WO2018182312A1 - Method for transmitting packet in wireless lan system and transmitting terminal using same - Google Patents

Abstract

A method for transmitting a packet in a wireless LAN system according to the present embodiment comprises: a step of generating a multi-user wake-up packet (MU WUP) for a plurality of wake-up receiver (WUR) terminals which are multi-users by a transmitting terminal, wherein a predetermined sequence is applied to a transmission band comprising a plurality of subbands for the MU WUP; and a step of transmitting the MU WUP to a plurality of WUR terminals on the basis of a plurality of subbands by the transmitting terminal.

Description

Method for transmitting packet in WLAN system and transmitting terminal using same

The present disclosure relates to wireless communication, and more particularly, to a method for transmitting a packet in a WLAN system and a transmitting terminal using the same.

Discussion is underway for the next generation wireless local area network (WLAN). In next-generation WLANs, 1) enhancements to the Institute of Electronic and Electronics Engineers (IEEE) 802.11 physical layer (PHY) and medium access control (MAC) layers in the 2.4 GHz and 5 GHz bands, and 2) spectral efficiency SIP1802-040 (spectrum efficiency) and area 3) aim to improve performance in real indoor and outdoor environments, such as environments with interference sources, dense heterogeneous network environments, and high user loads. Shall be.

The environment mainly considered in the next-generation WLAN is a dense environment having many access points (APs) and a station (STA), and improvements in spectral efficiency and area throughput are discussed in such a dense environment. In addition, in the next generation WLAN, there is an interest in improving practical performance not only in an indoor environment but also in an outdoor environment, which is not much considered in a conventional WLAN.

Specifically, in next-generation WLANs, we are interested in scenarios such as wireless office, smart-home, stadium, hot spot, building / apartment and based on the scenario. As a result, there is a discussion about improving system performance in a dense environment with many APs and STAs.

In addition, in the next-generation WLAN, there will be more discussion about improving system performance in outdoor overlapping basic service set (OBSS) environment, improving outdoor environment performance, and cellular offloading, rather than improving single link performance in one basic service set (BSS). It is expected. The directionality of these next-generation WLANs means that next-generation WLANs will increasingly have a technology range similar to that of mobile communications. Considering the recent situation in which mobile communication and WLAN technology are discussed together in the small cell and direct-to-direct (D2D) communication area, the technical and business convergence of next-generation WLAN and mobile communication is expected to become more active.

An object of the present specification is a multi-user wake-up packet for a plurality of WUR (Wake-Up Receiver) terminals which are multi-users in a WLAN system. WUP ') is provided to provide a transmitting terminal with improved performance in terms of peak-to-average power ratio (PAPR).

In a method for transmitting a packet in a WLAN system according to the present embodiment, a multi-user wake-up packet for a plurality of wake-up receiver (WUR) terminals, which is a multi-user, is a transmitting terminal. Generating an Up Packet, MU WUP, wherein a predetermined sequence is applied to a transmission band comprising a plurality of subbands for the MU WUP; And transmitting, by the transmitting terminal, the MU WUP to the plurality of WUR terminals based on the plurality of subbands.

According to the present specification, a transmitting terminal having improved performance in terms of PAPR may be provided based on MU WUP for a plurality of WUR terminals which are multiple users in a WLAN system.

1 is a conceptual diagram illustrating a structure of a WLAN system.

2 is a diagram illustrating an example of a PPDU used in the IEEE standard.

3 is a diagram illustrating an example of a HE PPDU.

4 shows an internal block diagram of a wireless terminal receiving a wakeup packet.

5 is a conceptual diagram illustrating a method for a wireless terminal to receive a wakeup packet and a data packet.

6 shows an example of a format of a wakeup packet.

7 shows a signal waveform of a wakeup packet.

FIG. 8 is a diagram for describing a procedure of determining power consumption according to a ratio of bit values constituting information in a binary sequence form.

9 is a diagram illustrating a design process of a pulse according to the OOK technique.

10 is a diagram for explaining a Manchester coding technique.

11 illustrates an example of a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

12 is another example illustrating a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

FIG. 13 is another example illustrating a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

14 is a flowchart illustrating a method of transmitting a packet based on a plurality of subbands in a WLAN system according to the present embodiment.

15 is a block diagram illustrating a wireless device to which the present embodiment can be applied.

16 is a block diagram illustrating an example of an apparatus included in a processor.

The above-described features and the following detailed description are all exemplary for ease of description and understanding of the present specification. That is, the present specification is not limited to this embodiment and may be embodied in other forms. The following embodiments are merely examples to fully disclose the present specification, and are descriptions to convey the present specification to those skilled in the art. Thus, where there are several methods for implementing the components of the present disclosure, it is necessary to clarify that any of these methods may be implemented in any of the specific or equivalent thereof.

In the present specification, when there is a statement that a configuration includes specific elements, or when a process includes specific steps, it means that other elements or other steps may be further included. That is, the terms used in the present specification are only for describing specific embodiments and are not intended to limit the concept of the present specification. Furthermore, the described examples to aid the understanding of the invention also include their complementary embodiments.

The terminology used herein has the meaning commonly understood by one of ordinary skill in the art to which this specification belongs. Terms commonly used should be interpreted in a consistent sense in the context of the present specification. In addition, terms used in the present specification should not be interpreted in an idealistic or formal sense unless the meaning is clearly defined. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a structure of a WLAN system. FIG. 1A shows the structure of an infrastructure network of the Institute of Electrical and Electronic Engineers (IEEE) 802.11.

Referring to FIG. 1A, the WLAN system 10 of FIG. 1A may include at least one basic service set (hereinafter, referred to as 'BSS', 100, 105). The BSS is a set of access points (APs) and stations (STAs) that can successfully synchronize and communicate with each other, and is not a concept indicating a specific area.

For example, the first BSS 100 may include a first AP 110 and one first STA 100-1. The second BSS 105 may include a second AP 130 and one or more STAs 105-1, 105-2.

The infrastructure BSS (100, 105) may include at least one STA, AP (110, 130) providing a distribution service (Distribution Service) and a distribution system (DS, 120) connecting a plurality of APs. have.

The distributed system 120 may connect the plurality of BSSs 100 and 105 to implement an extended service set 140 which is an extended service set. The ESS 140 may be used as a term indicating one network to which at least one AP 110 or 130 is connected through the distributed system 120. At least one AP included in one ESS 140 may have the same service set identification (hereinafter, referred to as SSID).

The portal 150 may serve as a bridge for connecting the WLAN network (IEEE 802.11) with another network (for example, 802.X).

In a WLAN having a structure as shown in FIG. 1A, a network between APs 110 and 130 and a network between APs 110 and 130 and STAs 100-1, 105-1, and 105-2 may be implemented. Can be.

1B is a conceptual diagram illustrating an independent BSS. Referring to FIG. 1B, the WLAN system 15 of FIG. 1B performs communication by setting a network between STAs without the APs 110 and 130, unlike FIG. 1A. It may be possible to. A network that performs communication by establishing a network even between STAs without the APs 110 and 130 is defined as an ad-hoc network or an independent basic service set (BSS).

Referring to FIG. 1B, the IBSS 15 is a BSS operating in an ad-hoc mode. Since IBSS does not contain an AP, there is no centralized management entity. Thus, in the IBSS 15, the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 are managed in a distributed manner.

All STAs 150-1, 150-2, 150-3, 155-4, and 155-5 of the IBSS may be mobile STAs, and access to a distributed system is not allowed. All STAs of the IBSS form a self-contained network.

The STA referred to herein includes a medium access control (MAC) conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and a physical layer interface to a wireless medium. As any functional medium, it can broadly be used to mean both an AP and a non-AP Non-AP Station (STA).

The STA referred to herein includes a mobile terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), and a mobile station (MS). It may also be called various names such as a mobile subscriber unit or simply a user.

2 is a diagram illustrating an example of a PPDU used in the IEEE standard.

As shown, various types of PHY protocol data units (PPDUs) have been used in the IEEE a / g / n / ac standard. Specifically, the LTF and STF fields included training signals, the SIG-A and SIG-B included control information for the receiving station, and the data fields included user data corresponding to the PSDU.

This embodiment proposes an improved technique for the signal (or control information field) used for the data field of the PPDU. The signal proposed in this embodiment may be applied on a high efficiency PPDU (HE PPDU) according to the IEEE 802.11ax standard. That is, the signals to be improved in the present embodiment may be HE-SIG-A and / or HE-SIG-B included in the HE PPDU. Each of HE-SIG-A and HE-SIG-B may also be represented as SIG-A or SIG-B. However, the improved signal proposed by this embodiment is not necessarily limited to the HE-SIG-A and / or HE-SIG-B standard, and controls / control of various names including control information in a wireless communication system for transmitting user data. Applicable to data fields.

3 is a diagram illustrating an example of a HE PPDU.

The control information field proposed in this embodiment may be HE-SIG-B included in the HE PPDU as shown in FIG. 3. The HE PPDU according to FIG. 3 is an example of a PPDU for multiple users. The HE-SIG-B may be included only for the multi-user, and the HE-SIG-B may be omitted in the PPDU for the single user.

As shown, a HE-PPDU for a multiple user (MU) includes a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), High efficiency-signal A (HE-SIG-A), high efficiency-signal-B (HE-SIG-B), high efficiency-short training field (HE-STF), high efficiency-long training field (HE-LTF) It may include a data field (or MAC payload) and a PE (Packet Extension) field. Each field may be transmitted during the time period shown (ie, 4 or 8 ms, etc.).

The PPDU used in the IEEE standard is mainly described as a PPDU structure transmitted over a channel bandwidth of 20 MHz. The PPDU structure transmitted over a wider bandwidth (eg, 40 MHz, 80 MHz) than the channel bandwidth of 20 MHz may be a structure applying linear scaling to the PPDU structure used in the 20 MHz channel bandwidth.

The PPDU structure used in the IEEE standard is generated based on 64 Fast Fourier Tranforms (FTFs), and a CP portion (cyclic prefix portion) may be 1/4. In this case, the length of the effective symbol interval (or FFT interval) may be 3.2us, the CP length is 0.8us, and the symbol duration may be 4us (3.2us + 0.8us) plus the effective symbol interval and the CP length.

4 shows an internal block diagram of a wireless terminal receiving a wakeup packet.

Referring to FIG. 4, the WLAN system 400 according to the present embodiment may include a first wireless terminal 410 and a second wireless terminal 420.

The first wireless terminal 410 includes a main radio module 411 associated with the main radio (ie, 802.11) and a module including a low-power wake-up receiver ('LP WUR') (hereinafter, WUR). Module 412. The main radio module 411 may transmit user data or receive user data in an activated state (ie, an ON state).

When there is no data (or packet) to be transmitted by the main radio module 411, the first radio terminal 410 may control the main radio module 411 to enter an inactive state (ie, an OFF state). For example, the main radio module 411 may include a plurality of circuits supporting Wi-Fi, Bluetooth® radio (hereinafter referred to as BT radio) and Bluetooth® low energy radio (hereinafter referred to as BLE radio).

According to the related art, a wireless terminal operating based on a power save mode may operate in an active state or a sleep state.

For example, a wireless terminal in an activated state can receive all frames from another wireless terminal. In addition, the wireless terminal in the sleep state may receive a specific type of frame (eg, a beacon frame transmitted periodically) transmitted by another wireless terminal (eg, AP).

It is assumed that the wireless terminal referred to herein can operate the main radio module in an activated state or in an inactive state.

A wireless terminal comprising a main radio module 411 in an inactive state (i.e., in an OFF state) may receive a frame transmitted by another wireless terminal (e.g., AP) until the main radio module is woken up by the WUR module 412. For example, it is not possible to receive an 802.11 type PPDU).

For example, a wireless terminal including the main radio module 411 in an inactive state (ie, in an OFF state) may not receive a beacon frame periodically transmitted by the AP.

That is, it may be understood that the wireless terminal including the main radio module (eg, 411) in the inactive state (ie, the OFF state) according to the present embodiment is in a deep sleep state.

In addition, a wireless terminal that includes a main radio module 411 that is in an active state (ie, in an ON state) may receive a frame (eg, an 802.11 type PPDU) transmitted by another wireless terminal (eg, an AP). have.

In addition, it is assumed that the wireless terminal referred to herein can operate the WUR module in a turn-off state or in a turn-on state.

A wireless terminal that includes a WUR module 412 in a turn-on state can only receive certain types of frames transmitted by other wireless terminals. In this case, a specific type of frame may be understood as a frame modulated by an on-off keying (OOK) modulation scheme described below with reference to FIG. 5.

A wireless terminal that includes a WUR module 412 in a turn-off state cannot receive certain types of frames transmitted by other wireless terminals.

In this specification, to indicate the ON state of a specific module included in the wireless terminal, the terms for the activation state and the turn-on state may be used interchangeably. In the same context, the terms deactivation state and turn-off state may be used interchangeably to indicate an OFF state of a particular module included in the wireless terminal.

The wireless terminal according to the present embodiment may receive a frame (or packet) from another wireless terminal based on the main radio module 411 or the WUR module 412 in an activated state.

The WUR module 412 may be a receiver for waking the main radio module 411. That is, the WUR module 412 may not include a transmitter. The WUR module 412 may remain turned on for a duration in which the main radio module 411 is inactive.

For example, when a wake-up packet (WUP) for the main radio module 411 is received, the first radio terminal 410 may be configured to have a main radio module 411 in an inactive state. It can be controlled to enter the activation state.

The low power wake up receiver (LP WUR) included in the WUR module 412 targets a target power consumption of less than 1 mW in an active state. In addition, low power wake-up receivers may use a narrow bandwidth of less than 5 MHz.

In addition, the power consumption by the low power wake-up receiver may be less than 1 Mw. In addition, the target transmission range of the low power wake-up receiver may be the same as the target transmission range of the existing 802.11.

The second wireless terminal 420 according to the present embodiment may transmit user data based on a main radio (ie, 802.11). The second wireless terminal 420 can transmit a wakeup packet (WUP) for the WUR module 412.

Referring to FIG. 4, the second wireless terminal 420 may not transmit user data or a wakeup packet (WUP) for the first wireless terminal 410. In this case, the main radio module 411 included in the second wireless terminal 420 may be in an inactive state (ie, an OFF state), and the WUR module 412 is in a turn-on state (ie, an ON state). There may be.

5 is a conceptual diagram illustrating a method for a wireless terminal to receive a wakeup packet and a data packet.

4 and 5, the WLAN system 500 according to the present embodiment may include a first wireless terminal 510 corresponding to the receiving terminal and a second wireless terminal 520 corresponding to the transmitting terminal. have. Basic operations of the first wireless terminal 510 of FIG. 5 may be understood through the description of the first wireless terminal 410 of FIG. 4. Similarly, the basic operation of the second wireless terminal 520 of FIG. 5 may be understood through the description of the second wireless terminal 420 of FIG. 4.

Referring to FIG. 5, when the wakeup packet 521 is received by the WUR module 512 in an active state, the WUR module 512 may transmit data to the main radio module 511 after the wakeup packet 521. The wakeup signal 523 may be transmitted to the main radio module 511 to correctly receive the packet 522.

For example, the wakeup signal 523 may be implemented based on primitive information inside the first wireless terminal 510.

For example, when the main radio module 511 receives the wake-up signal 523, all of the plurality of circuits (not shown) supporting Wi-Fi, BT radio, and BLE radio included in the main radio module 511 may be provided. It can be activated or only part of it.

As another example, the actual data included in the wakeup packet 521 may be directly transmitted to a memory block (not shown) of the receiving terminal even if the main radio module 511 is in an inactive state.

As another example, when the wake-up packet 521 includes an IEEE 802.11 MAC frame, the receiving terminal may activate only the MAC processor of the main radio module 511. That is, the receiving terminal may maintain the PHY module of the main radio module 511 in an inactive state. The wakeup packet 521 of FIG. 5 will be described in more detail with reference to the following drawings.

The second wireless terminal 520 can be set to transmit the wakeup packet 521 to the first wireless terminal 510. For example, the second wireless terminal 520 may control the main radio module 511 of the first wireless terminal 510 to enter an activated state (ie, an ON state) according to the wakeup packet 521. .

6 shows an example of a format of a wakeup packet.

1 to 6, the wakeup packet 600 may include one or more legacy preambles 610. For example, the legacy preamble 610 may be modulated according to an existing Orthogonal Frequency Division Multiplexing (OFDM) modulation technique.

In addition, the wakeup packet 600 may include a payload 620 after the legacy preamble 610. For example, payload 620 may be modulated according to a simple modulation scheme (eg, On-Off Keying (OOK) modulation technique. Wakeup packet 600 including payload) May be transmitted based on a relatively small bandwidth.

1 through 6, a second wireless terminal (eg, 520) may be configured to generate and / or transmit wakeup packets 521, 600. The first wireless terminal (eg, 510) can be configured to process the received wakeup packet 521.

The wakeup packet 600 may include a legacy preamble 610 or any other preamble (not shown) defined in the existing IEEE 802.11 standard.

The wakeup packet 600 may include one packet symbol 615 after the legacy preamble 610. In addition, the wakeup packet 600 may include a payload 620.

The legacy preamble 610 may be provided for coexistence with the legacy STA. In other words, the legacy preamble 610 may be provided for a third party STA (ie, a STA that does not include an LP-WUR). That is, the legacy preamble 610 may not be decoded by the WUR terminal including the WUR module.

In the legacy preamble 610 for coexistence, an L-SIG field for protecting a packet may be used. For example, an 802.11 STA may detect a start portion of a packet (ie, a start portion of a wakeup packet) through an L-STF field in the legacy preamble 610. The L-SIG field in the legacy preamble 610 may allow the 802.11 STA to know the last part of the packet (ie, the last part of the wakeup packet).

In order to reduce false alarm of the 802.11n terminal, a modulated symbol 615 may be added after the L-SIG of FIG. 6. One symbol 615 may be modulated according to a BiPhase Shift Keying (BPSK) technique. One symbol 615 may have a length of 4 us. One symbol 615 may have a 20 MHz bandwidth like a legacy part.

Payload 620 includes a wake-up preamble field 621, a MAC header field 623, a frame body field 625, and a Frame Check Sequence (FCS) field 627. can do.

The wakeup preamble field 621 may include a sequence for identifying the wakeup packet 600. For example, the wakeup preamble field 621 may include a pseudo random noise sequence (PN).

The MAC header field 624 may include address information (or an identifier of a receiving apparatus) indicating a receiving terminal receiving the wakeup packet 600. The frame body field 626 may include other information of the wakeup packet 600.

The frame body 626 may include length information or size information of the payload. Referring to FIG. 6, the length information of the payload may be calculated based on length LENGTH information and MCS information included in the legacy preamble 610.

The FCS field 628 may include a Cyclic Redundancy Check (CRC) value for error correction. For example, the FCS field 628 may include a CRC-8 value or a CRC-16 value for the MAC header field 623 and the frame body 625.

7 shows a signal waveform of a wakeup packet.

Referring to FIG. 7, the wakeup packet 700 may include payloads 722 and 724 modulated based on a legacy preamble (802.11 preamble, 710) and an On-Off Keying (OOK) scheme. That is, the wakeup packet WUP according to the present embodiment may be understood as a form in which a legacy preamble and a new LP-WUR signal waveform coexist.

In the legacy preamble 710 of FIG. 7, the OOK technique may not be applied. As mentioned above, payloads 722 and 724 may be modulated according to the OOK technique. However, the wakeup preamble 722 included in the payloads 722 and 724 may be modulated according to another modulation technique.

For example, it may be assumed that the legacy preamble 710 is transmitted based on a channel band of 20 MHz to which 64 FFTs are applied. In this case, payloads 722 and 724 may be transmitted based on a channel band of about 4.06 MHz.

FIG. 8 is a diagram for describing a procedure of determining power consumption according to a ratio of bit values constituting information in a binary sequence form.

Referring to FIG. 8, information in the form of a binary sequence having '1' or '0' as a bit value may be represented. Communication based on the OOK modulation scheme may be performed based on the bit values of the binary sequence information.

For example, when the light emitting diode is used for visible light communication, when the bit value constituting the binary sequence information is '1', the light emitting diode is turned on, and when the bit value is '0', the light emitting diode is turned off. (off) can be turned off.

As the light-emitting diode blinks, the receiver receives and restores data transmitted in the form of visible light, thereby enabling communication using visible light. However, since the blinking of the light emitting diode cannot be perceived by the human eye, the person feels that the illumination is continuously maintained.

For convenience of description, as shown in FIG. 8, information in the form of a binary sequence having 10 bit values may be provided. For example, information in the form of a binary sequence having a value of '1001101011' may be provided.

As described above, when the bit value is '1', when the transmitting terminal is turned on and when the bit value is '0', when the transmitting terminal is turned off, 6 bit values of the above 10 bit values are applied. The corresponding symbol is turned on.

Since the wake-up receiver WUR according to the present embodiment is included in the receiving terminal, the transmission power of the transmitting terminal may not be greatly considered. The reason why the OOK technique is used in the present embodiment is because power consumption in the decoding procedure of the received signal is very small.

Until the decoding procedure is performed, there may be no significant difference between the power consumed by the main radio and the power consumed by the WUR. However, as the decoding procedure is performed by the receiving terminal, a large difference may occur between power consumed by the main radio module and power consumed by the WUR module. Below is the approximate power consumption.

-The existing Wi-Fi power consumption is about 100mW. Specifically, power consumption of Resonator + Oscillator + PLL (1500uW)-> LPF (300uW)-> ADC (63uW)-> decoding processing (OFDM receiver) (100mW) may occur.

-WUR power consumption is about 1mW. Specifically, power consumption of Resonator + Oscillator (600uW)-> LPF (300uW)-> ADC (20uW)-> decoding processing (Envelope detector) (1uW) may occur.

9 is a diagram illustrating a design process of a pulse according to the OOK technique.

The wireless terminal according to the present embodiment may use an existing 802.11 OFDM transmitter to generate a pulse according to the OOK technique. The existing 802.11 OFDM transmitter can generate a sequence having 64 bits by applying a 64-point IFFT.

1 to 9, the wireless terminal according to the present embodiment may transmit a payload of a wakeup packet (WUP) modulated according to the OOK technique. The payload (eg, 620 of FIG. 6) according to the present embodiment may be implemented based on an ON time signal and an OFF time signal.

The OOK technique may be applied to the ON time signal included in the payload (eg, 620 of FIG. 6) of the wakeup packet WUP. In this case, the on time signal may be a signal having an actual power value.

Referring to the frequency domain graph 920, the on-time signal included in the payload (eg, 620 of FIG. 6) may be selected from among N1 subcarriers (N1 is a natural number) corresponding to the channel band of the wakeup packet (WUP). It can be obtained by performing IFFT on N2 subcarriers (N2 is a natural number). In addition, a predetermined sequence may be applied to the N2 subcarriers.

For example, the channel band of the wakeup packet WUP may be 20 MHz. The N1 subcarriers may be 64 subcarriers, and the N2 subcarriers may be 13 consecutive subcarriers (921 of FIG. 9). The subcarrier interval applied to the wakeup packet (WUP) may be 312.5 kHz.

The OOK technique may be applied to the OFF time signal included in the payload (eg, 620 of FIG. 6) of the wakeup packet WUP. The off time signal may be a signal that does not have an actual power value. That is, the off time signal may not be considered in the configuration of the wakeup packet WUP.

The on time signal included in the payload (620 of FIG. 6) of the wakeup packet (WUP) is a 1-bit ON signal (ie, a 1-bit ON signal) by the WUR module (eg, 512 of FIG. 5). '1'), i.e., demodulation. Similarly, the off time signal included in the payload may be determined (ie, demodulated) as a 1-bit off signal (ie, '0') by the WUR module (eg, 512 of FIG. 5).

A specific sequence may be preset for the subcarrier set 921 of FIG. 9. In this case, the preset sequence may be a 13-bit sequence. For example, a coefficient corresponding to the DC subcarrier in the 13-bit sequence may be '0', and the remaining coefficients may be set to '1' or '-1'.

Referring to the frequency domain graph 920, the subcarrier set 921 may correspond to a subcarrier having a subcarrier index of '-6' to '+6'.

For example, a coefficient corresponding to a subcarrier whose subcarrier indices are '-6' to '-1' in the 13-bit sequence may be set to '1' or '-1'. A coefficient corresponding to a subcarrier whose subcarrier indices are '1' to '6' in the 13-bit sequence may be set to '1' or '-1'.

For example, a subcarrier whose subcarrier index is '0' in a 13-bit sequence may be nulled. The coefficients of the remaining subcarriers (subcarrier indexes '-32' to '-7' and subcarrier indexes '+7' to '+31') except for the subcarrier set 921 are all set to '0'. Can be.

The subcarrier set 921 corresponding to 13 consecutive subcarriers may be set to have a channel bandwidth of about 4.06 MHz. That is, power by signals may be concentrated at 4.06 MHz in the 20 MHz band for the wakeup packet (WUP).

When the pulse according to the OOK technique is used according to the present embodiment, the power is concentrated in a specific band, so that the signal to noise ratio (SNR) may be increased, and the power consumption for conversion in the AC / DC converter of the receiver may be reduced. There is an advantage that it can. Since the sampling frequency band is reduced to 4.06 MHz, power consumption by the wireless terminal can be reduced.

According to the embodiment of the present invention, an OFDM transmitter of 802.11 may have N2 (e.g., 13 consecutive) subs of N1 (e.g., 64) subcarriers corresponding to the channel band (e.g., 20 MHz band) of the wake-up packet. IFFT (eg, 64-point IFFT) may be performed on the carrier.

In this case, a predetermined sequence may be applied to the N2 subcarriers. Accordingly, one on-signal may be generated in the time domain. One bit information corresponding to one on signal may be transmitted through one symbol.

For example, when a 64-point IFFT is performed, a symbol having a 3.2us length corresponding to the subcarrier set 921 may be generated. In addition, when CP (Cyclic Prefix, 0.8us) is added to a symbol having a 3.2us length corresponding to the subcarrier set 921, one symbol having a total length of 4us as shown in the time domain graph 910 of FIG. Can be generated.

In addition, the OFDM transmitter of 802.11 may not transmit the off signal at all.

According to the present embodiment, a first wireless terminal (eg, 510 of FIG. 5) including a WUR module (eg, 512 of FIG. 5) may receive a packet based on an envelope detector that extracts an envelope of the received signal. Can be demodulated.

For example, the WUR module (eg, 512 of FIG. 5) according to the present embodiment may compare a power level of a received signal obtained through an envelope of the received signal with a preset threshold level.

If the power level of the received signal is higher than the threshold level, the WUR module (eg, 512 of FIG. 5) may determine the received signal as a 1-bit ON signal (ie, '1'). If the power level of the received signal is lower than the threshold level, the WUR module (eg, 512 of FIG. 5) may determine the received signal as a 1-bit OFF signal (ie, '0').

According to the present embodiment, the basic data rate for one information may be 125 Kbps (8us) or 62.5Kbps (16us).

Generalizing the contents of FIG. 9, each signal having a length of K (eg, K is a natural number) in the 20 MHz band may be transmitted based on consecutive K subcarriers of 64 subcarriers for the 20 MHz band. For example, K may correspond to the number of subcarriers used to transmit the signal. K may also correspond to the bandwidth of a pulse according to the OOK technique.

All of the coefficients of the remaining subcarriers except K subcarriers among the 64 subcarriers may be set to '0'.

Specifically, for the 1-bit off signal corresponding to '0' (hereinafter, information 0) and the 1-bit on signal corresponding to '1' (hereinafter, information 1), the same K subcarriers may be used. have. For example, the index for the K subcarriers used may be expressed as 33-floor (K / 2): 33 + ceil (K / 2) -1.

In this case, the information 1 and the information 0 may have the following values.

Information 0 = zeros (1, K)

Information 1 = alpha * ones (1, K)

The alpha is a power normalization factor and may be, for example, 1 / sqrt (K).

10 is an explanatory diagram of a Manchester coding scheme according to the present embodiment.

Manchester coding is a type of line coding, and may indicate information as shown in the following table in a manner in which a transition of a magnitude value occurs in the middle of one bit period.

That is, Manchester coding means a method of converting data from 1 to 01, 0 to 10, 1 to 10, and 0 to 01. Table 1 shows an example in which data is converted from 1 to 10 and 0 to 01 using Manchester coding.

As shown in Fig. 10, the bit string to be transmitted, the Manchester coded signal, the clock reproduced on the receiving side, and the data reproduced on the clock are shown in order from top to bottom.

When the transmitting side transmits data using the Manchester coding scheme, the receiving side reads the data a little later on the basis of the transition point transitioning from 1 → 0 or 0 → 1 and recovers the data, and then transitions to 1 → 0 or 0 → 1 The clock is recovered by recognizing the transition point as the clock transition point. Alternatively, when the symbol is divided based on the transition point, it can be simply decoded by comparing the power at the front and the back at the center of the symbol.

As shown in FIG. 10, the bit string to be transmitted is 10011101, the Manchester coded signal is 0110100101011001, and the clock reproduced by the receiver recognizes the transition point of the Manchester coded signal as the transition point of the clock. Then, the data is recovered by using the reproduced clock.

By using the Manchester coding scheme, it is possible to communicate in a synchronous manner using only a data transmission channel without using a separate clock.

In addition, this method can use the TXD pin for data transmission and the RXD pin for reception by using only the data transmission channel. Therefore, synchronized bidirectional transmission is possible.

This specification proposes various symbol types that can be used in the WUR and thus data rates.

Since STAs requiring robust performance and STAs receiving strong signals from APs are mixed, it is necessary to support efficient data rates in some situations. In order to obtain reliable and robust performance, a symbol coding based symbol coding technique and a symbol repetition technique may be used. In addition, a symbol reduction technique may be used to obtain a high data rate.

In this case, each symbol may be generated using an existing 802.11 OFDM transmitter. In addition, the number of subcarriers used to generate each symbol may be thirteen. However, it is not limited thereto.

In addition, each symbol may use OOK modulation formed of an ON-signal and an OFF-signal.

One symbol generated for the WUR may be composed of a CP (Cyclic Prefix or Guard Interval) and a signal part representing actual information. Symbols having various data rates may be designed by variously setting or repeating the lengths of the CP and the actual information signal.

The following are various examples of symbol types.

For example, the basic WUR symbol may be represented as CP + 3.2us. That is, one bit is represented using a symbol having the same length as the existing Wi-Fi. Specifically, the transmitting apparatus applies a specific sequence to all available subcarriers (for example, 13 subcarriers) and then performs IFFT to form an information signal portion of 3.2 us. In this case, a coefficient of 0 may be loaded on the DC subcarrier or the middle subcarrier index among all available subcarriers.

Different sequences may be applied to the available subcarriers according to the 3.2us on signal and the 3.2us off signal. A 3.2us off signal can be generated by applying all coefficients to zero.

CP may be used by adopting a specific length from the rear of the information signal 3.2us immediately behind. At this time, CP may be 0.4us or 0.8us. This length is equal to the guard interval of 802.11ac.

Accordingly, one bit information corresponding to one basic WUR symbol may be represented as shown in the following table.

Table 2 does not indicate CP separately. In fact, CP + 3.2us including CP may point to one 1-bit information. That is, the 3.2us on signal can be viewed as a (CP + 3.2us) on signal. A 3.2us off signal can be seen as a (CP + 3.2us) off signal.

As another example, a symbol to which Manchester coding is applied may be represented as CP + 1.6us + CP + 1.6us or CP + 1.6us + 1.6us. The symbol to which the Manchester coding is applied may be generated as follows.

In the OOK transmission using the Wi-Fi transmitter, the time used for transmitting one bit (or symbol) except for the guard interval of the transmission signal is 3.2 us. In this case, if Manchester coding is applied, a signal size transition should occur at 1.6us. That is, each sub-information having a length of 1.6us should have a value of 0 or 1, and may configure a signal in the following manner.

-Information 0-> 1 0 (each can be referred to as sub information 1 0 or sub symbol 1 (ON) 0 (OFF))

First 1.6us (sub information 1 or sub symbol 1): Sub information 1 may have a value of beta * ones (1, K). Beta is a power normalization factor and may be, for example, 1 / sqrt (ceil (K / 2)).

In addition, a specific sequence is applied in units of two squares to all available subcarriers (eg, 13 subcarriers) to generate a symbol to which Manchester coding is applied. That is, even-numbered subcarriers of a particular sequence are nulled to zero. That is, in a particular sequence, coefficients may exist at intervals of two cells. For example, suppose that 13 subcarriers are used to construct an on-signal, a particular sequence with coefficients spaced two spaces apart is {a 0 b 0 c 0 d 0 e 0 f 0 g}, {0 a 0 b 0 c 0 d 0 e 0 f 0} or {a 0 b 0 c 0 0 0 d 0 e 0 method. At this time, a, b, c, d, e, f, g is 1 or -1.

That is, the transmitter maps a specific sequence to K consecutive subcarriers of 64 subcarriers (for example, 33-floor (K / 2): 33 + ceil (K / 2) -1) and the remaining subcarriers. IFFT is performed by setting the coefficient to 0. In this way, signals in the time domain can be generated. The signal in the time domain is a 3.2us long signal having a 1.6us period because coefficients exist at intervals of two spaces in the frequency domain. One of the first or second 1.6us period signals can be selected and used as sub information 1.

Second 1.6us (sub information 0 or sub symbol 0): The sub information 0 may have a value of zeros (1, K). Similarly, the transmitter maps a specific sequence to K consecutive subcarriers of 64 subcarriers (eg, 33-floor (K / 2): 33 + ceil (K / 2) -1) and performs IFFT. The signal in the time domain can be generated. The sub information 0 may correspond to a 1.6us off signal. The 1.6us off signal can be generated by setting all coefficients to zero.

One of the first or second 1.6us periodic signals of the signal in the time domain may be selected and used as the sub information 0. You can simply use the zeros (1,32) signal as subinformation zero.

Information 1-> 0 1 (each may be referred to as sub information '0', '1' or sub symbol 0 (OFF) 1 (ON))

Since information 1 is also divided into the first 1.6us (sub information 0) and the second 1.6us (sub information 1), a signal corresponding to each sub information may be configured in the same manner as the information 0 is generated.

By using a technique of generating information 0 and information 1 using Manchester coding, it is possible to prevent the off symbol from continuing as compared to the conventional method. Therefore, a coexistence problem with an existing Wi-Fi device may not occur. The coexistence problem is a problem caused by transmitting a signal by determining that another device is a channel idle state due to a continuous off symbol. If only OOK modulation is used, for example, the off-symbol may be contiguous with the sequence 100001 or the like, but if Manchester coding is used, the off-symbol cannot be contiguous with the sequence 100101010110.

According to the above description, the sub information may be referred to as a 1.6us information signal. The 1.6us information signal may be a 1.6us on signal or a 1.6 off signal. The 1.6us on signal and the 1.6 off signal may have different sequences applied to each subcarrier.

CP can be used by adopting a specific length from the back of the 1.6us of the information signal immediately after. At this time, CP may be 0.4us or 0.8us. This length is equal to the guard interval of 802.11ac.

Accordingly, one bit information corresponding to one Manchester coded symbol may be represented as shown in the following table.

Table 3 does not indicate CP separately. In fact, CP + 1.6us + CP + 1.6us or CP + 1.6us + 1.6us including CP may indicate one 1-bit information. That is, in the former case, the 1.6us on signal and the 1.6us off signal may be regarded as the (CP + 1.6us) on signal and the (CP + 1.6us) off signal.

As another example, a method of constructing a wake-up packet by repeating symbols for performance improvement is proposed.

The symbol repetition technique is applied to the wakeup payload 724. The symbol repetition technique means repetition of a time signal after insertion of an IFFT and a cyclic prefix (CP) of each symbol. Thus, the length (time) of the wakeup payload 724 is doubled.

That is, it is proposed to apply a symbol representing information such as information 0 or information 1 to a specific sequence and to repeat the configuration as follows.

Option 1: Information 0 and Information 1 may be repeatedly represented by the same symbol.

Info 0-> 0 0 (repeat Info 0 twice)

-Info 1-> 1 1 (repeat Info 1 twice)

Option 2: Information 0 and Information 1 can be repeatedly represented by different symbols.

Information 0-> 0 1 or 1 0 (repeat info 0 and info 1)

Info 1-> 1 0 or 0 1 (repeat Info 1 and Info 0)

Hereinafter, a method of decoding by a receiving apparatus a signal transmitted by applying a symbol repetition technique to the transmitting apparatus will be described.

The transmitted signal may correspond to a wakeup packet, and a method of decoding the wakeup packet can be largely divided into two types. The first is non-coherent detection and the second is coherent detection. In non-coherent detection, the phase relationship between the transmitter and receiver signals is not fixed. Thus, the receiver does not need to measure and adjust the phase of the received signal. In contrast, the coherent detection method requires that the phase of the signal between the transmitter and the receiver be aligned.

The receiver includes the low power wake-up receiver described above. The low power wake-up receiver may decode a packet (wake-up packet) transmitted using an OOK modulation scheme using an envelope detector to reduce power consumption.

The envelope detector measures and decodes the power or magnitude of the received signal. The receiver sets a threshold based on the power or magnitude measured by the envelope detector. When decoding the symbol to which the OOK is applied, it is determined as information 1 if it is greater than or equal to the threshold value, and as information 0 when it is smaller than the threshold value.

The method of decoding a symbol to which the symbol repetition technique is applied is as follows. In the option 1, the receiving apparatus may use the wake-up preamble 722 to calculate a power when symbol 1 (symbol including information 1) is transmitted and determine the threshold.

In detail, the average power of the two symbols may be determined to determine information 1 (1 1) if the value is equal to or greater than the threshold value, and to determine information 0 (0 0) if the value is less than the threshold value.

In addition, in option 2, information may be determined by comparing the power of two symbols without determining a threshold.

Specifically, if information 1 is composed of 0 1 and information 0 is composed of 1 0, it is determined as information 0 if the power of the first symbol is greater than the power of the second symbol. On the contrary, if the power of the first symbol is less than the power of the second symbol, it is determined as information 1.

This is because the order of symbols can be reconstructed by an interleaver. The interleaver may be applied in units of specific symbol numbers below the packet unit.

In addition, not only two symbols but also n can be extended as follows.

11 illustrates an example of a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

1 to 11, the transmission band 1110 may be a wireless channel having a 20 MHz bandwidth. For example, the transmission band 1110 may be a primary 20 MHz channel preset in the WLAN system. The transmission band 1110 of FIG. 11 may include a plurality of subbands 1111 and 1112.

The first subband 1111 may be formed based on N1 (eg, 13) subcarriers of the 64 subcarriers.

For example, the first subband 1111 may be formed based on a contiguous N1 (eg, 13) first subcarrier set among the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9. Can be.

The second subband 1112 may be formed based on 13 subcarriers that do not overlap with the first subband 1111 among the 64 subcarriers.

For example, the second subband 1112 may be formed based on a contiguous N2 (eg, 13) second subcarrier set among the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9. Can be.

According to the present specification, an M sequence determined based on an L-STF sequence may be applied to a plurality of subbands included in a transmission band. For example, the L-STF sequence may be as shown in Table 4 below.

According to Table 4 above, the coefficient of the L-STF sequence may be inserted in units of four spaces. Coefficients of the L-STF sequence of Table 4 may be represented by an M sequence consisting of 13 coefficients as shown in Table 5 below, including DC.

In addition, the M sequence of Table 5 may be expressed as shown in Table 6 below in a binary format.

Hereinafter, through FIG. 11 to FIG. 14, on the basis of the M sequence obtained by the transmitting terminal through the coefficient of the L-STF sequence or the M sequence in binary format, the on-line of the plurality of subbands for the multi-user is multiplied. The procedure for generating an ON-signal is described. In addition, an embodiment in which a phase rotation value is applied to each of a plurality of subbands of a plurality of user terminals so as to be advantageous in terms of PAPR is described.

64 subcarriers for the transmission band 1110 of FIG. 11 may be defined. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

In the first case, 64 subcarriers may be represented by five subcarrier sets, such as [13, 13, 13, 13, 12].

For example, '13' of the first position of [ 13 , 13, 13, 13, and 12] is a constant frequency interval to the right with respect to the first left subcarrier located in the frequency domain graph 920 of FIG. 9. 13 subcarriers (that is, the first subcarrier to the thirteenth subcarrier) positioned every (ie, 312.5k).

For example, '13' of the second position of [13, 13 , 13, 13, 12] is a certain frequency interval (ie, 312.5) to the right with respect to the fourteenth subcarrier in the frequency domain graph 920 of FIG. 13 subcarriers (that is, the 14th to 26th subcarriers) which are positioned for each k).

For example, '13' of the third position of [13, 13, 13 , 13, 12] is a certain frequency interval (ie, 312.5) to the right with respect to the 27th subcarrier in the frequency domain graph 920 of FIG. 13 subcarriers (that is, the 27th subcarrier to the 39th subcarrier) which are positioned for each k).

For example, '13' of the fourth position of [13, 13, 13, 13 , 12] is a certain frequency interval (ie, 312.5) to the right of the 40th subcarrier in the frequency domain graph 920 of FIG. 9. 13 subcarriers (ie, 40 th subcarrier to 52 th subcarrier) which are positioned every k).

For example, '12' of the fifth position of [13, 13, 13, 13, 12 ] is a certain frequency interval (ie, 312.5) to the right in reference to the 53 th subcarrier in the frequency domain graph 920 of FIG. 12 subcarriers (that is, the 53rd subcarrier to the 64th subcarrier) positioned every k).

[13, 13, 13, 13, 12], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,13), a1 * M, zeros (1,13), a2 * M, zeros (1, 12)} may apply.

For example, thirteen subcarriers (ie, first subcarrier to thirteenth subcarrier) at a first position may be nulled according to zeros (1,13). For example, a sequence according to a1 * M may be applied to thirteen subcarriers (ie, fourteenth to 26th subcarriers) of the second position.

For example, thirteen subcarriers (ie, 27 th subcarrier to 39 th subcarrier) at the third position may be nulled according to zeros (1,13). For example, a sequence according to a2 * M may be applied to 13 subcarriers (that is, the 40th to 52nd subcarriers) of the fourth position.

For example, twelve subcarriers (ie, 53rd subcarrier to 64th subcarrier) at the fifth position may be nulled according to zeros (1,12).

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 4.6817.

In the second case, 64 subcarriers may be represented by a set of seven subcarriers, such as [4, 10, 13, 11, 13, 10, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

For example, '4' of the first position of [ 4, 10, 13, 11, 13, 10, 3] is right with respect to the first subcarrier located on the leftmost side in the frequency domain graph 920 of FIG. That is, four subcarriers (ie, first subcarrier to fourth subcarrier) positioned at predetermined frequency intervals (ie, 312.5k) may be referred to. The leftmost four subcarriers (ie, the first subcarrier to the fourth subcarrier) may be defined as guard tones.

For example, '10' of the second position of [4, 10 , 13, 11, 13, 10, 3] is a constant frequency interval to the right with respect to the fifth subcarrier in the frequency domain graph 920 of FIG. 10 subcarriers (that is, the fifth subcarrier to the fourteenth subcarrier) positioned every (ie, 312.5k).

For example, '13' of the third position of [4, 10, 13 , 11, 13, 10, 3] is a predetermined frequency interval to the right with respect to the fifteenth subcarrier in the frequency domain graph 920 of FIG. 9. 13 subcarriers (that is, the 15th subcarrier to the 27th subcarrier) positioned every (ie, 312.5k).

For example, '11' at the fourth position of [4, 10, 13, 11 , 13, 10, 3] is a constant frequency interval to the right of the 28th subcarrier in the frequency domain graph 920 of FIG. 9. 11 subcarriers (that is, the 28th subcarrier to the 38th subcarrier) which are positioned every (ie, 312.5k).

For example, '13' at the fifth position of [4, 10, 13, 11, 13 , 10, 3] is a predetermined frequency interval to the right of the 39th subcarrier in the frequency domain graph 920 of FIG. 13 subcarriers (that is, the 39th subcarrier to the 51st subcarrier) positioned every (ie, 312.5k).

For example, '10' at the sixth position of [4, 10, 13, 11, 13, 10 , 3] is a predetermined frequency interval to the right with respect to the 52nd subcarrier in the frequency domain graph 920 of FIG. 10 subcarriers (that is, the 52nd subcarrier to the 61st subcarrier) positioned every (ie, 312.5k).

For example, '3' in the seventh position of [4, 10, 13, 11, 13, 10, 3 ] is a constant frequency interval to the right with respect to the 62nd subcarrier in the frequency domain graph 920 of FIG. It may mean three subcarriers (that is, the 62nd subcarrier to the 64th subcarrier) positioned every (ie, 312.5k). The three leftmost subcarriers (ie, the 62nd subcarrier to the 64th subcarrier) may be defined as guard tones.

[4, 10, 13, 11, 13, 10, 3], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,14), a1 * M, zeros (1,11), a2 * M, zeros (1,13)} may be applied.

For example, fourteen subcarriers (ie, first subcarrier to fourteenth subcarrier) of the first position and the second position may be nulled according to zeros (1,14).

For example, a sequence according to a1 * M may be applied to thirteen subcarriers (that is, the fifteenth subcarrier to the twenty seventh subcarrier) of the third position.

For example, eleven subcarriers (ie, twenty-eighth subcarriers to thirty-eight subcarriers) at a fourth position may be nulled according to zeros (1,11).

 For example, a sequence according to a2 * M may be applied to thirteen subcarriers (that is, the 39th subcarrier to the 51st subcarrier) at the fifth position.

For example, thirteen subcarriers (ie, 52nd subcarrier to 64th subcarrier) at the sixth and seventh positions may be nulled according to zeros (1,13).

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 5.0997.

In a third case, 64 subcarriers may be represented by a set of five subcarriers, such as [4, 13, 31, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 13, 31, 13, 3], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,4), a1 * M, zeros (1,31), a2 * M, zeros (1, 3)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, 1), (-1, -1), (j, j) or (-j, -j). In this case, the PAPR value may be 4.8873.

In a fourth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 9, 13, 9, 13, 9, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 9, 13, 9, 13, 9, 5], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,15), a1 * M, zeros (1,9), a2 * M, zeros (1,14)} may be applied.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 4.9021.

In a fifth case, 64 subcarriers may be represented by five subcarrier sets, such as [6, 13, 27, 13, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 27, 13, 5], which corresponds to 64 subcarriers, has a predetermined sequence of {zeros (1,6), a1 * M, zeros (1,27), a2 * M, zeros (1, 5)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 5.0997.

In a sixth case, 64 subcarriers may be represented by five subcarrier sets, such as [13, 13, 12, 13, 13]. [13, 13, 12, 13, 13] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,13), a1 * M, zeros (1,12), a2 * M, zeros (1, 13)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -j), (-1, j), (j, 1) or (-j, -1). In this case, the PAPR value may be 4.9940.

In a seventh case, 64 subcarriers may be represented by five subcarrier sets, such as [12, 13, 13, 13, 13]. [12, 13, 13, 13, 13] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,12), a1 * M, zeros (1,13), a2 * M, zeros (1, 13)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 4.6817.

In an eighth case, 64 subcarriers may be represented by a set of five subcarriers, such as [10, 13, 19, 13, 9]. [10, 13, 19, 13, 9], which corresponds to 64 subcarriers, has a predetermined sequence of {zeros (1,10), a1 * M, zeros (1,19), a2 * M, zeros (1, 9)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, 1), (-1, -1), (j, j) or (-j, -j). In this case, the PAPR value may be 5.0997.

In a ninth case, 64 subcarriers may be represented by five subcarrier sets, such as [12, 13, 15, 13, 11]. [12, 13, 15, 13, 11] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,12), a1 * M, zeros (1,15), a2 * M, zeros (1, 11)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1), (-1, 1), (j, -j) or (-j, j). In this case, the PAPR value may be 4.9714.

In a tenth case, 64 subcarriers may be represented by five subcarrier sets, such as [11, 13, 17, 13, 10]. [11, 13, 17, 13, 10] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,11), a1 * M, zeros (1,17), a2 * M, zeros (1, 10)} may apply.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, 1), (-1, -1), (j, j) or (-j, -j). In this case, the PAPR value may be 4.7435.

When there are two subbands as shown in FIG. 11, it may be most preferable to apply the sequence of the first case from the viewpoint of PAPR.

12 is another example illustrating a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

11 and 12, the transmission band 1210 may be a wireless channel having a 20 MHz bandwidth. For example, the transmission band 1210 may be a primary 20 MHz channel preset in the WLAN system. The transmission band 1210 of FIG. 12 may include a plurality of subbands 1211, 1212, and 1213.

The first subband 1211 may be formed based on N1 (eg, 13) subcarriers of the 64 subcarriers.

For example, the first subband 1211 may be formed based on a contiguous N1 (eg, 13) first subcarrier set among the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9. Can be.

The second subband 1212 may be formed based on 13 subcarriers that do not overlap the first subband 1211 among the 64 subcarriers.

For example, the second subband 1212 may include N2 (eg, 13) consecutive sub-seconds of the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9 that do not overlap with the first subcarrier set. It can be formed based on a carrier set.

The third subband 1213 may be formed based on 13 subcarriers that do not overlap the first subband 1211 and the second subband 1212 of the 64 subcarriers.

For example, the third subband 1213 may include N3 consecutive consecutive N3s (eg, 13) that do not overlap the first subcarrier set and the second subcarrier set among the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9. Can be formed based on a third set of subcarriers.

64 subcarriers for the transmission band 1210 of FIG. 12 may be defined. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

In a first case, 64 subcarriers may be represented by a set of seven subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), a1 * M, zeros (1,6), a2 * M, zeros (1,6), a3 * M, zeros (1,6)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -1, -1), (-1,1,1), (j, -j, -j) or (-j, j, j) have. In this case, the PAPR value may be 3.9356.

In the second case, 64 subcarriers may be represented by 9 subcarrier sets, such as [4, 5, 13, 4, 13, 4, 13, 5, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

For [4, 5, 13, 4, 13, 4, 13, 5, 3] corresponding to 64 subcarriers, the predetermined sequence {zeros (1,9), a1 * M, zeros (1,4), a2 * M, zeros (1,4), a3 * M, zeros (1,8)} may be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -j, 1), (-1, j, -1), (j, 1, j) or (-j, -1, -j) have. In this case, the PAPR value may be 4.1579.

In a third case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [4, 4, 13, 5, 13, 5, 13, 4, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 4, 13, 5, 13, 5, 13, 4, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,8), a1 * M, zeros (1,5), a2 * M, zeros (1,5), a3 * M, zeros (1,7)} may be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, -1), (-1, -1,1), (j, j, -j) or (-j, -j, j) have. In this case, the PAPR value may be 4.2103.

In a fourth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [4, 13, 9, 13, 9, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 13, 9, 13, 9, 13, 3], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,4), a1 * M, zeros (1,9), a2 * M, zeros (1,9), a3 * M, zeros (1,3)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -j, 1), (-1, j, -1), (j, 1, j) or (-j, -1, -j) have. In this case, the PAPR value may be 4.1146.

In a fifth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [6, 3, 13, 4, 13, 4, 13, 3, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 3, 13, 4, 13, 4, 13, 3, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,9), a1 * M, zeros (1,4), a2 * M, zeros (1,4), a3 * M, zeros (1,8)} may be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -j, 1), (-1, j, -1), (j, 1, j) or (-j, -1, -j) have. In this case, the PAPR value may be 4.1579.

In a sixth case, 64 subcarriers may be represented by 9 subcarrier sets, such as [6, 4, 13, 3, 13, 3, 13, 4, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 4, 13, 3, 13, 3, 13, 4, 5], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,10), a1 * M, zeros (1,3), a2 * M, zeros (1,3), a3 * M, zeros (1,9)} may be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, j, 1), (-1, -j, -1), (j, -1, j) or (-j, 1, -j) have. In this case, the PAPR value may be 4.3079.

In a seventh case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 7, 13, 7, 13, and 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 7, 13, 7, 13, 5], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,6), a1 * M, zeros (1,7), a2 * M, zeros (1,7), a3 * M, zeros (1,5)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, -1), (-1, -1,1), (j, j, -j) or (-j, -j, j) have. In this case, the PAPR value may be 4.3079.

In the eighth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 7, 13, 6, 13, 6]. [6, 13, 7, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,6), a1 * M, zeros (1,7), a2 * M, zeros (1,6), a3 * M, zeros (1,6)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, -1), (-1, -1,1), (j, j, -j) or (-j, -j, j) have. In this case, the PAPR value may be 5.8242.

In a ninth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 6, 13, 7, 13, and 6]. [6, 13, 6, 13, 7, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,6), a1 * M, zeros (1,6), a2 * M, zeros (1,7), a3 * M, zeros (1,6)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -1, -1) or (-1,1,1) or (j, -j, -j) or (-j, j, j) have. In this case, the PAPR value may be 5.8242.

In a tenth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 6, 13, 6, 13, and 7]. [6, 13, 6, 13, 6, 13, 7], corresponding to 64 subcarriers, has a predetermined sequence {zeros (1,6) a1 * M zeros (1,6) a2 * M zeros (1, 6) a3 * M zeros (1,7)} can be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, -1), (-1, -1,1), (j, j, -j) or (-j, -j, j) have. In this case, the PAPR value may be 3.9356.

In the eleventh case, 64 subcarriers may be represented by a set of seven subcarriers, such as [5, 13, 8, 13, 8, 13, 4]. [5, 13, 8, 13, 8, 13, 4], which corresponds to 64 subcarriers, has a predetermined {zeros (1,5), a1 * M, zeros (1,8), a2 * M, zeros ( 1,8), a3 * M, zeros (1,4)} may be applied.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, -j, 1), (-1, j, -1), (j, 1, j) or (-j, -1, -j) have. In this case, the PAPR value may be 4.1878.

When there are three subbands as shown in FIG. 12, it may be most preferable to apply the sequence of the first case from the viewpoint of PAPR.

FIG. 13 is another example illustrating a plurality of subbands to which an MU WUP is transmitted in a WLAN system according to the present embodiment.

11 to 13, the transmission band 1310 may be a wireless channel having a 20 MHz bandwidth. For example, the transmission band 1310 may be a primary 20MHz channel preset in the WLAN system. The transmission band 1310 of FIG. 13 may include a plurality of subbands 1311, 1312, 1313, and 1314.

The first subband 1311 may be formed based on N1 (eg, 13) subcarriers of the 64 subcarriers.

For example, the first subband 1311 may be formed based on a contiguous N1 (eg, 13) first subcarrier set among 64 subcarriers shown in the frequency domain graph 920 of FIG. 9. Can be.

The second subband 1312 may be formed based on 13 subcarriers that do not overlap the first subband 1311 of the 64 subcarriers.

For example, the second subband 1312 may include N2 (eg, 13) consecutive sub-seconds of the 64 subcarriers shown in the frequency domain graph 920 of FIG. 9 that do not overlap with the first subcarrier set. It can be formed based on a carrier set.

The third subband 1313 may be formed based on 13 subcarriers that do not overlap the first subband 1311 and the second subband 1312 of the 64 subcarriers.

For example, the third subband 1313 may include N3 consecutive consecutive non-overlapping (eg, 13) of the 64 subcarriers illustrated in the frequency domain graph 920 of FIG. 9 without overlapping with the first and second subcarrier sets. Can be formed based on a third set of subcarriers.

The fourth subband 1314 may be formed based on 13 subcarriers that do not overlap the first subband 1311 to the third subband 1313 among the 64 subcarriers.

For example, the fourth subband 1314 may include N3 consecutive consecutive non-overlapping N3s (eg, 13) among the 64 subcarriers illustrated in the frequency domain graph 920 of FIG. 9. Can be formed based on a third set of subcarriers.

64 subcarriers for the transmission band 1310 of FIG. 13 may be defined. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

In a first case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), a1 * M, zeros (1,2), a2 * M, zeros (1,3), a3 * M, zeros (1,2), a4 * M, zeros (1,2)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, j, -j, -1), (-1, -j, j, 1), (j, -1,1, -j) or ( -j, 1, -1, j). In this case, the PAPR value may be 4.2658.

In the second case, 64 subcarriers may be represented by 11 subcarrier sets, such as [4, 1, 13, 1, 13, 1, 13, 1, 13, 1, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 1, 13, 1, 13, 1, 13, 1, 13, 1, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,5), a1 * M zeros (1, 1), a2 * M zeros (1,1), a3 * M, zeros (1,1), a4 * M, zeros (1,4)}.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, -1,1,1), (-1,1, -1, -1), (j, -j, j, j) or (- j, j, -j, -j). In this case, the PAPR value may be 4.4120.

In a third case, 64 subcarriers may be represented by a set of nine subcarriers, such as [4, 13, 2, 13, 1, 13, 2, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

For [4, 13, 2, 13, 1, 13, 2, 13, 3] corresponding to 64 subcarriers, the predetermined sequence {zeros (1,4), a1 * M, zeros (1,2), a2 * M, zeros (1,1), a3 * M, zeros (1,2), a4 * M, zeros (1,3)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, j, -j, -1), (-1, -j, j, 1), (j, -1,1, -j) or ( -j, 1, -1, j). In this case, the PAPR value may be 4.4033.

In a fourth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 13, 1, 13, 13, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 13, 1, 13, 13, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), a1 * M, a2 * M, zeros (1,1), a3 * M, a4 * M, zeros (1,5)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1,1,1, -1), (-1, -1, -1,1), (j, j, j, -j) or (- j, -j, -j, j). In this case, the PAPR value may be 4.2100.

In a fifth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [3, 13, 2, 13, 2, 13, 2, 13, 3]. [3, 13, 2, 13, 2, 13, 2, 13, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), a1 * M, zeros (1,2), a2 * M, zeros (1,2), a3 * M, zeros (1,2), a4 * M, zeros (1,3)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, j, -1, j), (-1, -j, 1, -j), (j, -1, -j, -1) or (-j, 1, j, 1). In this case, the PAPR value may be 4.5828.

In a sixth case, 64 subcarriers may be represented by 9 subcarrier sets, such as [2, 13, 3, 13, 2, 13, 3, 13, 2]. [2, 13, 3, 13, 2, 13, 3, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,2), a1 * M, zeros (1,3), a2 * M, zeros (1,2), a3 * M, zeros (1,3), a4 * M, zeros (1,2)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, j, -j, -1), (-1, -j, j, 1), (j, -1,1, -j) or ( -j, 1, -1, j). In this case, the PAPR value may be 4.6808.

In a seventh case, 64 subcarriers may be represented by a set of nine subcarriers, such as [2, 13, 2, 13, 3, 13, 2, 13, 3]. [2, 13, 2, 13, 3, 13, 2, 13, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,2), a1 * M, zeros (1,2), a2 * M, zeros (1,3), a3 * M, zeros (1,2), a4 * M, zeros (1,3)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1, j, -j, -1), (-1, -j, j, 1), (j, -1,1, -j) or ( -j, 1, -1, j). In this case, the PAPR value may be 4.2658.

In an eighth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [2, 13, 3, 13, 3, 13, 3, 13, 1]. [2, 13, 3, 13, 3, 13, 3, 13, 1] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,2), a1 * M, zeros (1,3), a2 * M, zeros (1,3), a3 * M, zeros (1,3), a4 * M, zeros (1,1)} may be applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1,1,1, -1), (-1, -1, -1,1), (j, j, j, -j) or (- j, -j, -j, j). In this case, the PAPR value may be 4.3480.

In the case of four subbands as shown in FIG. 13, it may be most preferable to apply the sequence of the first case in terms of PAPR.

Unlike FIG. 11 to FIG. 13, it may be assumed that one single subband (not shown) is included in a transmission band of 20 MHz band.

A single subband may be formed based on N1 (eg, 13) subcarriers of 64 subcarriers.

For example, a single subband may be formed based on a contiguous N1 (eg, 13) subcarrier set among 64 subcarriers illustrated in the frequency domain graph 920 of FIG. 9.

64 subcarriers can be defined for a single subband. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

In a first case for a single subband, 64 subcarriers may be represented by a set of five subcarriers, such as [4, 22, 13, 22, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

A predetermined sequence of {zeros (1,26), a1 * M, zeros (1,25)} may be applied to [4, 22, 13, 22, 3] corresponding to 64 subcarriers.

For example, the phase rotation value a1 may be 1, -1, j or -j. In this case, the PAPR value may be 2.2394.

In a second case for a single subband, 64 subcarriers may be represented by a set of five subcarriers, such as [6, 20, 13, 20, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

A predetermined sequence {zeros (1,26), a1 * M, zeros (1,25)} may be applied to [6, 20, 13, 20, 5] corresponding to 64 subcarriers.

For example, the phase rotation value a1 may be 1, -1, j or -j. In this case, the PAPR value may be 2.2394.

Unlike the assumptions in FIGS. 11-14 described so far, a phase rotation value may not be applied to each of a plurality of subbands for a plurality of user terminals.

If no phase rotation is applied, 64 subcarriers can be defined for the 20 MHz bandwidth transmission band. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

It may be assumed that a single subband is formed in a transmission band having a 20 MHz bandwidth.

In a first case for a single subband, 64 subcarriers may be represented by a set of five subcarriers, such as [4, 22, 13, 22, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

A predetermined sequence of {zeros (1,26), M, zeros (1,25)} may be applied to [4, 22, 13, 22, 3] corresponding to 64 subcarriers. In this case, the PAPR value may be 2.2394.

Even when phase rotation is not applied, it will be understood that M included in the predetermined sequence corresponds to the sequence set forth in Table 4 or Table 5 above.

In a second case for a single subband, 64 subcarriers may be represented by a set of five subcarriers, such as [6, 20, 13, 20, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

A predetermined sequence {zeros (1,26), M, zeros (1,25)} may be applied to [6, 20, 13, 20, 5] corresponding to 64 subcarriers. In this case, the PAPR value may be 2.2394.

In addition, it may be assumed that two subbands are formed in a transmission band having a 20 MHz bandwidth.

In the first case, 64 subcarriers may be represented by a set of seven subcarriers, such as [4, 10, 13, 11, 13, 10, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 10, 13, 11, 13, 10, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,14), M, zeros (1,11), M, zeros (1, 13)} may apply. In this case, the PAPR value may be 5.2066.

In the second case, 64 subcarriers may be represented by a set of five subcarriers, such as [4, 13, 31, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 13, 31, 13, 3] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,4), M, zeros (1,31), M, zeros (1,3)}. Can be applied. In this case, the PAPR value may be 4.8873.

In a third case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 9, 13, 9, 13, 9, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 9, 13, 9, 13, 9, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,15), M, zeros (1,9), M, zeros (1, 14)} may apply. In this case, the PAPR value may be 5.0368.

In a fourth case, 64 subcarriers may be represented by a set of five subcarriers, such as [6, 13, 27, 13, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 27, 13, 5] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,6), M, zeros (1,27), M, zeros (1,5)}. Can be applied. In this case, the PAPR value may be 5.1232.

In a fifth case, 64 subcarriers may be represented by five subcarrier sets, such as [13, 13, 13, 13, 12]. [13, 13, 13, 13, 12] corresponding to 64 subcarriers have a predetermined sequence {zeros (1,13), M, zeros (1,13), M, zeros (1,12)} Can be applied. In this case, the PAPR value may be 5.2077.

In a sixth case, 64 subcarriers may be represented by five subcarrier sets, such as [13, 13, 12, 13, 13]. [13, 13, 12, 13, 13] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,13), M, zeros (1,12), M, zeros (1,13)}. Can be applied. In this case, the PAPR value may be 5.1551.

In a seventh case, 64 subcarriers may be represented by five subcarrier sets, such as [12, 13, 13, 13, 13]. Predetermined sequences {zeros (1,12), M, zeros (1,13), M, zeros (1,13)} can be applied to [12, 13, 13, 13, 13] for 64 subcarriers. have. In this case, the PAPR value may be 5.2077.

In an eighth case, 64 subcarriers may be represented by a set of five subcarriers, such as [10, 13, 19, 13, 9]. Predetermined sequences {zeros (1,10), M, zeros (1,19), M, zeros (1,9)} can be applied to [10, 13, 19, 13, 9] for 64 subcarriers. have. In this case, the PAPR value may be 5.0997.

In a ninth case, 64 subcarriers may be represented by five subcarrier sets, such as [12, 13, 15, 13, 11]. A predetermined sequence {zeros (1,12) M zeros (1,15) M zeros (1,11)} may be applied to [12, 13, 15, 13, 11] for 64 subcarriers. In this case, the PAPR value may be 4.9937.

In a tenth case, 64 subcarriers may be represented by five subcarrier sets, such as [11, 13, 17, 13, 10]. Predetermined sequences {zeros (1,11), M, zeros (1,17), M, zeros (1,10)} can be applied to [11, 13, 17, 13, 10] for 64 subcarriers. have. In this case, the PAPR value may be 4.7435.

In addition, it may be assumed that three subbands are formed in a transmission band having a 20 MHz bandwidth.

In a first case, 64 subcarriers may be represented by 9 subcarrier sets, such as [4, 5, 13, 4, 13, 4, 13, 5, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

For [4, 5, 13, 4, 13, 4, 13, 5, 3] corresponding to 64 subcarriers, the predetermined sequence {zeros (1,9), M, zeros (1,4), M, zeros (1,4), M, zeros (1,8)} may be applied. In this case, the PAPR value may be 6.7455.

In the second case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [4, 4, 13, 5, 13, 5, 13, 4, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 4, 13, 5, 13, 5, 13, 4, 3], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,8), M, zeros (1,5), M, zeros (1,5), M, zeros (1,7)} may be applied. In this case, the PAPR value may be 6.0761.

In a third case, 64 subcarriers may be represented by a set of seven subcarriers, such as [4, 13, 9, 13, 9, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 13, 9, 13, 9, 13, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,4), M, zeros (1,9), M, zeros (1, 9), M, zeros (1,3)} may be applied. In this case, the PAPR value may be 6.6880.

In a fourth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [6, 3, 13, 4, 13, 4, 13, 3, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 3, 13, 4, 13, 4, 13, 3, 5], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,9), M, zeros (1,4), M, zeros (1,4), M, zeros (1,8)} may be applied. In this case, the PAPR value may be 6.7455.

In a fifth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [6, 4, 13, 3, 13, 3, 13, 4, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 4, 13, 3, 13, 3, 13, 4, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,10), M, zeros (1,3), M, zeros (1,3), M, zeros (1,9)} may be applied. In this case, the PAPR value may be 6.8606.

In a sixth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 7, 13, 7, 13, and 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 7, 13, 7, 13, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), M, zeros (1,7), M, zeros (1, 7), M, zeros (1,5)} may be applied. In this case, the PAPR value may be 6.4538.

In a seventh case, 64 subcarriers may be represented by a set of seven subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,7), M, zeros (1,6), M, zeros (1, 6), M, zeros (1,6)} may be applied. In this case, the PAPR value may be 6.9826.

In the eighth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 7, 13, 6, 13, 6]. [6, 13, 7, 13, 6, 13, 6] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), M, zeros (1,7), M, zeros (1, 6), M, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.8242.

In a ninth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 6, 13, 7, 13, and 6]. [6, 13, 6, 13, 7, 13, 6] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), M, zeros (1,6), M, zeros (1, 7), M, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.8242.

In a tenth case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 6, 13, 6, 13, and 7]. [6, 13, 6, 13, 6, 13, 7] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), M, zeros (1,6), M, zeros (1, 6), M, zeros (1,7)} can be applied. In this case, the PAPR value may be 6.9826.

In the eleventh case, 64 subcarriers may be represented by a set of seven subcarriers, such as [5, 13, 8, 13, 8, 13, 4]. [5, 13, 8, 13, 8, 13, 4] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,5), M, zeros (1,8), M, zeros (1, 8), M, zeros (1,4)} may be applied. In this case, the PAPR value may be 6.7493.

In addition, it may be assumed that four subbands are formed in a transmission band having a 20 MHz bandwidth.

In the first case, 64 subcarriers may be represented by 11 subcarrier sets, such as [4, 1, 13, 1, 13, 1, 13, 1, 13, 1, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 1, 13, 1, 13, 1, 13, 1, 13, 1, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,5), M, zeros (1,1) ), M, zeros (1,1), M, zeros (1,1), M, zeros (1,4)} may be applied. In this case, the PAPR value may be 7.9546.

In a second case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [4, 13, 2, 13, 1, 13, 2, 13, 3]. In this case, the leftmost four subcarriers and the rightmost three subcarriers may be defined as guard tones.

[4, 13, 2, 13, 1, 13, 2, 13, 3] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,4), M, zeros (1,2), M, zeros (1,1), M, zeros (1,2), M, zeros (1,3)} may be applied. In this case, the PAPR value may be 7.8126.

In a third case, 64 subcarriers may be represented by a set of seven subcarriers, such as [6, 13, 13, 1, 13, 13, 5]. In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones.

[6, 13, 13, 1, 13, 13, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), M, M, zeros (1,1), M, M, zeros (1,5)} may be applied. In this case, the PAPR value may be 8.1217.

In a fourth case, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers is a predetermined sequence {zeros (1,3), M, zeros (1,2), M, zeros (1,3), M, zeros (1,2), M, zeros (1,2)} may be applied. In this case, the PAPR value may be 7.6078.

In a fifth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [3, 13, 2, 13, 2, 13, 2, 13, 3]. [3, 13, 2, 13, 2, 13, 2, 13, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), M, zeros (1,2), M, zeros (1,2), M, zeros (1,2), M, zeros (1,3)} may be applied. In this case, the PAPR value may be 7.7532.

In a sixth case, 64 subcarriers may be represented by 9 subcarrier sets, such as [2, 13, 3, 13, 2, 13, 3, 13, 2]. [2, 13, 3, 13, 2, 13, 3, 13, 2] corresponding to 64 subcarriers is a predetermined sequence {zeros (1,2), M, zeros (1,3), M, zeros (1,2), M, zeros (1,3), M, zeros (1,2)} may be applied. In this case, the PAPR value may be 7.6834.

In a seventh case, 64 subcarriers may be represented by a set of nine subcarriers, such as [2, 13, 2, 13, 3, 13, 2, 13, 3]. [2, 13, 2, 13, 3, 13, 2, 13, 3] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,2), M, zeros (1,2), M, zeros (1,3), M, zeros (1,2), M, zeros (1,3)} may be applied. In this case, the PAPR value may be 7.6078.

In an eighth case, 64 subcarriers may be represented by a set of 9 subcarriers, such as [2, 13, 3, 13, 3, 13, 3, 13, 1]. [2, 13, 3, 13, 3, 13, 3, 13, 1] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,2), M, zeros (1,3), M, zeros (1,3), M, zeros (1,3), M, zeros (1,1)} may be applied. In this case, the PAPR value may be 8.1100.

It can be understood that the sequence for transmitting the ON-signal is applied to all of the plurality of subbands described with reference to FIGS. 11 and 14 so far. However, it is to be understood that the present disclosure is not limited thereto and may be applicable to a case in which a sequence for an off-singal is applied to some subbands.

Specifically, an example in which only some subbands of the plurality of subbands of the transmission band are used may be as follows. If the phase rotation value is applied for the transmission band and four subbands are included in the transmission band, 64 subcarriers are divided into seven subbands as [6, 13, 13, 1, 13, 13, 5]. It can be expressed as a carrier set.

In this case, the leftmost six subcarriers and the rightmost five subcarriers may be defined as guard tones. In this case, it may be assumed that the subband of the third location is not used for a specific user terminal.

[6, 13, 13, 1, 13, 13, 5] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,6), a1 * M, zeros (1,13), zeros (1, 1), a3 * M, a4 * M, zeros (1,5)} can be applied. That is, 13 subcarriers of the subband of the third position may be nulled by a coefficient of '0'.

For example, the phase rotation value may be defined as a1, a3, and a4 as (a1, a3, a4). For Dl, (a1, a3, a4) can be (1,1, -1), (-1, -1,1), (j, j, -j) or (-j, -j, j) have. In this case, the PAPR value may be 6.7111.

14 is a flowchart illustrating a method of transmitting a packet based on a plurality of subbands in a WLAN system according to the present embodiment.

1 to 14, in step S1410, the transmitting terminal is a multi-user wake-up packet for a plurality of wake-up receiver (WUR) terminals that are multi-users. MU WUP).

In this case, a predetermined sequence may be applied to a transmission band including a plurality of subbands for MU WUP.

In the present specification, the transmission band may be a wireless channel having a 20 MHz bandwidth. 64 subcarriers can be defined for the transmission band. In addition, the frequency spacing between the 64 subcarriers may be 312.5k.

When there are two subbands, 64 subcarriers may be defined as [13, 13, 13, 13, 12]. A predetermined sequence {zeros (1,13), a1 * M, zeros (1,13), a2 * M, zeros (1,12)} may be applied to [13, 13, 13, 13, 12]. .

For example, M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j, 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1 day have. For example, a1 * M may be applied to the first subband allocated for the first WUR terminal. For example, a2 * M may be applied to the second subband allocated for the second WUR terminal. For example, a plurality of subcarriers defined at positions corresponding to zeros (1,13) may be nulled.

For example, a1 and a2 may be coefficients for phase rotation. When a1 and a2 are defined as (a1, a2), (a1, a2) can be (1, -1), (-1, 1), (j, -j) or (-j, j) have.

When there are three subbands, 64 subcarriers may be defined as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6] includes the predetermined sequence {zeros (1,7), a1 * M, zeros (1,6), a2 * M, zeros (1,6) , a3 * M, zeros (1,6)} can be applied.

For example, M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j, 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1 day have. For example, a1 * M may be applied to the first subband allocated for the first WUR terminal. For example, a2 * M may be applied to the second subband allocated for the second WUR terminal.

For example, a3 * M may be applied to the third subband allocated for the third WUR terminal. For example, a plurality of subcarriers defined at zeros (1,7) and positions corresponding to zeros (1,6) may be nulled.

For example, a1, a2 and a3 may be coefficients for phase rotation. When a1, a2 and a3 are defined as (a1, a2, a3), (a1, a2, a3) is (1, -1, -1), (-1, 1, 1), (j, -j , -j) or (-j, j, j).

When there are four subbands, 64 subcarriers may be defined as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] has a predetermined sequence of {zeros (1,3), a1 * M, zeros (1,2), a2 * M, zeros (1 , 3), a3 * M, zeros (1,2), a4 * M zeros (1,2)} may be applied.

For example, M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j, 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1 day have. For example, a1 * M may be applied to the first subband allocated for the first WUR terminal. For example, a2 * M may be applied to the second subband allocated for the second WUR terminal.

For example, a3 * M may be applied to the third subband allocated for the third WUR terminal. For example, a4 * M may be applied to the fourth subband allocated for the fourth WUR terminal. For example, a defined plurality of subcarriers corresponding to zeros (1,3) and zeros (1,2) may be nulled.

For example, a1, a2, a3 and a4 may be coefficients for phase rotation. When a1, a2, a3 and a4 are defined as (a1, a2, a3, a4), (a1, a2, a3, a4) is (1, j, -j, -1), (-1, -j , j, 1), (j, -1, 1, -j), (-j, 1, -1, j).

In operation S1420, the transmitting terminal may transmit the MU WUP to the plurality of WUR terminals based on the plurality of subbands.

Additionally, according to another embodiment of the present specification, an N sequence determined based on a VHT-LTF sequence may be applied to a plurality of subbands included in a transmission band. For example, the VHT-LTF sequence may be expressed as shown in Table 7 below.

LTF left of the VHT-LTF sequence of Table 7 above may be expressed as shown in Table 8.

The LTF right of the VHT-LTF sequence of Table 7 above may be expressed as shown in Table 9 below.

As described above with reference to FIG. 11, 64 subcarriers may be defined for a 20MHz bandwidth transmission band including two subbands. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

As a first case for two subbands, a VHT LTF sequence having the same index may be applied to each subband.

For example, 64 subcarriers may be represented by 5 subcarrier sets, such as [13, 13, 13, 13, 12]. [13, 13, 13, 13, 12] corresponding to 64 subcarriers has a predetermined sequence {zeros (1,13), M1, zeros (1,13), M2, zeros (1,12)} Can be applied. In this case, the PAPR value may be 5.5184.

For example, VHT-LTF (-19: -7) may be applied to M1. In this case, VHT-LTF (-19: -7) may be understood as a set of 10th to 22nd values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (7:19) may be applied to M2. In this case, VHT-LTF (7:19) may be understood as a set of 36th to 48th values of 57 values of Table 7 listed for the VHT LTF sequence.

In a second case for two subbands, phase rotation may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 5 subcarrier sets, such as [13, 13, 13, 13, 12]. [13, 13, 13, 13, 12] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,13), a1 * M1, zeros (1,13), a2 * M2, zeros (1, 12)} may apply. In this case, the PAPR value may be 5.2498.

For example, VHT-LTF (-19: -7) may be applied to M1. In this case, VHT-LTF (-19: -7) may be understood as a set of 10th to 22nd values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (7:19) may be applied to M2. In this case, VHT-LTF (7:19) may be understood as a set of 36th to 48th values of 57 values of Table 7 listed for the VHT LTF sequence.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1) or (-1,1) or (j, -j) or (-j, j).

In a third case for two subbands, DC puncturing may be applied to a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 5 subcarrier sets, such as [13, 13, 13, 13, 12]. Predetermined sequences {zeros (1,13), M1 zeros (1,13), M2, zeros (1,12)} are applied to [13, 13, 13, 13, 12] corresponding to 64 subcarriers. Can be. In this case, the PAPR value may be 5.9121.

For example, VHT-LTF (-19: -7) may be applied to M1. In this case, VHT-LTF (-19: -7) may be understood as a set of 10th to 22nd values among 57 values of Table 7 listed for the VHT LTF sequence. However, for DC puncturing, M1 (7), the seventh value of VHT-LTF (-19: -7), may be set to '0'.

For example, VHT-LTF (7:19) may be applied to M2. In this case, VHT-LTF (7:19) may be understood as a set of 36th to 48th values of 57 values of Table 7 listed for the VHT LTF sequence. However, M2 (7), which is the seventh value of the LTF (7:19), may be set to '0' for DC puncturing.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1) or (-1,1) or (j, -j) or (-j, j).

In a fourth case for two subbands, phase rotation and DC puncturing may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 5 subcarrier sets, such as [13, 13, 13, 13, 12]. [13, 13, 13, 13, 12] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,13), a1 * M1, zeros (1,13), a2 * M1, zeros (1, 12)} may apply. In this case, the PAPR value may be 5.5960.

For example, VHT-LTF (-19: -7) may be applied to M1. In this case, VHT-LTF (-19: -7) may be understood as a set of 10th to 22nd values among 57 values of Table 7 listed for the VHT LTF sequence. However, for DC puncturing, M1 (7), the seventh value of VHT-LTF (-19: -7), may be set to '0'.

For example, VHT-LTF (7:19) may be applied to M2. In this case, VHT-LTF (7:19) may be understood as a set of 36th to 48th values of 57 values of Table 7 listed for the VHT LTF sequence. However, M2 (7), which is the seventh value of the LTF (7:19), may be set to '0' for DC puncturing.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1) or (-1,1) or (j, -j) or (-j, j).

In a fifth case of two subbands, phase rotation may be applied to each subband along with 13 sequences located among the VHT LTF sequences.

For example, 64 subcarriers may be represented by 5 subcarrier sets, such as [13, 13, 13, 13, 12]. [13, 13, 13, 13, 12] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,13), a1 * M1, zeros (1,13), a2 * M1, zeros (1, 12)} may apply. In this case, the PAPR value may be 6.4425.

For example, VHT-LTF (-6: 6) may be applied to M1. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, the phase rotation values a1 and a2 may be defined as (a1, a2). In this case, (a1, a2) may be (1, -1) or (-1,1) or (j, -j) or (-j, j).

As described with reference to FIG. 12, 64 subcarriers may be defined for a 20MHz bandwidth transmission band including three subbands. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

As a first case for three subbands, a VHT LTF sequence having the same index may be applied to each subband.

For example, 64 subcarriers may be represented by a set of 7 subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), M1, zeros (1,6), M2, zeros (1, 6), M3, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.7447.

For example, VHT-LTF (-25: -13) may be applied to M1. In this case, VHT-LTF (-25: -13) may be understood as a set of 4th to 16th values of 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (-6: 6) may be applied to M2. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (13:25) may be applied to M3. In this case, VHT-LTF (13:25) may be understood as a set of 42 th to 54 th values among the 57 values of Table 7 listed for the VHT LTF sequence.

In a second case for three subbands, phase rotation may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by a set of 7 subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), a1 * M1, zeros (1,6), a2 * M2, zeros (1,6), a3 * M3, zeros (1,6)} can be applied. In this case, the PAPR value may be 5.3093.

For example, VHT-LTF (-25: -13) may be applied to M1. In this case, VHT-LTF (-25: -13) may be understood as a set of 4th to 16th values of 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (-6: 6) may be applied to M2. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (13:25) may be applied to M3. In this case, VHT-LTF (13:25) may be understood as a set of 42 th to 54 th values among the 57 values of Table 7 listed for the VHT LTF sequence.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, j) or (-1, -1, -j) or (j, j, -1) or (-j, -j, 1) have.

In a third case for three subbands, DC puncturing may be applied to a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by a set of 7 subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), M1, zeros (1,6), M2, zeros (1, 6), M3, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.7492.

For example, VHT-LTF (-25: -13) may be applied to M1. In this case, VHT-LTF (-25: -13) may be understood as a set of 4th to 16th values of 57 values of Table 7 listed for the VHT LTF sequence. However, for DC puncturing, M1 (7), which is the seventh value of VHT-LTF (-25: -13), may be set to '0'.

For example, VHT-LTF (-6: 6) may be applied to M2. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (13:25) may be applied to M3. In this case, VHT-LTF (13:25) may be understood as a set of 42 th to 54 th values among the 57 values of Table 7 listed for the VHT LTF sequence. However, for the DC puncturing, the seventh value of the VHT-LTF (13:25) M3 (7) may be set to '0'.

In a fourth case for three subbands, phase rotation and DC puncturing may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by a set of 7 subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), a1 * M1, zeros (1,6), a2 * M1, zeros (1,6), a3 * M1, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.5338.

For example, VHT-LTF (-25: -13) may be applied to M1. In this case, VHT-LTF (-25: -13) may be understood as a set of 4th to 16th values of 57 values of Table 7 listed for the VHT LTF sequence. However, for DC puncturing, M1 (7), which is the seventh value of VHT-LTF (-25: -13), may be set to '0'.

For example, VHT-LTF (-6: 6) may be applied to M2. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, VHT-LTF (13:25) may be applied to M3. In this case, VHT-LTF (13:25) may be understood as a set of 42 th to 54 th values among the 57 values of Table 7 listed for the VHT LTF sequence. However, for the DC puncturing, the seventh value of the VHT-LTF (13:25) M3 (7) may be set to '0'.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1,1, j) or (-1, -1, -j) or (j, j, -1) or (-j, -j, 1) have.

In a fifth case of three subbands, phase rotation may be applied to each subband along with 13 sequences located in the middle of the VHT LTF sequence.

For example, 64 subcarriers may be represented by a set of 7 subcarriers, such as [7, 13, 6, 13, 6, 13, 6]. [7, 13, 6, 13, 6, 13, 6], corresponding to 64 subcarriers, has a predetermined sequence of {zeros (1,7), a1 * M1, zeros (1,6), a2 * M1, zeros (1,6), a3 * M1, zeros (1,6)} may be applied. In this case, the PAPR value may be 5.8292.

For example, VHT-LTF (-6: 6) may be applied to M1. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, the phase rotation values a1, a2, and a3 may be defined as (a1, a2, a3). In this case, (a1, a2, a3) can be (1, j, 1) or (-1, -j, -1) or (j, -1, j) or (-j, 1, -j) have.

As described above with reference to FIG. 11, 64 subcarriers may be defined for a 20MHz bandwidth transmission band including 4 subbands. In this case, the frequency spacing between the 64 subcarriers may be 312.5k.

As a first case for four subbands, a VHT LTF sequence having the same index may be applied to each subband.

For example, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), M1, zeros (1,2), M2, zeros (1,3), M3, zeros (1,2), M4, zeros (1,2)} may be applied. In this case, the PAPR value may be 4.1904.

For example, VHT-LTF (-29: -17) may be applied to M1. In this case, VHT-LTF (-29: -17) may be understood as a VHT LTF (-29) to which a coefficient of zero is applied and VHT LTF (-28: -17), which is a subset of Table 7.

For example, VHT LTF (-14: -2) may be applied to M2. For example, VHT LTF (2:14) may be applied to M3.

For example, VHT LTFs 17:29 may be applied to M4. In this case, the VHT-LTF (17:29) can be understood as the VHT LTF (17:28) which is a subset of Table 7 and the VHT LTF 29 to which the coefficient of zero is applied.

In a second case for four subbands, phase rotation may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), a1 * M1, zeros (1,2), a2 * M2, zeros (1,3), a3 * M3, zeros (1,2), a4 * M4, zeros (1,2)}. In this case, the PAPR value may be 4.1904.

For example, VHT-LTF (-29: -17) may be applied to M1. In this case, VHT-LTF (-29: -17) may be understood as a VHT LTF (-29) to which a coefficient of zero is applied and VHT LTF (-28: -17), which is a subset of Table 7.

For example, VHT LTF (-14: -2) may be applied to M2. For example, VHT LTF (2:14) may be applied to M3.

For example, VHT LTFs 17:29 may be applied to M4. In this case, the VHT-LTF (17:29) can be understood as the VHT LTF (17:28) which is a subset of Table 7 and the VHT LTF 29 to which the coefficient of zero is applied.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1,1,1,1) or (-1, -1, -1, -1) or (j, j, j, j) or (-j , -j, -j, -j).

In a third case for four subbands, DC puncturing may be applied to a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3) M1 zeros (1,2) M2 zeros (1, 3) M3 zeros (1,2) M4 zeros (1,2)} can be applied. In this case, the PAPR value may be PAPR = 4.3220.

For example, VHT-LTF (-29: -17) may be applied to M1. In this case, VHT-LTF (-29: -17) may be understood as a VHT LTF (-29) to which a coefficient of zero is applied and VHT LTF (-28: -17), which is a subset of Table 7. However, M1 (7), which is the seventh value of VHT-LTF (-29: -17), may be set to '0' for DC puncturing.

For example, VHT LTF (-14: -2) may be applied to M2. However, M2 (7), which is the seventh value of the VHT LTF (-14: -2), may be set to '0' for DC puncturing.

For example, VHT LTF (2:14) may be applied to M3. However, for the DC puncturing, the seventh value of the VHT LTF (2:14) M3 (7) may be set to '0'.

For example, VHT LTFs 17:29 may be applied to M4. In this case, the VHT-LTF (17:29) can be understood as the VHT LTF (17:28) which is a subset of Table 7 and the VHT LTF 29 to which the coefficient of zero is applied. However, for the DC puncturing, the fourth value M4 (7) of the VHT LTF (17:29) may be set to '0'.

In a fourth case for four subbands, phase rotation and DC puncturing may be applied with a VHT LTF sequence having the same index for each subband.

For example, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), a1 * M1, zeros (1,2), a2 * M1, zeros (1,3), a3 * M1, zeros (1,2), a4 * M1, zeros (1,2)} may be applied. In this case, the PAPR value may be PAPR = 4.3220.

For example, VHT-LTF (-29: -17) may be applied to M1. In this case, VHT-LTF (-29: -17) may be understood as a VHT LTF (-29) to which a coefficient of zero is applied and VHT LTF (-28: -17), which is a subset of Table 7. However, M1 (7), which is the seventh value of VHT-LTF (-29: -17), may be set to '0' for DC puncturing.

For example, VHT LTF (-14: -2) may be applied to M2. However, M2 (7), which is the seventh value of the VHT LTF (-14: -2), may be set to '0' for DC puncturing.

For example, VHT LTF (2:14) may be applied to M3. However, for the DC puncturing, the seventh value of the VHT LTF (2:14) M3 (7) may be set to '0'.

For example, VHT LTFs 17:29 may be applied to M4. In this case, the VHT-LTF (17:29) can be understood as the VHT LTF (17:28) which is a subset of Table 7 and the VHT LTF 29 to which the coefficient of zero is applied. However, for the DC puncturing, the fourth value M4 (7) of the VHT LTF (17:29) may be set to '0'.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1,1,1,1) or (-1, -1, -1, -1) or (j, j, j, j) or (-j , -j, -j, -j).

In a fifth case of four subbands, phase rotation may be applied to each subband together with 13 sequences located in the middle of the VHT LTF sequence.

For example, 64 subcarriers may be represented by 9 subcarrier sets, such as [3, 13, 2, 13, 3, 13, 2, 13, 2]. [3, 13, 2, 13, 3, 13, 2, 13, 2] corresponding to 64 subcarriers has a predetermined sequence of {zeros (1,3), a1 * M1, zeros (1,2), a2 * M1, zeros (1,3), a3 * M1, zeros (1,2), a4 * M1, zeros (1,2)} may be applied. In this case, the PAPR value may be PAPR = 5.2288.

For example, VHT-LTF (-6: 6) may be applied to M1. In this case, VHT-LTF (-6: 6) may be understood as a set of 23rd to 35th values among 57 values of Table 7 listed for the VHT LTF sequence.

For example, the phase rotation values a1, a2, a3, and a4 may be defined as (a1, a2, a3, a4). In this case, (a1, a2, a3, a4) is (1,1,1, -1) or (-1, -1, -1,1) or (j, j, j, -j) or (- j, -j, -j, j).

15 is a block diagram illustrating a wireless device to which the present embodiment can be applied.

Referring to FIG. 15, a wireless device as an STA capable of implementing the above-described embodiment may operate as an AP or a non-AP STA. In addition, the wireless device may correspond to the above-described user, or may correspond to a transmitting terminal for transmitting a signal to the user.

The wireless device of FIG. 15 includes a processor 1510, a memory 1520, and a transceiver 1530 as shown. The illustrated processor 1510, memory 1520, and transceiver 1530 may be implemented as separate chips, or at least two blocks / functions may be implemented through one chip.

The transceiver 1530 is a device including a transmitter and a receiver. When a specific operation is performed, only one of the transmitter and the receiver may be performed, or both the transmitter and the receiver may be performed. have. The transceiver 1530 may include one or more antennas for transmitting and / or receiving wireless signals. In addition, the transceiver 1530 may include an amplifier for amplifying the reception signal and / or the transmission signal and a bandpass filter for transmission on a specific frequency band.

The processor 1510 may implement the functions, processes, and / or methods proposed herein. For example, the processor 1510 may perform an operation according to the above-described embodiment. That is, the processor 1510 may perform the operations disclosed in the embodiments of FIGS. 1 to 14.

The processor 1510 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a data processing device, and / or a converter for translating baseband signals and wireless signals. Memory 1520 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices.

16 is a block diagram illustrating an example of an apparatus included in a processor. For convenience of description, an example of FIG. 16 is described with reference to a block for a transmission signal, but it is obvious that the reception signal can be processed using the block.

The illustrated data processor 1610 generates transmission data (control data and / or user data) corresponding to the transmission signal. The output of the data processor 1610 may be input to the encoder 1620. The encoder 1620 may perform coding through a binary convolutional code (BCC) or a low-density parity-check (LDPC) technique. At least one encoder 1320 may be included, and the number of encoders 1620 may be determined according to various information (eg, the number of data streams).

The output of the encoder 1620 may be input to the interleaver 1630. The interleaver 1630 performs an operation of distributing consecutive bit signals over radio resources (eg, time and / or frequency) to prevent burst errors due to fading or the like. At least one interleaver 1630 may be included, and the number of the interleaver 1630 may be determined according to various information (eg, the number of spatial streams).

The output of the interleaver 1630 may be input to a constellation mapper 1640. The constellation mapper 1640 performs constellation mapping such as biphase shift keying (BPSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (n-QAM), and the like.

The output of the constellation mapper 1640 may be input to the spatial stream encoder 1650. Spatial stream encoder 1650 performs data processing to transmit the transmitted signal over at least one spatial stream. For example, the spatial stream encoder 1650 may perform at least one of space-time block coding (STBC), cyclic shift diversity (CSD) insertion, and spatial mapping on a transmission signal.

The output of the spatial stream encoder 1650 may be input to an IDFT 1660 block. The IDFT 1660 block performs an inverse discrete Fourier transform (IDFT) or an inverse Fast Fourier transform (IFFT).

The output of the IDFT 1660 block is input to the Guard Interval (GI) inserter 1670, and the output of the GI inserter 1670 is input to the transceiver 1530 of FIG. 15.

In the detailed description of the present specification, specific embodiments have been described, but various modifications are possible without departing from the scope of the present specification. Therefore, the scope of the present specification should not be limited to the above-described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims of the present invention.

Claims (13)

1. In the method for transmitting a packet in a WLAN system,

   The transmitting terminal generates a multi-user wake-up packet (MU WUP) for a plurality of wake-up receiver (WUR) terminals that are multi-users, and a predetermined sequence is used for the MU Applied to a transmission band comprising a plurality of subbands for WUP; And

   Transmitting, by the transmitting terminal, the MU WUP to the plurality of WUR terminals based on the plurality of subbands.
2. According to claim 1,

   The transmission band is a wireless channel of 20MHz bandwidth,

   64 subcarriers for the transmission band are defined,

   Frequency spacing between the 64 subcarriers is 312.5k.
3. The method of claim 2,

   When the plurality of subbands is two, the 64 subcarriers are defined as [13, 13, 13, 13, 12],

   The predetermined sequence {zeros (1,13), a1 * M, zeros (1,13), a2 * M, zeros (1,12)} is applied to [13, 13, 13, 13, 12]. How to be.
4. The method of claim 3, wherein

   M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j , 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1,

   The a1 * M is applied to the first subband allocated for the first WUR terminal,

   The a2 * M is applied to a second subband allocated for a second WUR terminal,

   And a plurality of subcarriers defined at positions corresponding to the zeros (1, 13) are nulled.
5. The method of claim 3, wherein

   A1 and a2 are coefficients for phase rotation,

   When a1 and a2 are defined as (a1, a2), (a1, a2) is (1, -1), (-1, 1), (j, -j) or (-j, j) How to be.
6. The method of claim 2,

   When the plurality of subbands is three, the 64 subcarriers are defined as [7, 13, 6, 13, 6, 13, 6],

   [7, 13, 6, 13, 6, 13, 6] has the predetermined sequence {zeros (1,7), a1 * M, zeros (1,6), a2 * M, zeros (1,6) ), a3 * M, zeros (1,6)}.
7. The method of claim 6,

   M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j , 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1,

   The a1 * M is applied to the first subband allocated for the first WUR terminal,

   The a2 * M is applied to a second subband allocated for a second WUR terminal,

   The a3 * M is applied to a third subband allocated for a third WUR terminal,

   And a plurality of subcarriers defined at positions corresponding to the zeros (1, 7) and the zeros (1, 6).
8. The method of claim 6,

   A1, a2 and a3 are coefficients for phase rotation,

   When a1, a2 and a3 are defined as (a1, a2, a3), (a1, a2, a3) is (1, -1, -1), (-1, 1, 1), ( j, -j, -j) or (-j, j, j).
9. The method of claim 2,

   When the plurality of subbands is four, the 64 subcarriers are defined as [3, 13, 2, 13, 3, 13, 2, 13, 2],

   [3, 13, 2, 13, 3, 13, 2, 13, 2] includes the predetermined sequence {zeros (1,3), a1 * M, zeros (1,2), a2 * M, zeros (1,3), a3 * M, zeros (1,2), a4 * M zeros (1,2)}.
10. The method of claim 9,

    M is (1 + j, -1-j, 1 + j, -1-j, -1-j, 1 + j, 0, -1-j, -1-j, 1 + j, 1 + j , 1 + j, 1 + j) / sqrt (2) or 1, -1, 1, -1, -1, 1, 0, -1, -1, 1, 1, 1, 1,

    The a1 * M is applied to the first subband allocated for the first WUR terminal,

    The a2 * M is applied to a second subband allocated for a second WUR terminal,

    The a3 * M is applied to a third subband allocated for a third WUR terminal,

    The a4 * M is applied to a fourth subband allocated for a fourth WUR terminal,

    And a defined plurality of subcarriers corresponding to the zeros (1, 3) and the zeros (1, 2) are nulled.
11. The method of claim 9,

    A1, a2, a3 and a4 are coefficients for phase rotation,

    When a1, a2, a3 and a4 are defined as (a1, a2, a3, a4), (a1, a2, a3, a4) is (1, j, -j, -1), ( -1, -j, j, 1), (j, -1, 1, -j) or (-j, 1, -1, j).
12. According to claim 1,

    Each of the plurality of WUR terminals includes a main radio module and a wake-up receiver (WUR) module.

    The MU WUP includes information for entering the activated state of the plurality of main radio modules included in the plurality of WUR terminals.
13. In the transmitting terminal for transmitting a packet for a plurality of WUR (Wake-Up Receiver) terminal that is a multi-user in a WLAN system,

    A transceiver for transmitting or receiving a wireless signal; And

    A processor for controlling the transceiver, wherein the processor,

    A multi-user wake-up packet (MU WUP) is generated for a plurality of wake-up receiver (WUR) terminals that are multi-users, and a predetermined sequence is used to generate the MU WUP. Applied to a transmission band including a plurality of subbands for

    And the transmitting terminal is configured to transmit the MU WUP to the plurality of WUR terminals based on the plurality of subbands.

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