field into the duration of the physical layer frame based on the data size that can be transmitted by the symbol of the legacy signaling field. In this case, the legacy wireless communication terminal rounds up the value of the L_LENGTH field after dividing the data size that can be transmitted by the symbol. Therefore, the legacy wireless communication terminal equally processes the value of the L_LENGTH field within the data size range that can be transmitted by the symbol. For example, when the data size that can be transmitted by the symbol is 3 bytes, the duration value of the physical layer frame acquired by the legacy wireless communication terminal when the value of the L_LENGTH field is 1201 and the value of the L_LENGTH field is 1202 or 1203. The duration values of the physical layer frames to be used are the same.

Accordingly, the wireless communication terminal may signal information other than the duration of the physical layer frame through the value of the L_LENGTH field. Specifically, the wireless communication terminal may signal information other than the duration of the physical layer frame through the remaining value when the value of the L_LENGTH field is divided by the size of data that one symbol transmitting the L-SIG field can transmit. In this case, information other than the duration of the physical layer frame through the value of the L_LENGTH field may be information about the format of the physical layer frame. Specifically, information other than the duration of the physical layer frame may indicate information about a cyclic prefix (CP) or a guard interval applied to the physical layer frame. In a specific embodiment, the wireless communication terminal may indicate the degree of the CP length applied to the duration of the physical layer frame through the value of the L_LENGTH field. Specifically, when the data size that can be transmitted by the symbol is 3 bytes, the wireless communication terminal may signal the CP length as follows.

The wireless communication terminal may signal that the CP duration of the physical layer frame is the shortest length by setting the remaining value obtained by dividing the value of the L_LENGTH field by 3 to 0. At this time. The physical layer frame may be a physical layer frame used indoors. Also, the HE-SIG-A field may not include a repeated field value in the time domain. In addition, the duration of the CP of the HE-SIG-A field is 0.8us, the duration of the CP of the HE-SIG-B field is 0.8us, and the duration of the CP of the signal modulated by 256 FFT after HE-STF is 0.8us can

The wireless communication terminal may signal that the CP duration of the physical layer frame is an intermediate length by setting the remainder obtained by dividing the value of the L_LENGTH field by 3 to 1. At this time. The physical layer frame may be a physical layer frame used both indoors and outdoors. Also, the HE-SIG-A field may include a repeated field value in the time domain or may not include a repeated field value in the time domain. If the HE-SIG-A field does not contain a repeated field value in the time domain, the duration of the CP of the HE-SIG-A field is 0.8us, and the HE-SIG-A field contains the repeated field value in the time domain. If included, the duration of the CP of the HE-SIG-A field is a value greater than 0.8us. Also, the duration of the CP of the HE-SIG-B field may be greater than 0.8us, and the duration of the CP of the signal modulated by 256 FFT after HE-STF may be 1.6us.

The wireless communication terminal may signal that the CP duration of the physical layer frame has the longest length by setting the remainder obtained by dividing the value of the L_LENGTH field by 3 to 2. At this time. The physical layer frame may be a physical layer frame used outdoors. In addition, the HE-SIG-A field includes repeated field values in the time domain. The duration of the CP of the HE-SIG-A field is 0.8us. Also, the duration of the CP of the HE-SIG-B field may be greater than 0.8us, and the duration of the CP of the signal modulated by 256 FFT after HE-STF may be 3.2us.

8 shows that the wireless communication terminal additionally transmits a subcarrier having a predetermined value to at least one of L-LTF, L-SIG, and RL-SIG according to an embodiment of the present invention.

As in the embodiment of Figure 8 (a), the wireless communication terminal modulates a signal based on 64 FFT and 256 FFT. Specifically, the wireless communication terminal is based on 64 FFT so that the legacy wireless communication terminal can decode L-STF, L-LTF, L-SIG field, RL-SIG field, HE-SIG-A, and HE-SIG-B modulate the field. The wireless communication terminal modulates a signal transmitted after the HE-SIG-B field based on 256 FFT.

When modulating a signal based on 64 FFT, the wireless communication terminal transmits 64 subcarriers. For convenience of description, 64 subcarriers are divided by indices from -32 to 31. The wireless communication terminal uses six left subcarriers corresponding to indices -32 to -27 and five subcarriers corresponding to indices 27 to 31 as guard carriers. In addition, the wireless communication terminal uses one central subcarrier having an index of 0 as a DC(0) subcarrier.

The wireless communication terminal transmits data and pilot signals through 52 subcarriers excluding the guard carrier and the DC subcarrier. Specifically, the wireless communication terminal transmits a pilot signal through subcarriers having indices corresponding to -21, -7, 7, and 21, and transmits data through the remaining 48 subcarriers.

When the wireless communication terminal uses some of the six subcarriers corresponding to the positions of the guard carriers for data transmission, a larger amount of information may be transmitted through the signaling field. Specifically, when the wireless communication terminal transmits the signaling field as in the embodiment of FIG. 8(e), a larger amount of information may be transmitted through the signaling field. However, since the legacy wireless communication terminal needs to decode the L-SIG, the wireless communication terminal cannot use some of the six subcarriers corresponding to the positions of the guard carriers of the L-SIG field for data transmission of the L-SIG field. Since the wireless communication terminal transmits the RL-SIG field based on the L-SIG field, some of the six subcarriers corresponding to the positions of the guard carriers of the RL-SIG field cannot be used for data transmission of the RL-SIG field.

The wireless communication terminal does not consider compatibility with the legacy wireless communication terminal when transmitting the non-legacy signaling field signaling information for the non-legacy wireless communication terminal. In this case, the non-legacy signaling field includes a HE-SIG-A field and a HE-SIG-B field. Therefore, the wireless communication terminal uses some of the six subcarriers corresponding to the positions of the guard carriers for data transmission when transmitting the legacy training signal for the legacy signaling field and the legacy signaling field reception setting to transmit the non-legacy signaling field. In this case, the legacy signaling field may include the L-SIG field described above. In addition, the training signal for the legacy signaling field may include at least one of L-STF and L-LTF. Specifically, the wireless communication terminal uses four left subcarriers corresponding to indices -32 to -29 and three right subcarriers corresponding to indices 29 to 31 as guard carriers, and a subcarrier corresponding to index 0 as DC. , it is possible to transmit a non-legacy signaling field through 52 subcarriers.

In order for a wireless communication terminal to receive a signal, it is necessary to estimate a channel state. For this, a wireless communication terminal transmitting a signal transmits an L-LTF. The wireless communication terminal receiving the physical layer frame estimates a channel state based on the L-LTF, and receives the physical layer frame based on the estimated channel state. When the wireless communication terminal transmits the non-legacy signaling field using some of the six subcarriers corresponding to the position of the guard carrier of the L-STF, the wireless communication terminal is located on the subcarrier corresponding to the position of the guard carrier of the L-STF. It may not be possible to stably receive a signal because channel estimation cannot be performed. To prevent this, when the wireless communication terminal transmits at least one of the L-LTF, the L-SIG field, and the RL-SIG field, at least one of a plurality of subcarriers corresponding to the position of the guard carrier of the L-STF. It is possible to transmit a preset signal to

Specifically, when the wireless communication terminal transmits the L-LTF, at least one subcarrier that is continuous with a plurality of subcarriers for transmitting a signal of the L-STF among a plurality of subcarriers corresponding to the positions of the guard carriers of the L-STF It is possible to transmit a predetermined signal to In a specific embodiment, when the wireless communication terminal transmits the L-LTF, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the L-STF and the position of the right guard carrier of the L-STF A predetermined signal may be transmitted to two subcarriers having the lowest frequency among a plurality of corresponding subcarriers. For example, the wireless communication terminal may transmit a signal as in the embodiment of FIG. 8(b). In this case, the predetermined signal may be a signal sequence capable of minimizing a Peak to Average Power Ratio (PAPR) of the L-LTF. Specifically, the predetermined signal may be 1, 1, -1, and -1 according to the index order. When the wireless communication terminal transmits the L-LTF, when transmitting a predetermined signal through some of a plurality of subcarriers corresponding to the position of the guard carrier of the L-STF, the wireless communication terminal transmits the L-SIG and RL-SIG fields. During transmission, additional data may be transmitted through a subcarrier through which a predetermined signal is transmitted. However, when the legacy wireless communication terminal receives the L-LTF, interference may occur due to an additionally transmitted predetermined signal.

In another specific embodiment, when transmitting the L-SIG field, the wireless communication terminal transmits data and pilot signals of the L-SIG field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. A predetermined signal may be transmitted to at least one subcarrier contiguous with the carrier. Specifically, when the wireless communication terminal transmits the L-SIG, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal and the position of the right guard carrier of the legacy training signal. A predetermined signal may be transmitted to two subcarriers having the lowest frequency among the plurality of subcarriers. For example, the wireless communication terminal may transmit a signal as in the embodiment of FIG. 8( c ). In this case, the predetermined signal may be a signal sequence capable of minimizing the Peak to Average Power Ratio (PAPR) of the L-SIG. Specifically, the predetermined signal may be 1, 1, -1, and -1 according to the index order. When the wireless communication terminal transmits the L-SIG, when a predetermined signal is transmitted through some of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal, the legacy training signal reception of the legacy wireless communication terminal is affected may not However, when the wireless communication terminal transmits the L-SIG, when transmitting a predetermined signal through some of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal, the RL-SIG generated based on the L-SIG It may reduce the efficiency of auto detection using the field.

In another specific embodiment, when transmitting the RL-SIG field, the wireless communication terminal transmits data and pilot signals of the RL-SIG field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. A predetermined signal may be transmitted to at least one subcarrier contiguous with the carrier. When the wireless communication terminal transmits the RL-SIG field, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal and a plurality of subcarriers corresponding to the position of the right guard carrier of the legacy training signal A predetermined signal may be transmitted to two subcarriers having the lowest frequency among subcarriers of . Specifically, the wireless communication terminal may transmit a signal as in the embodiment of FIG. 8(d). In this case, the predetermined signal may be a signal sequence capable of minimizing the Peak to Average Power Ratio (PAPR) of the L-SIG. Specifically, the predetermined signal may be 1, 1, -1, and -1 according to the index order. When the wireless communication terminal transmits a predetermined signal through some of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal when transmitting the RL-SIG field, the legacy training signal and L-SIG of the legacy wireless communication terminal Reception may not be affected. However, when the wireless communication terminal transmits a predetermined signal through some of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal when transmitting the RL-SIG field, automatic detection using the RL-SIG field (auto detection) efficiency.

In another specific embodiment, when transmitting the L-SIG and RL-SIG fields, the wireless communication terminal transmits data and pilot signals of the RL-SIG field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. A predetermined signal may be transmitted to at least one continuous subcarrier with a plurality of subcarriers. Specifically, when the wireless communication terminal transmits the L-SIG and RL-SIG fields, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal and the right guard carrier of the legacy training signal A predetermined signal may be transmitted to two subcarriers having the lowest frequency among a plurality of subcarriers corresponding to the position of . In this case, the predetermined signal transmitted by the wireless communication terminal through the L-SIG and the predetermined signal transmitted through the RL-SIG field may be different from each other. The wireless communication terminal transmits any one of a plurality of combinations of a predetermined signal transmitted through the L-SIG and a predetermined signal transmitted through the RL-SIG field to signal additional information other than the L-SIG field data. can

At this time, the additional information includes a new transmission mode of the physical layer frame, information for symbol configuration, information on the structure of the physical layer frame, information for performing CCA, information for decoding a non-legacy signaling field, and other BSS belonging to It may be at least any one of information for a wireless communication terminal.

Specifically, the new transmission mode of the physical layer frame may include a transmission mode for long range transmission. In a specific embodiment, the transmission mode for long-distance transmission may indicate that a physical layer frame having a new structure for long-distance transmission is used. In addition, the information for the symbol configuration may include at least one of OFDM symbol synchronization, FFT size, and CP length. In addition, information on the structure of the physical layer frame may include at least one of the number of STF/LTF transmission symbols, transmission order, signaling field type, signaling field length, and signaling field interpretation method. In addition, the information for performing CCA may include at least one of a BSS color, whether BSS color is applied, and an offset value for a threshold value in SD/ED to be used during CCA.

The information for decoding the non-legacy signaling field may specifically be information for decoding the TXOP duration indicated by the non-legacy signaling field. Specifically, the information for decoding the non-legacy signaling field may be the granularity of the TXOP duration indicated by the non-legacy signaling field. In another specific embodiment, the information for decoding the non-legacy signaling field may be an offset value of the TXOP duration indicated by the non-legacy signaling field.

Information for a wireless communication terminal belonging to another BSS may be information indicating a relative position of a frequency band in which the RL-SIG field is transmitted. In this case, the relative position may indicate high and low frequency bands. In addition, when the 80 MHz + 80 MHz frequency band is used, the relative position may indicate either a relatively high 80 MHz frequency band or a relatively low 80 MHz frequency band of the frequency band.

A wireless communication terminal belonging to another BSS may need to decode a value of a non-legacy signaling field in order to perform SR (Spatial Reuse). At this time, since the wireless communication terminal belonging to another BSS cannot know the relative position of the frequency band in which the signal is transmitted, when the non-legacy signaling field indicates information on a plurality of frequency bands, the non-legacy signaling corresponding to a certain frequency band I can't decide if I need to get the value of the field. Accordingly, the wireless communication terminal may transmit information indicating the relative position of the frequency band in which the RL-SIG field is transmitted through the RL-SIG field. In this case, the wireless communication terminal belonging to another BSS may determine the relative position of the frequency band in which the RL-SIG field is transmitted based on the RL-SIG field. A wireless communication terminal belonging to another BSS may decode the non-legacy signaling field based on the relative position. For example, a wireless communication terminal belonging to another BSS may decode information on spatial reuse (SR) indicated by a non-legacy signaling field based on a relative position.

When a predetermined signal is transmitted according to the above-described embodiment, the wireless communication terminal receiving the physical layer frame estimates the state of the channel based on the predetermined signal. The wireless communication terminal receives the non-legacy signaling field based on the estimated channel state.

In addition, the wireless communication terminal may transmit the predetermined signal described with reference to FIG. 8 in units of a 20 MHz frequency band.

9 shows the structure of the HE-SIG-A field according to an embodiment of the present invention.

As described above, the physical layer frame according to an embodiment of the present invention is a HE- that is commonly used when a wireless communication terminal transmits data to any one wireless communication terminal and when transmitting data to a plurality of wireless communication terminals. Contains the SIG-A field. Specifically, the HE-SIG-A field is at least any one of the bandwidth of the physical layer frame, the BSS Color, the number of HE-LTFs (Number_of_HE-LTF), and information about MCS used for HE-SIG-B field transmission. may contain one.

In addition, the wireless communication terminal may transmit the HE-SIG-A field including the repeated field in the time domain through four symbols based on 64 FFT. In particular, during long-distance transmission requiring high-reliability transmission, the wireless communication terminal may transmit the HE-SIG-A field including the field repeated in the time domain through four symbols based on 64 FFT.

In addition, when the wireless communication terminal transmits data to a plurality of wireless communication terminals, the wireless communication terminal may signal information on the plurality of wireless communication terminals through the HE-SIG-B field. When the wireless communication terminal transmits data to any one wireless communication terminal, HE-SIG-B may not be transmitted.

Therefore, the wireless communication terminal needs to signal the format of the physical layer frame. When the wireless communication terminal signals the format of the physical layer frame through the field included in HE-SIG-A, after decoding the HE-SIG-A field of the wireless communication terminal receiving the physical layer frame, the physical layer frame format can be determined. Therefore, when the wireless communication terminal signals the format of the physical layer frame through the field included in the HE-SIG-A, the decoding operation burden of the wireless communication terminal receiving the physical layer frame may increase. Therefore, there is a need for a method of signaling the format of the physical layer frame through a signal transmitted before transmission of the HE-SIG-A field by the wireless communication terminal.

Specifically, the wireless communication terminal may signal whether the HE-SIG-A field includes a repeated field in the time domain through the value of the L_LENGTH field of the L-SIG field described above. Specifically, the wireless communication terminal divides the value of the L_LENGTH field by the size of data that can be transmitted by one symbol transmitting the L-SIG field through the remaining value of the HE-SIG-A field repeated in the time domain. Whether or not to include may be signaled.

Also, the wireless communication terminal may signal whether the physical layer frame includes the HE-SIG-B field through the value of the L_LENGTH field. Specifically, the wireless communication terminal determines whether the physical layer frame includes the HE-SIG-B field through the remaining value when the value of the L_LENGTH field is divided by the size of data that one symbol transmitting the L-SIG field can transmit. can signal whether or not

In addition, the wireless communication terminal may signal whether the physical layer frame includes the HE-SIG-B field through the modulation method of the first symbol and the second symbol for transmitting the HE-SIG-A field. In this case, the wireless communication terminal modulates the first symbol transmitting the HE-SIG-A field with BPSK to distinguish it from the legacy physical layer frame. Accordingly, the wireless communication terminal may signal whether the physical layer frame includes the HE-SIG-B field through the modulation method of the second symbol for transmitting the HE-SIG-A field. Specifically, the wireless communication terminal may signal whether the physical layer frame includes the HE-SIG-B field according to whether the second symbol for transmitting the HE-SIG-A field is modulated with BPSK or QBPSK. For example, the wireless communication terminal modulates the second symbol for transmitting the HE-SIG-A field with BPSK to signal that the physical layer frame includes the HE-SIG-B field, and transmits the HE-SIG-A field It is possible to signal that the physical layer frame does not include the HE-SIG-B field by modulating the second symbol to QBPSK. In a specific embodiment, the wireless communication terminal modulates the second symbol for transmitting the HE-SIG-A field with QBPSK to signal that the physical layer frame includes the HE-SIG-B field, and the HE-SIG-A field By modulating the second symbol to be transmitted with BPSK, it is possible to signal that the physical layer frame does not include the HE-SIG-B field.

In another specific embodiment, the wireless communication terminal transmits the L-SIG field and the RL-SIG field, while transmitting the HE-SIG-B field of the physical layer frame through some of a plurality of subcarriers corresponding to the guard carriers of the L-STF. It may signal whether to include .

In another specific embodiment, the wireless communication terminal transmits the HE-SIG-A field including the repeated field in the time domain without separate signaling to signal that the physical layer frame does not include the HE-SIG-B field. can

10 to 11 show the structure of the HE-SIG-B field according to an embodiment of the present invention.

The HE-SIG-B field indicates information on a plurality of wireless communication terminals when any one wireless communication terminal transmits data to a plurality of wireless communication terminals as described above. The HE-SIG-B field includes common information common to a plurality of wireless communication terminals and user specific information about one wireless communication terminal among the plurality of wireless communication terminals. In this case, the user characteristic information includes information on resource unit allocation (Resource Unit Allocation), a sub-frequency band index indicating a sub-frequency band (Subband Indication), a resource unit size (Resource Unit Size), and an MCS for transmitting data. It may include at least one of information about the number of space-time streams (NSTS) used to transmit data and information about the number of space-time streams used to transmit data. Specifically, HE-SIG-B may have the same structure as in the embodiment of FIG. 10( b ).

When the wireless communication terminal transmits data through a frequency band having a bandwidth greater than 20 MHz, the wireless communication terminal transmits the same L-SIG field, RL-SIG field, and HE-SIG-A field every 20 MHz.

In addition, when the wireless communication terminal transmits a physical layer frame through a frequency band having a 40 MHz bandwidth, the wireless communication terminal may transmit different HE-SIG-B fields for each 20 MHz bandwidth. When the wireless communication terminal transmits a physical layer frame through a frequency band having a bandwidth of 80 MHz or 160 MHz, the wireless communication terminal may repeatedly transmit two different HE-SIG-B fields having a bandwidth of 20 MHz every 40 MHz. Specifically, when the wireless communication terminal transmits a physical layer frame through a frequency band having a bandwidth of 80 MHz, the wireless communication terminal transmits the first HE-SIG-B field in a frequency band having a first 20 MHz bandwidth, and a second 20 MHz The second HE-SIG-B field may be transmitted in a frequency band having a bandwidth. In this case, the wireless communication terminal may transmit the first HE-SIG-B field in a frequency band having a third 20 MHz bandwidth and transmit the second HE-SIG-B field in a frequency band having a fourth 20 MHz bandwidth. Specifically, the wireless communication terminal may transmit a physical layer frame having the same structure as in the embodiment of FIG. 10( a ). In another specific embodiment, when the wireless communication terminal transmits a physical layer frame through a frequency band having a 160 MHz bandwidth, the wireless communication terminal transmits the first HE-SIG-B field in a frequency band having a first 20 MHz bandwidth, and , the second HE-SIG-B field may be transmitted in a frequency band having a second 20 MHz bandwidth. At this time, the wireless communication terminal transmits the first HE-SIG-B field in frequency bands having third, fifth, and seventh 20 MHz bandwidths, and second in frequency bands having fourth, sixth, and eighth 20 MHz bandwidths. The HE-SIG-B field may be transmitted.

Therefore, each of the plurality of wireless communication terminals receiving data from any one wireless communication terminal must find out whether the HE-SIG-B field transmitted in which frequency band includes information corresponding to each of the plurality of wireless communication terminals.

To this end, the wireless communication terminal may simultaneously decode different frequency bands having a 20 MHz bandwidth using two decoders. Specifically, the wireless communication terminal may decode the HE-SIG-A field from L-STF through one decoder and the HE-SIG-B field through two decoders. However, this method may increase the computational burden of the wireless communication terminal receiving the physical layer frame.

In another specific embodiment, the wireless communication terminal may indicate the wireless communication terminal corresponding to information included in the HE-SIG-B field through CRC masking. In more detail, the wireless communication terminal may generate a CRC value of the HE-SIG-B field and mask it with an identifier of the wireless communication terminal corresponding to information included in the HE-SIG-B field. In this case, the identifier of the wireless communication terminal may be the MAC ID of the wireless communication terminal. Also, the identifier of the wireless communication terminal may be a group identifier (Group ID) indicating a group including the wireless communication terminal. Also, the masking may represent a bitwise operation such as an XOR operation.

At this time, the wireless communication terminal receiving the physical layer frame generates a CRC as a value of the HE-SIG-B field, and masks the generated CRC with an identifier of the wireless communication terminal and the CRC included in the HE-SIG-B field. Based on the value of the field, it may be determined whether the HE-SIG-B field includes information about the wireless communication terminal. Specifically, when the wireless communication terminal generates a CRC with the value of the HE-SIG-B field, and the value of the generated CRC is masked with the identifier of the wireless communication terminal and the value of the CRC field included in the HE-SIG-B field are the same , it can be determined that the corresponding HE-SIG-B field includes information about the wireless communication terminal. A specific operation of the wireless communication terminal may be the same as the flowchart of FIG. 11( a ). Since the wireless communication terminal can quickly perform the CRC operation and the masking operation, it is possible to quickly determine which frequency band the HE-SIG-B field includes information about the wireless communication terminal.

In addition, when the wireless communication terminal transmits long-distance data, the wireless communication terminal needs to increase the reliability of HE-SIG-B field transmission. To this end, the wireless communication terminal may transmit the HE-SIG-B field as in the following embodiments.

Specifically, the wireless communication terminal may transmit the HE-SIG-B field including the repeated field value in the time domain. Through this, the wireless communication terminal may increase the HE-SIG-B field transmission probability. However, since the wireless communication terminal transmits repeated data in the time domain, the transmission efficiency of the wireless communication terminal may decrease.

In another specific embodiment, the wireless communication terminal may use a CP having a longer duration than general transmission during long-distance transmission. For example, the wireless communication terminal may use 1.2us, 1.6us, or 3.2us larger than 0.8us as the size of the CP duration. In addition, the wireless communication terminal may signal the CP length through the embodiment described with reference to FIG. 6 .

In another specific embodiment, the wireless communication terminal may transmit the repeated field at the bit level. Specifically, the wireless communication terminal repeatedly transmits the common information (Common Info) of the HE-SIG-B field at the bit level, and repeatedly transmits user specific information (User Specific Info) regarding the wireless communication terminal located at a long distance. have. In a specific embodiment, the wireless communication terminal may transmit the HE-SIG-B field as in the embodiment of FIG. 11( b ).

10 to 11, it is assumed that a frequency bandwidth used by any one wireless communication terminal while transmitting data to a plurality of wireless communication terminals is any one of 20 MHz, 40 MHz, 80 MHz, and 160 MHz. According to a specific embodiment, the size of a frequency bandwidth used by one wireless communication terminal while transmitting data to a plurality of wireless communication terminals may vary.

12 shows a SIG-B structure of a physical layer frame when a wireless communication terminal transmits a physical layer frame to a plurality of wireless communication terminals according to an embodiment of the present invention.

11, when the wireless communication terminal transmits a physical layer frame through a frequency band having a 40 MHz bandwidth, the wireless communication terminal may transmit different HE-SIG-B fields for each 20 MHz bandwidth. In addition, when the wireless communication terminal transmits a physical layer frame through a frequency band having a bandwidth of 80 MHz or 160 MHz, the wireless communication terminal repeatedly transmits two different HE-SIG-B fields having a bandwidth of 20 MHz every 40 MHz. Can be transmitted. .

In this case, the HE-SIG-B field includes common information common to a plurality of wireless communication terminals and user specific information about one wireless communication terminal among the plurality of wireless communication terminals. do. The user characteristic information may include information about a wireless communication terminal that receives data through a frequency band in which the HE-SIG-B field including the user characteristic information is transmitted. Since the HE-SIG-B field having a frequency band with a 20 MHz bandwidth is repeatedly transmitted every 40 MHz, user characteristic information is transmitted to a wireless communication terminal that receives data through all frequency bands in which the same HE-SIG-B field is transmitted. It may contain information about

The wireless communication terminal receiving the physical layer frame may acquire information on resource unit allocation based on common information, and may acquire user characteristic information on the wireless communication terminal based on the resource unit allocation information. For example, the wireless communication terminal receiving the physical layer frame determines which frequency band HE-SIG-B field is located in the user characteristic information about the wireless communication terminal based on the common information.

However, when data transmission to any one wireless communication terminal is performed through a discontinuous frequency band, the wireless communication terminal must determine the discontinuous frequency band in which the corresponding wireless communication terminal transmits data to be received. Accordingly, the user characteristic information may include information indicating a frequency band in which data to be received by the wireless communication terminal corresponding to the user characteristic information is transmitted. Specifically, the user characteristic information may include a sub-frequency band index indicating a frequency band in which data to be received by the wireless communication terminal corresponding to the user characteristic information is transmitted. In this case, the HE-SIG-B field may include a plurality of sub-fields indicating user characteristic information. The plurality of sub-fields may be divided into a frequency band having a bandwidth of 20 MHz and each wireless communication terminal. For example, when the access point (AP) transmits data for the first station through the first frequency band and the third frequency band having a 20 MHz frequency bandwidth, HE- transmitted through the first frequency band and the third frequency band The SIG-B field may include two sub-fields indicating information on the first station. When a frequency band having a bandwidth of 20 MHz is divided for each wireless communication terminal, information about the wireless communication terminal is transmitted in duplicate in a plurality of sub-fields. Therefore, the transmission efficiency decreases.

In another specific embodiment, the sub-field may be divided for each wireless communication terminal. For example, when the access point (AP) transmits data for the first station through the first frequency band and the third frequency band having a 20 MHz frequency bandwidth, HE- transmitted through the first frequency band and the third frequency band The SIG-B field may include one sub-field indicating information on the first station. In this case, the length of the sub-field may be variable according to the change of the sub-frequency band. When the length of the sub-field is variable, the length of the sub-field must be signaled separately. To prevent this, the wireless communication terminal transmitting the physical layer frame may indicate the sub-frequency band index as a fixed-length field such as a bitmap. A specific embodiment indicating the sub-field of user characteristic information will be described with reference to FIGS. 12(a), 12(b)-1, and 12(b)-2.

In the embodiment of FIG. 12 ( a ), the access point (AP) includes a first station (A), a second station (B), a third station (C), a fourth station (D), and a fifth station (E). ) to send data. The access point AP transmits data to the first station A and the second station B through a first ^{frequency band (1 st 20 MHz) having a bandwidth of 20 MHz.} The access point AP transmits data to the third station C through a second frequency band (2 ^{nd 20 MHz) having a 20 MHz bandwidth.} The access point AP transmits data to the first station A through a third frequency band (3 ^{rd 20 MHz) having a 20 MHz bandwidth.} The access point AP transmits data to the fourth station D and the fifth station E through a fourth ^{frequency band (4 th 20 MHz) having a bandwidth of 20 MHz.}

The first HE-SIG-B field transmitted through the first frequency band (1 ^st 20 MHz) and the third frequency band (3 ^rd 20 MHz) includes information about the first station (A) and the second station (B) do. The second HE-SIG-B field transmitted through the second frequency band (2 ^nd 20 MHz) and the fourth frequency band (4 ^th 20 MHz) is the third station (C), the fourth station (D), and the fifth station (D) contains information about

FIG. 12(b)-1 shows a case in which a plurality of sub-fields indicating user characteristic information is divided into a frequency band having a bandwidth of 20 MHz and each wireless communication terminal. The access point (AP) transmits information about the first station (A) to a sub-field indicating a sub-frequency band index allocated to the first station (A) in ^{the first frequency band (1 st 20 MHz) and a third frequency band Signals} through a sub-field indicating a sub-frequency index assigned to the first station (A) at (3 rd 20 MHz).

12(b)-2 shows a case in which a plurality of sub-fields indicating user characteristic information are divided for each wireless communication terminal. The access point (AP) signals information about the first station (A) through one sub-field. In this case, the access point (AP) may signal the sub-frequency band index in a fixed-length field such as a bitmap.

When data to be received by any one wireless communication terminal is transmitted through frequency bands signaled by different HE-SIG-B fields, the different HE-SIG-B fields each include information about the wireless communication terminal. can In the embodiment of FIG. 12(c) , the access point AP transmits data to the first station A through a first ^{frequency band (1 st} 20 MHz) and a second frequency band (2 ^{nd 20 MHz).} At this time, the first HE-SIG-B field indicating information on the wireless communication terminal to receive data through ^{the first frequency band (1 st} 20 MHz) and the third frequency band (3 ^{rd 20 MHz) is the first station (A)} Includes user characteristic information about In addition, the first HE-SIG-B field indicating information on the wireless communication terminal to receive data through the second frequency band (2 ^nd 20 MHz) and the fourth frequency band (4 ^{th 20 MHz) is the first station (A)} Includes user characteristic information about

13 shows a method of signaling a discontinuous frequency band when a wireless communication terminal transmits data through a discontinuous frequency band within a frequency band having a 20 MHz bandwidth according to an embodiment of the present invention.

The wireless communication terminal may transmit data to any one wireless communication terminal through a discontinuous frequency band within a frequency band having a bandwidth of 20 MHz. In this case, the characteristic information of the HE-SIG-B field may include a sub-frequency band index indicating a sub-frequency band within a frequency band having a 20 MHz bandwidth. In this case, the HE-SIG-B field may include a plurality of sub-fields indicating user characteristic information. The plurality of sub-fields may be divided into sub-frequency bands within a frequency band having a 20 MHz bandwidth and each wireless communication terminal.

In the embodiment of FIG. 13 , the access point AP transmits data to the first station A through sub-frequency bands A1 and A2 ^{of the first frequency band (1 st 20 MHz, 1-00).} The access point AP transmits data to the first station A through A3, which is a sub-frequency band of the second frequency band (2 ^{nd 20 MHz, 2-00).} The access point AP transmits data to the first station A through A4, which is a sub-frequency band of the third frequency band (3 ^{rd 20 MHz, 1-01).} The access point AP transmits data to the first station A through the sub-frequency band A5 of the fourth frequency band (4 ^{th 20 MHz, 2-01).}

In this case, the user characteristic information of the first HE-SIG-B field includes a sub-field indicating information about the first station and sub-frequency band A1, and a sub-field indicating information about the first station and sub-frequency band A2. , and a sub-field indicating information about the first station and sub-frequency band A4. The user characteristic information of the second HE-SIG-B field includes a sub-field indicating information about the first station and sub-frequency band A3 and a sub-field indicating information about the first station and sub-frequency band A5 do. In this case, a method in which a wireless communication terminal transmitting a physical layer frame transmits data within a frequency band having a bandwidth of 20 MHz is a problem. This will be described with reference to FIG. 14 .

14 illustrates a data transmission method when a wireless communication terminal transmits data through a discontinuous frequency band according to an embodiment of the present invention.

As described above, the wireless communication terminal may transmit data for any one wireless communication terminal through a discontinuous frequency band. In this case, the wireless communication terminal may transmit the divided data through each of a plurality of sub-frequency bands included in the discontinuous frequency band. In this case, the divided data cannot be decoded as individual data, and the divided data may be integrated and decoded. Accordingly, the wireless communication terminal receiving the physical layer frame receives a plurality of divided data through a plurality of sub-frequency bands included in the discontinuous frequency band. The wireless communication terminal decodes the data by integrating a plurality of divided data. In this case, the data may be an Aggregated MAC Protocol Data Unit (A-MPDU). In the embodiment of FIG. 14( a ), the wireless communication terminal divides and transmits one A-MPDU through five sub-frequency bands (A1-A5). The wireless communication terminal receiving the physical layer frame generates an A-MDPU by integrating the divided data transmitted through each of the five sub-frequency bands (A1-A5), and decodes the A-MDPU. As such, when the wireless communication terminal transmits divided data through each of a plurality of sub-frequency bands included in the discontinuous frequency band, it is possible to increase transmission efficiency by minimizing header information required for data transmission. However, when the wireless communication terminal receiving the physical layer frame does not receive the divided data transmitted through any one sub-frequency band, the wireless communication terminal receiving the data cannot decode the entire data.

In another specific embodiment, the wireless communication terminal may transmit independent individual data through each of a plurality of sub-frequency bands. In this case, independent individual data may be decoded as individual data. Accordingly, the wireless communication terminal receiving the physical layer frame receives a plurality of individual data through a plurality of sub-frequency bands included in the discontinuous frequency band. The wireless communication terminal individually decodes a plurality of individual data. In this case, each individual data may be an Aggregated MAC Protocol Data Unit (A-MPDU). In the embodiment of FIG. 14(b), the wireless communication terminal transmits five A-MPDUs (A-MPDU1-A-MPDU2) through five sub-frequency bands (A1-A5), respectively. The wireless communication terminal receiving the physical layer frame receives each of the five A-MPDUs (A-MPDU1-A-MPDU2) through each of the five sub-frequency bands (A1-A5). The wireless communication terminal decodes each of the received five A-MPDUs (A-MPDU1-A-MPDU2). In this way, when the wireless communication terminal transmits independent individual data through each of a plurality of sub-frequency bands included in the discontinuous frequency band, the wireless communication terminal receiving the physical layer frame is transmitted through any one sub-frequency band. Even if individual data to be transmitted is not received, the remaining individual data can be decoded. However, the number of headers required for data transmission increases, which may decrease transmission efficiency.

15 shows the structure of HE-SIG-A when the wireless communication terminal repeatedly transmits HE-SIG-A according to an embodiment of the present invention.

As described above, when transmitting the HE-SIG-A field, the wireless communication terminal may repeatedly transmit the same field in the time domain. The wireless communication terminal may transmit HE-SIG-A including a repeated field in the time domain through 4 symbols and transmit a general HE-SIG-A field through 2 symbols. The general HE-SIG-A field refers to a HE-SIG-A field that does not include a repeated field in the time domain. When the wireless communication terminal transmits HE-SIG-A including a repeated field in the time domain, how the wireless communication terminal applies the CP is a problem.

The wireless communication terminal may apply a CP used for general HE-SIG-A field transmission before a subfield indicating data of the HE-SIG-A field and before a repeated subfield in which the corresponding subfield is repeated. Specifically, as in Fig. 15(a), the same CP before the subfields A1 and A2 indicating the data of the HE-SIG-A field and before the repeated subfields RA1 and RA2 in which the subfields indicating the data are repeated. can be transmitted In a specific embodiment, the duration of the CP may be 0.8us. When the HE-SIG-A includes the subfield and the repetition subfield, the wireless communication terminal receiving the physical layer frame may receive the HE-SIG-A subfield and the repetition subfield by soft combining. There are advantages that can be However, in an environment with a large delay variance, a CP having a duration as long as 0.8us, which is not long, does not adequately cancel the delay variance. Accordingly, there may be a problem that the wireless communication terminal cannot receive HE-SIG-A well.

The wireless communication terminal may apply a CP used for general HE-SIG-A field transmission before a subfield indicating data of the HE-SIG-A field and after a repeated subfield in which the corresponding subfield is repeated. Specifically, as shown in FIG. 15(b), the CP is transmitted before the subfields A1 and A2 indicating the data of the HE-SIG-A field, and after the repeated subfields RA1 and RA2 in which the subfield indicating the data is repeated The same CP may be transmitted. In a specific embodiment, the duration of the CP may be 0.8us. When the wireless communication terminal applies the CP used for general HE-SIG-A field transmission before the subfield indicating the data of the HE-SIG-A field and after the repeated subfield in which the subfield is repeated, the subfield It is possible to minimize the phase shift when converting from to a repeating subfield. Also, it is possible to increase the probability that the wireless communication terminal receiving the physical layer frame will receive the HE-SIG-A field.

The wireless communication terminal may apply a CP having a longer duration than that of a CP used for general HE-SIG-A field transmission before a subfield indicating data of the HE-SIG-A field. Specifically, as shown in FIG. 15C , the CP may be transmitted before the subfields A1 and A2 indicating data of the HE-SIG-A field. In a specific embodiment, the duration of the CP may be 1.6 us. When the wireless communication terminal applies a CP having a longer duration than the duration of a CP used for general HE-SIG-A field transmission before a subfield indicating data of the HE-SIG-A field, a repeat subfield in the subfield It is possible to minimize the phase shift when converting to . In addition, the long CP duration may appropriately offset delay dispersion, thereby increasing the probability that the wireless communication terminal receiving the physical layer frame will receive the HE-SIG-A field.

16 shows an operation of a wireless communication terminal according to an embodiment of the present invention.

Specifically, FIG. 16 shows operations of the first wireless communication terminal 1601 and the second wireless communication terminal 1603 according to an embodiment of the present invention.

The first wireless communication terminal 1601 sets a signaling field (S1601). The first wireless communication terminal 1601 may set the legacy signaling field as in the embodiments of FIGS. 6 to 9 . Specifically, when transmitting the legacy signaling field, the first wireless communication terminal 1601 transmits a predetermined first signal through at least one subcarrier among a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal. can In a specific embodiment, the first wireless communication terminal 1601 transmits data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signals. The first signal may be transmitted through one subcarrier. The first wireless communication terminal 1601 has two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal with reference to 0 in the frequency band and a plurality corresponding to the position of the right guard carrier The first signal may be transmitted through two subcarriers having the lowest frequency among subcarriers of . In this case, the legacy signaling field may be the L-SIG field described above.

After transmitting the legacy signaling field, the first wireless communication terminal 1601 may transmit the repeated legacy signaling field generated based on the legacy signaling field. In this case, the second wireless communication terminal 1603 may determine the received physical layer frame as a non-legacy physical layer frame based on the repetitive legacy signaling field.

When transmitting the repetitive legacy signaling field, the first wireless communication terminal 1601 may transmit a predetermined second signal through at least one of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal. . The first wireless communication terminal 1601 may generate a repeating legacy signaling field by repeating the legacy signaling field. Also, the first wireless communication terminal 1601 may signal information other than the legacy signaling field through a combination of the first signal and the second signal. In this case, information other than the legacy signaling field may correspond to the embodiment described with reference to FIG. 8 .

The legacy signaling field includes length information indicating the duration of the non-legacy physical layer frame after the legacy signaling field. In this case, the length information may be the L_LENGTH field described above. The first wireless communication terminal 1601 uses the remaining value obtained by dividing the length information by the data size that can be transmitted by one OFDM symbol for transmitting the legacy physical layer frame. Information other than information indicating the duration of the non-legacy physical layer frame. can be signaled. Information other than the information indicating the duration of the non-legacy physical layer frame indicates whether the non-legacy physical layer frame includes the first signaling field, and the first signaling field is the wireless communication terminal transmits data to a plurality of wireless communication terminals. In this case, information about a plurality of wireless communication terminals may be signaled. In addition, information other than information indicating the duration of the non-legacy physical layer frame indicates whether the second signaling field included in the non-legacy physical layer frame includes a repeated field in the time domain, and the second signaling field is any one It can be commonly used when transmitting data to a wireless communication terminal and when transmitting data to a plurality of wireless communication terminals. In this case, the second signaling field may be the HE-SIG-A field described above. Also, the first signaling field may be the HE-SIG-B field described above.

In a specific embodiment, the first wireless communication terminal 1601 transmits the remaining value obtained by dividing the length information by the data size that can be transmitted by one OFDM symbol transmitting the legacy physical layer frame and the second OFDM symbol transmitting the second signaling field. Information other than information indicating the duration of the non-legacy physical layer frame may be signaled through the modulation method of . Specifically, the modulation method may be binary phase shift keying (BPSK) or quadrature binary phase shift keying (QBPSK).

Also, the first wireless communication terminal 1601 may transmit a second signaling field including a repeated field in the time domain. Specifically, the first wireless communication terminal 1601 may transmit a second signaling field including a repeated field in the time domain for long-distance data transmission. In this case, the structure of the second signaling field may be the same as the embodiment described with reference to FIG. 15 .

Also, when transmitting data to a plurality of wireless communication terminals, the first wireless communication terminal 1601 may transmit a first signaling field. The first signaling field includes common information common to a plurality of wireless communication terminals and user specific information about any one wireless communication terminal among the plurality of wireless communication terminals. In this case, the user characteristic information includes information on resource unit allocation (Resource Unit Allocation), a sub-frequency band index indicating a sub-frequency band (Subband Indication), a resource unit size (Resource Unit Size), and an MCS for transmitting data. It may include at least one of information about the number of space-time streams (NSTS) used to transmit data and information about the number of space-time streams used to transmit data. The specific structure of the first signaling field may be the same as that of the embodiment described with reference to FIGS. 10 to 13 .

The first wireless communication terminal 1601 transmits a physical layer frame including a signaling field to the second wireless communication terminal 1603 (S1603). In this case, the first wireless communication terminal 1601 may transmit data to the second wireless communication terminal 1603 through a discontinuous frequency band. Specifically, the first wireless communication terminal 1601 may transmit data to the second wireless communication terminal 1603 through a discontinuous frequency band as in the embodiment of FIG. 14 .

The second wireless communication terminal 1603 receives a physical layer frame based on the signaling field (S1605). Specifically, the second wireless communication terminal 1603 receives a legacy training signal for setting reception of a legacy signaling field, and based on the legacy training signal, a legacy signaling field including information that the legacy wireless communication terminal can decode. do. At this time, the second wireless communication terminal 1603 receives a predetermined first signal through at least one subcarrier among a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal, and based on the first signal A non-legacy signaling field may be received. Specifically, when receiving the legacy signaling field, the second wireless communication terminal 1603 transmits data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal. The first signal may be received through at least one subcarrier that is continuous with . When the second wireless communication terminal 1603 receives the legacy signaling field, the two subcarriers having the highest frequency among the plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal based on 0 in the frequency band and the right The first signal may be received through two subcarriers having the lowest frequency among a plurality of subcarriers corresponding to the positions of the guard carriers.

In addition, after receiving the legacy signaling field, the second wireless communication terminal 1603 receives the repeated legacy signaling field generated based on the legacy signaling field. In this case, as described above, the second wireless communication terminal 1603 may determine whether the received physical layer frame is a non-legacy physical layer frame based on the repetitive legacy signaling field. When the second wireless communication terminal 1603 receives the repetitive legacy signaling field, the second signal specified in advance through at least one subcarrier among a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal. can

The second wireless communication terminal 1603 uses the remaining value obtained by dividing the length information by the data size that one OFDM symbol for transmitting the legacy physical layer frame can transmit. Information other than information indicating the duration of the non-legacy physical layer frame. can be obtained Information other than information indicating the duration of the non-legacy physical layer frame may be information according to the above-described embodiment. In addition, the second wireless communication terminal 1603 transmits the remainder of the length information divided by the data size that can be transmitted by one OFDM symbol for transmitting the legacy physical layer frame and the second OFDM symbol for transmitting the second signaling field. Modulation method Information other than information indicating the duration of the non-legacy physical layer frame may be acquired through . Specifically, the modulation method may be binary phase shift keying (BPSK) or quadrature binary phase shift keying (QBPSK).

As described above, the present invention has been described using wireless LAN communication as an example, but the present invention is not limited thereto and may be equally applied to other communication systems such as cellular communication. Further, although the method, apparatus and system of the present invention have been described with reference to specific embodiments, some or all of the components, operations of the present invention may be implemented using a computer system having a general-purpose hardware architecture.

Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

In the above, the embodiment has been mainly described, but this is only an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains are not exemplified above in the range that does not depart from the essential characteristics of this embodiment It will be appreciated that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

Claims (20)

In a wireless communication terminal that communicates wirelessly,
transceiver; and
including a processor;
the processor
Transmitting a legacy signaling field including information that can be decoded by a legacy wireless communication terminal through the transceiver and a legacy training signal for setting reception of the legacy signaling field,
When transmitting the legacy signaling field, a predetermined first signal is transmitted through at least one subcarrier among a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal.
wireless communication terminal. In claim 1,
the processor
When transmitting the legacy signaling field, at least one subcarrier contiguous with a plurality of subcarriers for transmitting data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal to transmit the first signal through
wireless communication terminal. In claim 2,
the processor
When transmitting the legacy signaling field, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal with reference to 0 in the frequency band and a plurality corresponding to the position of the right guard carrier Transmitting the first signal through two subcarriers having the lowest frequency among subcarriers of
wireless communication terminal. In claim 1,
the processor
After transmitting the legacy signaling field, a repeating legacy signaling field generated based on the legacy signaling field is transmitted;
When transmitting the repetitive legacy signaling field, a predetermined second signal is transmitted through at least one subcarrier among a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal.
wireless communication terminal. In claim 4,
the processor
repeating the legacy signaling field to generate the repeating legacy signaling field
wireless communication terminal. In claim 4,
the processor
Signaling information other than the legacy signaling field through a combination of the first signal and the second signal
wireless communication terminal. In claim 4,
The first signal and the second signal are the same
wireless communication terminal. In claim 1,
The legacy signaling field includes length information indicating the duration of the non-legacy physical layer frame after the legacy signaling field,
the processor
Signaling information other than information indicating the duration of the non-legacy physical layer frame through the remainder of dividing the length information by the data size that can be transmitted by one OFDM symbol for transmitting the legacy physical layer frame
wireless communication terminal. In claim 8,
the processor
Information other than information indicating the duration of the non-legacy physical layer frame indicates whether the non-legacy physical layer frame includes a first signaling field,
The first signaling field is configured to signal information about a plurality of wireless communication terminals when the wireless communication terminal transmits data to a plurality of wireless communication terminals.
wireless communication terminal. In claim 9,
Information other than the information indicating the duration of the non-legacy physical layer frame indicates whether the second signaling field included in the non-legacy physical layer frame includes a field repeated in the time domain,
The second signaling field is commonly used when transmitting data to any one wireless communication terminal and when transmitting data to a plurality of wireless communication terminals.
wireless communication terminal. In claim 10,
the processor
Through the modulation method of the remainder of dividing the length information by the data size that can be transmitted by one OFDM symbol for transmitting the legacy physical layer frame and the second OFDM symbol for transmitting the second signaling field, the non-legacy physical layer Signaling information other than information indicating the duration of the frame
wireless communication terminal. In claim 11,
The modulation method is BPSK (Binary Phase Shift Keying) or QBPSK (Quadrature Binary Phase Shift Keying).
wireless communication terminal. In a wireless communication terminal that communicates wirelessly,
transceiver; and
including a processor;
the processor
Receiving a legacy training signal for setting reception of a legacy signaling field through the transceiver, and receiving a legacy signaling field including information that a legacy wireless communication terminal can decode based on the legacy training signal,
Receiving a predetermined first signal through at least one subcarrier of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal,
Receiving a non-legacy signaling field signaling information for a non-legacy wireless communication terminal based on the first signal
wireless communication terminal. In claim 13,
the processor
When the legacy signaling field is received, at least one subcarrier that is continuous with a plurality of subcarriers for transmitting data and pilot signals of the legacy signaling field among a plurality of subcarriers corresponding to the positions of the guard carriers of the legacy training signal receiving the first signal through a carrier
wireless communication terminal. 15. In claim 14,
the processor
When receiving the legacy signaling field, two subcarriers having the highest frequency among a plurality of subcarriers corresponding to the position of the left guard carrier of the legacy training signal with reference to 0 in the frequency band and the position of the right guard carrier Receiving the first signal through two subcarriers having the lowest frequency among a plurality of subcarriers
wireless communication terminal. In claim 13,
the processor
After receiving the legacy signaling field, receive a repeating legacy signaling field generated based on the legacy signaling field through the transceiver;
When receiving the repetitive legacy signaling field, receiving a predetermined second signal through at least one subcarrier of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal
wireless communication terminal. 17. In claim 16,
The first signal and the second signal are the same
wireless communication terminal. In claim 13,
The legacy signaling field includes length information indicating the duration of the non-legacy physical layer frame after the legacy signaling field,
the processor
Obtaining information other than information indicating the duration of the non-legacy physical layer frame through the residual value obtained by dividing the length information by the data size that can be transmitted by one OFDM symbol transmitting the legacy physical layer frame
wireless communication terminal. In claim 18,
the processor
Information other than information indicating the duration of the non-legacy physical layer frame indicates whether the non-legacy physical layer frame includes a first signaling field,
The first signaling field is configured to signal information about a plurality of wireless communication terminals when the wireless communication terminal transmits data to a plurality of wireless communication terminals.
wireless communication terminal. In a method of operating a wireless communication terminal for wireless communication,
transmitting, by the legacy wireless communication terminal, a legacy training signal for setting reception of a legacy signaling field including information that can be decoded; and
transmitting a legacy signaling field;
Transmitting the legacy signaling field includes:
Transmitting a predetermined first signal through at least one subcarrier of a plurality of subcarriers corresponding to the position of the guard carrier of the legacy training signal
wireless communication terminal.

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