WO2019093811A1 - Method and device for transmitting wake-up packet in wireless lan system - Google Patents

Abstract

A method and a device for transmitting a wake-up packet by applying an OOK scheme to a wireless LAN system are presented. Specifically, a transmission device configures a wake-up packet having a first data rate, and transmits the wake-up packet to a reception device. The wake-up packet includes first information and second information. The first information is set in the order of a first ON signal, an OFF signal, a first ON signal, and an OFF signal. The second information is set in the order of an OFF signal, a first ON signal, an OFF signal, and a first ON signal. The first ON signal is generated by applying a first sequence to 13 continuous subcarriers in a 20 MHz band and performing 64-point IFFT. A part of the first ON signal is set as a partial ON signal, and the remaining part of the first ON signal is set as an OFF signal. The partial ON signal is set as a second ON signal included in a wake-up packet having a second data rate.

Description

Method and apparatus for transmitting a wakeup packet in a wireless LAN system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for performing low-power communication in a wireless LAN system, and more particularly, to a method and apparatus for transmitting a wakeup packet by applying an OOK scheme in a wireless LAN system.

Discussions are under way for the next generation wireless local area network (WLAN). In the next generation WLAN, 1) enhancement of IEEE 802.11 PHY (physical) layer and MAC (medium access control) layer in the 2.4GHz and 5GHz bands, 2) improvement of spectrum efficiency and area throughput throughput, and 3) to improve performance in real indoor and outdoor environments, such as environments where interference sources exist, dense heterogeneous networks, and environments with high user loads.

The environment that is considered mainly in the next generation WLAN is a dense environment with AP (access point) and STA (station), and improvement in spectrum efficiency and area throughput is discussed in this dense environment. In addition, the next generation WLAN is concerned not only with the indoor environment but also with the actual performance improvement in the outdoor environment which is not considered much in the existing WLAN.

Specifically, the next-generation WLAN is interested in scenarios such as wireless office, smart home, stadium, hotspot, and building / apartment, And STA in a dense environment.

In addition, in the next generation WLAN, improvement of system performance in an overlapping basic service set (OBSS) environment, improvement of outdoor environment performance, and cellular offloading will be actively discussed rather than improvement of single link performance in one basic service set (BSS) It is expected. The directionality of this next generation WLAN means that the next generation WLAN will have a technology range similar to that of mobile communication. Considering the recent discussions of mobile communication and WLAN technology in the area of small cell and D2D (direct-to-direct) communication, it is expected that the technological and business convergence of next generation WLAN and mobile communication will become more active.

The present invention proposes a method and apparatus for transmitting a wakeup packet by applying the OOK scheme in a wireless LAN system.

One example of the present disclosure proposes a method and apparatus for transmitting a wakeup packet to a WLAN system.

The present embodiment can be operated in the transmitting apparatus, the receiving apparatus can correspond to the low power wake up receiver, and the transmitting apparatus can correspond to the AP.

In summary, the on signal can correspond to a signal having an actual power value. An off signal may correspond to a signal that does not have an actual power value. The first information may correspond to information 0. The second information may correspond to information 1.

The transmitting apparatus constitutes a wakeup packet having a first data rate.

The transmitting apparatus transmits the wakeup packet to the receiving apparatus.

The configuration of the wakeup packet having the first data rate is as follows.

The wakeup packet includes an on-off keying (OOK) scheme and includes first information and second information. The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal. The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal.

The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform).

For example, coefficients may be inserted into all of the 13 subcarriers. At this time, the generated signal may be a signal having a length of 3.2 us having no period. A CP (Cyclic Prefix) may be inserted into the generated signal to generate an on signal or an off signal having a length of 4 us. The coefficient may be selected from 1, -1, j or -j.

As another example, coefficients may be inserted into the 13 subcarriers in units of two subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of two spaces, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 1.6 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. Here, the masking may correspond to a technique of covering a part of a signal and taking only a part of the signal. That is, a part of the generated signal can be taken to generate an on signal or an off signal having a length of 2us (CP + 1.6us).

As another example, a coefficient may be inserted into the 13 subcarriers in units of 4 subcarriers, and 0 may be inserted into the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of four cells, and the remainder may be set to zero. At this time, the generated signal may be a 3.2us signal having a period of 0.8us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal can be taken to generate an ON signal or an OFF signal having a length of 1us (CP + 0.8us).

As another example, a coefficient may be inserted into the 13 subcarriers in units of 8 subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of 8 squares, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 0.4 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal may be taken to generate an ON signal or an OFF signal having a length of 0.5us (CP + 0.4us).

The off signal may be generated by inserting zeros into 13 contiguous subcarriers of the 20 MHz band and performing 64-point IFFT. The off signal may also be masked to have a length of 2us, 1us, or 0.5us (CP + 1.6us, CP + 0.8us, CP + 0.4us).

However, this embodiment describes only a case where coefficients are inserted into all of the 13 subcarriers. That is, the first ON signal may be an ON signal having a length of 4 us, which is a CP inserted into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Accordingly, the length of the first ON signal may be 4us.

A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal. That is, a partial OOK technique may be used in which an ON signal (partial ON signal) is set only in a part of the ON signal (first ON signal) to improve the performance. Performance enhancement means that the length of the ON signal is further reduced, thereby increasing the power of the signal, resulting in an advantageous effect in terms of SNR gain or timing error.

The partial ON signal is set to a second ON signal included in the wakeup packet having the second data rate. The second on-signal is generated by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and masking half of the generated signal by performing 64-point IFFT.

For example, coefficients may be inserted into all of the 13 subcarriers. At this time, the generated signal may be a signal having a length of 3.2 us having no period. A CP (Cyclic Prefix) may be inserted into the generated signal to generate an ON signal having a length of 4 us. At this time, a part of the generated signal may be taken to generate an ON signal having a length of 2us (CP + 1.6us). In addition, an on signal having a length of 2us can be generated by masking half of the generated signal. Here, the masking may correspond to a technique of covering a part of a signal and taking only a part of the signal.

As another example, coefficients may be inserted into the 13 subcarriers in units of two subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the second sequence may be set to a coefficient in units of two spaces, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 1.6 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal may be taken to generate an ON signal having a length of 2us (CP + 1.6us).

However, this embodiment describes a case where masking is performed to generate a second ON signal. That is, the second on-signal may be an on-signal masking half of a signal having a length of 4 us that has inserted the CP into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Alternatively, the second on-signal may be an on-signal masking half of the CP-inserted signal in the 3.2 us signal having a period of 1.6 us generated by performing 64-point IFFT. Accordingly, the length of the second ON signal may be 2us, and the length of the partial ON signal may be 2us.

In this embodiment, the case where the wakeup packet has LDR (Low Data Rate) or HDR (High Data Rate) is described. The first data rate being LDR is 62.5 Kbps and the second data rate being HDR may be 250 Kbps.

For example, the partial ON signal may be located at the center of the first ON signal. This structure minimizes the effect of ISI (inter symbol interference) with the previous symbol or the back symbol, and minimizes the influence of intra symbol interference in the off signal period. That is, the partial ON signal having a length of 2us may be located at the center of the first ON signal having a length of 4us. The off signal may be located in the remaining part of the first ON signal other than the part where the partial ON signal is located. That is, an off signal having a length of 1 us before and after the partial ON signal can be located.

In another example, the first information may comprise two first on signals. (First ON signal + OFF signal + first ON signal + OFF signal) The first first ON signal of the two first ON signals may be set to an OFF signal. The partial on signal may be located at the end of the first on signal of the two first on signals. The first on signal preceding in the first information means that it is ahead of the first on signal in time.

In addition, the second information may include two first on signals. (Off signal + first on signal + off signal + first on signal) The first one of the two first on signals may be set to an off signal. The partial ON signal may be located at the beginning of the first ON signal of the two first ON signals. The first on signal preceding in the second information means that it is ahead of the first on signal in time.

This embodiment can further increase the power of the signal by further reducing the length of the partial ON signal (so that the partial ON signal is located in only one ON signal) by setting one of the two ON signals to the OFF signal. This reduces ISI and intra symbol interference, and can have a beneficial effect in terms of SNR gain or timing error.

Also, the transmitting apparatus can configure the ON signal and the OFF signal to know the power value of the ON signal and the OFF signal first. The receiving apparatus decodes the ON signal and the OFF signal using an envelope detector, thereby reducing power consumed in decoding.

According to an embodiment of the present invention, a transmission apparatus constructs and transmits a wakeup packet by applying an OOK modulation scheme, so that power consumption can be reduced by using an envelope detector in a wakeup decoding at a receiving apparatus. Therefore, the receiving apparatus can decode the wakeup packet with the minimum power.

Also, a partial OOK scheme may be used in which only the ON signal is set to a part of the ON signal and the OFF signal is set to the rest. In this way, ISI and intra symbol interference are reduced, and the length of the ON signal transmitted is further reduced, thereby increasing the power of the signal, which is advantageous in terms of SNR gain and timing error.

1 is a conceptual diagram illustrating a structure of a wireless local area network (WLAN).

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

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

Figure 4 is a diagram illustrating a low power wake up receiver in an environment where no data is received.

5 is a diagram illustrating a low power wake up receiver in an environment in which data is received;

6 shows an example of a wakeup packet structure according to the present embodiment.

Fig. 7 shows a signal waveform of the wakeup packet according to the present embodiment.

FIG. 8 is a diagram for explaining a principle in which power consumption is determined according to a ratio of 1 and 0 of a bit value constituting binary sequence type information using the OOK scheme.

9 shows a method of designing an OOK pulse according to the present embodiment.

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

11 shows various examples of a symbol repetition technique in which n symbols according to the present embodiment are repeated.

12 shows various examples of the symbol reduction technique according to the present embodiment.

13 shows an example of configuring the 2us on signal based on signal masking according to the present embodiment.

14 shows an example of a wakeup packet structure to which different sync parts are applied according to the present embodiment.

FIGS. 15 to 19 show examples of the positions of the Tus-on signal at information 0 and 1 having a data rate of 250 kbps.

Figs. 20 to 46 show examples of positions of the Tus-on signal at information 0 and 1, which have a data rate of 62.5 kbps.

47 is a flowchart illustrating a procedure for transmitting a wakeup packet by applying the partial OOK scheme according to the present embodiment.

48 shows a transmitting apparatus for implementing this embodiment.

FIG. 49 shows a procedure for transmitting a WUR PPDU configured by applying a partial OOK scheme between an AP and a WUR STA according to the present embodiment.

50 shows a receiving apparatus for implementing this embodiment.

1 is a conceptual diagram illustrating a structure of a wireless local area network (WLAN).

The upper part of FIG. 1 shows the structure of an infrastructure basic service set (BSS) of Institute of Electrical and Electronic Engineers (IEEE) 802.11.

1, the WLAN system may include one or more infrastructure BSSs 100 and 105 (hereinafter, BSS). The BSSs 100 and 105 are a set of APs and STAs such as an access point 125 and an STA1 (station 100-1) capable of successfully synchronizing and communicating with each other. The BSS 105 may include one or more associatable STAs 105-1 and 105-2 in one AP 130. [

The BSS may include at least one STA, APs 125 and 130 providing a distribution service, and a distribution system (DS) 110 connecting a plurality of APs.

The distributed system 110 may implement an extended service set (ESS) 140 that is an extended service set by connecting a plurality of BSSs 100 and 105. ESS 140 may be used to refer to one network in which one or more APs 125 and 230 are connected through a distributed system 110. [ An AP included in one ESS 140 may have the same service set identification (SSID).

A portal 120 may serve as a bridge for performing a connection between a wireless LAN network (IEEE 802.11) and another network (for example, 802.X).

A network between the APs 125 and 130 and a network between the APs 125 and 130 and the STAs 100-1, 105-1 and 105-2 may be implemented in the BSS as shown in the upper part of FIG. However, it is also possible to establish a network and perform communication between the STAs without the APs 125 and 130. [ An ad-hoc network or an independent basic service set (IBSS) is defined as a network that establishes a network and establishes communication between STAs without APs 125 and 130. [

1 is a conceptual diagram showing IBSS.

1, the IBSS is a BSS operating in an ad-hoc mode. Since IBSS does not include APs, there is no centralized management entity. That is, in the IBSS, the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 are managed in a distributed manner. In the IBSS, all the STAs 150-1, 150-2, 150-3, 155-4, and 155-5 may be mobile STAs, and the access to the distributed system is not allowed, network.

The STA is an arbitrary functional medium including a medium access control (MAC) conforming to IEEE (Institute of Electrical and Electronics Engineers) IEEE 802.11 standard and a physical layer interface for a wireless medium. May be used to mean both an AP and a non-AP STA (Non-AP Station).

The STA may be a mobile terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit Mobile Subscriber Unit), or simply a user.

Meanwhile, the term 'user' may be used in various meanings. For example, the term 'user' may be used to mean an STA participating in uplink MU MIMO and / or uplink OFDMA transmission in wireless LAN communication, But is not limited thereto.

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

As shown, various types of PPDU (PHY protocol data unit) are used in IEEE a / g / n / ac standards. Specifically, the LTF and STF fields included training signals, SIG-A and SIG-B included control information for the receiving station, and the data field 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 can be applied on the HE PPDU (high efficiency PPDU) according to the IEEE 802.11ax standard. That is, the signal to be improved in this 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 can also be expressed as SIG-A, SIG-B. However, the improved signal proposed by the present embodiment is not necessarily limited to the HE-SIG-A and / or HE-SIG-B standards, and various control and control schemes including control information in a wireless communication system, It is applicable to data fields.

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

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

As shown, an HE-PPDU for a Multiple User (MU) includes a legacy-short training field (L-STF), a legacy-long training field (L-LTF) (HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF) , A data field (or MAC payload), and a Packet Extension (PE) field. Each field may be transmitted during the time interval shown (i.e., 4 or 8 ㎲, etc.).

The PPDU used in the IEEE standard is mainly described by a PPDU structure transmitted over a channel bandwidth of 20 MHz. The PPDU structure transmitted over a wide bandwidth (for example, 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 channel bandwidth of 20 MHz.

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

Wireless networks are ubiquitous and are usually installed indoors and often outdoors. Wireless networks transmit and receive information using a variety of technologies. For example, but not by way of limitation, the two widely deployed technologies used in communications are those that comply with the IEEE 802.11 standard, such as the IEEE 802.11n standard and the IEEE 802.11ac standard.

The IEEE 802.11 standard specifies a common Medium Access Control (MAC) layer that provides various functions to support the operation of an IEEE 802.11-based wireless LAN (WLAN). The MAC layer utilizes a protocol that coordinates access to the shared radio and improves communication over the wireless medium to enable the wireless network card (NIC) or other wireless device or station (STA) and access point AP)).

IEEE 802.11ax is a follow-on product of 802.11ac and has been proposed to increase the efficiency of WLAN networks, especially in high density areas such as public hotspots and other high density traffic areas. IEEE 802.11 may also use orthogonal frequency division multiple access (OFDMA). The High Efficiency WLAN Study Group (HEW SG) within the IEEE 802.11 Work Group has been developing a spectrum for improving the system throughput / area in high density scenarios of AP (Access Point) and / or STA (Station) Efficiency is being considered.

Small computing devices such as wearable devices and sensors and mobile devices are limited by small battery capacities, but are not limited to wireless communication technologies such as Wi-Fi, Bluetooth®, and Bluetooth® Low Energy (BLE) Support, and connect to and exchange data with other computing devices such as smart phones, tablets, and computers. Since such communication consumes power, it is important to minimize the energy consumption of such communication in such devices. One ideal strategy for minimizing energy consumption is to turn off the power to the communication block as often as possible while maintaining data transmission and reception without increasing the delay too much. That is, the communication block is transmitted immediately before data reception, and the communication block is turned on only when there is data to be woken up, and the communication block is turned off for the remaining time.

Hereinafter, a low-power wake-up receiver (LP-WUR) will be described.

The communication system (or communication subsystem) described herein includes a main radio (802.11) and a low power wake up receiver.

The main radio is used for transmitting and receiving user data. The main radio turns off if there is no data or packet to transmit. A low-power wake-up receiver wakes up the main radio when there are packets to receive. At this time, the user data is transmitted and received by the main radio.

A low power wakeup receiver is not for user data. It is simply a receiver for waking up the main radio. That is, the transmitter is not included. A low-power wake-up receiver is active while the main radio is off. A low-power wake-up receiver targets a target power consumption of less than 1mW in the active state. A low power wake up receiver also uses a narrow bandwidth of less than 5 MHz. In addition, the target transmission range of the low power wakeup receiver is the same as the target transmission range of the existing 802.11.

Figure 4 is a diagram illustrating a low power wake up receiver in an environment where no data is received. 5 is a diagram illustrating a low power wake up receiver in an environment in which data is received;

As shown in Figures 4 and 5, if there is data to send / receive, one way to implement an ideal transmission / reception strategy is to use a main radio such as Wi-Fi, Bluetooth® radio, Bluetooth® Radio (BLE) Wake up receiver (LP-WUR) that can wake up the system.

Referring to FIG. 4, the Wi-Fi / BT / BLE 420 is off and the low power wakeup receiver 430 is turned on with no data received. Some studies show that the power consumption of these low-power wake-up receivers (LP-WUR) can be less than 1mW.

However, as shown in FIG. 5, when a wakeup packet is received, the low power wakeup receiver 530 sends a full Wi-Fi / BT / BLE radio 520 ). In some cases, however, actual data or IEEE 802.11 MAC frames may be included in the wakeup packet. In this case, it is not necessary to wake up the entire Wi-Fi / BT / BLE radio 520, but only a part of the Wi-Fi / BT / BLE radio 520 should be woken up to perform the required process. This can result in significant power savings.

One exemplary technique disclosed herein defines a method for a granular wake-up mode for Wi-Fi / BT / BLE using a low power wake-up receiver. For example, the actual data contained in the wakeup packet can be passed directly to the device's memory block without waking the Wi-Fi / BT / BLE radio.

As another example, if an IEEE 802.11 MAC frame is included in the wakeup packet, only the MAC processor of the Wi-Fi / BT / BLE wireless device needs to be woken up to handle the IEEE 802.11 MAC frame included in the wakeup. That is, the PHY module of the Wi-Fi / BT / BLE radio can be turned off or kept in a low power mode.

A number of fine-grained wake-up modes are defined for Wi-Fi / BT / BLE radios using low-power wake-up receivers to power on the Wi-Fi / BT / BLE radio when a wakeup packet is received. However, according to this embodiment, only necessary parts (or components) of the Wi-Fi / BT / BLE radio are selectively awakened, saving energy and reducing standby time. Many solutions that use a low-power wake-up receiver to wake up a wake-up packet wake up the entire Wi-Fi / BT / BLE radio. One exemplary aspect discussed herein is to wake up only the necessary portion of the Wi-Fi / BT / BLE radio needed to process the received data, thereby saving a significant amount of energy and reducing unnecessary latency in waking up the main radio .

Further, in the above embodiment, the low power wakeup receiver 530 may wake up the main radio 520 based on the wakeup packet transmitted from the transmitting apparatus 500. [

In addition, the transmitting apparatus 500 can be set to transmit a wakeup packet to the receiving apparatus 510. [ For example, the main radio 520 may instruct the low power wake up receiver 530 to wake up.

6 shows an example of a wakeup packet structure according to the present embodiment.

The wakeup packet may include one or more legacy preambles. One or more legacy devices may decode or process the legacy preamble.

The wakeup packet may also include a payload after the legacy preamble. The payload may be modulated by a simple modulation scheme, e.g., an On-Off Keying (OOK) modulation scheme.

Referring to FIG. 6, a transmitting device may be configured to generate and / or transmit a wakeup packet 600. The receiving device may be configured to process the received wakeup packet (600).

In addition, the wakeup packet 600 may include a legacy preamble defined by the IEEE 802.11 specification or any other preamble 610. In addition, the wakeup packet 600 may include a payload 620.

The legacy preamble provides coexistence with the legacy STA. The legacy preamble 610 for coexistence uses the L-SIG field to protect the packet. Through the L-STF field in the legacy preamble 610, the 802.11 STA can detect the beginning of a packet. Through the L-SIG field in the legacy preamble 610, the 802.11 STA can know the end of the packet. In addition, by adding one symbol modulated with BPSK after the L-SIG, a false alarm of the 802.11n terminal can be reduced. One symbol (4us) modulated with BPSK also has a bandwidth of 20MHz like a legacy part. The legacy preamble 610 is a field for a third party legacy STA (STA not including the LP-WUR). The legacy preamble 610 is not decoded from the LP-WUR.

The payload 620 may include a wakeup preamble 622. [ The wake-up preamble 622 may comprise a sequence of bits configured to identify the wake-up packet 600. The wakeup preamble 622 may include, for example, a PN sequence.

The payload 620 may also include a MAC header 624 that includes the address information of the receiving device that receives the wakeup packet 600 or the identifier of the receiving device.

In addition, the payload 620 may include a frame body 626 that may contain other information of the wakeup packet. For example, frame body 626 may include payload length or size information.

In addition, the payload 620 may include a Frame Check Sequence (FCS) field 628 that includes a Cyclic Redundancy Check (CRC) value. For example, the MAC header 624 and the CRC-8 value or CRC-16 value of the frame body 626. [

7 shows a signal waveform of the wakeup packet according to this embodiment.

Referring to FIG. 7, the wakeup packet 700 includes a legacy preamble (802.11 preamble, 710) and a payload modulated with OOK. That is, the legacy preamble and the new LP-WUR signal waveform coexist.

In addition, the legacy preamble 710 can be modulated according to the OFDM modulation scheme. That is, the legacy preamble 710 does not use the OOK scheme. On the other hand, the payload can be modulated according to the OOK scheme. However, the payload wakeup preamble 722 may be modulated according to another modulation scheme.

Assuming that the legacy preamble 710 is transmitted on a channel bandwidth of 20 MHz to which 64 FFT is applied, the payload may be transmitted on a channel bandwidth of about 4.06 MHz. This will be described in the OOK pulse design method described later.

First, the modulation scheme using OOK scheme and the Manchester coding scheme will be described.

FIG. 8 is a diagram for explaining a principle in which power consumption is determined according to a ratio of 1 and 0 of a bit value constituting binary sequence type information using the OOK scheme.

Referring to FIG. 8, a binary sequence type information having 1 or 0 as a bit value is represented. By using the bit value of 1 or 0 of the information of the binary sequence type, it is possible to perform communication in the OOK modulation method. That is, the communication of the OOK modulation method can be performed in consideration of the bit values of the binary sequence type information. For example, when the light emitting diode is used for visible light communication, the light emitting diode is turned on when the bit value constituting the binary sequence information is 1, and the light emitting diode is turned off when the bit value is 0 The light emitting diode can be made to blink. As the light emitting diode is turned on and off, the data received in the form of visible light is received and restored by the receiving device, thereby enabling communication using visible light. However, since the human eye can not recognize the blinking of such a light emitting diode, the person feels that the illumination is continuously maintained.

For convenience of description, information of a binary sequence type having 10 bit values is used as shown in FIG. Referring to FIG. 8, there is binary sequence type information having a value of '1001101011'. As described above, when the bit value is 1, the transmitting apparatus is turned on. When the bit value is 0, when the transmitting apparatus is turned off, 6 bits of the 10 bit values are turned on. ) do. Therefore, assuming that all the 10 bit values have a power consumption of 100% when a symbol is turned on, it can be said that the power consumption is 60% in accordance with the duty cycle of FIG. 8.

That is, it can be said that the power consumption of the transmitter is determined by the ratio of 1 and 0 composing binary sequence type information. In other words, if there is a constraint that the power consumption of the transmitter should be maintained at a specific value, the ratio of 1 to 0 constituting binary sequence information should also be maintained. For example, in the case of a lighting device, since the illumination should be maintained at a specific luminance value desired by a person, the ratio of 1 and 0 constituting binary sequence information should also be maintained.

However, since the receiving apparatus is the main body of the wake-up receiver (WUR), the transmission power is not important. The main reason for using OOK is that the power consumption in decoding the received signal is very low. There is no significant difference in power consumption in the main radio or WUR until decoding, but there is a big difference in the decoding process. 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) can occur.

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

9 shows a method of designing an OOK pulse according to the present embodiment.

The OFDM transmitter of 802.11 can be reused to generate OOK pulses. The transmitting apparatus can generate a sequence having 64 bits by applying a 64-point IFFT like the existing 802.11.

The transmitting apparatus must generate the payload of the wakeup packet by modulating it in the OOK manner. However, since the wakeup packet is for low power communication, the OOK method is applied to the ON signal. The ON signal is a signal having an actual power value, and the OFF signal (OFF-signal) corresponds to a signal having no actual power value. Off signal is also applied to the OOK scheme, but the signal is not generated using the transmitting apparatus, but is not considered in the configuration of the wakeup packet because there is no signal actually transmitted.

In the OOK scheme, information (bit) 1 is an ON signal and information (bit) 0 can be an OFF signal. Alternatively, applying the Manchester coding scheme may indicate that information 1 transitions from an off signal to an on signal, and information 0 may be transited from an on signal to an off signal. On the contrary, information 1 indicates that transition from the on-signal to the off-signal, and information 0 indicates that the transition from the off-signal to the on-signal. The Manchester coding scheme will be described later.

Referring to FIG. 9, like the right frequency domain graph 920, the transmitter applies a sequence by selecting 13 consecutive subcarriers in the 20 MHz band, which is a reference band, as a sample. In Fig. 9, thirteen subcarriers located in the middle of the 20 MHz band subcarriers are selected as samples. That is, subcarriers whose subcarrier indices are from -6 to +6 out of 64 subcarriers are selected. At this time, the subcarrier index 0 can be nulled to 0 on the DC subcarrier. A specific sequence is set only for thirteen subcarriers selected as samples, and the remaining subcarriers excluding subcarriers (subcarrier indices -32 to -7 and subcarrier indices +7 to +31) are all set to 0 .

Also, since the subcarrier spacing is 312.5 KHz, 13 subcarriers have a channel bandwidth of about 4.06 MHz. That is, it can be seen that there is power only for 4.06 MHz in the 20 MHz band in the frequency domain. Thus, the signal to noise ratio (SNR) can be increased and the power consumption of the AC / DC converter of the receiving apparatus can be reduced. In addition, since the sampling frequency band is reduced to 4.06 MHz, power consumption can be reduced.

Also, as in the left time domain graph 910 of FIG. 9, the transmitter can perform one 64-point IFFT on 13 subcarriers to generate one ON signal in the time domain. One ON signal has a size of 1 bit. That is, a sequence composed of 13 subcarriers can correspond to one bit. On the other hand, the transmitting apparatus may not transmit the OFF signal at all. If IFFT is performed, a symbol of 3.2 us can be generated, and if a CP (Cyclic Prefix, 0.8 us) is included, a symbol having a length of 4 us can be generated. That is, one bit indicating one on-signal can be stored in one symbol.

The reason why the bits are constructed and transmitted as in the above-described embodiment is to reduce the power consumption by using an envelope detector in the receiving apparatus. Thereby, the receiving apparatus can decode the packet with the minimum power.

However, the basic data rate for one piece of information may be 125 Kbps (8 us) or 62.5 Kbps (16 us).

The signals transmitted in the frequency domain by generalizing the above are as follows. That is, each signal having a length K in the 20 MHz band can be transmitted on K consecutive subcarriers out of a total of 64 subcarriers. That is, K can correspond to the bandwidth of the OOK pulse by the number of subcarriers used for transmitting the signal. The coefficients of subcarriers other than K are all zero. At this time, the indexes of the K subcarriers used by the signals corresponding to information 0 and information 1 are the same. For example, the subcarrier index used may be expressed as 33-floor (K / 2): 33 + ceil (K / 2) -1.

At this time, information 1 and information 0 may have the following values.

- information 0 = zeros (1, K)

- information 1 = alpha * ones (1, K)

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

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

Manchester coding is a kind of line coding, and it can represent information as shown in the following table in such a manner that a transition of a magnitude value takes place in the middle of one bit period.

In other words, the Manchester coding scheme refers to a method of converting data with 1 as 01, 0 as 10, or 1 as 10 and 0 as 01. Table 1 shows an example in which Manchester coding is used and data is converted to 1 by 10 and 0 by 01.

As shown in Fig. 10, the bit stream 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 data is transmitted from the transmitting side using the Manchester coding scheme, the receiving side reads data slightly after the transition point transition from 1? 0 or 0? 1 to recover data, and transitions from 1? 0 or 0? 1 And the clock is restored by recognizing the transition advantage of the clock as a transition point of the clock. Alternatively, when the symbol is divided based on the transition point, it can be simply decoded by comparing the power of the front part and the rear part at the center of the symbol.

As shown in FIG. 10, the bit string to be transmitted is 10011101, the Manchester coded bit stream to be transmitted is 0110100101011001, and the clock reproduced at the receiving side recognizes the transition point of the Manchester coded signal as the transition point of the clock And recover data using the recovered clock.

With the Manchester coding scheme, a synchronous communication can be performed using only a data transmission channel without using a separate clock.

Also, such a scheme can use the TXD pin for data transmission, and the RXD pin for data transmission by using only the data transmission channel. Therefore, synchronized bidirectional transmission is possible.

The present specification proposes various symbol types that can be used in WUR and the corresponding data rates.

Because STA that needs robust performance and STA that receives strong signal from AP are mixed, it is necessary to support efficient data rate depending on the situation. To obtain reliable and robust performance, a symbol-based Manchester coding scheme and a symbol repetition scheme can be used. Also, a symbol reduction technique can be used to obtain a high data rate.

At this time, each symbol can be generated using existing 802.11 OFDM transmission. In addition, the number of subcarriers used for generating each symbol may be 13. However, it is not limited thereto.

Also, each symbol can use OOK modulation, which is formed by 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 portion indicating actual information. It is possible to design a symbol having various data rates by repeatedly setting or repeating the CP and the length of the actual information signal.

The following shows various examples of symbol types.

For example, the basic WUR symbol can be represented as CP + 3.2us. That is, 1 bit is represented using a symbol having the same length as the existing Wi-Fi. Specifically, the transmitter applies a specific sequence to all available subcarriers (e.g., 13 subcarriers) and then performs an IFFT to form an information signal portion of 3.2 us. At this time, a coefficient of 0 may be stored in the DC subcarrier or the middle subcarrier index among all available subcarriers.

Depending on the 3.2us on signal and the 3.2us off signal, different sequences may be applied to the available subcarriers. The 3.2 off signal can be generated by applying all coefficients to zero.

The CP can be used by adopting a specific length behind the information signal 3.2us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, 1-bit information corresponding to one basic WUR symbol can be represented as shown in the following table.

Information '0'	Information '1'
3.2us OFF-signal	3.2us ON-signal

In Table 2, CP is not indicated separately. In practice, CP + 3.2us, including CP, can point to a single bit of information. That is, the 3.2us on signal can be seen as (CP + 3.2us) on signal. 3.2 us off signal can be seen as (CP + 3.2us) off signal.

As another example, the Manchester coded symbols can be represented as CP + 1.6us + CP + 1.6us or CP + 1.6us + 1.6us. The Manchester coded symbols can be generated as follows.

In the OOK transmission using a Wi-Fi transmission apparatus, the time used for transmission of one bit (or symbol) excluding the guard interval of the transmission signal is 3.2us. At this time, if the coding is applied to Manchester coding, the signal size should be shifted at 1.6us. That is, each sub-information having a length of 1.6us must have a value of 0 or 1, and a signal can be configured in the following manner.

* Information 0 -> 1 0 (each can be called sub information 1 0 or sub symbol 1 (ON) 0 (OFF))

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

In addition, a specific sequence is applied to all available subcarriers (e.g., 13 subcarriers) in units of two to generate Manchester coded symbols. That is, even-numbered subcarriers in a specific sequence are null-nulled. That is, a particular sequence may have coefficients at intervals of two squares. For example, assuming that 13 subcarriers are used to construct an on-signal, a specific sequence with coefficients in two spaces 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 f}. In this case, a, b, c, d, e, f, and g are 1 or -1.

That is, the transmitting apparatus maps a specific sequence to consecutive K subcarriers among 64 subcarriers (for example, 33-floor (K / 2): 33 + ceil (K / 2) And sets the coefficient to 0 to perform IFFT. Thus, a signal in the time domain can be generated. The signal in the time domain is a signal having a length of 3.2us having a period of 1.6us because the coefficient exists at intervals of two spaces in the frequency domain. The first or second 1.6us period signal can be selected and used as sub information 1.

- second 1.6us (sub information 0 or sub symbol 0): sub information 0 can have the value of zeros (1, K). Similarly, the transmitting apparatus maps a specific sequence to consecutive K subcarriers among 64 subcarriers (for example, 33-floor (K / 2): 33 + ceil (K / 2) -1) IFFT So that a signal in the time domain can be generated. Sub information 0 can correspond to 1.6us off signal. The 1.6us off signal can be generated by setting all coefficients to zero.

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

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

- Information 1 is divided into the first 1.6 us (sub information 0) and the second 1.6 us (sub information 1), so that a signal corresponding to each sub information can be configured in the same manner as the method of generating information 0.

If the technique of generating information 0 and information 1 using Manchester coding is used, it is possible to prevent the consecutive off-symbols from being consecutive compared to the conventional method. Therefore, coexistence with existing Wi-Fi devices may not occur. The coexistence problem is a problem that occurs when another device determines a channel idle state due to consecutive off-symbols and transmits a signal. If only OOK modulation is used, for example, the off-symbol may be continuous with a sequence of 100001 or the like, but when Manchester coding is used, the off-symbol can not be continuous with the sequence of 100101010110.

According to the above description, the sub information may be called 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 can be applied to different subcarriers.

CP can be used by adopting a specific length behind the information signal 1.6us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Therefore, 1-bit information corresponding to a symbol to which one Manchester coding is applied can be represented as shown in the following table.

Information '0'	Information '1'
1.6us ON-signal + 1.6us OFF-signal	1.6us OFF-signal + 1.6us ON-signal
Or 1.6us OFF-signal + 1.6us ON-signal	Or 1.6us ON-signal + 1.6us OFF-signal

In Table 3, CP is not indicated separately. In fact, CP + 1.6us + CP + 1.6us or CP + 1.6us + 1.6us, including CP, can point to a single bit of information. That is, in the case of the former, the signal is 1.6us on, the signal 1.6us off is (CP + 1.6us) on, and (CP + 1.6us) is off.

As another example, a method of constructing a wakeup packet by repeating symbols is proposed to improve performance.

The symbol repetition scheme is applied to the wakeup payload 724. The symbol repetition scheme means repetition of time signals after insertion of IFFT and CP (Cyclic Prefix) of each symbol. Thus, the length (time) of the wakeup payload 724 is doubled.

That is, it is proposed that a symbol representing information such as information 0 or information 1 is applied to a specific sequence and it is repeatedly constructed as follows.

Option 1: Information 0 and information 1 can be repeated with the same symbol.

- Information 0 -> 0 0 (Repeat information 0 twice)

- Information 1 -> 1 1 (repeat information 1 twice)

Option 2: Information 0 and information 1 can be repeated with different symbols.

- Information 0 -> 0 1 or 1 0 (Repeat information 0 and information 1)

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

Hereinafter, a method in which a receiving apparatus decodes a signal transmitted by applying a symbol repetition technique in a transmitting apparatus will be described.

The transmitted signal can correspond to the wakeup packet, and the method for decoding the wakeup packet can be largely divided into two methods. The first is the non-coherent detection method and the second is the coherent detection method. The non-coherent detection scheme is such that the phase relationship between signals of the transmitting apparatus and the receiving apparatus is not fixed. Therefore, the receiving apparatus does not need to measure and adjust the phase of the received signal. Conversely, the coherent detection scheme must be in phase between the transmitter and receiver signals.

The receiving device includes the low-power wake-up receiver described above. A low-power wake-up receiver can decode packets (wake-up packets) transmitted using an OOK modulation scheme using an envelope detector to reduce power consumption.

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

A method for decoding a symbol to which a symbol repetition scheme is applied is as follows. In the above option 1, the receiving apparatus can calculate the power or the like when symbol 1 (symbol containing information 1) is transmitted using the wakeup preamble 722 and use it to determine a threshold value.

More specifically, the average power in two symbols is determined to be information 1 (1 1) if it is greater than or equal to a threshold value, and information 0 (0 0) can be determined to be less than a threshold value.

In Option 2, the power of two symbols can be compared to determine information without a procedure for determining a threshold value.

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

This allows the order of the symbols to be reconstructed by the interleaver. The interleaver can be applied in units of a specific number of symbols under a packet unit.

In addition, you can use n symbols as follows, as well as two symbols. 11 shows various examples of a symbol repetition technique in which n symbols according to the present embodiment are repeated.

Option 1: As shown in FIG. 11, information 0 and information 1 can be represented by repeating the same symbol n times.

- information 0 -> 0 0 ... 0 (information 0 is repeated n times)

- Information 1 -> 1 1 ... 1 (Repeat information 1 n times)

Option 2: As shown in FIG. 11, information 0 and information 1 can be repetitively represented by n symbols with different symbols.

- Information 0 -> 0 1 0 1 ... or 1 0 1 0 ... (repeat information 0 and information 1 n times each other)

- Information 1 -> 1 0 1 0 ... or 0 1 0 1 ... (Repeat information 1 and information 0 n times each other)

Option 3: As shown in FIG. 11, half of the symbols can be composed of information 0 and the other half can be composed of information 1 to represent n symbols.

- information 0 -> 0 0 ... 1 1 ... or 1 1 ... 0 0 ... (n / 2 symbols are composed of information 0 and the remaining n / 2 symbols are composed of information 1) do)

- Information 1 -> 1 1 ... 0 0 ... or 0 0 ... 1 1 ... (n / 2 symbols are composed of information 0 and the remaining n / 2 symbols are composed of information 1) do)

Option 4: As shown in FIG. 11, when n is an odd number, a total of n symbols can be represented by dividing the number of symbols 1 (symbols containing information 1) and the number of symbols 0 (symbols containing information 0).

- information 0 -> n symbols in which the number of symbols 1 is an odd number and the number of symbol 0 is an even number, or n symbols in which the number of symbol 1 is an even number and the number of symbol 0 is an odd number

- information 1 -> n symbols where the number of symbols 0 is odd and the number of symbols 1 is an even number, or n symbols where the number of symbols 0 is an even number and the number of symbols 1 is an odd number

Also, the order of the symbols can be reconstructed by the interleaver. The interleaver can be applied in units of packets and specific symbols.

Further, as described above, the receiving apparatus can determine whether the information is 0 or 1 by comparing the power of n symbols with the threshold value.

However, using a consecutive symbol 0 (or off symbol) may cause coexistence problems with existing Wi-Fi devices and / or other devices. The coexistence problem is a problem that occurs when another device determines a channel idle state due to consecutive off-symbols and transmits a signal. Therefore, it is desirable to avoid the use of consecutive off-symbols to solve the problem of solving the problem, so the option of the above option 2 may be preferred.

Also, it can be extended to a method of representing m pieces of information using n symbols. In this case, the first or last m is represented by a symbol of 0 (OFF) or 1 (ON) according to information, and a redundant symbol of 0 (OFF) or 1 (ON) can do.

For example, if the code rate 3/4 is applied to the information 010, it can be 1,010 or 010,1 or 0,010 or 010,0. However, it may be desirable to apply a code rate of 1/2 or less to prevent the use of consecutive off-symbols.

Likewise in the above embodiment, the order of the symbols can be reconstructed by the interleaver. The interleaver can be applied in units of packets and specific symbols.

Hereinafter, various embodiments of symbols to which the symbol repetition technique is applied will be described.

In general, symbols with symbol repetition can be represented as n (CP + 3.2us) or CP + n (1.6us).

As shown in FIG. 11, a specific sequence is applied to all usable subcarriers (for example, 13) representing 1 bit using n (n> = 2) information signals (symbols) To form a signal (symbol).

Depending on the 3.2us on signal and the 3.2us off signal, different sequences may be applied to the available subcarriers. The 3.2 off signal can be generated by applying all coefficients to zero.

The CP can be used by adopting a specific length behind the information signal 3.2us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, 1-bit information corresponding to a symbol to which a general symbol repetition technique is applied can be represented as shown in the following table.

Information '0'	Information '1'
All 3.2us OFF-signal	All 3.2us ON-signal
Or 3.2us ON-signal + 3.2us OFF-signal for any two consecutive signals, ON or OFF for all other signals	3.2us OFF-signal + 3.2us ON-signal, and all other signals are ON or OFF.
3.2us OFF-signal + 3.2us ON-signal, and all other signals are ON or OFF.	Or 3.2us ON-signal + 3.2us OFF-signal for any two consecutive signals, ON or OFF for all other signals
Or a specific number (or ceil (n / 2) or floor (n / 2) number) located at a specific position is 3.2us OFF-signal. The remaining is 3.2us ON-signalEx) ON + OFF + ON + OFF ...	Or a specific number (or ceil (n / 2) or floor (n / 2) number) placed at a specific position is 3.2us ON-signal and the rest is 3.2us OFF-signalEx) OFF + ON + OFF + ON + OFF ...

In Table 4, CP is not indicated separately. In fact, n (CP + 3.2us) or CP + n (3.2us), including CP, can point to a single bit of information. That is, in the case of n (CP + 3.2us), the 3.2us on signal can be regarded as (CP + 3.2us) on signal and the 3.2us off signal can be regarded as (CP + 3.2us) off signal.

As another example, symbols with symbol repetition technique can be represented as CP + 3.2us + CP + 3.2us or CP + 3.2us + 3.2us.

According to this embodiment, a specific sequence is applied to all available subcarriers (for example, thirteen) representing one bit by using two information signals (symbols), and IFFT is taken to obtain an information signal (symbol) of 3.2 us .

Depending on the 3.2us on signal and the 3.2us off signal, different sequences may be applied to the available subcarriers. The 3.2 off signal can be generated by applying all coefficients to zero.

The CP can be used by adopting a specific length behind the information signal 3.2us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, the 1-bit information corresponding to the symbol to which the symbol repetition scheme is applied can be represented as shown in the following table.

Information '0'	Information '1'
3.2us OFF-signal + 3.2us OFF-signal	3.2us ON-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us OFF-signal	Or 3.2us OFF-signal + 3.2us ON-signal
Or 3.2us OFF-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us OFF-signal

In Table 5, CP is not indicated separately. In practice, CP + 3.2us + CP + 3.2us, including CP, or CP + 3.2us + 3.2us may point to a single bit of information. In the case of CP + 3.2us + CP + 3.2us, the 3.2us on signal can be regarded as (CP + 3.2us) on signal and the 3.2us off signal can be regarded as (CP + 3.2us) off signal .

As another example, symbols with symbol repetition can be represented as CP + 3.2us + CP + 3.2us + CP + 3.2us or CP + 3.2us + 3.2us + 3.2us.

According to this embodiment, a specific sequence is applied to all available subcarriers (for example, thirteen) representing one bit by using three information signals (symbols), and IFFT is then taken to obtain an information signal (symbol) of 3.2 us .

Depending on the 3.2us on signal and the 3.2us off signal, different sequences may be applied to the available subcarriers. The 3.2 off signal can be generated by applying all coefficients to zero.

The CP can be used by adopting a specific length behind the information signal 3.2us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, the 1-bit information corresponding to the symbol to which the symbol repetition scheme is applied can be represented as shown in the following table.

Information '0'	Information '1'
3.2us OFF-signal + 3.2us OFF-signal + 3.2us OFF-signal	3.2us ON-signal + 3.2us ON-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal	Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal
Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal	Or 3.2us OFF-signal + 3.2us ON-signal + 3.2us OFF-signal

In Table 6, CP is not indicated separately. In practice, CP + 3.2us + CP + 3.2us + CP + 3.2us or CP + 3.2us + 3.2us + 3.2us, including CP, may point to a single bit of information. In the case of CP + 3.2us + CP + 3.2us + CP + 3.2us, the 3.2us on signal can be viewed as (CP + 3.2us) It can be seen as a signal.

As another example, symbols with symbol repetition can be represented as CP + 3.2us + CP + 3.2us + CP + 3.2us + CP + 3.2us or CP + 3.2us + 3.2us + 3.2us + 3.2us.

According to this embodiment, a specific sequence is applied to all usable subcarriers (for example, thirteen) representing one bit by using four information signals (symbols), and IFFT is then taken to obtain an information signal (symbol) of 3.2 us .

Depending on the 3.2us on signal and the 3.2us off signal, different sequences may be applied to the available subcarriers. The 3.2 off signal can be generated by applying all coefficients to zero.

The CP can be used by adopting a specific length behind the information signal 3.2us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, the 1-bit information corresponding to the symbol to which the symbol repetition scheme is applied can be represented as shown in the following table.

Information '0'	Information '1'
3.2us OFF-signal + 3.2us OFF-signal + 3.2us OFF-signal + 3.2us OFF-signal	3.2us ON-signal + 3.2us ON-signal + 3.2us ON-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal	Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal
Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal + 3.2us OFF-signal	Or 3.2us OFF-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us ON-signal
Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us OFF-signal	Or 3.2us OFF-signal + 3.2us OFF-signal + 3.2us ON-signal + 3.2us ON-signal
Or 3.2us OFF-signal + 3.2us OFF-signal + 3.2us ON-signal + 3.2us ON-signal	Or 3.2us ON-signal + 3.2us ON-signal + 3.2us OFF-signal + 3.2us OFF-signal

In Table 7, CP is not indicated separately. In practice, CP + 3.2us + CP + 3.2us + CP + 3.2us + CP + 3.2us or CP + 3.2us + 3.2us + 3.2us + 3.2us containing CP may point to a single bit of information. In the case of CP + 3.2us + CP + 3.2us + CP + 3.2us + CP + 3.2us, the 3.2us on signal can be seen as (CP + 3.2us) + 3.2us) off signal.

As another example, based on symbol repetition, Manchester coded symbols can be represented as n (CP + 1.6us + CP + 1.6us) or CP + n (1.6us + 1.6us).

According to this embodiment, a certain sequence is applied to all available subcarriers (for example, 13) representing 1 bit using n (> = 2) repeated symbols and the remainder is a coefficient of 0 When the IFFT is set, a signal of 3.2us having a period of 1.6us is generated. Take one of them and set it to 1.6us information signal (symbol).

The sub information may be called 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 can be applied to different subcarriers. The 1.6us off signal can be generated by applying all coefficients to zero.

CP can be used by adopting a specific length behind the information signal 1.6us immediately behind it. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac.

Accordingly, the 1-bit information corresponding to the Manchester-coded symbol based on the symbol repetition can be represented as shown in the following table.

Information '0'	Information '1'
(1.6us ON-signal + 1.6us OFF-signal) Repeat n times	(1.6us OFF-signal + 1.6us ON-signal) Repeat n times
Or (1.6us OFF-signal + 1.6us ON-signal) n times	(1.6us ON-signal + 1.6us OFF-signal) Repeat n times
(1.6us ON-signal + 1.6us OFF-signal) + (1.6us OFF-signal + 1.6us ON-signal) floor (n / 2)	(1.6us OFF-signal + 1.6us ON-signal) + (1.6us ON-signal + 1.6us OFF-signal) floor (n / 2)
(1.6us OFF-signal + 1.6us ON-signal) + (1.6us ON-signal + 1.6us OFF-signal) floor (n / 2)	(1.6us ON-signal + 1.6us OFF-signal) + (1.6us OFF-signal + 1.6us ON-signal) floor (n / 2)

In Table 8, CP is not indicated separately. In practice, n (CP + 1.6us + CP + 1.6us) or CP + n (1.6us + 1.6us), including CP, can point to a single bit of information. That is, in the case of n (CP + 1.6us + CP + 1.6us), the 1.6us ON signal can be viewed as (CP + 1.6us) Can be seen as.

As with the embodiments described above, the use of symbol repetition techniques can satisfy a range requirement of low power wake up communication. When only the OOK scheme is applied, the data rate for one symbol is 250 Kbps (4 us). If the symbols are repeated twice using the symbol repetition technique, the data rate may be 125 Kbps (8 us), the data rate may be 62.5 Kbps (16 us) if it is repeated four times, and the data rate may be 31.25 Kbps have. In the case of low power wakeup communication, if there is no BCC, the symbol can be repeated eight times to satisfy the range requirement.

In the following, various embodiments of symbols subjected to a symbol reduction technique that can be used in the WUR will be described.

12 shows various examples of the symbol reduction technique according to the present embodiment.

According to the embodiment of FIG. 12, as the value of m increases, the symbol is further reduced so that the length of a symbol carrying one information is reduced. When m = 2, the length of a symbol carrying information is CP + 1.6us. When m = 4, the length of a symbol carrying information is CP + 0.8us. When m = 8, the length of a symbol carrying information is CP + 0.4us.

As the symbol length decreases, a higher data rate can be secured. If only the OOK scheme is applied, the data rate for one symbol is 250 Kbps (4 us). If m = 2, the data rate is 500 Kbps (2 us). If m = 4, the data rate is 1 Mbps (1 us), and if m = 8, the data rate can be 2 Mbps (0.5 us) .

For example, symbols with the symbol reduction technique can be represented as CP + 3.2us / m (m = 2,4,8,16,32, ...) (option 1).

As in option 1 of FIG. 12, a certain sequence is applied to all available subcarriers (for example, 13) by a unit of m, representing 1 bit by using a symbol reduction scheme applied symbol, do. If IFFT is applied to the subcarrier to which the specific sequence is applied, a signal of 3.2 us having a period of 3.2 us / m is generated. Take one of them and map it to the 3.2 us / m information signal (information 1).

For example, if a specific sequence is applied in units of two cells (m = 2) to thirteen subcarriers, the on-signal can be configured as follows.

B0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, e, f, and g are 1 or -1.

As another example, if a specific sequence is applied in units of four cells (m = 4) to thirteen subcarriers, the on-signal can be configured as follows.

- On signal (information 1): {a 0 0 0 b 0 0 0 c 0 0 0 d} or {0 a 0 0 0 b 0 0 0 c 0 0 0} or {0 0 a 0 0 0 b 0 0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1.

As another example, if a specific sequence is applied in 8 subcarriers (m = 8) to thirteen subcarriers, the on-signal can be configured as follows.

- On signal (information 1): {a 0 0 0 0 0 0 0 b 0 0 0 0} or {0 a 0 0 0 0 0 0 0 b 0 0 0} or {0 0 a 0 0 0 0 0 0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, .

The 3.2us / m information signal is divided into 3.2us / m on signal and 3.2us / m off signal. In addition, the 3.2 us / m on signal and the 3.2 us / m off signal can each have different sequences applied to (available) subcarriers. The 3.2 us / m off signal can be generated by applying all coefficients to zero.

The CP can be used after a specific length of 3.2 us / m behind the information signal. At this time, CP may be 0.4us or 0.8us. This length is the same as the guard interval of the 802.11ac. However, when m = 8, CP can not be 0.8us. Or CP may be 0.1us or 0.2us and may be other values.

Therefore, 1-bit information corresponding to a symbol to which a general symbol reduction technique is applied can be represented as shown in the following table.

Information '0'	Information '1'
3.2us / m OFF-signal	3.2us / m ON-signal

In Table 9, CP is not indicated separately. In practice, CP + 3.2us / m, including CP, can point to a single bit of information. In other words, the 3.2us / m on signal can be viewed as CP + 3.2us / m on signal, and the 3.2us / m off signal can be seen as CP + 3.2us / m off signal.

As another example, symbols with symbol reduction techniques can be represented as CP + 3.2us / m + CP + 3.2us / m (m = 2, 4, 8) (option 2).

In the OOK transmission using a Wi-Fi transmission apparatus, the time used for transmission of one bit (or symbol) excluding the guard interval of the transmission signal is 3.2us. At this time, if the symbol reduction technique is applied, the time used for one bit transmission is 3.2 us / m. However, in this embodiment, the time to be used for one bit transmission is set to 3.2 us / m + 3.2 us / m by repeating the symbols with the symbol reduction technique applied thereto, Size transition. That is, each sub-information having a length of 3.2 us / m should have a value of 0 or 1, and a signal can be constructed in the following manner.

* Information 0 -> 1 0 (each can be called sub information 1 0 or sub symbol 1 (ON) 0 (OFF))

- the first 3.2 us / m signal (sub information 1 or sub symbol 1): for every available subcarrier (e.g., 13 subcarriers) to generate a symbol with symbol reduction technique, Is applied. That is, a particular sequence may have coefficients at intervals of m squares.

The transmitter performs IFFT by mapping a specific sequence to consecutive K subcarriers among 64 subcarriers and setting a coefficient to 0 for the remaining subcarriers. Thus, a signal in the time domain can be generated. Since the signal in the time domain has a coefficient at intervals of m cells in the frequency domain, a signal of 3.2us having a period of 3.2us / m is generated. You can take one of these and use it as a 3.2 us / m on signal (sub information 1).

- The second 3.2 us / m signal (sub information 0 or sub symbol 0): As with the first 3.2 us / m signal, the transmitter maps a specific sequence to consecutive K subcarriers out of 64 subcarriers, So that a signal in the time domain can be generated. Sub information 0 can correspond to a 3.2 us / m off signal. The 3.2 us / m off signal can be generated by setting all coefficients to zero.

One of the first or second 3.2 us / m periodic signals of the time domain signal may be selected and used as the sub information 0.

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

- Information 1 is divided into the first 3.2 us / m signal (sub information 0) and the second 3.2 us / m signal (sub information 1), so that the signal corresponding to each sub information Can be configured.

Further, the information 0 may be composed of 01 and the information 1 may be composed of 10.

As shown in option 2 of FIG. 12, the 1-bit information corresponding to the symbols to which the symbol reduction technique is applied can be represented as shown in the following table.

Information '0'	Information '1'
3.2us / m OFF-signal + 3.2us / m ON-signal or 3.2us / m ON-signal + 3.2us / m OFF-signal	3.2us / m ON-signal + 3.2us / m OFF-signal or 3.2us / m OFF-signal + 3.2us / m ON-signal

In Table 10, CP is not indicated separately. In practice, CP + 3.2us / m, including CP, can point to a single bit of information. In other words, the 3.2us / m on signal can be viewed as CP + 3.2us / m on signal, and the 3.2us / m off signal can be seen as CP + 3.2us / m off signal.

The embodiments in which option 1 and option 2 of FIG. 12 are described can be generalized as shown in the following table.

	Information '0'	Information '1'
Option 1 (m = 2, 4, 8)	2us OFF-signal	2us ON-signal
	1us OFF-signal	1us ON-signal
	0.5us OFF-signal	0.5us ON-signal
Option 2 (m = 4,8)	1us OFF-signal + 1us ON-signal or 1us ON-signal + 1us OFF-signal	1us ON-signal + 1us OFF-signal or 1us OFF-signal + 1us ON-signal
	0.5us OFF-signal + 0.5us ON-signal or 0.5us ON-signal + 0.5us OFF-signal	0.5us ON-signal + 0.5us OFF-signal or 0.5us OFF-signal + 0.5us ON-signal

In Table 11, each signal is represented by a length including CP. That is, CP + 3.2us / m including CP can indicate one 1-bit information.

For example, in case of m = 4 in Option 2, the length of a symbol carrying information is CP + 0.8us, so 1us off signal or 1us on signal consists of CP (0.2us) + 0.8us signal. In Option 2, since Manchester coding is applied and the symbols are repeated, when m = 4, the data rate for one piece of information can be 500 Kbps.

As another example, when m = 8 in Option 2, the length of a symbol carrying information is CP + 0.4us, so 0.5us off signal or 0.5us on signal consists of CP (0.1us) + 0.4us signal. In Option 2, since Manchester coding is applied and symbols are repeated, the data rate for one piece of information can be 1 Mbps when m = 8.

In the following table, the data rates obtainable through the above-described embodiments are compared for each of the embodiments.

CP	Basic symbol (Example 1) (CP + 3.2us)	Man. Symbol (Example 2) (CP + 1.6 + CP + 1.6)	Man. Symbol (Example 3) (CP + 1.6 + 1.6)
0.4us	277.8	250.0	277.8
0.8us	250.0	208.3	250.0

CP	Symbol rep.n (CP + 3.2us)			Symbol rep.CP + n (3.2us)			Man. symbol rep.n (CP + 1.6us + CP + 1.6us)
	n = 2 (Example 4)	n = 3 (Example 5)	n = 4 (Example 6)	n = 2 (Example 7)	n = 3 (Example 8)	n = 4 (Example 9)	n = 2 (Example 10)	n = 3 (Example 11)	n = 4 (Example 12)
0.4us	138.9	92.6	69.4	147.1	100.0	75.8	125.0	83.3	62.5
0.8us	125.0	83.3	62.5	138.9	96.2	73.5	104.2	69.4	52.1

CP	Man. symbol rep.CP + n (1.6us + 1.6us)			Symbol reductionCP + 3.2us / m
	n = 2 (Example 13)	n = 3 (Example 14)	n = 4 (Example 15)	m = 2 (Example 16)	m = 4 (Example 17)	m = 8 (Example 18)
0.4us	147.1	100.0	75.8	500.0	833.3	1250.0
0.8us	138.9	96.2	73.5	416.7	625.0	NA

CP	Symbol reductionCP + 3.2us / m		Man. symbol rep. w / Man.CP + 3.2us / m + CP + 3.2us / m
	m = 4	m = 8	m = 4	m = 8
0.1us	1111.1	2000	555.6	1000
0.2us	1000	1666.7	500	833.3

13 shows an example of configuring the 2us on signal based on signal masking according to the present embodiment.

The data rate can be secured according to various symbol types that can be used in WUR. At this time, a method for generating a 2us on signal may be proposed to secure a data rate of 250 Kbps. FIG. 13 proposes a masking-based technique using a sequence of length 13 (a coefficient is inserted into all 13 consecutive subcarriers in the 20 MHz band).

Referring to FIG. 13, in the case of the masking-based approach, first, 4us OOK symbols can be generated. A sequence of length 13 is applied to 13 consecutive subcarriers in the 20 MHz band to perform a 64-point IFFT, and a 4us OOK symbol is generated by adding 0.8 us CP or GI. Then, the 2us on signal can be constructed by masking half of the 4us OOK symbol.

For example, referring to FIG. 13, the information 0 can constitute a 2us on signal by taking a half of a 4us symbol. The half of the 4us symbol does not transmit any information, so a 2us off signal can be constructed. Also, information 1 can constitute a 2 os signal by taking the latter half of the symbol. A half of the 4us symbol does not transmit any information, so it can constitute a 2us off signal.

In the following, various data rates in an 802.11ba system can be applied to the payload of the WUR PPDU and two types of sync parts or sync fields of different lengths are used to reduce the overhead of the WUR PPDU. Can be used to configure the WUR PPDU. We propose various schemes in this specification for indicating the data rate applied to the payload using two types of syncpaths or sync fields.

14 shows an example of a wakeup packet structure to which different sync parts are applied according to the present embodiment.

14 is an example of a WUR PPDU to which a sync part (or sync field) having two types of different lengths and sequences in an IEEE 802.11 ba system is applied, respectively. Each of Sync 1 and Sync 2 is formed with a sequence having the same number of 1's and 0's (or -1's) and can be designed to have good auto-correlation properties, the cross-correlation value is designed to have a small value so that it is easy to distinguish which sync is applied to the PPDU at the receiving end. (The receiver simultaneously performs cross-correlation of the received signal using the sequence of sync 1 and 2), which can be used to indicate two data rates without additional PHY signaling. For example, sync 1 can be used for WUR PPDUs with a data rate of 62.5 kbps on the payload using long sequences and symbols. It can also be used for WUR PPDUs with a data rate of 250kbps in the payload using relatively short sequences and symbols.

14 shows a PPDU used in the IEEE 802.11 ba system. Two data rates of 62.5 kbps and 250 kbps are used in the data field, and the information at each data rate is shown in Table 16 below.

	62.5 kbps	250kbps
Information 0	4us on + 4us off + 4us on + 4us off	2us on + 2us off
Information 1	4us off + 4us on + 4us off + 4us on	2us off + 2us on

In Table 16 above, there is always energy in 2 / 4us on-signal and conversely there is always energy in 2 / 4us off-signal. However, in order to improve the performance, a partial OOK which selectively uses part or all of the on-signal as the off-signal may be used. On the other hand, when using the on-signal and off-signal at each data rate, . FIGS. 15 to 19 show examples of positions of the Tus-on signal at information 0 and 1 having a data rate of 250 kbps.

A. 250kbps

On the other hand, T (0us <T <2us) can be configured as an on-signal of 2us on-signal. If T is small, SNR gain is obtained, but performance may be deteriorated due to timing error. For example, T may be 1us, which may be a SNR gain but not a good timing error. The on-signal position of T may be as shown in Figs. 15 to 17 in each information.

FIG. 15 shows a case where an on-signal is located for the first time T within a 2 on-signal in each information. Figure 16 shows the effect of the ISI on the previous signal, the effect of the ISI on the next signal, and the on-signal of T such that an off-signal is generated at the beginning and end of the 2us on-signal to reduce intra-symbol interference . 17 shows a case where an on-signal of T is located at the rear side. Considering the influence of ISI and intra-symbol interference, the off-signal of (2-T) / 2 in the second case can be located in the second case and can be the most favorable structure in terms of performance. However, if the decision is made by comparing the on-signal of T with the corresponding off-signal (ie, the interval corresponding to T of each information) during decoding, the first and last structures may not have a performance problem. However, since the first symbol of the data filed after the preamble may be affected by ISI, the first structure may have some performance loss.

Alternatively, as shown in FIG. 18, the T on-signals at different positions in each information may be used.

The receiver can determine the information by comparing the energy of the on-signal and off-signal sections corresponding to T of each information when decoding. However, the structure of FIG. 18 may be a bad structure in terms of ISI. In order to reduce this, the on-signal of T may be positioned as shown in FIG. However, the structure of FIG. 19 may be a bad structure in terms of intra symbol interference.

Finally, the structure of FIG. 16 among the structures in which the on-signal is located in the same section may be advantageous in terms of ISI and intra symbol interference.

Figs. 20 to 46 show examples of positions of the Tus-on signal at information 0 and 1, which have a data rate of 62.5 kbps.

B. 62.5 kbps

(1) Use 8us on / off

For simple partial OOK implementations, on + off / off + on structures are available which are identical to 250kbps. However, the on- and off-signal is 8us. That is, T may be less than 0us but less than 8us. In this case, we can change 2us to 8us in the example of various structures proposed by A, for example, T may be 1/2/4 / 6us and 2us may be an advantageous value in consideration of tradeoff between SNR gain and timing error. To reduce ISI and intra-symbol interference, an on-signal of T may be located at the center of the 8us on-signal, where (8-T) / 2 off-signals are located at both ends of the 8us on-signal.

(2) Use of original structure

1) On-signal location of T on all 4us on-signal

A partial OOK can be applied using the same structure as Mandatory. As shown in FIG. 20 to FIG. 22, on-signals of T (0us <T <4us) can be located on all 4us on-signals in each information.

For each piece of information, FIG. 20 shows a case where an on-signal is located for the first time T in the 4us on-signal. FIG. 21 shows a case where an on-signal of T is located so that an off-signal is generated at a part of the beginning and end of the 4us on-signal. 22 shows a case where an on-signal of T is located at the rear side.

The structure of FIG. 20 can be influenced by the ISI in the preceding symbol (the first structure of information 0) and the structure of FIG. 22 can influence the ISI in the latter symbol (third structure of information 1). The structure of FIG. 22 is also a structure that can affect intra symbol interference in off section. Considering the effect of ISI or intra-symbol interference, the structure of FIG. 21 may be advantageous and off-signals of (4-T) / 2 may be located back and forth within 4 us on-signal. However, if the decision is made by comparing the on-signal of T and the corresponding off-signal during decoding, the structure of FIG. 20 and FIG. 22 may have no performance problem. However, the structure of FIG. 20 may have some performance loss since the first symbol of the data filed following the preamble may be affected by ISI. For example, each T may be 0.5 / 1/2 / 3us, that is, the sum of the two Ts may be 1/2/4 / 6us, and 2us may be advantageous when considering tradeoffs between SNR gain and timing error Lt; / RTI &gt;

T1 + T2 may be 1/2/4 / 6us as shown in FIGS. 23 to 25. For example, considering the tradeoff between SNR gain and timing error, T1 + T2 may be 4us May be an advantageous value.

Or may be configured as shown in Figs. 26 to 28. In this case, considering the ISI, it may be possible to set the length of the first T1 of Information 0 and the second T1 of Information 1 to be short. For example, T1 can be set to 1us T2 to be 3us and T1 + T2 to be 4us.

Alternatively, the positions of the first and second partial on-signal sections may be different or the length of the section may be different as shown in FIG.

In this case, the positions of the T1 pairs in each information may be the same in terms of decoding complexity (the same is true of the pair positions of T2), but the proposal is not limited. That is, the case shown in FIG. 30 may be possible.

By setting the length of T1 to be short, the influence of ISI can be reduced. The receiver can determine the information by comparing the energy of the on-signal and the off-signal corresponding to T1 and T2 of each information when decoding.

However, the structure of FIG. 29 and FIG. 30 may cause performance loss due to influence of intra symbol interference.

2) On-signal location of T only for some 4us on-signals

As shown in FIGS. 31 to 33, on-signals corresponding to T can be configured for only the first 4-on-signal in each information.

This structure can minimize the effect of ISI on the back symbol and additionally the structure of FIG. 32 may be advantageous considering the ISI effect of the preceding symbol and intra-symbol interference, and the backward (4-T) / 2 off-signal can be located. The receiving end can determine the information by comparing the energy of the section corresponding to T within 4us of FIG. 31 and FIG. 32 at the time of decoding.

Alternatively, as shown in FIGS. 34 to 36, on-signals corresponding to T can be configured for only the second 4-on-signal in each information.

This structure can minimize the effect of the ISI of the preceding symbol and additionally the structure of FIG. 35 may be advantageous considering the ISI effect on the back symbol and the intra-symbol interference, and the backward (4-T) / 2 off-signal can be located. The receiver can determine the information by comparing the energy of the interval corresponding to T in the third and fourth 4us at the time of decoding.

Alternatively, as shown in FIGS. 37 to 39, the on-signal of T may be located in the first 4us on-signal in information 0 and in the fourth 4us on-signal in information 1.

However, this structure may be the worst structure considering the influence of ISI. Nevertheless, the structure of FIG. 38 may be advantageous and off-signals of (4-T) / 2 may be located at both ends of the 4us on-signal. The receiving end can decide the information by comparing the energy of the interval corresponding to T in the first and fourth 4us in decoding.

Alternatively, as shown in FIG. 40 to FIG. 42, the on-signal of T may be located in the third 4us on-signal in information 0 and in the second 4us on-signal in information 1. FIG.

This structure may be the best structure considering the ISI effect, and in particular the structure of FIG. 41 may be preferred, in which case off-signals of (4-T) / 2 forward and backward have. The receiver can determine the information by comparing the energy of the interval corresponding to T in the second and third 4us at the time of decoding.

Alternatively, the positions of information 0 and information 1 may be different, and FIG. 43 is an example.

The structure of FIG. 43 may be an optimal structure in consideration of ISI. However, the effect of intra-symbol interference is large. The receiver can determine the information by comparing the energy of the on-signal and the off-signal of the section corresponding to T of each information upon decoding.

Figure 44 may be the most optimal structure in consideration of intra symbol interference, but it may be the worst structure in terms of ISI.

45 and 46 are examples of structures that can reduce ISI and intra symbol interference, and may be advantageous in terms of performance. That is, in FIG. 45, information 0 is 8us on-signal + 8us off-signal structure, and information 1 is 8us off-signal + 8us on-signal structure. 46 shows that information 0 is 8us off-signal + 8us on-signal structure and information 1 is 8us on-signal + 8us off-signal structure.

In the various examples described above, T may be 1/2 / 4us and 2us may be an advantageous value in consideration of the trade-off between SNR gain and timing error.

C. Partial OOK on-signal formation method

First, the 4us on-signal of 62.5kbps and the 2us on-signal of 250kbps in the existing OOK are subjected to 64 point IFFT by applying a specific sequence to 13 subcarriers corresponding to 4MHz among 64 subcarriers of 20MHz, And a method of selecting the substrate.

There are two main ways of forming part-on-OOK on-signal using signals of 62.5kbps and 250kbps.

The first method uses the existing on-signal corresponding to the on-signal section of the Partial OOK. For example, if you use a partial on-signal of 2us among the 4us on-signals of 62.5kbps, you can replace the first 1us and last 1us of 4us on-signal by off-signal or masking and select only middle 2us on-signal. have.

The second method is to use some signal with good PAPR or signal characteristics. In other words, it can be formed by selecting a signal with good PAPR or signal characteristics equal to the partial on-signal length of the existing 2 / 4us on-signal irrespective of the partial on-signal position.

If 2us partial on-signal is used at 62.5kbps, the existing 2k on-signal of 250kbps can be used as it is.

It can also form signals in new ways. It can be used for partial on-signal formation with a length of 4 / mus and m is a natural number greater than 1. In this case, if a coefficient is inserted into 13 subcarriers in units of m cells and a 64 point IFFT is performed, the same m time domain signals are generated (cycle 3.2 / m us) have.

For example, if m = 2, the partial on-signal is 2us, which means that if a 64-point IFFT is applied to only the first, third, fifth, ninth, And one can be formed by applying 0.4 μs CP. If there are 32 subcarriers at 20MHz, insert the 1, 3, 5, 9, 11, 13th coefficients into 7 subcarriers corresponding to 4MHz, Method. However, when 32 point IFFT is taken, power correction is required by dividing by sqrt (2) (ie dividing by sqrt (m)).

For example, if m = 4, the partial on-signal is 1us, which means that if the 64th point IFFT is applied to only the 1,5th, 9th, and 13th tones of thirteen tones, And applying 0.2 μs CP. If there are 16 subcarriers at 20MHz, the above method is the same as applying 1 / 4CP after inserting the above 1,5,9,13th coefficient into 4 subcarriers corresponding to 4MHz and taking 16 IFFTs. In the case of 16 point IFFT, power correction is required by dividing by sqrt (4).

47 is a flowchart illustrating a procedure for transmitting a wakeup packet by applying the partial OOK scheme according to the present embodiment.

47 is performed in the transmitting apparatus, the receiving apparatus can correspond to the low power wake up receiver, and the transmitting apparatus can correspond to the AP.

In summary, the on signal can correspond to a signal having an actual power value. An off signal may correspond to a signal that does not have an actual power value. The first information may correspond to information 0. The second information may correspond to information 1.

In step S4710, the transmitting apparatus constructs a wakeup packet having a first data rate.

In step S4720, the transmitting apparatus transmits the wakeup packet to the receiving apparatus.

The configuration of the wakeup packet having the first data rate is as follows.

The wakeup packet includes an on-off keying (OOK) scheme and includes first information and second information. The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal. The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal.

The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform).

For example, coefficients may be inserted into all of the 13 subcarriers. At this time, the generated signal may be a signal having a length of 3.2 us having no period. A CP (Cyclic Prefix) may be inserted into the generated signal to generate an on signal or an off signal having a length of 4 us. The coefficient may be selected from 1, -1, j or -j.

As another example, coefficients may be inserted into the 13 subcarriers in units of two subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of two spaces, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 1.6 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. Here, the masking may correspond to a technique of covering a part of a signal and taking only a part of the signal. That is, a part of the generated signal can be taken to generate an on signal or an off signal having a length of 2us (CP + 1.6us).

As another example, a coefficient may be inserted into the 13 subcarriers in units of 4 subcarriers, and 0 may be inserted into the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of four cells, and the remainder may be set to zero. At this time, the generated signal may be a 3.2us signal having a period of 0.8us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal can be taken to generate an ON signal or an OFF signal having a length of 1us (CP + 0.8us).

As another example, a coefficient may be inserted into the 13 subcarriers in units of 8 subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the first sequence may be set to a coefficient in units of 8 squares, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 0.4 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal may be taken to generate an ON signal or an OFF signal having a length of 0.5us (CP + 0.4us).

The off signal may be generated by inserting zeros into 13 contiguous subcarriers of the 20 MHz band and performing 64-point IFFT. The off signal may also be masked to have a length of 2us, 1us, or 0.5us (CP + 1.6us, CP + 0.8us, CP + 0.4us).

However, this embodiment describes only a case where coefficients are inserted into all of the 13 subcarriers. That is, the first ON signal may be an ON signal having a length of 4 us, which is a CP inserted into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Accordingly, the length of the first ON signal may be 4us.

A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal. That is, a partial OOK technique may be used in which an ON signal (partial ON signal) is set only in a part of the ON signal (first ON signal) to improve the performance. Performance enhancement means that the length of the ON signal is further reduced, thereby increasing the power of the signal, resulting in an advantageous effect in terms of SNR gain or timing error.

The partial ON signal is set to a second ON signal included in the wakeup packet having the second data rate. The second on-signal is generated by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and masking half of the generated signal by performing 64-point IFFT.

For example, coefficients may be inserted into all of the 13 subcarriers. At this time, the generated signal may be a signal having a length of 3.2 us having no period. A CP (Cyclic Prefix) may be inserted into the generated signal to generate an ON signal having a length of 4 us. At this time, a part of the generated signal may be taken to generate an ON signal having a length of 2us (CP + 1.6us). In addition, an on signal having a length of 2us can be generated by masking half of the generated signal. Here, the masking may correspond to a technique of covering a part of a signal and taking only a part of the signal.

As another example, coefficients may be inserted into the 13 subcarriers in units of two subcarriers, and 0 may be inserted in the remaining subcarriers. That is, the second sequence may be set to a coefficient in units of two spaces, and the remainder may be set to zero. At this time, the generated signal may be a 3.2 us signal having a period of 1.6 us. Masking can be performed without inserting or inserting a CP (Cyclic Prefix) into the generated signal. That is, a part of the generated signal may be taken to generate an ON signal having a length of 2us (CP + 1.6us).

However, this embodiment describes a case where masking is performed to generate a second ON signal. That is, the second on-signal may be an on-signal masking half of a signal having a length of 4 us that has inserted the CP into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Alternatively, the second on-signal may be an on-signal masking half of the CP-inserted signal in the 3.2 us signal having a period of 1.6 us generated by performing 64-point IFFT. Accordingly, the length of the second ON signal may be 2us, and the length of the partial ON signal may be 2us.

In this embodiment, the case where the wakeup packet has LDR (Low Data Rate) or HDR (High Data Rate) is described. The first data rate being LDR is 62.5 Kbps and the second data rate being HDR may be 250 Kbps.

For example, the partial ON signal may be located at the center of the first ON signal. That is, the first information and the second information may have a structure as shown in FIG. This structure minimizes the effect of ISI (inter symbol interference) with the previous symbol or the back symbol, and minimizes the influence of intra symbol interference in the off signal period. That is, the partial ON signal having a length of 2us may be located at the center of the first ON signal having a length of 4us. The off signal may be located in the remaining part of the first ON signal other than the part where the partial ON signal is located. That is, an off signal having a length of 1 us before and after the partial ON signal can be located.

In another example, the first information may comprise two first on signals. (First ON signal + OFF signal + first ON signal + OFF signal) The first first ON signal of the two first ON signals may be set to an OFF signal. The partial on signal may be located at the end of the first on signal of the two first on signals. The first on signal preceding in the first information means that it is ahead of the first on signal in time.

In addition, the second information may include two first on signals. (Off signal + first on signal + off signal + first on signal) The first one of the two first on signals may be set to an off signal. The partial ON signal may be located at the beginning of the first ON signal of the two first ON signals. That is, the first information and the second information may have a structure as shown in FIG. The first on signal preceding in the second information means that it is ahead of the first on signal in time.

This embodiment can further increase the power of the signal by further reducing the length of the partial ON signal (so that the partial ON signal is located in only one ON signal) by setting one of the two ON signals to the OFF signal. This reduces ISI and intra symbol interference, and can have a beneficial effect in terms of SNR gain or timing error.

Also, the transmitting apparatus can configure the ON signal and the OFF signal to know the power value of the ON signal and the OFF signal first. The receiving apparatus decodes the ON signal and the OFF signal using an envelope detector, thereby reducing power consumed in decoding.

48 shows a transmitting apparatus for implementing this embodiment.

Referring to FIG. 48, a wireless device is a transmitting device capable of implementing the above-described embodiment, and can operate as an AP. In addition, the wireless device may correspond to a transmitting device that transmits a signal to a user.

48 includes a processor 4810, a memory 4820, and a transceiver 4830 as shown. The illustrated processor 4810, memory 4820 and transceiver 4830 may each be implemented as separate chips, or at least two blocks / functions may be implemented on a single chip.

The transceiver 4830 is a device including a transmitter and a receiver. When a specific operation is performed, only the operation of either the transmitter or the receiver is performed, or both the transmitter and the receiver are performed . The transceiver 4830 may include one or more antennas for transmitting and / or receiving wireless signals. In addition, the transceiver 4830 may include an amplifier for amplifying a received signal and / or a transmitted signal, and a band-pass filter for transmitting on a specific frequency band.

The processor 4810 may implement the functions, processes, and / or methods suggested herein. For example, the processor 4810 may perform the operations according to the embodiment described above. That is, the processor 4810 constructs a wakeup packet having the first data rate, and transmits the wakeup packet to the receiving apparatus.

The configuration of the wakeup packet having the first data rate is as follows.

The wakeup packet includes an on-off keying (OOK) scheme and includes first information and second information. The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal. The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal.

The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform).

However, this embodiment describes only a case where coefficients are inserted into all of the 13 subcarriers. That is, the first ON signal may be an ON signal having a length of 4 us, which is a CP inserted into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Accordingly, the length of the first ON signal may be 4us.

A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal. That is, a partial OOK technique may be used in which an ON signal (partial ON signal) is set only in a part of the ON signal (first ON signal) to improve the performance. Performance enhancement means that the length of the ON signal is further reduced, thereby increasing the power of the signal, resulting in an advantageous effect in terms of SNR gain or timing error.

The partial ON signal is set to a second ON signal included in the wakeup packet having the second data rate. The second on-signal is generated by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and masking half of the generated signal by performing 64-point IFFT.

However, this embodiment describes a case where masking is performed to generate a second ON signal. That is, the second on-signal may be an on-signal masking half of a signal having a length of 4 us that has inserted the CP into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Alternatively, the second on-signal may be an on-signal masking half of the CP-inserted signal in the 3.2 us signal having a period of 1.6 us generated by performing 64-point IFFT. Accordingly, the length of the second ON signal may be 2us, and the length of the partial ON signal may be 2us.

In this embodiment, the case where the wakeup packet has LDR (Low Data Rate) or HDR (High Data Rate) is described. The first data rate being LDR is 62.5 Kbps and the second data rate being HDR may be 250 Kbps.

For example, the partial ON signal may be located at the center of the first ON signal. That is, the first information and the second information may have a structure as shown in FIG. This structure minimizes the effect of ISI (inter symbol interference) with the previous symbol or the back symbol, and minimizes the influence of intra symbol interference in the off signal period. That is, the partial ON signal having a length of 2us may be located at the center of the first ON signal having a length of 4us. The off signal may be located in the remaining part of the first ON signal other than the part where the partial ON signal is located. That is, an off signal having a length of 1 us before and after the partial ON signal can be located.

In another example, the first information may comprise two first on signals. (First ON signal + OFF signal + first ON signal + OFF signal) The first first ON signal of the two first ON signals may be set to an OFF signal. The partial on signal may be located at the end of the first on signal of the two first on signals. The first on signal preceding in the first information means that it is ahead of the first on signal in time.

In addition, the second information may include two first on signals. (Off signal + first on signal + off signal + first on signal) The first one of the two first on signals may be set to an off signal. The partial ON signal may be located at the beginning of the first ON signal of the two first ON signals. That is, the first information and the second information may have a structure as shown in FIG. The first on signal preceding in the second information means that it is ahead of the first on signal in time.

This embodiment can further increase the power of the signal by further reducing the length of the partial ON signal (so that the partial ON signal is located in only one ON signal) by setting one of the two ON signals to the OFF signal. This reduces ISI and intra symbol interference, and can have a beneficial effect in terms of SNR gain or timing error.

The processor 4810 may include an application-specific integrated circuit (ASIC), another chipset, logic circuitry, a data processing device, and / or a transducer to convert baseband signals and radio signals. Memory 4820 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices.

FIG. 49 shows a procedure for transmitting a WUR PPDU configured by applying a partial OOK scheme between an AP and a WUR STA according to the present embodiment.

One example of Fig. 49 is performed in the transmitting apparatus and the receiving apparatus, the receiving apparatus can correspond to the low power wake up receiver (WUR STA), and the transmitting apparatus can correspond to the AP.

In summary, the on signal can correspond to a signal having an actual power value. An off signal may correspond to a signal that does not have an actual power value.

In step S4910, the AP constructs a wakeup packet having a first data rate.

In step S4920, the AP transmits the wakeup packet to the WUR STA.

The configuration of the wakeup packet having the first data rate is as follows.

The wakeup packet includes an on-off keying (OOK) scheme and includes first information and second information. The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal. The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal.

The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform).

However, this embodiment describes only a case where coefficients are inserted into all of the 13 subcarriers. That is, the first ON signal may be an ON signal having a length of 4 us, which is a CP inserted into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Accordingly, the length of the first ON signal may be 4us.

A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal. That is, a partial OOK technique may be used in which an ON signal (partial ON signal) is set only in a part of the ON signal (first ON signal) to improve the performance. Performance enhancement means that the length of the ON signal is further reduced, thereby increasing the power of the signal, resulting in an advantageous effect in terms of SNR gain or timing error.

The partial ON signal is set to a second ON signal included in the wakeup packet having the second data rate. The second on-signal is generated by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and masking half of the generated signal by performing 64-point IFFT.

However, this embodiment describes a case where masking is performed to generate a second ON signal. That is, the second on-signal may be an on-signal masking half of a signal having a length of 4 us that has inserted the CP into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Alternatively, the second on-signal may be an on-signal masking half of the CP-inserted signal in the 3.2 us signal having a period of 1.6 us generated by performing 64-point IFFT. Accordingly, the length of the second ON signal may be 2us, and the length of the partial ON signal may be 2us.

In this embodiment, the case where the wakeup packet has LDR (Low Data Rate) or HDR (High Data Rate) is described. The first data rate being LDR is 62.5 Kbps and the second data rate being HDR may be 250 Kbps.

For example, the partial ON signal may be located at the center of the first ON signal. That is, the first information and the second information may have a structure as shown in FIG. This structure minimizes the effect of ISI (inter symbol interference) with the previous symbol or the back symbol, and minimizes the influence of intra symbol interference in the off signal period. That is, the partial ON signal having a length of 2us may be located at the center of the first ON signal having a length of 4us. The off signal may be located in the remaining part of the first ON signal other than the part where the partial ON signal is located. That is, an off signal having a length of 1 us before and after the partial ON signal can be located.

In another example, the first information may comprise two first on signals. (First ON signal + OFF signal + first ON signal + OFF signal) The first first ON signal of the two first ON signals may be set to an OFF signal. The partial on signal may be located at the end of the first on signal of the two first on signals. The first on signal preceding in the first information means that it is ahead of the first on signal in time.

In addition, the second information may include two first on signals. (Off signal + first on signal + off signal + first on signal) The first one of the two first on signals may be set to an off signal. The partial ON signal may be located at the beginning of the first ON signal of the two first ON signals. That is, the first information and the second information may have a structure as shown in FIG. The first on signal preceding in the second information means that it is ahead of the first on signal in time.

This embodiment can further increase the power of the signal by further reducing the length of the partial ON signal (so that the partial ON signal is located in only one ON signal) by setting one of the two ON signals to the OFF signal. This reduces ISI and intra symbol interference, and can have a beneficial effect in terms of SNR gain or timing error.

50 shows a receiving apparatus for implementing this embodiment.

Referring to FIG. 50, a wireless device is a receiving device capable of implementing the above-described embodiment, and can operate as a non-AP STA or a WUR STA. Also, the wireless device may correspond to the above-described user.

50 includes a processor 5010, a memory 5020, and a transceiver 5030, as shown. The illustrated processor 5010, memory 5020 and transceiver 5030 may each be implemented as separate chips, or at least two blocks / functions may be implemented on a single chip.

The transceiver 5030 is a device including a transmitter and a receiver. When a specific operation is performed, only the operation of either the transmitter or the receiver is performed, or both the transmitter and the receiver are operated . The transceiver 5030 may include one or more antennas for transmitting and / or receiving wireless signals. In addition, the transceiver 5030 may include an amplifier for amplifying a received signal and / or a transmitted signal, and a band-pass filter for transmitting on a specific frequency band.

The processor 5010 may implement the functions, processes and / or methods suggested herein. For example, the processor 5010 can perform the operations according to the present embodiment described above. That is, the processor 5010 receives the wakeup packet having the first data rate configured from the transmitting apparatus.

The configuration of the wakeup packet having the first data rate is as follows.

The wakeup packet includes an on-off keying (OOK) scheme and includes first information and second information. The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal. The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal.

The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform).

However, this embodiment describes only a case where coefficients are inserted into all of the 13 subcarriers. That is, the first ON signal may be an ON signal having a length of 4 us, which is a CP inserted into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Accordingly, the length of the first ON signal may be 4us.

A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal. That is, a partial OOK technique may be used in which an ON signal (partial ON signal) is set only in a part of the ON signal (first ON signal) to improve the performance. Performance enhancement means that the length of the ON signal is further reduced, thereby increasing the power of the signal, resulting in an advantageous effect in terms of SNR gain or timing error.

The partial ON signal is set to a second ON signal included in the wakeup packet having the second data rate. The second on-signal is generated by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and masking half of the generated signal by performing 64-point IFFT.

However, this embodiment describes a case where masking is performed to generate a second ON signal. That is, the second on-signal may be an on-signal masking half of a signal having a length of 4 us that has inserted the CP into a signal having a length of 3.2 us having no period generated by performing 64-point IFFT. Alternatively, the second on-signal may be an on-signal masking half of the CP-inserted signal in the 3.2 us signal having a period of 1.6 us generated by performing 64-point IFFT. Accordingly, the length of the second ON signal may be 2us, and the length of the partial ON signal may be 2us.

In this embodiment, the case where the wakeup packet has LDR (Low Data Rate) or HDR (High Data Rate) is described. The first data rate being LDR is 62.5 Kbps and the second data rate being HDR may be 250 Kbps.

For example, the partial ON signal may be located at the center of the first ON signal. That is, the first information and the second information may have a structure as shown in FIG. This structure minimizes the effect of ISI (inter symbol interference) with the previous symbol or the back symbol, and minimizes the influence of intra symbol interference in the off signal period. That is, the partial ON signal having a length of 2us may be located at the center of the first ON signal having a length of 4us. The off signal may be located in the remaining part of the first ON signal other than the part where the partial ON signal is located. That is, an off signal having a length of 1 us before and after the partial ON signal can be located.

In another example, the first information may comprise two first on signals. (First ON signal + OFF signal + first ON signal + OFF signal) The first first ON signal of the two first ON signals may be set to an OFF signal. The partial on signal may be located at the end of the first on signal of the two first on signals. The first on signal preceding in the first information means that it is ahead of the first on signal in time.

In addition, the second information may include two first on signals. (Off signal + first on signal + off signal + first on signal) The first one of the two first on signals may be set to an off signal. The partial ON signal may be located at the beginning of the first ON signal of the two first ON signals. That is, the first information and the second information may have a structure as shown in FIG. The first on signal preceding in the second information means that it is ahead of the first on signal in time.

This embodiment can further increase the power of the signal by further reducing the length of the partial ON signal (so that the partial ON signal is located in only one ON signal) by setting one of the two ON signals to the OFF signal. This reduces ISI and intra symbol interference, and can have a beneficial effect in terms of SNR gain or timing error.

The processor 5010 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, a data processing device, and / or a converter for converting baseband signals and radio signals. Memory 5020 can include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and / or other storage devices.

Claims (12)

1. A method for transmitting a wake-up packet by applying an On-Off Keying (OOK) scheme in a wireless LAN system,

   The transmitting apparatus configuring a wakeup packet having a first data rate; And

   Wherein the transmitting apparatus transmits the wakeup packet to a receiving apparatus,

   Wherein the wakeup packet includes first information and second information,

   The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal,

   The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal,

   The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform)

   A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal,

   The partial on signal is set to a second on signal contained in a wakeup packet having a second data rate,

   The second on signal is generated by masking half of the generated signal by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT

   Way.
2. The method according to claim 1,

   The first data rate is 62.5 Kbps,

   Wherein the second data rate is 250 Kbps

   Way.
3. The method according to claim 1,

   The length of the first on signal is 4us,

   The length of the second on signal is 2us,

   The length of the partial on signal is 2us

   Way.
4. The method according to claim 1,

   The partial ON signal is located at the center of the first ON signal

   Way.
5. The method according to claim 1,

   Wherein the first information comprises two first on signals,

   The first first ON signal of the two first ON signals is set to an OFF signal,

   The partial on signal is located at the end of the first on signal of the two first on signals

   Way.
6. 6. The method of claim 5,

   Wherein the second information comprises two first on signals,

   The first one of the two first on signals is set to an off signal,

   The partial ON signal is located at the beginning of the first ON signal of the two first ON signals

   Way.
7. A transmitting apparatus for transmitting a wake-up packet by applying an On-Off Keying (OOK) scheme in a wireless LAN system,

   A transceiver for transmitting or receiving a radio signal; And

   A processor for controlling the transceiver, the processor comprising:

   Construct a wakeup packet having a first data rate; And

   Transmitting the wakeup packet to a receiving device,

   Wherein the wakeup packet includes first information and second information,

   The first information is set in the order of a first on signal, an off signal, a first on signal, and an off signal,

   The second information is set in the order of an off signal, a first on signal, an off signal, and a first on signal,

   The first ON signal is generated by applying a first sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT (Inverse Fast Fourier Transform)

   A part of the first on signal is set as a partial on signal and the remaining part of the first on signal is set as an off signal,

   The partial on signal is set to a second on signal contained in a wakeup packet having a second data rate,

   The second on signal is generated by masking half of the generated signal by applying a second sequence to 13 consecutive subcarriers in the 20 MHz band and performing 64-point IFFT

   Transmitting apparatus.
8. 8. The method of claim 7,

   The first data rate is 62.5 Kbps,

   Wherein the second data rate is 250 Kbps

   Transmitting apparatus.
9. 8. The method of claim 7,

   The length of the first on signal is 4us,

   The length of the second on signal is 2us,

   The length of the partial on signal is 2us

   Transmitting apparatus.
10. 8. The method of claim 7,

    The partial ON signal is located at the center of the first ON signal

    Transmitting apparatus.
11. 8. The method of claim 7,

    Wherein the first information comprises two first on signals,

    The first first ON signal of the two first ON signals is set to an OFF signal,

    The partial on signal is located at the end of the first on signal of the two first on signals

    Transmitting apparatus.
12. 12. The method of claim 11,

    Wherein the second information comprises two first on signals,

    The first one of the two first on signals is set to an off signal,

    The partial ON signal is located at the beginning of the first ON signal of the two first ON signals

    Transmitting apparatus.

Images