Determines the tone sequence used for the wake-up procedure

Abstract

The present disclosure provides systems, methods, and apparatus for determining one or more frequency-modulated sequences (e.g., for a wake-up procedure), including a computer program encoded on a computer storage medium. In one aspect, an access point (AP) may use a wake-up packet to wake up a mobile station (STA) from a low power mode, wherein the ON codeword of the wake-up packet is modulated using a frequency-modulated sequence. In order to reduce the likelihood that the STA will mistakenly identify the ON codeword as a packet preamble, the AP may implement a frequency-modulated sequence that satisfies a correlation metric threshold. For example, for a set of candidate frequency-modulated sequences, each frequency-modulated sequence may be associated with a correlation metric and a peak-to-average power ratio (PAPR) coordinate pair, and the frequency-modulated sequence used to modulate the ON codeword of the wake-up packet may be selected from the lower convex hull of these coordinate pairs.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 873,469, entitled “DETERMINING ATONE SEQUENCE FOR WAKE-UP PROCEDURES,” filed by AWATER et al. on July 12, 2019, and U.S. Patent Application No. 16 / 924,567, entitled “DETERMINING ATONE SEQUENCE FOR WAKE-UP PROCEDURES,” filed by AWATER et al. on July 9, 2020, each of which is assigned to the assignee of this application. Technical Field

[0003] The present disclosure relates generally to wireless communications and, more particularly, to determining a tone sequence for a wake-up procedure. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be multiple access systems capable of supporting communication with multiple users by sharing available system resources, such as time, frequency, and power. A wireless network (e.g., a wireless local area network (WLAN), such as a Wi-Fi (i.e., an Institute of Electrical and Electronics Engineers (IEEE) 802.11) network) may include an access point (AP) that can communicate with one or more stations (STAs) or mobile devices. An AP may be coupled to a network (such as the Internet) and may enable mobile devices to communicate via the network (or communicate with other devices coupled to the AP). A wireless device may communicate bidirectionally with a network device. For example, in a WLAN, a STA may communicate with an associated AP via downlink and uplink transmissions. A downlink (or forward link) may refer to a communication link from an AP to a STA, and an uplink (or reverse link) may refer to a communication link from a STA to an AP. Summary of the invention

[0005] The systems, methods, and devices of the disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0006] One innovative aspect of the subject matter described in the present disclosure may be implemented in an apparatus for an access point (AP) for wireless communication. The apparatus may include a processing system and an interface. The processing system may be configured to: determine that a station (STA) associated with the AP is to wake up from a low power mode; and generate a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet including a frequency-tone sequence of an ON symbol for the wake-up packet, wherein the frequency-tone sequence satisfies a correlation metric threshold. The interface may be configured to output the wake-up packet for transmission to the STA.

[0007] Another innovative aspect of the subject matter described in the present disclosure can be implemented in an additional device for an AP for wireless communication. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. These instructions can be executed by the processor to cause the device to: determine that a STA associated with the AP is to wake up from a low power mode; generate a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet including a frequency-modulated sequence of ON codewords for the wake-up packet, wherein the frequency-modulated sequence satisfies a correlation metric threshold; and transmit the wake-up packet to the STA.

[0008] Another innovative aspect of the subject matter described in the present disclosure may be implemented in an additional device of an AP for wireless communication. The device may include: a device for determining that a STA associated with the AP is to be awakened from a low power mode; a device for generating a wake-up packet for reception by a wake-up radio of the STA to trigger awakening of the STA, the wake-up packet including a frequency-modulated sequence of ON symbols for the wake-up packet, wherein the frequency-modulated sequence satisfies a correlation metric threshold; and a device for transmitting the wake-up packet to the STA.

[0009] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a method for wireless communication at a device of an AP. The method may include: determining that a STA associated with the AP is to wake up from a low power mode; generating a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet including a frequency-tone sequence of an ON symbol for the wake-up packet, wherein the frequency-tone sequence satisfies a correlation metric threshold; and transmitting the wake-up packet to the STA.

[0010] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a non-transitory computer-readable medium storing code for wireless communication at a device of an AP. The code may include instructions executable by a processor for: determining that a STA associated with the AP is to wake up from a low power mode; generating a wake-up packet for reception by a wake-up radio of the STA to trigger wake-up of the STA, the wake-up packet including a frequency-modulated sequence of ON codewords for the wake-up packet, wherein the frequency-modulated sequence satisfies a correlation metric threshold; and transmitting the wake-up packet to the STA.

[0011] In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, the correlation metric threshold may be a maximum correlation metric threshold; and the frequency-modulated sequence includes a maximum correlation metric that satisfies the maximum correlation metric threshold by being less than the maximum correlation metric threshold.

[0012] In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, the satisfaction of the maximum correlation metric threshold may be based on each of the set of cyclic shifts of the ON symbol satisfying the maximum correlation metric threshold.

[0013] In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, satisfaction of the maximum correlation metric threshold may be based on a maximum value among a set of absolute values ​​of normalized autocorrelations at one or more sampling start times of the frequency-modulated sequence, one or more repetitions of the frequency-modulated sequence, or a combination thereof. In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, these normalized autocorrelations correspond to repetition intervals over a time length equal to the duration of a short training sequence within an ON symbol using the frequency-modulated sequence.

[0014] In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, the frequency modulation sequence further includes a maximum PAPR that satisfies a maximum peak-to-average power ratio (PAPR) threshold by being less than a maximum PAPR threshold. In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, satisfying the maximum PAPR threshold may be based on each of the cyclic shift set of the ON symbol satisfying the maximum PAPR threshold.

[0015] In some implementations of the methods, devices, and non-transitory computer-readable media described herein, the frequency-modulated sequence includes a frequency-modulated sequence modulated by binary phase shift keying (BPSK), a frequency-modulated sequence modulated by quadrature phase shift keying (QPSK), a frequency-modulated sequence modulated by quadrature amplitude modulation (QAM), or a combination thereof.

[0016] Some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein may further include operations, features, apparatus, or instructions for: selecting a data rate for the ON codewords of the wake-up packet; and determining the frequency modulation sequence based on the data rate.

[0017] In some implementations of the methods, devices (apparatus), and non-transitory computer-readable media described herein, the data rate includes a high data rate and the ON codeword spans a first time period and uses a first number of subcarriers; or the data rate includes a low data rate and the ON codeword spans a second time period longer than the first time period and uses a second number of subcarriers greater than the first number of subcarriers.

[0018] In some implementations of the methods, devices, and non-transitory computer-readable media described herein, the frequency-modulation sequence may include one of the following sequences: [1 -1 1 1 -1-1 0 -1 1 1 -1-1 -1], [-1 11-1-1 1 0 1-1-1-1-1-1], [1-1 1 1-1 1 0 1 1 1-1-1-1], [1-1 1-1-1-1 0-1 1-1-1 -1-1], [-1 1 -11 1 -1 0 1 1 -1-1 -1-1], or [-1 1 1 1 -1 1 0 -1-1 -1 1 -1-1].

[0019] Another innovative aspect of the subject matter described in the present disclosure may be implemented in an additional apparatus for selecting a frequency-modulation sequence. The apparatus may include a processing system and a memory. The processing system may be configured to: identify a set of candidate frequency-modulation sequences; store a correlation metric and a PAPR for each of the set of candidate frequency-modulation sequences in the memory and in association with an identifier of the corresponding candidate frequency-modulation sequence; associate the correlation metric and the PAPR for each of the set of candidate frequency-modulation sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-modulation sequences; identify one or more coordinate pairs of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and select a frequency-modulation sequence for an ON symbol of a wake-up packet from the one or more coordinate pairs that define the lower convex hull.

[0020] Another innovative aspect of the subject matter described in the present disclosure may be implemented in an additional apparatus for selecting a frequency-modulation sequence. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: identify a set of candidate frequency-modulation sequences; store a correlation metric and a PAPR for each of the set of candidate frequency-modulation sequences in the memory and in association with an identifier of the corresponding candidate frequency-modulation sequence; associate the correlation metric and the PAPR for each of the set of candidate frequency-modulation sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-modulation sequences; identify one or more coordinate pairs of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and select a frequency-modulation sequence for an ON symbol of a wake-up packet from the one or more coordinate pairs that define the lower convex hull.

[0021] Another innovative aspect of the subject matter described in the present disclosure may be implemented in an additional device for selecting a frequency-modulation sequence. The device may include: a device for identifying a set of candidate frequency-modulation sequences; a device for storing a correlation metric and a PAPR for each of the set of candidate frequency-modulation sequences in a memory and in association with an identifier of the corresponding candidate frequency-modulation sequence; a device for associating the correlation metric and the PAPR for each of the set of candidate frequency-modulation sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-modulation sequences; a device for identifying one or more coordinate pairs of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and a device for selecting a frequency-modulation sequence for an ON codeword of a wake-up packet from the one or more coordinate pairs that define the lower convex hull.

[0022] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a method for selecting a frequency-modulated sequence. The method may include: identifying a set of candidate frequency-modulated sequences; storing a correlation metric and a PAPR for each of the set of candidate frequency-modulated sequences in a memory and in association with an identifier of the corresponding candidate frequency-modulated sequence; associating the correlation metric and the PAPR for each of the set of candidate frequency-modulated sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-modulated sequences; identifying one or more coordinate pairs of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and selecting a frequency-modulated sequence for an ON symbol of a wake-up packet from the one or more coordinate pairs that define the lower convex hull.

[0023] Another innovative aspect of the subject matter described in the present disclosure may be implemented in a non-transitory computer-readable medium storing code for selecting a frequency-modulation sequence. The code may include instructions executable by a processor for the following operations: identifying a set of candidate frequency-modulation sequences; storing a correlation metric and a PAPR for each of the set of candidate frequency-modulation sequences in a memory and in association with an identifier of the corresponding candidate frequency-modulation sequence; associating the correlation metric and the PAPR for each of the set of candidate frequency-modulation sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-modulation sequences; identifying one or more coordinate pairs of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and selecting a frequency-modulation sequence for an ON codeword of a wake-up packet from the one or more coordinate pairs that define the lower convex hull.

[0024] Some implementations of the methods, devices, and non-transitory computer-readable media described herein for identifying one or more of the coordinate pairs that define the lower convex hull of the set of coordinate pairs may further include operations, features, devices, or instructions for the following actions: identifying a first coordinate pair in the set of coordinate pairs having a minimum correlation metric; identifying a second coordinate pair in the set of coordinate pairs having a steepest negative slope relative to the first coordinate pair; and identifying additional coordinate pairs in the set of coordinate pairs, each of the additional coordinate pairs having a correlation metric greater than the correlation metric of the most recently identified coordinate pair and having a steepest negative slope relative to the most recently identified coordinate pair, wherein the first coordinate pair, the second coordinate pair, and the additional coordinate pairs form the one or more coordinate pairs among the coordinate pairs that define the lower convex hull of the set of coordinate pairs.

[0025] Some implementations of the methods, apparatus (means), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for sorting the set of coordinate pairs based on the PAPR before identifying the first coordinate pair.

[0026] Some implementations of the methods, apparatuses, and non-transitory computer-readable media described herein for identifying one or more of the coordinate pairs that define the lower convex hull of the set of coordinate pairs may further include operations, features, apparatus, or instructions for: representing the set of coordinate pairs in a scatter plot wherein a first axis represents the correlation metric and a second axis represents the PAPR grid; and identifying one or more of the coordinate pairs that define the lower convex hull of the set of coordinate pairs.

[0027] In some implementations of the methods, devices, and non-transitory computer-readable media described herein, the correlation metric of each of the set of candidate frequency-modulation sequences includes the maximum correlation metric of each candidate frequency-modulation sequence; and the PAPR of each of the set of candidate frequency-modulation sequences includes the maximum PAPR of each candidate frequency-modulation sequence.

[0028] Details of one or more implementations of the subject matter described in the present disclosure are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages will become apparent from this description, the accompanying drawings, and the claims. It should be noted that the relative dimensions of the following drawings may not be drawn to scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 and Figure 2 An example of a wireless communication system that supports determining a frequency-frequency tone sequence for a wake-up procedure is shown.

[0030] Figure 3 The packet structure of an example signal is shown.

[0031] Figure 4 An example flow chart for determining a tone sequence is shown.

[0032] Figure 5 An example plot for determining a tone sequence is shown.

[0033] Figure 6 An example waveform generation process using the determined frequency-tone sequence is shown.

[0034] Figure 7 An example flow diagram for use with devices in the system is shown.

[0035] Figure 8 A block diagram of an example system including a device that supports a wake-up procedure using a determined tone sequence is shown.

[0036] Fig. 9 A block diagram of an example system including devices that support determining a tone sequence is shown.

[0037] Figure 10-13 A flow chart illustrating an example method for determining a tone sequence, performing a wake-up procedure, or both is shown.

[0038] Like reference numbers and designations in the various drawings indicate like elements. DETAILED DESCRIPTION

[0039] The following description is directed to certain implementations in order to describe the innovative aspects of the present disclosure. However, one of ordinary skill in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals in accordance with any of the IEEE 16.11 standards or any of the IEEE 802.11 standards, (Bluetooth) standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), global system for mobile communications (GSM), GSM / general packet radio service (GPRS), enhanced data GSM environment (EDGE), terrestrial trunked radio (TETRA), wideband CDMA (W-CDMA), evolution data optimized (EV-DO), 1xEV-DO, EV-DO Revision A, EV-DO Revision B, high speed packet access (HSPA), high speed downlink packet access (HSDPA), high speed uplink packet access (HSUPA), evolved high speed packet access (HSPA+), long term evolution (LTE), AMPS, or other known signals for communication within a wireless network, cellular network, or Internet of Things (IoT) network (such as, a system utilizing 3G, 4G or 5G or further implementations thereof).

[0040] In some implementations, when a mobile station (STA) is idle, the STA may be configured to operate in a deep sleep mode to save power and extend battery life. An access point (AP) may wake up the STA from a low power mode by transmitting a wake-up packet to the STA. The STA may use a receiver (such as a wake-up radio) to receive the wake-up packet. Based on receiving the wake-up packet, the wake-up radio may wake up the STA from a low power mode (e.g., by activating a primary Wi-Fi radio at the STA) and start data exchange between the STA and the AP. By using the wake-up radio functionality, the STA may operate according to an ultra-low power budget while maintaining high performance.

[0041] Transmissions to or from a STA may include several different packet types. For example, transmissions to or from a STA or within a wireless network may include wake-up packets, legacy packets (such as legacy orthogonal frequency division multiplexing (OFDM) packets), and other packet types. A STA may be configured to receive legacy OFDM packets. Therefore, other types of packets may include an OFDM preamble so that the STA can identify the packet as a packet that can be received by the STA. Some packets may include a preamble that contains information about the packet type or may otherwise indicate the packet type to the receiving device. These preambles may additionally or alternatively indicate that the packet will be received by the receiving device. For example, a wake-up packet may include an OFDM preamble that itself includes a binary phase shift keying (BPSK) marker symbol indicating that the packet is not a legacy packet of a particular type. For example, a STA may suppress classification of a wake-up packet as an 802.11n high throughput (HT) packet based on the BPSK marker symbol. In some other examples, the OFDM preamble may indicate that the packet cannot be received by the receiving device. For example, the receiving device may begin receiving a preamble of an OFDM packet, but may identify a BPSK marker symbol indicating that the OFDM packet is not a valid OFDM packet. Based on identifying the BPSK marker symbol, the receiving device may transition to a deferral mode so that the receiving device refrains from decoding the remainder of the OFDM packet.

[0042] The OFDM preamble of the legacy OFDM packet and the wake-up packet may include a short training field (STF) containing a repeated short training sequence. The STF may identify or otherwise indicate to the receiving device the presence of the OFDM packet, or the OFDM preamble of the wake-up packet. The STA may determine a correlation metric between short training sequences detected at the beginning of OFDM packet transmission. For example, if the STA determines a high correlation level between two or more subsequent short training sequences in the first part of the OFDM preamble, the STA may determine that the packet is an OFDM packet, and therefore may expect the OFDM preamble to include a long training field (LTF), a signal (SIG) field, or the second part of both.

[0043] However, in some implementations, the STA may not detect the preamble or packet type indication. For example, the STA may not receive the preamble or identifier of the packet due to various factors (such as interference), or the STA may start receiving the packet after the preamble or identifier has been transmitted. As a result, the STA may mistakenly detect one packet type as another. In one example, the STA may begin to detect the data field of the wake-up packet and may mistakenly determine that the packet is an OFDM packet. The erroneous determination may be due to the STA determining the correlation metric of the received data field and determining that the received data field is related to the OFDM packet. In other words, if the data field of the wake-up packet is similar to the STF of the old OFDM packet, and if the STA does not correctly receive or interpret the wake-up packet preamble, the STA may confuse the wake-up data field as the preamble of the old OFDM packet. For example, for a transmission received by the STA (such as a wake-up packet data field), the STA may determine that the correlation metric value is greater than the threshold correlation value, and may determine that the transmission is part of the old OFDM preamble (such as when the STF contains a short training sequence with high correlation). As a result, the STA may incorrectly believe that it has detected a legacy OFDM packet when it instead detects the data field of the wake-up packet. Such false detection events may introduce network and communication inefficiencies. For example, a STA may falsely detect a packet preamble multiple times during the transmission of the wake-up packet data field, which may consume STA power and may cause the STA to miss other transmissions. Additionally or alternatively, frequent false detections may cause the STA to adjust the detection sensitivity (e.g., detection threshold) for receiving packets. Increasing the detection threshold may cause the STA to fail to detect OFDM packets intended for the STA.

[0044] To reduce false detection events, various frequency-tone sequences may be used to modulate portions of the wake-up packet. In some implementations, a frequency-tone sequence may be determined and transmitted with the wake-up packet. The frequency-tone sequence may be determined as a frequency-tone sequence in a selected set of frequency-tone sequences, wherein each frequency-tone sequence in the selected set of frequency-tone sequences may be associated with a correlation metric and a peak-to-average power ratio (PAPR), such as a low correlation metric and a low PAPR. The frequency-tone sequence used for the wake-up packet may satisfy a correlation metric threshold, such as a maximum correlation metric threshold (e.g., including a correlation metric that is lower than the correlation metric threshold), which may reduce the likelihood that the STA will mistake the wake-up packet for an OFDM preamble, at least because the STA may determine that the wake-up packet transmission has a correlation metric between transmission repetition intervals that is different from the correlation metric in the OFDM preamble.

[0045] The device may determine one or more "optimal" tone sequences for a set of potential tone sequences. For example, the set of potential tone sequences may include any tone sequence that is possible for a given modulation scheme and data rate. In some implementations, for a tone sequence to be "optimal" (e.g., supporting both reliable wake-up radio performance and low false triggering probability), it is impossible for any other tone sequence in the set of potential tone sequences to have both a lower correlation metric and a lower PAPR. In order to determine the "optimal" tone sequence, the device may identify the tone sequence with the smallest correlation metric as the first "optimal" tone sequence in the set of tone sequences. The device may determine a correlation metric and a PAPR metric coordinate pair for each tone sequence, and may iteratively traverse the set to determine one or more additional "optimal" tone sequences. For example, based on the most recently identified "optimal" tone sequence, the device may determine the slope value calculated for each coordinate pair corresponding to a tone sequence having a lower PAPR than the most recently identified "optimal" tone sequence, and the device may identify the next "optimal" tone sequence as the sequence corresponding to the steepest (negative) slope. The device can repeat the iterative process using each identified "optimal" frequency tone sequence until the final "optimal" frequency tone sequence is identified (e.g., the frequency tone sequence with the smallest PAPR metric in the set of potential frequency tone sequences). The device can output the determined "optimal" frequency tone sequence set (such as to an AP). The AP can be configured with an "optimal" frequency tone sequence from the "optimal" frequency tone sequence set for modulating the data portion of the wake-up packet. In some examples, the device that determines the "optimal" frequency tone sequence set can be a processing device operating at an original equipment manufacturer (OEM) (e.g., not operating in a wireless communication system), and the resulting "optimal" frequency tone sequence can be stored at a wireless device used for communication (such as an AP or STA).

[0046] Specific implementations of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. As described herein, modulating portions of a wake-up packet with an "optimal" frequency-tone sequence from a set of frequency-tone sequences may potentially reduce the number of false detections made by a STA. By limiting the false detection events, the STA may reduce the amount of time the STA waits to receive a transmission and may increase the amount of time the STA may be in deep sleep or low power mode. Thus, limiting false detections may increase the battery life of the STA. Additionally or alternatively, reducing the number of false detections may increase the throughput of the communication link between the STA and the AP or other communication links within the network, which may further increase the battery life and service life of the STA. In addition, limiting false detections may potentially reduce the amount of time that the STA misses receiving other packet transmissions designated for the STA. This may reduce the amount of time a transmitting device (such as an AP) may retransmit a packet to the STA after the STA misses a reception opportunity. Additionally or alternatively, limiting false detections may cause the STA to suppress adjusting the detection sensitivity of the receiver. Such sensitivity adjustments based on error detection may potentially cause a STA to miss actual packets intended for the STA, so maintaining the sensitivity threshold due to limiting error detection can support reliable packet reception at the STA and potentially reduce retransmissions on the channel. Reducing retransmissions can further reduce power consumption and improve communication efficiency by reducing channel overhead (and correspondingly reducing latency) in the network.

[0047] Figure 1 An example of a wireless communication system 100 that supports determining a frequency-modulation sequence for a wake-up procedure is shown. The system can be an example of a wireless local area network (WLAN) (such as a next-generation, or Next Big Thing (NBT), or extremely high throughput (EHT) Wi-Fi network). The wireless communication system 100 may include an AP 105 and a plurality of associated STAs 115, which may represent devices such as mobile stations, personal digital assistants (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (such as TVs, computer monitors, etc.), printers, and the like. The AP 105 and the associated STAs 115 may represent a basic service set (BSS) or an extended service set (ESS). The various STAs 115 in the network are able to communicate with each other through the AP 105. Also shown is a coverage area 110 of the AP 105, which may represent a basic service area (BSA) of the wireless communication system 100. An extended network station (not shown) associated with the wireless communication system 100 may be connected to a wired or wireless distribution system that may allow multiple APs 105 to be connected in an ESS.

[0048] Although not in Figure 1100 , but a STA 115 may be located at the intersection of more than one coverage area 110 and may be associated with more than one AP 105. A single AP 105 and a collection of associated STAs 115 may be referred to as a BSS. An ESS is a collection of connected BSSs. A distribution system (not shown) may be used to connect the APs 105 in an ESS. In some implementations, the coverage area 110 of an AP 105 may be divided into sectors (also not shown). The wireless communication system 100 may include APs 105 of different types (such as urban areas, home networks, etc.) with different and overlapping coverage areas 110. Two STAs 115 may also communicate directly via a direct wireless link 125, regardless of whether the two STAs 115 are in the same coverage area 110. Examples of a direct wireless link 125 may include a Wi-Fi direct connection, a Wi-Fi tunneling direct link setup (TDLS) link, and other group connections. The STA 115 and the AP 105 may communicate according to WLAN radio and baseband protocols for the physical layer and the medium access control (MAC) layer from IEEE 802.11 and its versions, including but not limited to 802.11b, 802.11g, 802.11a, 802.11n, 802.11ac, 802.11ad, 802.11ah, 802.11ax, 802.11ba and subsequent versions, etc. In some other implementations, a peer-to-peer connection or an ad hoc network may be implemented within the wireless communication system 100.

[0049] In some implementations, a STA 115 (or AP 105) may be detected by a central AP 105, but may not be detected by other STAs 115 in the coverage area 110 of the central AP 105. For example, one STA 115 may be at one end of the coverage area 110 of the central AP 105, while another STA 115 may be at the other end. As a result, the two STAs 115 may communicate with the AP 105, but may not receive each other's transmissions. This may result in conflicting transmissions of two STAs 115 in a contention-based environment (such as an environment that supports carrier sense multiple access with collision avoidance (CSMA / CA)), because the STAs 115 may not refrain from transmitting over each other. STAs 115 whose transmissions cannot be identified but are within the same coverage area 110 may be referred to as hidden nodes. CSMA / CA can be supplemented by exchanging a request to send (RTS) packet transmitted by the sender STA 115 (or AP 105) and a clear to send (CTS) packet transmitted by the receiver STA 115 (or AP 105). This can alert other devices within the range of the sender and receiver not to transmit during the duration of the main transmission. Thus, RTS / CTS can help alleviate the hidden node problem.

[0050] In some implementations, the STAs 115 in the wireless communication system 100 may operate in a low power mode (i.e., a sleep mode) when not communicating to save power. The AP 105 may transmit a wake-up packet to one or more STAs 115 to trigger the wake-up of the STAs 115. For example, the AP 105 may wake up the STAs 115 to transmit data to or receive data from the STAs 115. The wake-up packet transmitted by the AP 105 may be generated using a frequency-tone sequence, wherein the frequency-tone sequence satisfies a correlation metric threshold. Based on using a frequency-tone sequence that satisfies a correlation metric threshold, the AP 105 may reduce the likelihood of triggering STAs 115 other than the STAs 115 intended to be woken up.

[0051] Figure 2 An example of a wireless communication system 200 that supports determining a frequency tone sequence for a wake-up procedure is shown. The wireless communication system 200 may include an AP 105-a and a STA 115-a, which may be reference Figure 1 An example of a corresponding device described. The AP 105-a can serve a coverage area 110-a. In some implementations, the AP 105-a can transmit a wake-up packet 210 to the STA 115-a to trigger a wake-up process (ramp up power) at the STA 115-a. The AP 105-a can use a frequency modulation sequence 215 to generate the wake-up packet 210, which supports reliable reception at the STA 115-a while mitigating false triggering at other STAs 115 in the wireless communication system 200.

[0052] In some implementations, STA 115-a can operate in a deep sleep mode to save power and extend battery life. AP 105-a can transmit a wake-up packet 210 to STA 115-a for reception by the wake-up radio of STA 115-a. The wake-up radio can be used to wake up STA 115-a from deep sleep or another low-power operating mode. AP 105-a can use a low-power auxiliary radio to wake up STA 115-a, which can achieve a longer sleep mode for STA 115-a. Once STA 115-a wakes up (e.g., based on the wake-up packet 210 transmission), data exchange between devices can begin. For example, AP 105-a can transmit data to STA 115-a on a downlink, STA 115-a can transmit data to AP 105-a on an uplink, or STA 115-a can transmit or receive on a side link channel. In some examples, STA 115-a may use a low power secondary radio to monitor and receive wake-up packets 210 while in low power mode, and may use the primary Wi-Fi radio when "awake" (when STA 115-a is operating in full power mode). This wake-up procedure may support longer sleep modes for the primary Wi-Fi radio, allowing STA 115-a to operate with an ultra-low power budget, since operating the primary Wi-Fi radio may use significantly more power than operating the low power secondary radio. These power savings may extend the battery life of devices (such as STA 115-a) operating in the wireless communication system 200 while maintaining communication performance.

[0053] When the device wakes up, a communication link 205 may be established between radio devices (such as between STA 115-a and AP 105-a) using a primary radio (such as a primary Wi-Fi radio) at STA 115-a. In an example where STA 115-a has entered a deep sleep mode, the communication link 205 may support wake-up radio functionality. In such an example, AP 105-a may transmit a wake-up packet 210 to the wake-up radio of STA 115-a to wake up STA 115-a. AP 105-a may determine to wake up STA 115-a to transmit data to STA 115-a or request data from STA 115-a. In some implementations, STA 115-a may not transmit a response (such as a positive acknowledgement (ACK) response) to AP 105-a upon receiving the wake-up packet 210. In implementations described herein, the channel used to transmit the wake-up packet 210 may be different from the primary Wi-Fi channel (e.g., the wake-up channel may be one of several channels in a 2.4 gigahertz (GHz) frequency band, while the primary Wi-Fi channel may be one of several channels in a 5 GHz frequency band).

[0054] In some implementations, the wireless communication system 200 may include several different wireless devices that may transmit information according to several different packet types. For example, the network may support wake-up packets and data packets (such as orthogonal frequency division multiplexing (OFDM) packets). Some packets may include a preamble that may include information for indicating the type of packet to a receiving device (such as STA 115-a) and may indicate that the packet is to be received by the receiving device. For example, the wake-up packet may include an indicator or marker (such as a specific binary phase shift keying (BPSK) symbol set) that may indicate that the packet is not a specific type of packet (e.g., an 802.11n packet). Additionally, the preamble of some packets may include one or more short training fields (STFs) that include short training sequences that may identify the packet. STA 115-a may use various techniques to identify the packet preamble (such as determining an autocorrelation metric between one or more pairs of STF candidates).

[0055] However, in some implementations, a receiving device (such as STA 115-a) may not detect the preamble or may not otherwise identify the packet type. For example, STA 115-a may not begin receiving packets until after the preamble of the packet has been transmitted, or STA 115-a may not receive the preamble due to various other factors (such as interference), or STA 115-a may not begin receiving packets until after the preamble has been transmitted. As a result, STA 115-a may mistakenly detect one packet type as another. For example, STA 115-a may wake up and may detect a wake-up packet 210 (intended to wake up a different STA 115). STA 115-a may incorrectly identify the wake-up packet 210 as a data packet intended for STA 115-a because the data field of the wake-up packet 210 may be similar to the preamble of the data packet. That is, STA 115-a may interpret the data field of the wake-up packet 210 as an STF sequence included in the packet preamble based on the autocorrelation value. For example, the frequency-modulated sequence used by AP 105-a for the data field of wake-up packet 210 may have a high autocorrelation between transmission samples as determined by STA 115-a. As a result, STA 115-a may incorrectly determine that it has detected an OFDM data packet when it has actually detected the data field (e.g., the on-off keying (OOK) portion) of wake-up packet 210.

[0056] STA 115-a may introduce several inefficiencies into the network by false detection events. For example, false detections may consume power of STA 115-a and may cause STA 115-a to miss other transmissions when attempting to receive a non-existent data packet. In some implementations, STA 115-a may falsely detect multiple times during the transmission of the wake-up packet 210 data field.

[0057] In order to reduce the number or likelihood of false detection events, various frequency-tone sequences may be used to modulate the data portion of the wake-up packet 210. In some implementations, a frequency-tone sequence 215 may be determined and used to generate a waveform for transmitting the wake-up packet 210. The frequency-tone sequence 215 may be determined as one of several "optimal" frequency-tone sequences, each of which may be associated with a low correlation metric and a low PAPR (or some other strong performance metric). For example, the frequency-tone sequence 215 for the wake-up packet 210 may satisfy a maximum correlation metric threshold (which means that the frequency-tone sequence 215 may be associated with a correlation metric that is less than the maximum correlation metric threshold), which may reduce the likelihood that the STA 115 will mistake the ON codeword of the wake-up packet 210 for the preamble of a different packet.

[0058] Certain modulation techniques may be used to encode the wake-up packet 210. Modulation types (e.g., OOK, line coding, amplitude shift keying modulation, etc.) may be used to implement a low-power RF design for the wake-up packet 210. For some modulation types (such as OOK modulation), a device (such as a STA 115-a or an AP 105-a) may be configured to transmit power (e.g., via a carrier waveform) for one or more ON states and suppress transmission (e.g., reduce the transmit power to zero, suppress the transmission of a carrier waveform, etc.) for one or more OFF states. A device may use OOK to transmit symbols and other data over a specific bandwidth (such as 4 megahertz (MHz)) (so that an ON symbol of OOK modulation may be configured to use a 4MHz bandwidth). OOK may be further configured to operate according to different data rates. For example, the AP 105-a may transmit using a high data rate (such as 250 kilobits per second (kb / s)) or a low data rate (such as 62.5kb / s).

[0059] Figure 3 An example signal packet structure 300 is shown. The packet structure 300 may be implemented by the AP 105 for transmitting Wi-Fi signals. The packet structure 300-a may correspond to an STF, while the packet structures 300-b and 300-c may correspond to wake-up packets.

[0060] The AP 105 and the STA 115 may transmit information according to a given packet structure 300. For example, an OFDM packet (such as a non-HT packet, an HT packet, a very high throughput (VHT) packet, a high efficiency (HE) packet, or some similar Wi-Fi packet) may begin with a short training field (STF) containing a set of repeated short training sequences 305 (e.g., ten short training sequences 305) according to a first packet structure 300-a. Each short training sequence 305 has the same duration in the time domain (e.g., 800 nanoseconds (ns) duration), thereby obtaining a total duration of the STF, which may be referred to as a legacy STF (L-STF). In some implementations, the duration of the L-STF may vary based on the channel bandwidth. A receiver in the network may use the short training sequence 305 for various input signal operations and obtain information about the OFDM packet. For example, a receiver may use the short training sequence 305 for packet detection, automatic gain control (AGC), coarse time and frequency offset estimation, diversity selection, or a combination of these functions.

[0061] In some implementations, a device may detect an STF and use various identification techniques to determine that the STF is part of an OFDM packet header (such as, for example, determining an autocorrelation metric between one or more pairs of short training sequences 305 within the STF). In such implementations, a device may detect two or more short training sequences 305 and determine that the short training sequences 305 have a normalized autocorrelation metric that exceeds a threshold (e.g., the STF has a relatively high autocorrelation between the short training sequences 305). Based on this determination, the device may determine that the short training sequence is part of the STF of the OFDM packet. Accordingly, the device may determine to receive an OFDM data packet associated with the received STF based on packet start detection.

[0062] The wireless device may respond to detecting a wake-up packet in different ways. Some receiving devices may detect the start of a wake-up packet and may refrain from receiving the remainder of the wake-up packet (e.g., the receiving device may defer reception because the wake-up packet may not be destined for the receiving device). The receiving device may instead detect and receive a packet destined for the receiving device. The wake-up packet may include a length field (e.g., in the legacy signal (L-SIG) field 320) that specifies the packet as having a particular duration, so the receiving device may refrain from monitoring a different packet in the same resource as the wake-up packet during the remainder of the packet duration.

[0063] However, in some implementations (e.g., in a relatively busy network), the receiving device may not detect the entire packet (e.g., the receiving device may not detect the packet from the beginning to the end) and may instead detect a portion of the packet. For example, the receiving device may detect the data portion of the packet (including synchronization information, payload, or both) without the preamble 340. Failure to detect the preamble 340 may be based on interference in the network or a device (e.g., a half-duplex device) transmitting a signal when the preamble 340 would otherwise be received. The receiving device may incorrectly identify the data portion of the packet (e.g., OOK packet 345) as a preamble of a different packet type. For example, a device may receive the data portion of a wake-up packet and may incorrectly identify the data portion as an STF of a different packet based on the frequency modulation sequence of the data portion of the wake-up packet being similar to the repeated short training sequence 305. This incorrect identification of a packet may be referred to as an error trigger at the receiving device. Such an error trigger based on the wake-up packet may cause the device to receive and attempt to decode an OFDM packet that was not transmitted.

[0064] In some implementations, the device may use various detection techniques to determine certain characteristics of the received signal. The device may use these received signal characteristics to determine whether the received signal is, for example, part of a packet preamble of a packet to be received by the device. In some examples, the receiving device may use autocorrelation techniques to determine the characteristics of the received signal. Such techniques may be used to detect the start of a packet based on one or more detection metrics (e.g., based on a repeated short training sequence 305). The autocorrelation technique may involve the STA 115 determining an autocorrelation metric based on a normalized autocorrelation of one or more pairs of candidate short training sequences 305 (e.g., a signal received according to a short training sequence 305 format). The autocorrelation lag time for the STA 115 to determine the autocorrelation metric may be equal to the duration of the short training sequence 305 (e.g., approximately 800ns).

[0065] The receiving device may monitor a first portion of a packet preamble, which may include an 8 microsecond (μs) waveform (e.g., L-STF) consisting of a plurality (e.g., ten) of repeated short training sequences 305, and each short training sequence may be approximately 800ns in duration. In some examples, the receiving device may calculate an autocorrelation metric for a signal received over a first short training sequence duration and another signal received over a second short training sequence duration, wherein the signals are received over the same channel within a candidate STF duration. The receiving device may calculate a normalized autocorrelation for N (e.g., six) signals received over N short training sequences 305 or over a received signal period using an autocorrelation formula (e.g., Formula 1):

[0066]

[0067] where x t is the complex baseband signal at sampling time t, and T is the duration of the short training sequence 305 in samples (e.g., sixteen samples sampled at 20 MHz in an 800 ns period). In some examples, other similar autocorrelation formulas may be implemented. If the autocorrelation metric C calculated for the signal received on one or more pairs of short training sequences 305 is XX,N If the absolute value of (t) is relatively high (e.g., above an autocorrelation threshold (such as 0.3, 0.4, 0.5, 0.6, or some other threshold), the receiving device can determine that the received signal corresponds to the STF in the packet preamble 340, and the device can determine that the remainder of the packet (e.g., the data portion) is to be received.

[0068] In some implementations, the method of calculating autocorrelations to identify the start of a packet may introduce several challenges. For example, a receiving device may receive several highly correlated signals (e.g., signals corresponding to the data payload portion of a wake-up packet) and may incorrectly determine that these signals are part of the start of an OFDM packet. The receiving device may erroneously trigger the reception process for a new packet (even if the signal does not correspond to a new packet, but rather corresponds to a portion of a packet following a preamble 340 that the receiving device partially or completely missed). False triggering may occur in a network that includes several devices transmitting different types of packets (such as wake-up packets, legacy data packets, etc.). In some examples, a specific preamble 340 of a wake-up packet (such as an L-STF 315-a in a preamble) can identify a wake-up packet and can trigger delay behavior for a receiving device that is not configured to receive a wake-up packet or is already in full power mode. However, if the preamble 340 is missed (e.g., due to interference or the transmission of partially concurrent messages), the device may detect the data portion of the packet (such as the synchronization field 330, the payload data field 335, or both) and attempt to determine whether the signal corresponding to the data portion is a packet preamble. In some implementations, the receiving device may be erroneously triggered based on mistaking the synchronization field 330, the payload data field 335, or a portion of one or both of these fields for the L-STF preamble of the OFDM packet. In some implementations, the ON codeword included in the data portion of the wake-up packet may have a repetition characteristic similar to the rate at which the short training sequence 305 of the OFDM preamble is repeated (e.g., the repetition within the ON waveform may occur at a rate similar to the expected repetition of the short training sequence 305). Such repetitions in the wake-up packet waveform may cause the ON codeword to be frequently mistaken for the STF of the OFDM packet preamble.

[0069] In order to reduce the possibility of false identification of the packet preamble at the receiving device, the ON symbol or constellation can be designed so that the ON symbols of each portion of the detected packet are less likely to trigger the autocorrelator of the receiving device. For example, the ON symbol can be configured so that the ON symbol results in a low autocorrelation (according to the repetition duration of the short training sequence 305). In general, if the value of the correlation metric calculated for the received signal exceeds a threshold, the receiving device can identify the start of the OFDM packet (for example, when the absolute value of the correlation metric exceeds the threshold correlation value, the autocorrelator can be triggered). This relationship over N short training sequences 305 can be expressed by Formula 2:

[0070] |C xx,N (t)|>Th, (2)

[0071] Among them C xx is the correlation metric, t is the sampling time, and Th is the threshold correlation value. N can be the number of different values, and can generally be between 2 and 6, although other values ​​of N are possible. In addition, the threshold correlation value Th used to determine highly correlated transmissions can be static or dynamic. The correlation metric threshold can be set to 0.3, 0.4, 0.5, 0.6, or the like, although other values ​​are possible.

[0072] The effect of false triggering at a receiving device may occur when a high correlation is determined for a signal that is not a packet preamble of a packet designated for the receiving device. Such false triggering events may be harmful to an OFDM receiver in several ways. For example, false triggering may cause a receiver to miss receiving other valid OFDM packets, or may cause a receiving device to reduce the sensitivity of its receiver (e.g., increase the detection threshold at the receiver) to reduce sensitivity to system noise. Such effects may lead to inefficiencies in the network.

[0073] Various packet structures may be used for wake-up packets in wake-up radio (WUR) applications. The wake-up packet may include 48 bits, although shorter or longer wake-up packets may be supported. In some implementations, the wake-up packet may include an OFDM preamble 340 that may span a bandwidth of 16.25 MHz. In some aspects, the OFDM preamble 340 may be the same or similar to the preamble 340 of other types of packets transmitted in a Wi-Fi network. The preamble 340 of the wake-up packet may be used to notify a receiving device of an incoming transmission and prevent transmission collisions in the network. In addition to the OFDM preamble 340, the wake-up packet may also include other parts, including an OOK packet 345 (e.g., a data portion of a packet), which includes a synchronization portion and a payload data portion. The OOK packet 345 may span a bandwidth of 4 MHz. In some implementations, the OFDM preamble 340 can cause multiple receiving devices (such as devices that do not support processing of wake-up packets) to postpone transmitting on the data portion of the packet (such as the OOK packet 345 following the preamble 340 of the wake-up packet). In some implementations, the wake-up OOK packet 345 can be configured for different data rates. For example, the packet structure 300-b can be configured for a high data rate (HDR), while the packet structure 300-c can be configured for a low data rate (LDR). In some examples, HDR can support a data rate of 250kb / s, while LDR can support a data rate of 62.5kb / s, although other data rates are possible.

[0074] The HDR packet structure 300-b may include a 28μs preamble 340-a, which may include several training fields 315, including an L-STF 315-a and a legacy long training field (L-LTF) 315-b. In addition, the preamble 340-a may include an L-SIG field 320 and several BPSK markers 325 (such as two BPSK markers 325-a and 325-b). The length field of the L-SIG field 320 may indicate the duration of the OOK packet 345-a of the wake-up packet. The BPSK marker 325 may distinguish the HDR packet from other types of packets (for example, the BPSK marker 325 may distinguish the packet from other 802.11n HT or 802.11ac VHT packets). In addition to the preamble 340-a, the HDR packet structure 300-b may also include an OOK packet 345-a. The OOK packet 345-a may include a synchronization (SYNC) field 330, such as a 32-bit SYNC field, which may be 64 μs in length. The OOK packet 345-a may also include a payload data field 335, which may be 192 μs in length.

[0075] The LDR packet structure 300-c may include the same parts as the HDR packet structure 300-b, but may be transmitted at a different data rate. For example, the LDR packet structure 300-c may include a 28μs preamble 340-b, which may include an L-STF 315-a and an L-LTF 315-b, an L-SIG field 320 containing information (such as rate, length, parity information, etc.). The LDR packet structure 300-c may also include BPSK markers 325-a and 325-b. In addition to the preamble 340-b, the wake-up packet may also include an OOK packet 345-b (e.g., a data portion), and the OOK packet 345-b includes a synchronization field 330 (such as a 64-bit SYNC field) and a payload data field 335. Based on the LDR packet having a lower data rate than the HDR packet, the synchronization field 330 of the LDR packet may span a length of 128 μs, and the payload data field 335 of the LDR packet may span a length of 768 μs.

[0076] In some implementations, the sync field 330 of the LDR packet structure 300-c may include more information than the sync field 330 of the HDR packet structure 300-b (e.g., a 32-bit SYNC field for HDR at 250 kb / s and a 64-bit SYNC field for LDR at 62.5 kb / s). Additionally or alternatively, the payload data field 335 of the LDR packet may contain the same number of payload bits as the payload data field 335 of the HDR packet or a different number of payload bits.

[0077] The OOK packet 345 may include several symbols, including ON symbols and OFF symbols. Based on the data rate of the OOK packet 345, the ON symbols may be different for the OOK packet 345. For example, the ON symbols of the HDR OOK packet 345-a may include 6 indexed OFDM subcarriers (e.g., with indices {-6, -4, -2, 2, 4, 6} with respect to the reference subcarrier). The HDRON symbol may have a duration of 2 μs. The ON of the LDR OOK packet 345-b may include 12 indexed OFDM subcarriers (e.g., with indices {-6, -5, -4, -3, -2, -1, 1, 2, 3, 4, 5, 6} with respect to the reference subcarrier). The LDR ON symbol may have a duration of 4 μs.

[0078] The ON symbols of the grouping may be further modulated according to a frequency-modulated sequence, which may be referred to as a subcarrier data pattern, a set of values ​​selected from a constellation, or a value from an alphabet (such as a QPSK alphabet). In some implementations, the transmitting device may select an arbitrary frequency-modulated sequence to modulate the ON symbols of the grouping. The selection of the frequency-modulated sequence (e.g., constellation) may be subject to certain constraints (such as tolerance constraints, signal flatness constraints, transmission characteristics, etc.) so that the packets resulting from the modulation can be successfully received. The frequency-modulated sequence may be preconfigured at the transmitting device. In some examples, the frequency-modulated sequence may be selected from a set of frequency-modulated sequences defined in the standard, as described throughout. In some other examples, a single frequency-modulated sequence may be defined in the standard, and each transmitting device may implement the frequency-modulated sequence. In some implementations, the type of frequency-modulated sequence, the modulation scheme, or both used by the transmitting device may affect other parameters in the network.

[0079] The modulation technique used for the wake-up packet may include BPSK, quadrature phase shift keying (QPSK), or 2n quadrature amplitude modulation (QAM), or any other supported modulation technique. In some implementations, the receiving device may not obtain information about the transmitted waveform (or other subcarrier data). As such, the receiving device may not be able to identify a specific modulation scheme or waveform to monitor, so the receiving device may monitor any potential modulation scheme or waveform. For example, the receiving device may monitor the transmitted power (or lack of transmitted power) in the channel, rather than a specific type of waveform, to detect the wake-up packet.

[0080] In some implementations, the HDR ON symbol may be used in the sync fields of both HDR and LDR packets. The LDR packet may include a SYNC ON / OFF bit pattern designated as {S, S}, while the HDR packet may include a SYNC ON / OFF bit pattern designated as the bitwise complement of S. In one example, S = {1,0,1,0,0,1,0,0,1,0,1,1,1,0,1,1,0,1,1,0,0,0,1,0,1,1,1,0,0,0}, and accordingly, the bitwise complement of S = {0,1,0,1,1,0,1,1,0,1,0,0,0,1,0,0,1,1,1,0,1,0,0,0,1,1,0,0,0,1,1,1}. This may result in 32 bits for the HDR SYNC field and 64 bits for the LDR SYNC field.

[0081] The data symbols of the HDR and LDR wake-up packets may have different forms corresponding to different bit values. For example, the HDR data symbol may be {ON, OFF} for bit value 0 and {OFF, ON} for bit value 1. For a total HDR data symbol duration of 4 μs, the duration of the HDR ON symbol may be 2 μs. Additionally or alternatively, the LDR data symbol structure may be {ON, OFF, ON, OFF} for bit value 0 and {OFF, ON, OFF, ON} for bit value 1. For a total LDR data symbol duration of 16 μs, the duration of the LDR ON symbol may be 4 μs. Other symbol types, lengths, and bit rates for HDR, LDR, or other data rates may be supported.

[0082] OOK coding and modulation can have several benefits, including reducing the data rate of packets, improving receiver sensitivity, supporting clock recovery, or some combination of these or other supported benefits. For example, OOK coding and modulation can support power-efficient radio receiver architectures (such as super-regenerative radio receiver architectures), which can improve power conservation of communication devices in wireless networks. Data can be encoded according to several different coding types (e.g., Manchester coding that can be implemented by a transmitting device).

[0083] However, in some implementations, the frequency modulation sequence (for any data rate, such as HDR or LDR) used to modulate the ON codeword of the OOK packet 345 may result in a waveform similar to two or more repeated short training sequences 305. The receiver may confuse such data portions (e.g., synchronization field 330, payload data field 335, or some portion of either or both) as a sequence of short training sequences 305 of OFDM preamble 340. In such examples, the receiver may determine that it has detected a legacy OFDM packet when it has actually detected the data portion of the wake-up packet. Such erroneous detection of packets may cause several inefficiencies in the network and at the associated receiving device. For example, a receiving device may continue to receive a wake-up packet that is incorrectly identified as a preamble of a legacy packet, and after an amount of time may determine that the packet is not a legacy packet. In some implementations, the receiving device may continue to erroneously detect throughout the duration of the wake-up packet transmission. Such erroneous detection may cause the receiving device to consume too much power. In addition, the receiver may miss other packet transmissions destined for the receiving device during such an error detection, which may cause the transmitting device to retransmit packets to the receiving device, thereby increasing the processing overhead at both the transmitting device and the receiving device and increasing the signal overhead of the channel. To mitigate these inefficiencies, the transmitting device may use a frequency-modulated sequence that reduces the probability of error detection at the receiving device.

[0084] Figure 4 An example flowchart 400 for determining a tone sequence is shown. In some examples, flowchart 400 may correspond to a process performed to determine an "optimal" set of tone sequences from which a tone sequence may be selected to modulate a wake-up packet. To reduce the likelihood of false triggering, a transmitting device (e.g., AP 105) may modulate the ON symbol using a tone sequence such that the resulting signal does not have a repetitive characteristic similar to the STF field of the OFDM preamble of the packet. Such tone sequences may reduce autocorrelation and satisfy a maximum correlation metric threshold.

[0085] In some implementations, in order to maintain performance while reducing autocorrelation, the PAPR of the signal resulting from modulation using the frequency-modulated sequence can also be optimized (e.g., minimized). In some examples, reducing the PAPR can result in a low packet error rate (PER), thereby supporting reliable reception at a receiving device (e.g., STA 115). However, in some examples, for a given frequency-modulated sequence, a low autocorrelation metric may not correspond to a low PAPR. Thus, one or more frequency-modulated sequences that support both an autocorrelation threshold and a performance threshold can be determined for modulation.

[0086] Selecting an ON symbol (or similarly, selecting a tone sequence for an ON symbol) may include selecting an ON symbol from a set of ON symbols (or selecting a tone sequence from a set of tone sequences). In some aspects, there may be many different potential ON symbols to select from, since OFDM tones may be modulated by arbitrarily complex tone sequences. However, the number of potential ON symbols to select from may be reduced to a smaller set of ON symbols based on several constraints. In one example, the ON symbols may be limited based on a restricted tone sequence alphabet size for a particular type of modulation. For example, the tone sequence may be limited to a BPSK constellation (such as values ​​from the alphabet {-1,1}) or some other alphabet size (such as the QPSK alphabet size, or 2 n QAM alphabet size, etc.). Such parameters can reduce the number of different possible ON symbols to a finite set.

[0087] In some implementations, the number of different tones used for a tone sequence may vary based on a number of factors, including data rate and modulation type. For example, the number of different tones may correspond to the alphabet size of the modulation type raised to the power of X, where X is the number of tones. Accordingly, an HDR ON symbol may use 6 tones, so a BPSK modulation with an alphabet size of 2 may correspond to 64 possible tone sequences (e.g., 2 6=64 different HDR tone sequences). Additionally, for an LDR ON symbol using 12 tones and a BPSK constellation with two possible values, there may be 4096 tone sequences (e.g., 2 12 =4096 different LDR tone sequences). In this implementation, a finite set of HDR and LDR tone sequences can be generated limited to the BPSK constellation.

[0088] In some other implementations, various other modulation schemes may be used to modulate the frequency tone sequence. For example, the frequency tone sequence may be a QPSK frequency tone sequence, which may have 4 possible values ​​(e.g., corresponding to the orthogonal alphabet size) for each OFDM frequency tone in an ON symbol. In the example of QPSK modulation, there may be 4 6 Different HDR tone sequences and 4 12 Different LDR frequency modulation sequences. In addition to or in lieu of QPSK, BPSK, or both, higher order modulation schemes may also be used.

[0089] Each potential ON symbol (determined by modulation) can be associated with several metrics, including, for example, a maximum correlation metric and a PAPR value. For each tone sequence, a correlation metric |C_(xx,N)(t)| can be calculated for all potential samples, and a maximum correlation metric C can be determined for each tone sequence. N , where N is the number of short training sequences on which the samples are correlated. Additionally or alternatively, for each tone sequence, the PAPR may also be calculated, and a maximum PAPR value may be determined for each tone sequence. The values ​​of both the maximum correlation metric and the maximum PAPR metric may be tabulated and indexed using an identifier of the corresponding tone sequence.

[0090] In some implementations, a cyclic shift may additionally be applied to each ON symbol. Accordingly, in some examples, a cyclic shift may be selected from a number of cyclic shift values ​​(such as 8 different cyclic shift values) and applied to the ON symbol. To determine the metric for each frequency-modulated sequence, the maximum PAPR and the maximum C may be selected from all possible cyclic shifts. N value.

[0091] In some implementations, one or more "optimal" frequency-modulation sequences may be based on, for example, Figure 4 Several processes are explained, according to the algorithm, to determine. For a tone sequence to be "optimal" with respect to maximum correlation metric and maximum PAPR metric, no other tone sequence in the set of tone sequences can have both a lower maximum correlation metric and a lower maximum PAPR metric. Figure 4The processing illustrated in can be implemented by a number of different computing components or devices, including, for example, a server or server cluster, a virtual machine, a STA 115, an AP 105, or some other type of computing device. An example procedure for designing an "optimal" ON waveform is described below, where Q is the frequency-modulated constellation size, and these processes may be performed in alternate orders and may include additional or alternate functionality.

[0092] At 405, the device may calculate a metric for a set of tone sequences. For example, a metric may be calculated for a set of tone sequences according to one or more specific modulation schemes such as BPSK, QPSK, 2 N QAM, or one or more other modulation schemes) uses different frequency modulation sequences to modulate each ON symbol and calculate the maximum correlation metric C N and maximum PAPR metric.

[0093] At 410, the device may index each tone sequence, C N and the maximum PAPR metric are stored in memory. For example, these values ​​may be stored in a table, where each row of the table corresponds to a different frequency tone sequence. Accordingly, the table in memory may include Q 6 Row (for HDR ON symbol) or Q 12 rows (for LDR ON symbols) and 3 columns (for the three stored metrics). The index values ​​stored in the memory may uniquely identify each tone sequence (eg, there is a one-to-one mapping between tone sequences and index values).

[0094] The tone sequences stored in the memory may be sorted according to the maximum PAPR metric at 415. For example, the table may be sorted in descending order such that the largest maximum PAPR metric is stored in the first row of the table and the smallest maximum PAPR metric is stored in the last row of the table.

[0095] At 420, the device may identify the device having the smallest C N For example, the device may determine the frequency-modulated sequence containing the minimum C N The index value for the row identifies a first "optimal" tone sequence. The tone sequence may be "optimal" because it corresponds to the minimum C of the set of tone sequences. N . This frequency-tone sequence can be set as the current frequency-tone sequence for the following iterative process.

[0096] At 425, the device may determine all frequency-tuning sequences having a maximum PAPR metric less than the maximum PAPR metric of the current frequency-tuning sequence. For example, the device may identify k rows in the table that are lower than the current row (the row with the current frequency-tuning sequence identified at 420). At 430, the device may determine a slope value for each of the identified subsets of frequency-tuning sequences. The slope values ​​may correspond to coordinate pairs, where each coordinate pair may be defined as (C N , the maximum PAPR metric). The coordinate pair (C N , maximum PAPR metric) to the slope of a line of coordinate pairs (CN, PAPR) for each of the k tone sequences identified in the tone sequence subset. Each of these slopes may have a negative value. At 435, the device may identify the tone sequence corresponding to the minimum (or steepest downward) slope calculated at 430. The tone sequence may be an additional "optimal" tone sequence. At 440, the device may determine whether the additional "optimal" tone sequence contains the minimum maximum PAPR metric for the tone sequence set. For example, the device may determine whether the additional "optimal" tone sequence corresponds to the last row in the table. If the tone sequence does not correspond to the minimum maximum PAPR metric for the tone sequence set, the device may use the additional "optimal" tone sequence as the current tone sequence to iterate through the iterative process again at 445.

[0097] If the frequency-modulated sequence corresponds to the minimum maximum PAPR metric of the frequency-modulated sequence set, then at 450, the device may output the determined "optimal" frequency-modulated sequence set. For example, the "optimal" frequency-modulated sequence set may include the first "optimal" frequency-modulated sequence identified by the device and each additional "optimal" frequency-modulated sequence. The coordinate pair (C N , the maximum PAPR metric) can span all coordinate pairs (C N , the maximum PAPR metric) set (e.g., when plotted as coordinates in a scatter plot, as referred to herein). Figure 5 described).

[0098] A replacement procedure may be performed by the device to determine an "optimal" set of frequency-modulation sequences. For example, a different performance metric may be used to replace the PAPR value. Additionally or alternatively, the table ordering, coordinate pairs, or both may be defined in a different order. In some implementations, the device may output a full set of "optimal" frequency-modulation sequences. A user or code may select one or more "optimal" frequency-modulation sequences from the set of "optimal" frequency-modulation sequences for configuration of the AP 105. In some other implementations, the device may output a subset of "optimal" frequency-modulation sequences based on one or more selection parameters.

[0099] The "optimal" tone sequences determined according to this procedure for N=2 and N=6 using LDR BPSK modulation are listed in Table 1. However, this procedure can support any value of N and any modulation type.

[0100]

[0101] Table 1: Example "optimal" tone sequences

[0102] In some examples, "optimal" frequency-modulation sequences using the same type of modulation but using different N values ​​(corresponding to different numbers of short training sequences correlated thereon) can overlap. For example, Table 1 shows three common sequences between the C2 and C6 correlation metrics for BPSK modulation. Accordingly, if the AP 105 uses frequency-modulation sequence B, C, or E to modulate the ON codeword of the wake-up packet, the frequency-modulation sequence can result in strong performance for any receiving device that correlates on 2 short training sequences or 6 short training sequences.

[0103] Figure 5 An example plot 500 for determining a tone sequence is shown. The plot 500 (and the associated lower convex hull) may correspond to a reference Figure 4 The described flowchart 400. A coordinate pair for each of the set of possible tone sequences may be plotted in a plot 500 (eg, a scatter plot). The device may determine a correlation metric C for each tone sequence. N and the value of the maximum PAPR metric. Figure 5 As explained in , C can be determined for LDR BPSK modulation and N = 2 N and maximum PAPR metric. In this example, 4096 points corresponding to 4096 possible ON waveforms for LDR BPSK modulation can be generated on the plot. However, some frequency-modulated sequences can have equal correlation metrics and PAPR values, so the number of points may appear to be less than 4096 (because some points overlap). Other scatter plots can be determined for other data rates, modulation types, numbers of short training fields used for correlation, or combinations thereof.

[0104] The plot explains (C N , the maximum PAPR metric). To determine the "optimal" frequency-modulated sequence graphically, the coordinate pairs of the frequency-modulated sequence that span the lower convex hull of the set of all coordinate pairs (C N, PAPR) (e.g., coordinate pairs 505, 510, 515, 520, and 525). The number of "optimal" values ​​selected can vary depending on several factors (such as the value of N, modulation type, data rate, etc.). For example, when operating using BPSK modulation and LDR, the described procedure can produce 5 "optimal" frequency-frequency tone sequences (e.g., sequences associated with coordinate pairs 505, 510, 515, 520, and 525) for the C2 correlation metric and 4 "optimal" frequency-frequency tone sequences for the C6 correlation metric.

[0105] The point with the lowest correlation metric value or autophase value (coordinate pair 505) can be selected first. A line can be calculated to connect coordinate pair 505 with all points in the scatter plot below the horizontal position of coordinate pair 505. A second point (coordinate pair 510) can be selected based on determining the line with the steepest downward slope from coordinate pair 505. Additional lines can be calculated to connect the second coordinate pair 510 to all points in the scatter plot below the horizontal position of the second coordinate pair 510. The procedure can be repeated until the final point with the lowest PAPR metric is found (coordinate pair 525). The optimal frequency modulation sequence can be associated with the optimal coordinate pairs 505, 510, 515, 520 and 525.

[0106] In some implementations, additional "optimal" tone sequences may be determined that are not located in the lower convex hull (or are not vertices of the lower convex hull) of plot 500. For example, the device may determine a set of "optimal" tone sequences where no other tone sequence in the set has a lower C N The "optimal" set of tone sequences may include points in the scatter plot that are above the lower convex hull, such as coordinate pair 530, which has a lower PAPR metric than the vertex to its left (e.g., coordinate pair 510) and a lower C than the vertex to its right (e.g., coordinate pair 515). N Metric. In one example, the device can determine other "optimal" frequency-frequency tone sequences (as illustrated by 535) by implementing a step-by-step approach between the vertices of the lower convex hull. Any coordinate pair (such as coordinate pair 530) located between 535 and the lower convex hull may correspond to an "optimal" frequency-frequency tone sequence (although not all of these coordinate pairs may be "optimal"). The device can implement a plot-based approach, a table-based approach, an algorithm-based approach, or some combination thereof to determine a complete subset of "optimal" frequency-frequency tone sequences for a set of frequency-frequency tone sequences, wherein no frequency-frequency tone sequence in the set has a lower C than any "optimal" frequency-frequency tone sequence. Nmetric and a lower PAPR metric. In some examples of the algorithm-based approach, the device may determine the resulting lower convex hull of the points within 535. The device may further use the points of the resulting lower convex hull to calculate additional lower convex hulls (e.g., in an iterative or recursive process). The device may continue to recursively calculate additional lower convex hulls for different sets of points to determine an "optimal" frequency-modulated sequence subset for the set of frequency-modulated sequences.

[0107] Figure 6 An example waveform generation process 600 using the determined frequency tone sequence is shown. The waveform generation process 600 may be performed by a transmitting device (such as a transmitter). Figure 1-5 The AP 105 described herein may be used to perform the waveform generation procedure. The AP 105 may generate one or more ON symbols based on the waveform generation procedure. At 605, the AP 105 may generate a frequency-modulated sequence. The frequency-modulated sequence may be an "optimal" frequency-modulated sequence calculated based on a maximum correlation metric threshold. At 610, the AP 105 may map the frequency-modulated sequence to an OFDM waveform. At 615, the AP 105 may apply an inverse discrete Fourier transform (IDFT) to the waveform, and at 620, symbol randomization may be performed on the waveform (e.g., by applying a cyclic shift). Applying a cyclic shift to an input waveform may include various processes (such as those performed by a linear feedback shift register). For example, a linear feedback shift register may convert bits to integer values ​​(such as -1 or +1), may look up a cyclic shift, and may apply a cyclic shift. Cyclic shifts may be applied to each antenna according to cyclic shift diversity (CSD) or other transmit diversity schemes. The AP 105 may insert a guard interval at 625 and transmit the resulting waveform (e.g., as the OOK portion of a wake-up packet). For each of the sequences generated for BPSK, QPSK, or other modulation schemes, the sequence may undergo a process for generating a sequence, mapping the sequence, applying IDFT to the sequence, randomizing the sequence, and inserting a guard period for the sequence. In some implementations, a maximum correlation metric and a maximum PAPR metric may be calculated for each generated sequence based on these processes (or after a subset of these processes). The values ​​of the correlation metric and the PAPR metric may be used in various applications (such as graphical or algorithmic applications) to determine an "optimal" frequency-modulated sequence for modulation.

[0108] Figure 7 An example flow chart 700 for use with devices in a system is shown. The example flow chart 700 may be performed by an AP 105-b and a STA 115-b, where the AP 105-b and the STA 115-b may be reference Figure 1-6 Examples of corresponding devices described. AP 105-b may implement an "optimal" frequency modulation sequence for modulating wake-up packets to improve transmission reliability and reduce false triggering.

[0109] The AP 105-b may determine that the STA 115-b is to be awakened from a low power mode, such as a deep sleep mode, at 705. The AP 105-b may determine to awaken the STA 115-b based on identifying data to be transmitted to the STA 115-b.

[0110] At 710, the AP 105-b may generate a wake-up packet for reception by the wake-up radio of the STA 115-b to trigger the wake-up of the STA 115-b. In some implementations, the wake-up packet may include a frequency-modulated sequence of ON codewords for the wake-up packet, wherein the frequency-modulated sequence may satisfy a maximum correlation metric threshold. In some examples, the frequency-modulated sequence may satisfy the maximum correlation metric threshold based on several cyclic shifts of the ON codeword satisfying the maximum correlation metric threshold. Additionally, the frequency-modulated sequence may be associated with a PAPR less than a maximum PAPR threshold based on the number of cyclic shifts of the ON codeword. In some other examples, the frequency-modulated sequence may satisfy the maximum correlation metric based on the maximum of several absolute values ​​of the normalized autocorrelations at one or more start times, the number of repetitions of the frequency-modulated sequence, or a combination thereof. In some examples, the frequency-modulated sequence may include BPSK, QPSK, QAM, or other modulated frequency-modulated sequence.

[0111] In some implementations, the frequency modulation sequence can be further based on the data rate of the ON codewords of the wake-up packet. In some examples, the data rate can be HDR and the ON codewords can span a first time period and be associated with a first number of subcarriers. In some other examples, the data rate can be LDR and the ON codewords can span a second time period longer than the first time period. Additionally or alternatively, the data rate can be LDR and the ON codewords can use a second number of subcarriers that is larger than the first number of subcarriers.

[0112] At 715, STA 115-b may transmit a wake-up packet to STA 115-a. The wake-up packet may be received by a wake-up radio of STA 115-b. For example, STA 115-b may successfully receive the wake-up packet based on the low PAPR of the tone sequence. Additionally, other STAs 115 in the system may not falsely trigger on the wake-up packet based on the low correlation metric of the tone sequence.

[0113] At 720, the STA 115-b may wake up (eg, the STA 115-b may no longer be operating in a low power or deep sleep mode), and the AP 105-b and the STA 115-b may communicate with each other.

[0114] Figure 8An example block diagram of a system 800 including a device 805 that supports a wake-up procedure using a determined frequency-tone sequence is shown. The device 805 can be an example of an AP 105 as described herein or include components thereof. The device 805 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a wake-up manager 810, a network communication manager 815, a transceiver 820, an antenna 825, a memory 830, a processor 840, and an inter-station communication manager 845. These components can be in electronic communication via one or more buses, such as a bus 850.

[0115] The wake-up manager 810 may determine that a STA 115 associated with the AP 105 is to wake up from a low power mode; generate a wake-up packet for reception by a wake-up radio of the STA 115 to trigger a wake-up of the STA 115, the wake-up packet including a frequency-modulated sequence of ON symbols for the wake-up packet, wherein the frequency-modulated sequence satisfies a correlation metric threshold; and transmit the wake-up packet to the STA 115. In some implementations, the wake-up manager 810 may be a component of the transceiver 820.

[0116] In some examples, wake-up manager 810 , when functioning as a processor or processing system, may obtain signaling from a receiver such as transceiver 820 using the second interface and may output signaling for transmission via a transmitter such as transceiver 820 using the first interface.

[0117] The network communication manager 815 may manage communications with the core network (such as via one or more wired backhaul links). For example, the network communication manager 815 may manage the delivery of data communications for client devices (such as one or more STAs 115).

[0118] The transceiver 820 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 820 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 820 can also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0119] In some implementations, a wireless device may include a single antenna 825. However, in some other implementations, the device may have more than one antenna 825, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0120] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed by a processor (such as the processor 840), cause the device 805 to perform various functions described herein. In some implementations, the memory 830 may include, among other things, a basic input / output system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0121] Processor 840 may include a hardware device (e.g., a general purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). Processor 840 may be configured to execute computer readable instructions stored in a memory (such as memory 830) to cause device 805 to perform various functions (such as functions or tasks that support wake-up procedures).

[0122] Processor 840 may be any suitable processor or processors capable of executing scripts or instructions of one or more software programs stored in device 805, such as within memory 830. For example, processor 840 may execute wake manager 810.

[0123] In some implementations, processor 840 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receive inputs and process those inputs to produce a set of outputs that may be delivered to other systems or components such as device 805. For example, a processing system of device 805 may refer to a system that includes various other components or subcomponents of device 805.

[0124] The processing system of device 805 can be docked with other components of device 805, and can process information (such as input or signal) received from other components, output information to other components, etc. For example, the chip or modem of device 805 may include a processing system, a first interface for outputting information, and a second interface for obtaining information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a transmitter, so that the device 805 can transmit information output from the chip or modem. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a receiver, so that the device 805 can obtain information or signal input, and the information can be passed to the processing system. Those of ordinary skill in the art will easily appreciate that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0125] The inter-station communication manager 845 may manage communications with other APs 105 and may include a controller or scheduler for controlling communications with STAs 115 in cooperation with other APs 105. For example, the inter-station communication manager 845 may coordinate the scheduling of transmissions to STAs 115 for various interference mitigation techniques such as beamforming or joint transmissions. In some implementations, the inter-station communication manager 845 may provide an X2 interface within a wireless communication network technology to provide communications between APs 105.

[0126] The code 835 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. In some implementations, the code 835 may not be directly executed by the processor 840, but may cause a computer (such as when compiled and executed) to perform the functions described herein.

[0127] Additionally or alternatively, the device 805 may include one or more interfaces and a processing system. The processing system may be in electronic communication with the one or more interfaces. In some implementations, the interface and processing system may be components of a chip or modem, which may be a component of the device 805. The processing system and one or more interfaces may include aspects of a wake-up manager 810, a memory 830, a processor 840, or a combination thereof. The processing system and one or more interfaces may also be in electronic communication (such as via a bus 850) with a network communication manager 815, an inter-station communication manager 845, a transceiver 820, or a combination thereof.

[0128] For example, the first interface may be configured to obtain information from other components of the device 805. The second interface may be configured to output information to other components of the device 805. Information may be sent and received in the form of encoded or unencoded bits. The processing system may perform any number of processes to modify or determine the information output from the second interface.

[0129] In some implementations, the processing system may be configured to determine that a STA 115 associated with the AP 105 is to be awakened from a low power mode. The processing system may generate a wake-up packet for reception by a wake-up radio of the STA 115 to trigger awakening of the STA 115, the wake-up packet including a frequency-tone sequence of ON symbols for the wake-up packet, wherein the frequency-tone sequence satisfies a correlation metric threshold (e.g., a maximum correlation metric threshold). An interface (e.g., a second interface described herein) may be configured to output the wake-up packet for transmission to the STA 115.

[0130] Fig. 9An example block diagram of a system 900 including a device 905 that supports determining a frequency tone sequence is shown. The device 905 can be an example of an AP 105, a STA 115, or another computing device as described herein or include components thereof. The device 905 may include components for two-way voice and data communications, including components for transmitting and receiving communications. In some implementations, the device 905 may include a frequency tone selection manager 910, an input / output (I / O) controller 915, a transceiver 920, an antenna 925, a memory 930, a processor 940, or some combination thereof. These components can be in electronic communication via one or more buses (such as a bus 945).

[0131] The frequency tone selection manager 910 may select a frequency tone sequence. The frequency tone selection manager 910 may identify a set of candidate frequency tone sequences; store a correlation metric and a PAPR for each of the set of candidate frequency tone sequences in a memory and in association with an identifier of the corresponding candidate frequency tone sequence; and associate the correlation metric and the PAPR for each of the set of candidate frequency tone sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency tone sequences. The frequency tone selection manager 910 may identify one or more of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and may select a frequency tone sequence from the one or more coordinate pairs that define the lower convex hull. The frequency tone sequence may be selected for the ON codeword of a wake-up packet. In some examples, the frequency tone selection manager 910 may select a frequency tone sequence for the ON codeword of a wake-up packet, which will be transmitted by the AP 105 and received by the wake-up radio of the STA 115 to trigger the wake-up of the STA 115.

[0132] I / O controller 915 can manage input and output signals of device 905. I / O controller 915 can also manage peripheral devices that are not integrated into device 905. In some implementations, I / O controller 915 can represent a physical connection or port to an external peripheral device. In some examples, I / O controller 915 can utilize an operating system, such as or another known operating system. In some other examples, I / O controller 915 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some examples, I / O controller 915 may be implemented as part of a processor. In some examples, a user may interact with device 905 via I / O controller 915 or via hardware components controlled by I / O controller 915.

[0133] The transceiver 920 can communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 920 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 920 can also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0134] In some implementations, a wireless device may include a single antenna 925. However, in some implementations, the device may have more than one antenna 925, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0135] The memory 930 may include RAM and ROM. The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform various functions described herein. In some examples, the memory 930 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0136] The processor 940 may include a hardware device (such as a general purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some examples, the processor 940 may be configured to operate a memory array using a memory controller. In some other examples, the memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (such as memory 930) to cause the device 905 to perform various functions (such as functions or tasks that support determining a frequency-modulation sequence).

[0137] Processor 940 may be any suitable processor or processors capable of executing scripts or instructions of one or more software programs stored in device 905, such as within memory 930. For example, processor 940 may execute tone selection manager 910 or I / O controller 915.

[0138] In some implementations, processor 940 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receive inputs and process those inputs to produce a set of outputs that may be delivered to other systems or components such as device 905. For example, a processing system of device 905 may refer to a system that includes various other components or subcomponents of device 905.

[0139] The processing system of device 905 can be docked with other components of device 905, and can process information (such as input or signal) received from other components, output information to other components, etc. For example, the chip or modem of device 905 may include a processing system, a first interface for outputting information, and a second interface for obtaining information. In some cases, the first interface may refer to an interface between the processing system of the chip or modem and a transmitter, so that the device 905 can transmit information output from the chip or modem. In some cases, the second interface may refer to an interface between the processing system of the chip or modem and a receiver, so that the device 905 can obtain information or signal input, and the information can be passed to the processing system. Those of ordinary skill in the art will easily appreciate that the first interface may also obtain information or signal input, and the second interface may also output information or signal output.

[0140] The code 935 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 935 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some implementations, the code 935 may not be directly executed by the processor 940, but may cause a computer (such as when compiled and executed) to perform the functions described herein.

[0141] Additionally or alternatively, the device 905 may include one or more interfaces and a processing system. The processing system may be in electronic communication with the one or more interfaces. In some implementations, the interface and processing system may be components of a chip or modem, which may be a component of the device 905. The processing system and one or more interfaces may include aspects of a frequency tone selection manager 910, a memory 930, a processor 940, or a combination thereof. The processing system and one or more interfaces may also be in electronic communication (such as via a bus 945) with an I / O controller 915, a transceiver 920, or both. In some implementations, a first interface may be configured to output information to other components of the device 905. A second interface may be configured to obtain information from other components of the device 905. Information may be sent and received in the form of encoded or unencoded bits. The processing system may perform any number of processes to modify or determine information (such as information related to frequency tone sequence selection)

[0142] In some implementations, the processing system may support selecting a frequency-frequency tone sequence. The processing system may be configured to: identify a set of candidate frequency-frequency tone sequences; store a correlation metric and a PAPR for each of the set of candidate frequency-frequency tone sequences in a memory and in association with an identifier of the corresponding candidate frequency-frequency tone sequence; and associate the correlation metric and the PAPR for each of the set of candidate frequency-frequency tone sequences to a set of coordinate pairs, each pair representing one of the set of candidate frequency-frequency tone sequences. The processing system may be further configured to: identify one or more of the coordinate pairs that define a lower convex hull of the set of coordinate pairs; and may select a frequency-frequency tone sequence from the one or more coordinate pairs that define the lower convex hull. The frequency-frequency tone sequence may be selected for use in an ON symbol of a wake-up packet.

[0143] In some examples, the tone selection manager 910 may be implemented as an integrated circuit or chipset for a mobile device modem, and the I / O controller 915 and transceiver 920 may be implemented as analog components (e.g., amplifiers, filters, antennas, etc.) coupled to the mobile device modem to enable wireless transmission and reception.

[0144] The frequency selection manager 910 as described herein can be implemented to achieve one or more potential advantages. Various implementations can reduce the number of false detections made by the device 905 for packets not intended for the device 905, and can reduce the number of times the device 905 fails to receive other packets intended for the device 905. At least one implementation can enable the frequency selection manager 910 to increase the amount of time that the device 905 can be maintained in a deep sleep mode.

[0145] Based on implementing techniques for determining tone sequences as described herein, one or more processors of device 905 (e.g., a processor controlling one or more of transceiver 920, tone selection manager 910, and I / O controller 915 or incorporated therein) can increase the battery life of device 905 by reducing the amount of time that device 905 is awake and monitoring packet transmissions. Additionally, limiting error detection by device 905 can improve overall communication efficiency in a wireless network by supporting reliable packet reception.

[0146] Fig.10 A flow chart illustrating an example method 1000 for determining a tone sequence, performing a wake-up procedure, or both is shown. The operations of the method 1000 may be implemented by the AP 105 or components thereof as described herein. For example, the operations of the method 1000 may be implemented by the AP 105 or components thereof as described herein. Figure 8 In some implementations, the AP 105 may execute an instruction set to control the functional elements of the AP 105 to perform the functions described below. Additionally or alternatively, the AP 105 may use dedicated hardware to perform various aspects of the functions described below.

[0147] At 1005, the AP 105 may determine that a STA 115 associated with the AP 105 is to wake up from a low power mode. The operations of 1005 may be performed according to the methods described herein.

[0148] At 1010, the AP 105 may generate a wakeup packet for reception by a wakeup radio of the STA 115 to trigger wakeup of the STA 115, the wakeup packet including a tone sequence for an ON symbol of the wakeup packet, wherein the tone sequence satisfies a correlation metric threshold. The operations of 1010 may be performed according to the methods described herein.

[0149] At 1015, the AP 105 may transmit the wake-up packet to the STA 115. The operations of 1015 may be performed according to the methods described herein.

[0150] Fig.11 A flow chart illustrating an example method 1100 for determining a frequency tone sequence, performing a wake-up procedure, or both is shown. The operations of the method 1100 may be implemented by the AP 105 or its components as described herein. For example, the operations of the method 1100 may be implemented by the AP 105 or its components as described herein. Figure 8 In some implementations, the AP 105 may execute an instruction set to control the functional elements of the AP 105 to perform the functions described below. Additionally or alternatively, the AP 105 may use dedicated hardware to perform various aspects of the functions described below.

[0151] At 1105, the AP 105 may determine that a STA 115 associated with the AP 105 is to wake up from a low power mode. The operations of 1105 may be performed according to the methods described herein.

[0152] At 1110, the AP 105 may select a data rate for the ON symbols of the wake-up packet. The operations of 1110 may be performed according to the methods described herein.

[0153] At 1115, the AP 105 may determine a tone sequence based on the data rate. The operations of 1115 may be performed according to the methods described herein.

[0154] At 1120, the AP 105 may generate the wakeup packet for reception by the wakeup radio of the STA 115 to trigger wakeup of the STA 115, the wakeup packet including a frequency-tone sequence of ON symbols for the wakeup packet, wherein the frequency-tone sequence satisfies the correlation metric threshold. The operation of 1120 may be performed according to the methods described herein.

[0155] At 1125, the AP 105 may transmit the wake-up packet to the STA 115. The operations of 1125 may be performed according to the methods described herein.

[0156] Fig.12 A flow chart illustrating an example method 1200 for determining a tone sequence, performing a wake-up procedure, or both is shown. The operations of the method 1200 may be implemented by a device or components thereof as described herein. For example, the operations of the method 1200 may be implemented by a device or components thereof as described herein. Fig. 9 The device may perform the following functions. In some implementations, the device may execute a set of instructions to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the functions described below. The device may perform the selection of a frequency tone sequence.

[0157] At 1205, the device may identify a set of candidate tone sequences. The operations of 1205 may be performed according to the methods described herein.

[0158] At 1210, the device may store in a memory and in association with an identifier of the corresponding candidate tone sequence a correlation metric and a PAPR for each of the set of candidate tone sequences. The operations of 1210 may be performed according to the methods described herein.

[0159] At 1215, the device may associate the correlation metric and the PAPR for each of the set of candidate tone sequences to a set of coordinate pairs, each pair representing one of the set of candidate tone sequences. The operations of 1215 may be performed according to the methods described herein.

[0160] At 1220, the device may identify one or more of the coordinate pairs that define a lower convex hull of the set of coordinate pairs. The operation of 1220 may be performed according to the methods described herein.

[0161] At 1225, the device may select a frequency-modulated sequence for an ON symbol of a wake-up packet from one or more coordinate pairs defining the lower convex hull. The operation of 1225 may be performed according to the methods described herein.

[0162] Fig.13 A flow chart illustrating an example method 1300 for determining a tone sequence, performing a wake-up procedure, or both is shown. The operations of the method 1300 may be implemented by a device or components thereof as described herein. For example, the operations of the method 1300 may be implemented by a device or components thereof as described herein. Fig. 9 The device may perform the following functions. In some implementations, the device may execute a set of instructions to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the device may use dedicated hardware to perform various aspects of the functions described below. The device may perform the selection of a frequency tone sequence.

[0163] At 1305, the device may identify a set of candidate tone sequences. The operations of 1305 may be performed according to the methods described herein.

[0164] At 1310, the device may store in a memory and in association with an identifier of the corresponding candidate tone sequence a correlation metric and a PAPR for each of the set of candidate tone sequences. The operations of 1310 may be performed according to the methods described herein.

[0165] At 1315, the device may associate the correlation metric and the PAPR for each of the set of candidate tone sequences to a set of coordinate pairs, each pair representing one of the set of candidate tone sequences. The operations of 1315 may be performed according to the methods described herein.

[0166] At 1320, the device may identify a first coordinate pair in the set of coordinate pairs that has a minimum correlation metric. The operations of 1320 may be performed according to the methods described herein.

[0167] At 1325, the device may identify a second coordinate pair in the set of coordinate pairs that has a steepest negative slope relative to the first coordinate pair. The operation of 1325 may be performed according to the methods described herein.

[0168] At 1330, the device may identify additional coordinate pairs in the set of coordinate pairs, each of the additional coordinate pairs having a correlation metric greater than the correlation metric of the most recently identified coordinate pair and having a steepest negative slope relative to the most recently identified coordinate pair. In some implementations, the first coordinate pair, the second coordinate pair, and the additional coordinate pairs define a lower convex hull of the set of coordinate pairs. The operations of 1330 may be performed according to methods described herein.

[0169] At 1335, the device may select a frequency-modulated sequence for an ON symbol of a wake-up packet from one or more coordinate pairs defining the lower convex hull. The operation of 1335 may be performed according to the methods described herein.

[0170] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc.

[0171] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes described in conjunction with the implementations disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. This interchangeability of hardware and software has been generally described in terms of their functionality and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether such functionality is implemented in hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0172] The hardware and data processing apparatus for implementing the various illustrative logics, logic blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed with a general purpose single-chip or multi-chip processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in cooperation with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by circuit systems dedicated to a given function.

[0173] In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware (including the structures disclosed in this specification and their structural equivalents), or in any combination thereof. Implementations of the subject matter described in this specification may also be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by a data processing apparatus or for controlling the operation of a data processing apparatus.

[0174] If implemented in software, each function can be stored on a computer-readable medium or transmitted therethrough as one or more instructions or codes. The process of the method or algorithm disclosed herein can be implemented in a processor executable software module that can reside on a computer-readable medium. Computer-readable media include both computer storage media and communication media, including any medium that can be implemented to transfer a computer program from one place to another. Storage media can be any available medium that can be accessed by a computer. As an example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage devices, or any other medium that can be used to store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection may also be appropriately referred to as a computer-readable medium. As used herein, disks and discs include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks and blue-ray discs, wherein disks often reproduce data magnetically and discs reproduce data optically with lasers. The above combination should also be included in the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine-readable medium and a computer-readable medium, which may be incorporated into a computer program product.

[0175] Various modifications to the implementations described in this disclosure may be apparent to those skilled in the art, and the universal principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but should be granted the widest scope consistent with the disclosure, the principles and novel features disclosed herein.

[0176] In addition, one of ordinary skill in the art will readily appreciate that the terms "upper" and "lower / lower" are sometimes used for convenience in describing the drawings and indicate relative positions corresponding to the orientation of the drawings on a correctly oriented page, and may not reflect the actual orientation of any device as implemented.

[0177] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations separately or in any suitable subcombination. Furthermore, while features may be described above as functioning in certain combinations and even initially claimed as such, one or more features from a claimed combination may in some examples be removed from the combination, and a claimed combination may be directed to a subcombination, or a variation of a subcombination.

[0178] Similarly, although operations are depicted in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order, or to perform all the operations described in order to achieve the desired result. In addition, the accompanying drawings may schematically depict one or more example processes in the form of a flow chart. However, other operations not depicted may be incorporated into the schematically illustrated example processes. For example, one or more additional operations may be performed before, after, simultaneously or between any illustrated operations. In some environments, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the implementation described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations also fall within the scope of the appended claims. In some implementations, the actions described in the claims may be performed in different orders and still achieve the desired result.

Claims

1. An access point (AP) device for wireless communication, comprising: A processing system configured to: Determining that a station (STA) associated with the AP is to wake up from a low power mode; as well as generating a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet comprising a tone sequence for an ON symbol of the wake-up packet, wherein the tone sequence is associated with a maximum correlation metric that is less than a maximum correlation metric threshold; and interface, which is configured as: The wake-up packet is output for transmission to the STA.

2. The device of claim 1, wherein: Each of a plurality of cyclic shifts of the ON symbol satisfies the maximum correlation metric threshold.

3. The device of claim 1, wherein: The maximum correlation metric is based at least in part on a maximum of a plurality of absolute values ​​of normalized autocorrelations at one or more sampling start times of the frequency-modulated sequence, one or more repetition numbers of the frequency-modulated sequence, or a combination thereof.

4. The device of claim 3, wherein: The normalized autocorrelation corresponds to a repetition interval over a time length equal to the duration of a short training sequence within the ON symbol using the frequency-modulated sequence.

5. The device of claim 1, wherein: The frequency-modulated sequence further includes a maximum peak-to-average power ratio that satisfies the maximum peak-to-average power ratio threshold by being less than the maximum peak-to-average power ratio threshold.

6. The device of claim 5, wherein: Satisfaction of the maximum peak-to-average power ratio threshold is based at least in part on each of a plurality of cyclic shifts of the ON symbol satisfying the maximum peak-to-average power ratio threshold.

7. The device of claim 1, wherein: The frequency-modulated tone sequence comprises a binary phase-shift keying modulated tone sequence, a quadrature phase-shift keying modulated tone sequence, a quadrature amplitude modulated tone sequence, or a combination thereof.

8. The apparatus of claim 1, wherein: The processing system is further configured to: selecting a data rate for the ON symbols of the wake-up packet; and The frequency-modulation sequence is determined based at least in part on the data rate.

9. The apparatus of claim 8, wherein: The data rate comprises a high data rate and the ON symbols span a first time period and use a first number of subcarriers; or The data rate comprises a low data rate, and the ON symbols span a second time period longer than the first time period and use a second number of subcarriers greater than the first number of subcarriers.

10. The apparatus of claim 1, wherein: The frequency modulation sequence includes one of the following sequences: [1 -1 1 1 -1 -1 0 -1 1 1 -1 -1 -1], [-1 1 1 -1 -1 1 0 1 -1 -1 -1 -1 -1], [1-1 1 1 -1 1 0 1 1 1 -1 -1 -1], [1 -1 1 -1 -1 -1 0 -1 1 -1 -1 -1 -1], [-1 1 -1 11 -1 0 1 1 -1 -1 -1 -1], or [-11 1 1 -1 1 0 -1 -1 -1 1 -1 -1].

11. An apparatus for selecting a frequency-modulation sequence, comprising: Memory; as well as A processing system configured to: identifying a plurality of candidate tone sequences; storing a correlation metric and a peak-to-average power ratio for each of the plurality of candidate tone sequences in the memory and in association with an identifier of the corresponding candidate tone sequence; associating the correlation metric and the peak-to-average power ratio for each of the plurality of candidate tone sequences to a plurality of coordinate pairs, each pair representing one of the plurality of candidate tone sequences; identifying one or more coordinate pairs of the plurality of coordinate pairs that define a lower convex hull of the plurality of coordinate pairs; as well as The frequency-modulated sequence for an ON symbol of a wake-up packet is selected from the one or more coordinate pairs defining the lower convex hull.

12. The apparatus of claim 11, wherein: The processing system configured to identify the one or more of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs is further configured to: identifying a first coordinate pair of the plurality of coordinate pairs having a minimum correlation measure; identifying a second coordinate pair of the plurality of coordinate pairs having a steepest negative slope relative to the first coordinate pair; as well as identifying additional coordinate pairs of the plurality of coordinate pairs, each of the additional coordinate pairs having a correlation metric greater than a correlation metric of a most recently identified coordinate pair and having a steepest negative slope relative to the most recently identified coordinate pair, The first coordinate pair, the second coordinate pair, and the additional coordinate pair include the one or more coordinate pairs among the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs.

13. The apparatus of claim 12, wherein: The processing system is further configured to: The plurality of coordinate pairs are sorted based on the peak-to-average power ratio prior to identifying the first coordinate pair.

14. The apparatus of claim 11, wherein: The processing system configured to identify the one or more of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs is further configured to: representing the plurality of coordinate pairs in a scatter plot wherein a first axis represents the correlation metric and a second axis represents a peak-to-average power ratio grid; and The one or more coordinate pairs of the plurality of coordinate pairs are identified from the lower convex hull of the scatter plot.

15. The apparatus of claim 11, wherein: The correlation measure for each of the plurality of candidate tone sequences comprises a maximum correlation measure for each candidate tone sequence; as well as The peak-to-average power ratio of each candidate frequency tone sequence in the plurality of candidate frequency tone sequences comprises a maximum peak-to-average power ratio of each candidate frequency tone sequence.

16. A method for wireless communication at an access point (AP) device, comprising: Determining that a station (STA) associated with the AP is to wake up from a low power mode; generating a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet comprising a tone sequence for an ON symbol of the wake-up packet, wherein the tone sequence is associated with a maximum correlation metric that is less than a maximum correlation metric threshold; as well as The wake-up packet is transmitted to the STA.

17. The method of claim 16, wherein: Each of a plurality of cyclic shifts of the ON symbol satisfies the maximum correlation metric threshold.

18. The method of claim 16, wherein: The maximum correlation metric is based at least in part on a maximum of a plurality of absolute values ​​of normalized autocorrelations at one or more sampling start times of the frequency-modulated sequence, one or more repetition numbers of the frequency-modulated sequence, or a combination thereof.

19. The method of claim 18, wherein: The normalized autocorrelation corresponds to a repetition interval over a time length equal to the duration of a short training sequence within the ON symbol using the frequency-modulated sequence.

20. The method of claim 16, wherein: The frequency-modulated sequence further includes a maximum peak-to-average power ratio that satisfies the maximum peak-to-average power ratio threshold by being less than the maximum peak-to-average power ratio threshold.

21. The method of claim 20, wherein: Satisfaction of the maximum peak-to-average power ratio threshold is based at least in part on each of a plurality of cyclic shifts of the ON symbol satisfying the maximum peak-to-average power ratio threshold.

22. The method of claim 16, wherein: The frequency-modulated tone sequence comprises a binary phase-shift keying modulated tone sequence, a quadrature phase-shift keying modulated tone sequence, a quadrature amplitude modulated tone sequence, or a combination thereof.

23. The method of claim 16, further comprising: selecting a data rate for the ON symbols of the wake-up packet; as well as The frequency-modulation sequence is determined based at least in part on the data rate.

24. The method of claim 23, wherein: The data rate comprises a high data rate and the ON symbols span a first time period and use a first number of subcarriers; or The data rate comprises a low data rate, and the ON symbols span a second time period longer than the first time period and use a second number of subcarriers greater than the first number of subcarriers.

25. The method of claim 16, wherein: The frequency modulation sequence includes one of the following sequences: [1 -1 1 1 -1 -1 0 -1 1 1 -1 -1 -1], [-1 1 1 -1 -1 1 0 1 -1 -1 -1 -1 -1], [1-1 1 1 -1 1 0 1 1 1 -1 -1 -1], [1 -1 1 -1 -1 -1 0 -1 1 -1 -1 -1 -1], [-1 1 -1 11 -1 0 1 1 -1 -1 -1 -1], or [-11 1 1 -1 1 0 -1 -1 -1 1 -1 -1].

26. A method for selecting a frequency-modulated sequence, comprising: identifying a plurality of candidate tone sequences; storing a correlation metric and a peak-to-average power ratio for each of the plurality of candidate tone sequences in a memory and in association with an identifier of the corresponding candidate tone sequence; associating the correlation metric and the peak-to-average power ratio for each of the plurality of candidate tone sequences to a plurality of coordinate pairs, each pair representing one of the plurality of candidate tone sequences; identifying one or more coordinate pairs of the plurality of coordinate pairs that define a lower convex hull of the plurality of coordinate pairs; as well as The frequency-modulated sequence for an ON symbol of a wake-up packet is selected from the one or more coordinate pairs defining the lower convex hull.

27. The method of claim 26, wherein: Identifying the one or more coordinate pairs of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs comprises: identifying a first coordinate pair of the plurality of coordinate pairs having a minimum correlation measure; identifying a second coordinate pair of the plurality of coordinate pairs having a steepest negative slope relative to the first coordinate pair; and identifying additional coordinate pairs of the plurality of coordinate pairs, each of the additional coordinate pairs having a correlation metric greater than a correlation metric of a most recently identified coordinate pair and having a steepest negative slope relative to the most recently identified coordinate pair, The first coordinate pair, the second coordinate pair, and the additional coordinate pair include the one or more coordinate pairs among the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs.

28. The method of claim 27, further comprising: The plurality of coordinate pairs are sorted based on the peak-to-average power ratio prior to identifying the first coordinate pair.

29. The method of claim 26, wherein: Identifying the one or more coordinate pairs of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs comprises: representing the plurality of coordinate pairs in a scatter plot wherein a first axis represents the correlation metric and a second axis represents a peak-to-average power ratio grid; and The one or more coordinate pairs of the plurality of coordinate pairs are identified from the lower convex hull of the scatter plot.

30. The method of claim 26, wherein: The correlation measure for each of the plurality of candidate tone sequences comprises a maximum correlation measure for each candidate tone sequence; as well as The peak-to-average power ratio of each candidate frequency tone sequence in the plurality of candidate frequency tone sequences comprises a maximum peak-to-average power ratio of each candidate frequency tone sequence.

31. A device for an access point (AP) for wireless communication, comprising: means for determining that a station (STA) associated with the AP is to wake up from a low power mode; means for generating a wake-up packet for reception by a wake-up radio of the STA to trigger wake-up of the STA, the wake-up packet comprising a tone sequence for an ON symbol of the wake-up packet, wherein the tone sequence is associated with a maximum correlation metric that is less than a maximum correlation metric threshold; and means for transmitting the wake-up packet to the STA.

32. A device for selecting a frequency-modulation sequence, comprising: means for identifying a plurality of candidate tone sequences; means for storing, in a memory and in association with an identifier of the corresponding candidate tone sequence, a correlation metric and a peak-to-average power ratio for each of the plurality of candidate tone sequences; means for associating the correlation metric and the peak-to-average power ratio for each of the plurality of candidate tone sequences to a plurality of coordinate pairs, each pair representing one of the plurality of candidate tone sequences; means for identifying one or more of the plurality of coordinate pairs that define a lower convex hull of the plurality of coordinate pairs; as well as Means for selecting the frequency-modulated sequence for an ON symbol of a wake-up packet from the one or more coordinate pairs defining the lower convex hull.

33. A non-transitory computer readable medium storing code for wireless communication at a device of an access point (AP), the code comprising instructions executable by a processor for: Determining that a station (STA) associated with the AP is to wake up from a low power mode; generating a wake-up packet for reception by a wake-up radio of the STA to trigger a wake-up of the STA, the wake-up packet comprising a tone sequence for an ON symbol of the wake-up packet, wherein the tone sequence is associated with a maximum correlation metric that is less than a maximum correlation metric threshold; as well as The wake-up packet is transmitted to the STA.

34. The non-transitory computer readable medium of claim 33, wherein: Each of a plurality of cyclic shifts of the ON symbol satisfies the maximum correlation metric threshold.

35. The non-transitory computer readable medium of claim 33, wherein: The maximum correlation metric is based at least in part on a maximum of a plurality of absolute values ​​of normalized autocorrelations at one or more sampling start times of the frequency-modulated sequence, one or more repetition numbers of the frequency-modulated sequence, or a combination thereof.

36. The non-transitory computer readable medium of claim 35, wherein: The normalized autocorrelation corresponds to a repetition interval over a time length equal to the duration of a short training sequence within the ON symbol using the frequency-modulated sequence.

37. The non-transitory computer readable medium of claim 33, wherein: The frequency-modulated sequence further includes a maximum peak-to-average power ratio that satisfies the maximum peak-to-average power ratio threshold by being less than the maximum peak-to-average power ratio threshold.

38. The non-transitory computer readable medium of claim 37, wherein: Satisfaction of the maximum peak-to-average power ratio threshold is based at least in part on each of a plurality of cyclic shifts of the ON symbol satisfying the maximum peak-to-average power ratio threshold.

39. The non-transitory computer readable medium of claim 33, wherein: The frequency-modulated tone sequence comprises a binary phase-shift keying modulated tone sequence, a quadrature phase-shift keying modulated tone sequence, a quadrature amplitude modulated tone sequence, or a combination thereof.

40. The non-transitory computer readable medium of claim 33, wherein: The instructions are further executable by the processor to: selecting a data rate for the ON symbols of the wake-up packet; and The frequency-modulation sequence is determined based at least in part on the data rate.

41. The non-transitory computer readable medium of claim 40, wherein: The data rate comprises a high data rate and the ON symbols span a first time period and use a first number of subcarriers; or The data rate comprises a low data rate, and the ON symbols span a second time period longer than the first time period and use a second number of subcarriers greater than the first number of subcarriers.

42. The non-transitory computer readable medium of claim 33, wherein: The frequency modulation sequence includes one of the following sequences: [1 -1 1 1 -1 -1 0 -1 1 1 -1 -1 -1], [-1 1 1 -1 -1 1 0 1 -1 -1 -1 -1 -1], [1-1 1 1 -1 1 0 1 1 1 -1 -1 -1], [1 -1 1 -1 -1 -1 0 -1 1 -1 -1 -1 -1], [-1 1 -1 11 -1 0 1 1 -1 -1 -1 -1], or [-11 1 1 -1 1 0 -1 -1 -1 1 -1 -1].

43. A non-transitory computer readable medium storing code for selecting a tone sequence, the code comprising instructions executable by a processor to: identifying a plurality of candidate tone sequences; storing a correlation metric and a peak-to-average power ratio for each of the plurality of candidate tone sequences in a memory and in association with an identifier of the corresponding candidate tone sequence; associating the correlation metric and the peak-to-average power ratio for each of the plurality of candidate tone sequences to a plurality of coordinate pairs, each pair representing one of the plurality of candidate tone sequences; identifying one or more coordinate pairs of the plurality of coordinate pairs that define a lower convex hull of the plurality of coordinate pairs; as well as The frequency-modulated sequence for an ON symbol of a wake-up packet is selected from the one or more coordinate pairs defining the lower convex hull.

44. The non-transitory computer readable medium of claim 43, wherein: The instructions for identifying the one or more of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs are executable by the processor to: identifying a first coordinate pair of the plurality of coordinate pairs having a minimum correlation measure; identifying a second coordinate pair of the plurality of coordinate pairs having a steepest negative slope relative to the first coordinate pair; as well as identifying additional coordinate pairs of the plurality of coordinate pairs, each of the additional coordinate pairs having a correlation metric greater than a correlation metric of a most recently identified coordinate pair and having a steepest negative slope relative to the most recently identified coordinate pair, The first coordinate pair, the second coordinate pair, and the additional coordinate pair include the one or more coordinate pairs among the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs.

45. The non-transitory computer readable medium of claim 44, wherein: The instructions are further executable by the processor to: The plurality of coordinate pairs are sorted based on the peak-to-average power ratio prior to identifying the first coordinate pair.

46. ​​The non-transitory computer readable medium of claim 43, wherein: The instructions for identifying the one or more of the plurality of coordinate pairs that define the lower convex hull of the plurality of coordinate pairs are executable by the processor to: representing the plurality of coordinate pairs in a scatter plot wherein a first axis represents the correlation metric and a second axis represents a peak-to-average power ratio grid; and The one or more coordinate pairs of the plurality of coordinate pairs are identified from the lower convex hull of the scatter plot.

47. The non-transitory computer readable medium of claim 43, wherein: The correlation measure for each of the plurality of candidate tone sequences comprises a maximum correlation measure for each candidate tone sequence; as well as The peak-to-average power ratio of each candidate frequency tone sequence in the plurality of candidate frequency tone sequences comprises a maximum peak-to-average power ratio of each candidate frequency tone sequence.

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