Physical Layer Protocol Data Unit (PPDU) Format for WiFi Sensing

Abstract

In one aspect, a wireless device is configured to transmit a physical layer protocol data unit on one or more channels, the physical layer protocol data unit including a first portion and a second portion. The first portion includes a signal length field indicating a duration of transmission of the physical layer protocol data unit. The second portion includes a plurality of Wi-Fi sensing fields. The wireless device is configured to receive a reflected signal and a leakage signal associated with the physical layer protocol data unit. The reflected signal includes the physical layer protocol data unit reflected from a target object. The leakage signal is associated with the physical layer protocol data unit.

Description

[Technical field]

[0001] Aspects of the present disclosure relate generally to Wi-Fi sensing, and in particular to data unit formats for use to enable Wi-Fi sensing. [Background technology]

[0002] Wi-Fi sensing uses Wi-Fi-based signals, e.g., signals conforming to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, to provide short-range (within a radius of about 7 meters) capabilities. In Wi-Fi sensing, a single device may transmit and receive signals. Wi-Fi sensing may be used, for example, in a vehicle to determine the distance between the vehicle and another vehicle, determine whether the distance is increasing or decreasing (e.g., indicating a possible collision between the vehicle and another vehicle), monitor and identify undesirable driver behavior (e.g., distraction, dozing, drowsing, etc.), etc. Indoors, Wi-Fi sensing may be used to determine location, track the movements of people, pets, etc. However, there is currently no standard format for transmitting data for use in Wi-Fi sensing. Summary of the Invention [Means for solving the problem]

[0003] The following presents a simplified summary related to one or more aspects disclosed herein. As such, the following summary is not intended to be an extensive overview of all contemplated aspects, nor is it intended to identify key or critical elements of all contemplated aspects or to delineate the scope related to any particular aspect. As such, the following summary is intended solely to present some concepts related to one or more aspects of the mechanisms disclosed herein in a simplified form prior to the detailed description presented below.

[0004] In one aspect, a physical layer protocol data unit (PPDU) includes a first portion and a second portion. The first portion includes a signal length field indicating a duration of the transmission of the PPDU. The first portion is recognized by an 802.11 compatible device to prevent the 802.11 compatible device from transmitting for the duration of the transmission of the PPDU. The second portion includes a Wi-Fi signal field and a number of Wi-Fi sensing fields. A device transmits a PPDU on one or more 802.11 compatible channels and receives (i) a reflected signal including a PPDU reflected from a target and (ii) a leakage signal associated with the PPDU. The device determines a distance to the target and a direction of the target relative to the device. Based on the distance and direction, the device creates a map including the target.

[0005] Other objects and advantages associated with the embodiments disclosed herein will become apparent to those skilled in the art based on the accompanying drawings and detailed description.

[0006] The accompanying drawings are presented to aid in the description of various aspects of the present disclosure and are provided only for illustration of the aspects, not for limitation of the aspects. A more complete understanding of the present disclosure may be obtained by reference to the following detailed description taken in conjunction with the accompanying drawings. In the figures, the left-most digit(s) of a reference number identifies the figure in which that reference number first appears. The same reference number in different figures indicates similar or identical items. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 illustrates an exemplary wireless sensing system in accordance with various aspects of the present disclosure. [Diagram 2] FIG. 2 illustrates an example PPDU format according to an aspect of the present disclosure. [Diagram 3] FIG. 1 illustrates an example process including creating a PPDU, according to an aspect of the disclosure. [Figure 4]FIG. 1 illustrates an example process including receiving a leakage signal associated with a PPDU and a reflected signal associated with the PPDU, in accordance with an aspect of the disclosure. [Diagram 5] FIG. 1 illustrates an example process including receiving a signal, according to an aspect of the disclosure. [Figure 6] FIG. 1 illustrates a wireless device according to an aspect of the present disclosure. [Figure 7A] 1 is a simplified block diagram of an example aspect of components that may be utilized in a wireless communication node and configured to support communications as described herein. [Figure 7B] 1 is a simplified block diagram of an example aspect of components that may be utilized in a wireless communication node and configured to support communications as described herein. [Figure 8] FIG. 1 illustrates an example process including determining a transmission time according to an aspect of the disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Systems and techniques are disclosed for object detection based on radio frequency (RF) signals from wireless devices, such as access points (APs), user equipment (UEs), etc. The wireless devices may include both transmitters and receivers. The wireless devices may transmit a set of RF signals (e.g., one or more) for at least object detection, and possibly for both object detection and communication. For example, the RF signals may be used to transmit one or more physical layer protocol data units (PPDUs). Each PPDU may include a first portion that is backward compatible with the 802.11 standard. Transmitting the PPDU may cause other devices (e.g., other 802.11 devices) within reception range of the PPDU to stop transmitting for the time the PPDU is being transmitted, for example, to avoid packet collisions with the PPDU. Each PPDU may include a second portion used for Wi-Fi sensing. In some cases, the first portion of the PPDU may be transmitted at a first power level, and the second portion of the PPDU may be transmitted at a second power level that is less than the first power level. Transmitting the first portion of the PPDU at a first (e.g., higher) power level may prevent other devices from transmitting while the PPDU is being transmitted, thereby keeping the RF spectrum within a certain distance from the computing device free from other packets that could potentially interfere with Wi-Fi sensing. Transmitting the second portion of the PPDU at a second (e.g., lower) power level may prevent the receiver from becoming saturated (overloaded) because the transmitter and receiver are within the wireless device.

[0009] The second part of the PPDU may include a signal data field (WiS-SIG) and a sequence of Wi-Fi sensing signals (WiS-1 to WiS-N, where N is an integer and N>0). The signal data field may include the length of the second part of the PPDU (e.g., length=N), the sequence type, the number of transmit (Tx) antennas, whether the signal is single-stream or multi-stream (e.g., multiple-input multiple-output (MIMO)), other data associated with the Wi-Fi sensing signal, or any combination thereof. The sequence type may indicate whether the Wi-Fi sensing signal is (1) a time-domain based sequence (e.g., Zadoff-Chu) or (2) a frequency-domain based (e.g., long training field (LTF)-based orthogonal frequency division multiplexing (OFDM)) sequence. The contents of each of the Wi-Fi sensing signals WiS-1 to WiS-N may be the same. After being received, the Wi-Fi sensing signals WiS-1 to WiS-N may be averaged to improve the signal-to-noise ratio (SNR).

[0010] The transmitted PPDU may reflect off a target within the sensing area (e.g., about 7 meters) to create a reflected PPDU that is received by the receiver. The transmitted PPDU may, for example, not reflect off a target and be directly received by the receiver as a leaked PPDU. The wireless device may use the reflected PPDU and the leaked PPDU to determine the distance between the wireless device and the target and to determine the direction of the target relative to the wireless device. In this manner, the wireless device can create a map of objects within the sensing area, including the target.

[0011] Aspects of the present disclosure are provided in the following description and associated drawings, directed to various examples provided for illustrative purposes. Alternative aspects may be devised without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0012] The words "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" should not necessarily be construed as preferred or advantageous over other aspects. Similarly, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the described feature, advantage or mode of operation.

[0013] Those skilled in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc.

[0014] Further, many aspects are described in terms of a sequence of actions to be performed, for example, by elements of a computing device. It will be recognized that the various actions described herein may be performed by specific circuitry (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of both. In addition, a sequence of actions described herein may be considered to be fully embodied in any form of non-transitory computer-readable storage medium storing a corresponding set of computer instructions that, when executed, cause or instruct an associated processor of a device to perform the functions described herein. Thus, various aspects of the present disclosure may be embodied in a number of different forms, all of which are contemplated to fall within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspect may be described herein, for example, as "logic configured to" perform the described actions.

[0015] The terms "user equipment" (UE) and "base station" as used herein are not intended to be specific or otherwise limited to any particular radio access technology (RAT) unless otherwise stated. In general, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a consumer asset tracking device, a wearable device (e.g., a smart watch, glasses, an augmented reality (AR) / virtual reality (VR) headset, etc.), a vehicle (e.g., an automobile, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE may be mobile or stationary (e.g., at some time) and may communicate with a radio access network (RAN). The term "UE" as used herein may be referred to interchangeably as an "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or UT, "mobile device", "mobile terminal", "mobile station", or variations thereof. In general, a UE may communicate with a core network via the RAN, through which the UE may be connected to external networks, such as the Internet, and to other UEs. Of course, other mechanisms for a UE to connect to the core network and / or the Internet are also possible, such as via a wired access network, a Wireless Local Area Network (WLAN) network (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11, etc.), etc.

[0016] A base station may operate according to one of several RATs in communication with the UE depending on the network in which the base station is deployed and may alternatively be referred to as an access point (AP), network node, Node B, evolved Node B (eNB), next generation eNB (ng-eNB), new radio (NR) Node B (also referred to as gNB or gNodeB), etc. A base station may be used primarily to support wireless access by UEs, including supporting data, voice, and / or signaling connections for supported UEs. In some systems, the base station may provide purely edge node signaling functionality, while in other systems, the base station may provide additional control and / or network management functionality. A communication link through which a UE may send RF signals to a base station is referred to as an uplink (UL) channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). A communication link through which a base station may send RF signals to a UE is referred to as a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). As used herein, the term Traffic Channel (TCH) can refer to either an uplink / reverse traffic channel or a downlink / forward traffic channel.

[0017] The term "base station" may refer to a single physical transmission / reception point (TRP) or to multiple physical TRPs that may or may not be co-located. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station that corresponds to a cell (or several cell sectors) of the base station. When the term "base station" refers to multiple physical TRPs that are co-located, the physical TRPs may be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or when the base station employs beamforming). When the term "base station" refers to multiple physical TRPs that are not co-located, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, a non-co-located physical TRP may be a serving base station that receives measurement reports from the UE and neighboring base stations whose reference RF signals (or simply "reference signals") the UE is measuring. A TRP is a point from which a base station transmits and receives wireless signals, so as used herein, references to transmission from or reception at a base station should be understood as references to the particular TRP of the base station.

[0018] In some implementations that support positioning of UEs, a base station may not support wireless access by the UE (e.g., may not support data, voice, and / or signaling connections for the UE) but may instead transmit reference signals to the UE to be measured by the UE and / or receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning beacon (e.g., when it transmits signals to the UE) and / or a position measurement unit (e.g., when it receives and measures signals from the UE).

[0019] An "RF signal" includes electromagnetic waves of a given frequency that transport information through space between a transmitter and a receiver. As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through a multipath channel. The same RF signal transmitted on different paths between a transmitter and a receiver may be referred to as a "multipath" RF signal. As used herein, an RF signal may also be referred to as a "wireless signal," "sensing signal," "radio wave," "waveform," etc., or simply as a "signal," when it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

[0020] As a first example, a computing device, such as an access point, may execute a method. The method may include transmitting a physical layer protocol data unit (PPDU) on one or more channels. The PPDU may include (1) a first portion including a short training field (STF), a long training field (LTF), and a signal length field (L-SIG) indicating a duration of transmission of the PPDU, and (2) a second portion including a plurality of Wi-Fi sensing (WiS) fields. The first portion of the PPDU may conform to the 802.11a standard, the 802.11n standard, the 802.11ac standard, the 802.11ax standard, the 802.11be standard, or the like. The second portion of the PPDU may include a sequence type field to indicate that each WiS field of the multiple WiS fields includes either a time domain sequence (e.g., a Zadoff-Chu based sequence) or a frequency domain sequence (e.g., an Orthogonal Frequency Division Multiplexing (OFDM) based sequence), a number of transmit antennas used to transmit the PPDU, and a stream type field to indicate that the multiple WiS fields include either a single stream or a multiple-input multiple-output (MIMO) stream. Transmitting the PPDU on one or more channels includes (1) transmitting a first portion of the PPDU at a first power level, and (2) transmitting a second portion of the PPDU at a second power level less than the first power level (e.g., up to 20 decibels (db)). The method may include receiving a reflected signal associated with the PPDU. For example, the reflected signal may include a PPDU reflected from a target object. The method may include receiving a leakage signal associated with the PPDU. The method may include determining an average WiS of the multiple WiS fields (e.g., of the reflected signal and of the leakage signal). For example, the average WiS has an increased signal-to-noise ratio relative to an individual WiS field of the multiple WiS fields. The method may include performing channel estimation (e.g., of the reflected signal and of the leakage signal) based at least in part on comparing the multiple WiS fields to one or more reference fields.The method may include determining a distance to a target object based at least in part on the reflected signal and the leak signal, determining a direction of the target object based at least in part on the reflected signal and the leak signal, and creating a map including an approximate location of the target object based at least in part on the distance to the target object and the direction of the target object.

[0021] As another example, an access point may include (1) a transmit antenna array and (2) a transmit module configured to transmit a physical layer protocol data unit (PPDU) on one or more channels using the transmit antenna array. The PPDU may include (1) a first portion including a short training field (STF), a long training field (LTF), and a signal length field (L-SIG) indicating a duration of transmission of the PPDU, and (2) a second portion including multiple Wi-Fi sensing (WiS) fields, such as a sequence type field to indicate that an individual WiS field of the multiple WiS fields includes either a time-domain sequence (e.g., a Zadoff-Chu based sequence) or a frequency-domain sequence (e.g., an Orthogonal Frequency Division Multiplexing (OFDM) based sequence), a number of transmit antennas used to transmit the PPDU, and a stream type field to indicate that the multiple WiS fields include either a single stream or a multiple-input multiple-output (MIMO) stream. A first portion of the PPDU is transmitted at a first power level, and a second portion of the PPDU is transmitted at a second power level that is less than the first power level (e.g., up to 20db). The first portion of the PPDU is compliant with 802.11a, 802.11n, 802.11ac, 802.11ax, and 802.11be standards. For example, an 802.11 compliant device receiving the PPDU stops transmitting for a duration based at least in part on the signal length field (L-SIG). The access point may include a receive antenna array and a receive module configured to (1) receive a reflected signal associated with the PPDU, where the reflected signal includes the PPDU reflected from the target object, and (2) receive a leakage signal associated with the PPDU. The access point may include one or more processors and one or more non-transitory computer-readable storage media for storing instructions executable by the one or more processors to perform various operations.For example, the instructions may be executable to determine a distance to a target object based at least in part on the reflected signal and the leakage signal, determine a direction of the target object based at least in part on the reflected signal and the leakage signal, and create a map including an approximate location of the target object based at least in part on the distance to the target object and the direction of the target object. The instructions may be executable to determine an average WiS of the multiple WiS fields, since the average WiS has an increased signal-to-noise ratio relative to an individual WiS field of the multiple WiS fields. The instructions may be executable to perform a channel estimation based at least in part on comparing the multiple WiS fields to one or more reference fields.

[0022] As a further example, one or more non-transitory computer-readable storage media may store instructions executable by one or more processors to perform various operations. The instructions may be executable to transmit a physical layer protocol data unit (PPDU) on one or more channels. The PPDU includes (1) a first portion including a short training field (STF), a long training field (LTF), and a signal length field (L-SIG) indicating a duration of transmission of the PPDU, and (2) a second portion including multiple Wi-Fi sensing (WiS) fields, such as a sequence type field to indicate that an individual WiS field of the multiple WiS fields includes either a time-domain sequence (e.g., a Zadoff-Chu based sequence) or a frequency-domain sequence (e.g., an Orthogonal Frequency Division Multiplexing (OFDM) based sequence), a number of transmit antennas used to transmit the PPDU, and a stream type field to indicate that the multiple WiS fields include either a single stream or a multiple-input multiple-output (MIMO) stream. The first portion of the PPDU may conform to various 802.11 standards, such as, for example, 802.11a, 802.11n, 802.11ac, 802.11ax, and 802.11be. The first portion of the PPDU may be transmitted at a first power level and the second portion of the PPDU may be transmitted at a second power level less than the first power level (e.g., up to 20db). The instructions may be executable to receive a reflected signal associated with the PPDU, the reflected signal including the PPDU reflected from the target object, and to receive a leakage signal associated with the PPDU. The instructions may be executable to determine an average WiS of the multiple WiS fields (e.g., of the reflected signal and the leakage signal). For example, the average WiS has an increased signal-to-noise ratio relative to an individual WiS field of the multiple WiS fields. The instructions may be executable to perform channel estimation (eg, of reflected and leakage signals) based at least in part on comparing the multiple WiS fields to one or more reference fields.The instructions may be executable to determine a distance to a target object based at least in part on the reflected signal and the leakage signal, determine a direction of the target object based at least in part on the reflected signal and the leakage signal, and create a map including an approximate location of the target object based at least in part on the distance to the target object and the direction of the target object.

[0023] FIG. 1 illustrates an example wireless sensing system 100 according to various aspects of the disclosure. The system 100 may include a wireless device 102, such as, for example, an access point (AP), a user equipment (UE), etc. The wireless device 102 may include a digital-to-analog converter 104 coupled to a transmission module 106. For example, the digital-to-analog converter 104 may convert a digital signal to an analog signal and provide the analog signal to the transmission module 106 for transmission. The transmission module 106 may create a PPDU 108 based on the analog signal. The transmission module 106 may transmit the PPDU 108 using a transmit antenna array 110 (e.g., one or more transmit (Tx) antennas).

[0024] A receive antenna array 112 (e.g., one or more receive (Rx) antennas) of the wireless device 102 may be used to receive one or more signals derived from the PPDU 108. For example, the PPDU 108 may reflect off a representative target 114 to create a reflected signal 116 corresponding to the PPDU 108. The Rx antenna array 112 may receive the reflected signal 116. The Rx antenna array 112 may receive the PPDU 108 directly, for example, without reflecting off the target 114, in the form of a leakage signal 118. After being received by the Rx antenna 112, the reflected signal 116 and the leakage signal 118 may be sent to a receive module 120 and then processed using an analog-to-digital converter 122 to convert each of the signals 116, 118 from analog to digital.

[0025] The wireless device 102 may use the reflected signal 116 and the leakage signal 118 to perform channel estimation 124. The PPDU 108 may be sent using one or more channels and may be distorted or noise may be added while the PPDU 108 travels through the channel. To remove the distortion and noise added by the channel to the received signal 116, 118, the wireless device 102 may determine characteristics of the channel through which the PPDU 108 passed by performing channel estimation 124.

[0026] The wireless device 102 may use the reflected signal 116 and the leakage signal 118 to determine a distance 126 between the wireless device 102 and the target 114. The wireless device 102 may use the reflected signal 116 and the leakage signal 118 to determine a direction 128 (e.g., in two or three dimensions) of the target 114 relative to the wireless device 102. The wireless device 102 may use the distance 126 in the direction 128 to create a mapping 130 of objects within a particular distance (e.g., at least about 7 meters) from the wireless device 102.

[0027] The wireless device 102 may perform a correlation 132 of the reflected signal 116 and the leakage signal 118 by comparing the received signal (e.g., one of the signals 116, 118) to a reference signal 134 (e.g., a known signal) to identify which field of the PPDU 108 was received. The correlation 132 process may enable the wireless device 102 to determine where the Wi-Fi sensing portion of the PPDU begins and ends to enable synchronization 133 in which the receiving module 120 synchronizes reception of signals such as the reflected signal 116 and the leakage signal 118. If the channel estimation 124 is performed in the time domain, the time domain waveform may be stored as a reference signal 134, the received signals (e.g., the leakage signal 118, the reflected signal 116) may be transformed to the time domain, and the correlation 132 may be performed to estimate the channel. If the channel estimation 124 is performed in the frequency domain, a frequency domain waveform may be stored as a reference signal 134, the received signal may be transformed to the frequency domain, and a frequency domain channel estimation algorithm (e.g., zero-forcing channel estimation or similar) may be used to perform the channel estimation 124.

[0028] Of course, in some cases, the system 100 may include more than the representative target 114, such as other targets 136. For example, the mapping 130 may include the target 114 as well as other targets 136.

[0029] The PPDU 108 may have a format that is backward compatible with other 802.11 standards. For example, the PPDU 108 may appear as an 802.11 data unit when the wireless device 102 begins broadcasting the PPDU 108, causing other wireless devices 138 to not transmit for a certain amount of time, e.g., specified in a signal length field of the PPDU 108. The other wireless devices 138 may not transmit packets while the wireless device 102 is transmitting the PPDU 108 to prevent packet collisions with the PPDU 108.

[0030] Although there may be a small amount of delay between the time the transmitting module 106 transmits the PPDU 108 and the time the receiving module 120 receives the reflected signal 116, the leakage signal 118, or both, such use is considered simultaneous Tx and Rx because the transmission of the PPDU 108 and the reception of the signals 116, 118 occur substantially simultaneously.

[0031] In this manner, the wireless device may use the Tx antenna to transmit the PPDU. The first portion of the PPDU may be backward compatible with the 802.11 standard, thereby preventing other wireless devices from transmitting packets while the PPDU is being transmitted. The second portion of the PPDU may be used for wireless sensing. For example, the PPDU may reflect off a target object to create a reflected signal that is received by the Rx antenna of the wireless device. As another example, the PPDU may be received directly by the Rx antenna in the form of a leakage signal without being reflected off the target object. The wireless device may use the reflected signal and the leakage signal to determine the distance between the wireless device and the target, and the direction of the target relative to the wireless device. In this manner, the wireless device may create a mapping of one or more targets within a particular vicinity of the wireless device. For example, the wireless device may be used in a vehicle to determine whether the distance between the vehicle and a second vehicle is decreasing, potentially causing a collision. In such a situation, the vehicle's collision avoidance system may use the distance data from the wireless device to warn the vehicle's driver, automatically apply braking to slow the vehicle and maintain a minimum distance between the vehicle and a second vehicle, take another action (e.g., evasive maneuver) to avoid or mitigate the effects of the collision, or any combination thereof.

[0032] 2 illustrates an example PPDU format 200 according to an aspect of the present disclosure. The PPDU 108 may include a first portion 202 and a second portion 204. The first portion 202 (also referred to as a legacy preamble) may be backward compatible with various versions of the IEEE 802.11 standard. The second portion 204 may be used for Wi-Fi sensing as described herein.

[0033] The first portion 202 of the PPDU 108 may include a short training field (L-STF) 206, a long training field (L-LTF) 208, a signal field (L-SIG) 210, a Mark1 field 212, and a Mark2 field 214. The L-STF 206 may be used for coarse synchronization, and the L-LTF may be used for fine synchronization (e.g., synchronization 133 of FIG. 1) and initial channel estimation (e.g., when performing channel estimation 124 of FIG. 1). The L-SIG 210 may be decoded by receiving devices, such as the wireless device 102 and other wireless devices 138, to determine transmission parameters including the length (e.g., duration) of the PPDU 108. When the wireless device 102 begins transmitting the PPDU 108, other wireless (e.g., 802.11 compatible) devices 138 may receive the PPDU 108, determine the duration of the PPDU 108 based on the L-SIG 210, and may not transmit for the duration of the PPDU 108, e.g., to avoid packet collisions. The Mark 1 field 212 and the Mark 2 field 214 may be encoded using binary phase shift keying (BPSK), as may be present in some of the previous IEEE 802.11 standards, as shown in Table 1.

[0034] [Table 1]

[0035] The second portion 204 of the PPDU 108 may include a Wi-Fi sensing (WiS) signal field (WiS-SIG) 216 and multiple Wi-Fi sensing fields 218, e.g., WiS field 218(1) through WiS field 218(N), where N>1. Typically, N=32 or N=64, with the larger N being the greater the signal-to-noise ratio (SNR). The contents of each of the WiS fields 218 may be identical during transmission. A receiver, such as the wireless device 102, may determine a WiS average 220 for each of the WiS fields 218. For example, the WiS average 220 may have an increased SNR compared to one or more of the WiS fields 218.

[0036] To reduce packet collisions, the wireless device 102 may transmit the first portion 202 at a first power level that is higher than the second power level at which the second portion 204 is transmitted. By doing so, the first portion 202 may be received by other wireless devices 138 within a distance from the wireless device 102, which may be at least 7 meters, for example, thereby preventing the other wireless devices 138 from transmitting packets while the PPDU 108 is being transmitted. To prevent a receiver, such as the receiving module 120 of FIG. 1, from being saturated when receiving the second portion 204, the wireless device 102 may transmit the second portion 204 at a second power level that is lower than the first power level. In this manner, the higher power level of the first portion 202 clears the 802.11 spectrum while the lower power level of the second portion 204 prevents saturation of the receiving module 120 of FIG. 1. For example, the first power level (at which the first portion 202 is transmitted) may be up to about 20 decibels (dB) greater than the second power level (at which the second portion 204 is transmitted) to reduce the possibility of receiver saturation.

[0037] The WiS-SIG 216 may optionally include a dummy field 222 transmitted prior to the data field 224. The dummy field 222 may allow a receiving device, such as the wireless device 102, to delay turning on a receiver (e.g., the receiving module 120 of FIG. 1) until the first portion 202 is transmitted. Because the receiving device may not be able to precisely time when the transmission of the second portion 204 begins (e.g., to turn on the receiver after the first portion 202 is transmitted), the dummy field 222 provides a time window during which the receiving device can turn on the receiver without missing useful fields (e.g., starting with the data field 224) of the second portion 204. The dummy field 222 may be up to about 4 microseconds (μs) in length to match the length of the individual fields 206, 208, 210 of the first portion 202.

[0038] The data field 224 may provide information associated with the second portion 204, such as the sequence length of the WiS field 218 (e.g., the value of N). The data field 224 may provide information about the sequence type of the WiS field 218, such as, for example, whether the WiS field 218 includes a time domain sequence (e.g., a Zadoff-Chu sequence) or a frequency domain sequence (e.g., an LTF type OFDM sequence). Zadoff-Chu or OFDM may be used because both have superior correlation properties compared to other types of sequences. The correlation may enable the Rx module 120 of FIG. 1 to perform the correlation and channel estimation 124 immediately (e.g., with fewer calculations). The correlation may enable the Rx module 120 to determine where the WiS field 218(1) begins and where the WiS field 218(N) ends. The data field 224 may indicate the number of transmit (Tx) antennas used to transmit the PPDU 108. The data field 224 may indicate whether the PPDU 108 is being transmitted as a single stream or as a multiple-input multiple-output (MIMO) stream. Of course, the data field 224 may include additional information associated with the second portion 204 of the PPDU 108. The Rx module 120 may perform synchronization 133 and channel estimation 124. Synchronization 133 may use correlation 132, as typically done in the time domain, or may be done at least initially in the time domain by using correlation and then fine-tuned in the frequency domain by using other algorithms other than correlation 132. Channel estimation 124 may use correlation 132 in the time domain or may use zero forcing (or other algorithms) in the frequency domain.

[0039] In some variants of 802.11 (e.g., 802.11ax and 802.11be), the contents of the Mark 1 field 212 and the Mark 2 field 214 may be the L-SIG 210 modified using the modifier 226. For example, in some variants of 802.11, the contents of the Mark 1 field 212 and the Mark 2 field 214 may be the logical complement of the L-SIG 210. In some cases, the wireless device 102 may set the contents of the Mark 1 field 212 and the Mark 2 field 214 of the PPDU 108 to be the logical complement of the L-SIG 210. In other cases, the wireless device 102 may set the contents of the Mark 1 field 212 and the Mark 2 field 214 of the PPDU 108 to be the exclusive OR (XOR) of the L-SIG 210. Of course, other logic modifiers than logical complement or XOR may be used to modify the L-SIG 210 for use in the Mark1 field 212, the Mark2 field 214, or both.

[0040] The wireless device 102 includes both a transmit module 106 and a receive module 120, but the WiS-SIG 216 may be used to provide the signal related information rather than communicating the signal related information using connections on a circuit board of the wireless device 102. For example, if the transmit module 106 uses a first integrated circuit (IC) and the Rx module 120 uses a second IC, the signal latency when transmitting the signal related information between the two ICs may not be suitable for use with Wi-Fi sensing.

[0041] Each of the WiS fields 218 may have a length between about 3.6 microseconds (μs) and about 4 μs when a very high throughput (VHT)-LTF is used. When a high efficiency (HE)-LTF is used, the length of each of the WiS fields 218 may be about 4 μs (e.g., 1×LTF=1×4 μs), about 8 μs (e.g., 2×LTF=2×4 μs), about 16 μs (e.g., 4×LTF=4×4 μs), or another length according to the 802.11 specification. In MIMO, the number of streams may be up to 8 streams. The WiS fields 218 may have a bandwidth of, for example, 20 megahertz (MHz), 40 MHz, 80 MHz, 160 MHz, or 320 MHz.

[0042] Thus, by creating a first portion of a PPDU that is recognized by 802.11 compliant devices and broadcasting the first portion at a first power level, the wireless device may prevent packet collisions from occurring during the broadcast of the PPDU. For example, an 802.11 compliant device may receive a transmission of a PPDU, determine a duration of the PPDU, and not transmit for the duration of the transmission of the PPDU. A second portion of the PPDU may be broadcast at a second power level that is lower than the first power level to avoid saturating a receiver in the wireless device. The second portion of the PPDU may include multiple WiS fields, each field having the same content. The multiple WiS fields may be averaged to increase the SNR. The signal field of the second portion may include a dummy field at the beginning of the second portion to allow a receiver to be turned on after the first portion of the PPDU is broadcast without missing a data field of the signal field.

[0043] In the flow diagrams of Figures 3, 4, and 5, each block represents one or more operations that may be implemented in hardware, software, or a combination thereof. In the context of software, the blocks represent computer-executable instructions that, when executed by one or more processors, cause the processors to perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, modules, components, data structures, etc. that perform particular functions or implement particular abstract data types. The order in which the blocks are described is not intended to be construed as limiting, and any number of the operations described can be combined in any order and / or in parallel to implement a process. For purposes of explanation, processes 300, 400, and 500 are described with respect to Figures 1 and 2, as described above, although other models, frameworks, systems, and environments may be used to implement these processes.

[0044] 3 illustrates an example process 300 that includes creating a PPDU in accordance with an aspect of the disclosure. The process 300 may be performed by a device such as the wireless device 102 of FIGS.

[0045] At 302, the process may create a first portion of a PPDU that is backward compatible with other 802.11 devices. At 304, the process may create a second portion of the PPDU for use in Wi-Fi sensing. The second portion may include a signal data field and a number of Wi-Fi sensing fields. For example, in FIG. 2, the wireless device 102 may create a first portion 202 of a PPDU 108. The first portion 202 may be backward compatible with and understood by the other wireless devices 138. The second portion 204 of the PPDU 108 may be used for Wi-Fi sensing. After the wireless device 102 begins transmitting the PPDU 108, the other wireless devices 138 may recognize the first portion 202 and temporarily refrain from transmitting while the PPDU 108 is being transmitted to avoid packet collisions. For example, the other wireless devices 138 may decode the duration of the PPDU 108 based on the L-SIG field 210 and not transmit for the duration of the PPDU 108.

[0046] At 306, the process may transmit, using the transmitter, a first portion of the PPDU at a first power level. At 308, the process may transmit, using the transmitter, a second portion of the PPDU at a second power level. The second power level may be less than the first power level. For example, in FIG. 2, the wireless device 102 may transmit the first portion 202 at a first power level and the second portion 204 at a second power level. The second power level may be less than the first power level. By transmitting the first portion 202 at the first power level, the PPDU 108 may be transmitted at least a predetermined distance (e.g., 7 meters) from the wireless device 102 to prevent interference from other wireless devices 138. By transmitting the second portion 204 at the second power level, a receiver module of the wireless device 102 may not be saturated. Because the PPDU 108 is being transmitted and received substantially simultaneously by the same device, eg, the wireless device 102, transmitting the PPDU 108 using an incorrect power level may result in saturation of the receiver module.

[0047] 4 illustrates an example process 400 that includes receiving a leakage signal associated with a PPDU and a reflected signal associated with the PPDU, according to an aspect of the disclosure. The process 400 may be performed by a device such as the wireless device 102 of FIGS. 1 and 2.

[0048] At 402, the process may receive a leakage signal associated with a transmitted PPDU using a receiver (e.g., a receiving module). At 404, the process may receive a reflected signal associated with the transmitted PPDU using the receiver. For example, in FIG. 1, the Rx module 120 of the wireless device 102 may receive the reflected signal 116 after the PPDU 108 is transmitted and reflects off the target 114. The Rx module 120 may receive the leakage signal 118 directly after the PPDU 108 is transmitted, for example, without the leakage signal 118 reflecting off a target, such as the target 114.

[0049] At 406, the process may determine a distance to a target (e.g., a reflector) based on the time difference between the leakage signal and the reflected signal. For example, in FIG. 1, the wireless device 102 may determine a distance 126 between the wireless device 102 and the target 114 based on the time difference between (i) a first time point at which the leakage signal 118 is received and (ii) a second time point at which the reflected signal 116 is received.

[0050] At 408, the process may determine a direction (e.g., relative to the wireless device) of the target based on the channel information from the one or more antennas. For example, in FIG. 1, the wireless device 102 may determine a direction 128 of the target 114 relative to the wireless device 102 based on the channel information determined based on when the reflected signal 116 in the leakage signal 118 is received by each of the one or more Rx antennas 112. For example, if the reflected signal 116 is received by a first antenna before being received by a second antenna, the wireless device 102 may determine that the target 114 is closer to the first antenna compared to the second antenna and determine an approximate direction 128 of the location of the target 114 relative to the wireless device 102.

[0051] At 410, the process may create a map based on one or more of the distance, direction, and channel information. For example, in FIG. 1, the wireless device 102 may create a mapping 130 that includes a map of an area within a predetermined distance from the wireless device 102. The mapping 130 may include the target 114 and other targets 136.

[0052] Thus, a receiving module of the wireless device may receive a leakage signal associated with the PPDU and a reflected signal associated with the PPDU reflected from the target. The receiving module may determine the distance and direction to the target based on the leakage signal and the reflected signal. A similar process may be used to determine the distance and direction of other targets in the area. The receiving module may create a map that includes the target and other targets, if any. In this manner, 802.11 based signals may be used to enable Wi-Fi sensing.

[0053] 5 illustrates an example process 500 including receiving a signal according to an aspect of the disclosure. The process 500 may be performed by a device such as the wireless device 102 of FIGS.

[0054] At 502, the process may determine that a signal associated with the transmitted PPDU (e.g., a reflected signal or a leakage signal) has been received. At 504, the process may initiate use of a receiver (e.g., an Rx module) to receive a second portion of the signal. For example, in FIG. 2, the Rx module 120 may determine that a signal associated with the PPDU 108 has been received and initiate use of the Rx module 120 to receive the second portion 204.

[0055] At 506, the process may perform signal correlation and channel estimation based on the reference. For example, in FIG. 1, the wireless device 102 may use the reference 134 to perform correlation 132 and channel estimation 124.

[0056] At 508, the process may synchronize the reception of the second portion of the signal. At 510, the process may determine the signal data field of the second portion of the signal (including the length of the second portion and a single type of additional field). At 510, the process may receive the additional fields of the second portion of the signal. At 514, the process may determine an average of the additional fields. For example, in FIG. 2, the Rx module 120 may synchronize the reception of the second portion 204 and receive the data field 224 of the WiS-SIG field 216. The Rx module 120 may receive additional Wi-Fi sensing fields WiS 218(1) through WiS 218(N) and determine the WiS average 220. For example, the WiS average 220 may have a higher SNR compared to one or more of the WiS fields 218.

[0057] Figure 6 shows a wireless device 600 that may be used to implement the wireless device 102 and other wireless devices 138 of Figure 1. The wireless device 102 (and other wireless devices 138) may include one or more processors 602 (e.g., CPU, GPU, etc.), memory 604, a communications interface 606, a display device 608, other input / output (I / O) devices 610 (e.g., keyboard, trackball, etc.), and one or more mass storage devices 612 (e.g., disk drives, solid-state disk drives, etc.) configured to communicate with each other, such as via one or more system buses 614 or other suitable connections. For ease of understanding, a single system bus 614 is shown, however, it should be understood that the system bus 614 may include multiple buses, such as a memory device bus, a storage device bus (e.g., Serial ATA (SATA)), a data bus (e.g., Universal Serial Bus (USB)), a video signal bus (e.g., ThunderBolt®, DVI, HDMI®, etc.), a power bus, and the like.

[0058] The processor 602 is one or more hardware devices that may include a single processing unit or several processing units, all of which may include a single or multiple computing units, or multiple cores. The processor 602 may include a graphics processing unit (GPU) integrated into the CPU, or the GPU may be a processor device separate from the CPU. The processor 602 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, graphics processing units, state machines, logic circuits, and / or any device that manipulates signals based on operational instructions. Among other capabilities, the processor 602 may be configured to fetch and execute computer-readable instructions stored in the memory 604, mass storage device 612, or other computer-readable medium.

[0059] The memory 604 and the mass storage device 612 are examples of computer storage media (e.g., memory storage devices) for storing instructions executable by the processor 602 to perform various functions described herein. For example, the memory 604 may include both volatile and non-volatile memory devices (e.g., RAM, ROM, etc.). Additionally, the mass storage device 612 may include hard disk drives, solid state drives, external and removable drives, memory cards, flash memory, removable media including floppy disks, optical disks (e.g., CDs, DVDs), storage arrays, network attached storage, storage area networks, etc. Both the memory 604 and the mass storage device 612 may be collectively referred to herein as memory or computer storage media, and may be any type of non-transitory medium capable of storing computer-readable, processor-executable program instructions as computer program code executable by the processor 602 as a particular machine configured to perform the operations and functions described in the implementations herein.

[0060] The device 600 may include one or more communication interfaces 606 for exchanging data. The communication interface 606 can facilitate communication within a wide variety of network and protocol types, including wired networks (e.g., Ethernet, DOCSIS, DSL, fiber, USB, etc.) and wireless networks (e.g., WLAN, GSM, CDMA, 802.11, Bluetooth, wireless USB, ZigBee, cellular, satellite, etc.), the Internet, etc. The communication interface 606 can also provide communication with external storage, such as a storage array, network attached storage, storage area network, cloud storage, etc.

[0061] The display device 608 may be used to display content (e.g., information and images) to a user. The other I / O devices 610 may be devices that receive various inputs from a user and provide various outputs to a user, and may include a keyboard, a touchpad, a mouse, a printer, audio input / output devices, etc.

[0062] Computer storage media such as memory 604 and mass storage device 612 may be used to store software and data. For example, computer storage media may be used to store channel estimates 124, distance 126, direction 128, mapping 130, correlation 132, other applications 415, other data 418. Wireless device 102 (and other wireless devices 138) may each include a transmit module 106, a transmit antenna array 110, a receive module 120, and a receive (Rx) antenna array 112.

[0063] 7A and 7B, several example components (represented by corresponding blocks) are shown that may be incorporated in a UE, a base station (which may correspond to any of the base stations described herein), and a network entity (which may correspond to or embody any of the network functions described herein) to support file transmission operations. It will be appreciated that these components may be implemented in different types of devices in different implementations (e.g., in an ASIC, in a system on a chip (SoC), etc.). The illustrated components may also be incorporated in other devices in a communication system. For example, other devices in the system may include similar components to the described components to provide similar functionality. Also, a given device may include one or more of the components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0064] A UE, base station, or network entity may include a wireless wide area network (WWAN) transceiver 710 and 750, respectively, configured to communicate over one or more wireless communications networks (not shown), such as an NR network, an LTE network, a GSM network, etc. The WWAN transceivers 710 and 750 may be connected to one or more antennas 716 and 756, respectively, to communicate with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., over at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communications medium of interest (e.g., some set of time / frequency resources in a particular frequency spectrum). The WWAN transceivers 710 and 750 may be variously configured to transmit and encode signals 718 and 758 (e.g., messages, instructions, information, etc.), respectively, and conversely, to receive and decode signals 718 and 758 (e.g., messages, instructions, information, pilots, etc.), respectively, in accordance with the designated RAT. Specifically, transceivers 710 and 750 include one or more transmitters 714 and 754, respectively, for transmitting and encoding signals 718 and 758, respectively, and include one or more receivers 712 and 752, respectively, for receiving and decoding signals 718 and 758, respectively.

[0065] The UE and base station also, at least in some cases, include wireless local area network (WLAN) transceivers 720 and 760, respectively. The WLAN transceivers 720 and 760 may be connected to one or more antennas 726 and 766, respectively, for communicating with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth, etc.) over a wireless communication medium of interest. The WLAN transceivers 720 and 760 may be variously configured to transmit and encode signals 728 and 768, respectively (e.g., messages, instructions, information, etc.), and conversely, to receive and decode signals 728 and 768, respectively (e.g., messages, instructions, information, pilots, etc.), in accordance with the designated RAT. Specifically, transceivers 720 and 760 include one or more transmitters 724 and 764, respectively, for transmitting and encoding signals 728 and 768, respectively, and include one or more receivers 722 and 762, respectively, for receiving and decoding signals 728 and 768, respectively.

[0066] The transceiver circuitry including at least one transmitter and at least one receiver may in some implementations comprise an integrated device (e.g., embodied as transmitter and receiver circuits in a single communications device), in some implementations comprise separate transmitter devices and separate receiver devices, or in other implementations may be embodied in other ways. In an aspect, the transmitter may include or be coupled to multiple antennas, such as an antenna array (e.g., antennas 716, 726, 756, 766), that enable each device to perform transmit "beamforming" as described herein. Similarly, the receiver may include or be coupled to multiple antennas, such as an antenna array (e.g., antennas 716, 726, 756, 766), that enable each device to perform receive beamforming as described herein. In one aspect, the transmitters and receivers may share the same multiple antennas (e.g., antennas 716, 726, 756, 766), such that each device can only receive or transmit at a given time, but not both at the same time. The wireless communication device of the UE and / or base station (e.g., one or both of the transceivers 710 and 720 and / or 750 and 760) may also include a network listen module (NLM) or the like for performing various measurements.

[0067] The UE and base station may, at least in some cases, include satellite positioning system (SPS) receivers 730 and 770. The SPS receivers 730 and 770 may be connected to one or more antennas 736 and 776, respectively, for receiving SPS signals 738 and 778, respectively, such as Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, Beidou signals, Navigation Satellite System of India (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. The SPS receivers 730 and 770 may comprise any suitable hardware and / or software for receiving and processing the SPS signals 738 and 778, respectively. The SPS receivers 730 and 770 request information and actions from other systems as appropriate, and perform the necessary calculations to determine the position of the UE and base station using measurements obtained by any suitable SPS algorithms.

[0068] The base stations and network entities may each include at least one network interface 780 for communicating with other network entities. For example, the network interface 780 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wire-based or wireless backhaul connection. In some aspects, the network interface 780 may be implemented as a transceiver configured to support wire-based or wireless signal communication. This communication may include, for example, sending and receiving messages, parameters, and / or other types of information.

[0069] The UE, base station, and network entities may include other components that may be used in conjunction with the operations disclosed herein. The UE may include a processor circuit implementing a processing system 732, for example, for providing functionality related to RF sensing and for providing other processing functions. The base station may include a processing system 784, for example, for providing functionality related to RF sensing as disclosed herein and for providing other processing functions. The network entities may include a processing system, for example, for providing functionality related to Wi-Fi sensing or RF sensing as disclosed herein and for providing other processing functions. In an aspect, the processing system 732, 784 may include, for example, one or more general-purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), or other programmable logic devices or processing circuits.

[0070] The UE, base station, and network entity may include memory circuitry implementing memory components 740, 786 (e.g., each including a memory device) for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, etc.). In some cases, the UE, base station, and network entity may include sensing components 742, 788, respectively. The sensing components 742, 788 may be hardware circuits that are part of or coupled to the processing systems 732, 784, respectively, that, when executed, cause the UE, base station, and network entity to perform the functions described herein. In other aspects, the sensing components 742, 788 may be external to the processing systems 732, 784 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the sensing components 742, 788 may be memory modules stored in the memory components 740, 786, respectively (as shown in Figures 7A, 7B) that, when executed by the processing systems 732, 784 (or a modem processing system, another processing system, etc.), cause the UE, base station, and network entities to perform the functions described herein.

[0071] The UE may include one or more sensors 744 coupled to the processing system 732 to provide motion and / or orientation information independent of motion data derived from signals received by the WWAN transceiver 710, the WLAN transceiver 720, and / or the SPS receiver 730. By way of example, the sensors 744 may include an accelerometer (e.g., a microelectromechanical system (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of motion detection sensor. Additionally, the sensors 744 may include multiple different types of devices and combine their outputs to provide motion information. For example, the sensors 744 may use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate a position in a 2D and / or 3D coordinate system.

[0072] Additionally, the UE may include a user interface 746 for providing instructions (e.g., audible and / or visual instructions) to a user and / or receiving user input (e.g., upon user activation of a sensing device such as a keypad, touch screen, microphone, etc.) Although not shown, base stations and network entities may also include user interfaces.

[0073] Referring more particularly to the processing system 784, on the downlink, IP packets from a network entity may be provided to the processing system 784. The processing system 784 may implement functionality for an RRC layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer. The processing system 784 may provide RRC layer functions related to broadcasting of system information (e.g., Master Information Block (MIB), System Information Block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions related to header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions related to transfer of upper layer packet data units (PDUs), error correction through automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions related to mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0074] The transmitter 754 and receiver 752 may implement Layer 1 functions related to various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping onto the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The transmitter 754 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with reference signals (e.g., pilots) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying the time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimates may be derived from a reference signal and / or channel condition feedback transmitted by the UE. Each spatial stream may then be provided to one or more different antennas 756. The transmitter 754 may modulate an RF carrier with each spatial stream for transmission.

[0075] At the UE, the receiver 712 receives the signal through its respective antenna 716. The receiver 712 recovers the information modulated onto the RF carrier and provides the information to the processing system 732. The transmitter 714 and the receiver 712 implement Layer 1 functions related to various signal processing functions. The receiver 712 may perform spatial processing on the information to recover any spatial streams destined for the UE. If multiple spatial streams are destined for the UE, they may be combined by the receiver 712 into a single OFDM symbol stream. The receiver 712 then converts the OFDM symbol stream from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most likely signal constellation point transmitted by the base station. These soft decisions may be based on channel estimates calculated by a channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by the base station on the physical channel. The data and control signals are then provided to a processing system 732 that implements Layer 3 and Layer 2 functions.

[0076] In the uplink, the processing system 732 performs demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the core network. The processing system 732 is also responsible for error detection.

[0077] Similar to the functionality described with respect to downlink transmissions by the base station, the processing system 732 provides RRC layer functionality related to system information (e.g., MIBs, SIBs) acquisition, RRC connection, and measurement reporting; PDCP layer functionality related to header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality related to transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality related to mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0078] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station may be used by the transmitter 714 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial streams generated by the transmitter 714 may be provided to different antennas 716. The transmitter 714 may modulate an RF carrier with each spatial stream for transmission.

[0079] The uplink transmissions are processed at the base station in a manner similar to that described with respect to the receiver function at the UE. The receiver 752 receives the signals through its respective antenna 756. The receiver 752 recovers the information modulated onto the RF carrier and provides the information to a processing system 784.

[0080] In the uplink, the processing system 784 performs demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the UE. The IP packets from the processing system 784 may be provided to the core network. The processing system 784 is also responsible for error detection.

[0081] For convenience, the UE, base station, and / or network entity are illustrated in Figures 7A-7B as including various components that may be configured in accordance with various examples described herein, however, it will be appreciated that the illustrated blocks may have different functions in different designs.

[0082] The various components of the UE, base station, and network entity may communicate with each other via data buses 734, 782, respectively. The components of FIG. 7A, 7B may be implemented in various ways. In some implementations, the components of FIG. 7A, 7B may be implemented in one or more circuits, such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by 710-746 may be implemented by the processor and memory components of the UE (e.g., by execution of appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functionality represented by 750-788 may be implemented by the processor and memory components of the base station (e.g., by execution of appropriate code and / or by appropriate configuration of the processor components). For simplicity, various operations, acts, and / or functions are described herein as being performed "by a UE," "by a base station," "by a positioning entity," etc. However, it will be appreciated that such operations, acts, and / or functions may actually be performed by a particular component or combination of components, such as a UE, a base station, a positioning entity, such as processing systems 732, 784, transceivers 710, 720, 750, and 760, memory components 740, 786, positioning components 742, 788, etc.

[0083] 8 shows an example process 800 including determining a transmission time according to an aspect of the disclosure. Process 800 may be performed by one or more of the other wireless devices 138.

[0084] At 802, the process may receive a PPDU on one or more channels from a second wireless device. At 804, the process may determine a transmission time associated with the PPDU based at least in part on a signal length field included in a first portion of the PPDU. At 806, the process may stop transmitting for at least the transmission time of the PPDU. At 808, the process may schedule one or more data transmissions after the PPDU is transmitted. For example, in FIG. 1, a particular wireless device among the other wireless devices 138 may receive the PPDU 108 transmitted by the wireless device 102. The particular wireless device may determine a length of the transmission of the PPDU 108 based on a signal length specified by the L-SIG 210 of FIG. 2. The particular wireless device may stop transmitting for at least the length of the transmission of the PPDU 108. The particular wireless device may schedule one or more data transmissions after the transmission by the wireless device 102 of the PPDU is completed. In this manner, the particular wireless device avoids a transmission collision with the PPDU 108.

[0085] It should be noted that although specific frequencies, integrated circuits (ICs), hardware, and other features are described in the embodiments herein, alternative embodiments may vary. That is, alternative embodiments may utilize additional or alternative frequencies (e.g., other 60 GHz and / or 28 GHz frequency bands), antenna elements (e.g., having antenna element arrays of different sizes / shapes), scanning periods (including both static and dynamic scanning periods), electronic devices (e.g., WLAN APs, cellular base stations, smart speakers, IoT devices, mobile phones, tablets, personal computers (PCs), etc.), and / or other features. Those skilled in the art will appreciate such variations.

[0086] It should be understood that any reference to an element herein using a designation such as "first," "second," etc., does not generally limit the quantity or order of those elements. Rather, these designations may be used herein as a convenient way of distinguishing between two or more elements or instances of an element. Thus, reference to a first element and a second element does not imply that only two elements may be employed therein, or that the first element must precede the second element in some manner. Also, unless otherwise stated, a set of elements may comprise one or more elements. In addition, a term of the form "at least one of A, B, or C" or "one or more of A, B, or C" or "at least one of the group consisting of A, B, and C" as used in this description or claims means "A or B or C or any combination of these elements." For example, the term may include A, or B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, etc.

[0087] In view of the above description and explanation, those skilled in the art will appreciate that the various exemplary logic blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various exemplary components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in various ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0088] In the detailed description above, it is seen that various features are grouped together in the examples. This manner of disclosure should not be understood as an intention that the example clauses have more features than are expressly stated in each clause. Rather, various aspects of the disclosure may include fewer than all features of each individual example clause disclosed. Thus, the following clauses should be considered to be incorporated in the description, and each clause may stand alone as a separate example. Although each dependent clause may refer to a specific combination with one of the other clauses in the clause, the aspects of that dependent clause are not limited to that specific combination. It will be understood that other example clauses may also include combinations of aspects of the dependent clause with the subject matter of any other dependent clause or independent clause, or combinations of any features with other dependent clauses and independent clauses. Unless a specific combination is not intended (e.g., conflicting aspects such as defining an element as both an insulator and a conductor) is expressly expressed or can be easily inferred, the various aspects disclosed herein expressly include these combinations. It is further contemplated that aspects of a clause may be included in any other independent clause, even if the clause is not directly dependent on an independent clause.

[0089] Example implementations are described in the following numbered clauses. Clause 1. A method of operating a wireless device, the method including transmitting a physical layer protocol data unit on one or more channels, the physical layer protocol data unit including a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit and a second portion including a plurality of Wi-Fi sensing fields, receiving a reflected signal associated with the physical layer protocol data unit, the reflected signal including the physical layer protocol data unit reflected from a target object, and receiving a leakage signal associated with the physical layer protocol data unit. Clause 2. The method of clause 1, further comprising determining a distance to and a direction of the target object based at least in part on the reflected signal and the leakage signal, and generating a map including an approximate location of the target object based at least in part on the distance to and direction of the target object. Clause 3. The method of any of clauses 1 to 2, wherein the first portion of the physical layer protocol data unit includes a short training field (STF), a long training field (LTF), and a signal length field, and the first portion of the physical layer protocol data unit complies with the 802.11a standard, the 802.11n standard, the 802.11ac standard, the 802.11ax standard, and the 802.11be standard. Clause 4. The method of any of clauses 1 to 3, wherein the second portion of the physical layer protocol data unit further includes a sequence type field to indicate that each Wi-Fi sensing field of the multiple Wi-Fi sensing fields includes either a time-domain sequence or a frequency-domain sequence, and a stream type field to indicate a number of transmit antennas used to transmit the physical layer protocol data unit and that the multiple Wi-Fi sensing fields include either a single stream or a multiple-input multiple-output (MIMO) stream. Clause 5. The method of clause 4, wherein the time-domain sequence comprises one of a Zadoff-Chu based sequence or an Orthogonal Frequency Division Multiplexing (OFDM) based sequence. Clause 6. The method of any of clauses 1 to 5, wherein transmitting a physical layer protocol data unit on one or more channels comprises transmitting a first portion of the physical layer protocol data unit at a first power level, and transmitting a second portion of the physical layer protocol data unit at a second power level that is less than the first power level. Clause 7. The method of any of clauses 1-6, further comprising determining an average Wi-Fi sensing field value of the plurality of Wi-Fi sensing fields, the average Wi-Fi sensing field value having an increased signal-to-noise ratio relative to an individual Wi-Fi sensing field of the plurality of Wi-Fi sensing fields. Clause 8. The method of any of clauses 1 to 7, wherein the time domain sequence comprises one of a Zadoff-Chu based sequence or an Orthogonal Frequency Division Multiplexing (OFDM) based sequence. Clause 9. The method of any of clauses 1 to 7, wherein the time domain sequence comprises one of a Zadoff-Chu based sequence or an Orthogonal Frequency Division Multiplexing (OFDM) based sequence. Clause 10. A method of operating a first wireless device, the method comprising: receiving, from a second wireless device, a physical layer protocol data unit on one or more channels, the physical layer protocol data unit including a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit and a second portion including a plurality of Wi-Fi sensing fields; and scheduling one or more data transmissions based on the physical layer protocol data unit. Clause 11. The method of clause 10, wherein scheduling one or more data transmissions based on the physical layer protocol data unit includes determining a transmission based at least in part on a signal length field, and scheduling the one or more data transmissions after the physical layer protocol data unit has completed being transmitted. Clause 12. The method of any of clauses 10-11, further comprising determining an amount of time to stop transmitting based at least in part on the signal length field, and ceasing transmission for at least the amount of time. Clause 13. The method of any of clauses 10 to 12, wherein the first portion of the physical layer protocol data unit includes a short training field (STF), a long training field (LTF), and a signal length field, and the first portion of the physical layer protocol data unit complies with the 802.11a standard, the 802.11n standard, the 802.11ac standard, the 802.11ax standard, and the 802.11be standard. Clause 14. The method of any of clauses 12-13, further comprising means for determining an amount of time to stop transmitting based at least in part on the signal length field, and means for stopping transmission for at least that amount of time. Clause 15. The method of any of clauses 12 to 14, wherein the first portion of the physical layer protocol data unit includes a short training field (STF), a long training field (LTF), and a signal length field, and the first portion of the physical layer protocol data unit complies with the 802.11a standard, the 802.11n standard, the 802.11ac standard, the 802.11ax standard, and the 802.11be standard. Clause 16. An apparatus comprising a memory and at least one processor communicatively coupled to the memory, the memory and the at least one processor configured to perform a method according to any of clauses 1 to 15. Clause 17. Apparatus comprising means for carrying out the method according to any of clauses 1 to 15. Clause 18. A non-transitory computer readable medium storing computer executable instructions, the computer executable instructions comprising at least one instruction for causing a computer or processor to perform a method according to any of clauses 1 to 15.

[0090] Thus, for example, it will be appreciated that a device or any component of a device may be configured (or enabled or adapted) to provide functionality as taught herein. This may be accomplished, for example, by manufacturing (e.g., fabricating) the device or component to provide the functionality, by programming the device or component to provide the functionality, or through the use of some other suitable implementation technique. As one example, an integrated circuit may be fabricated to provide the requisite functionality. As another example, an integrated circuit may be fabricated to support the requisite functionality and then configured (e.g., via programming) to provide the requisite functionality. As yet another example, a processor circuit may execute code to provide the requisite functionality.

[0091] Moreover, the methods, sequences, and / or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a random access memory (RAM), a flash memory, a read only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from and write information to the storage medium. Alternatively, the storage medium may be integral to the processor (e.g., a cache memory).

[0092] While the above disclosure sets forth various exemplary aspects, it should be noted that various changes and modifications may be made to the illustrated examples without departing from the scope defined by the appended claims. The present disclosure is not limited to only the specifically illustrated examples. For example, unless otherwise stated, the functions, steps, and / or actions of the method claims according to the aspects of the present disclosure described herein need not be performed in any particular order. Furthermore, although some aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. [Explanation of symbols]

[0093] 100 Wireless Sensing System 102 Wireless Devices 104 Digital to Analog Converter 106 Transmitting Module 108 Physical Layer Protocol Data Unit (PPDU) 110 Transmitting Antenna Array 112 Receiving Antenna Array 114 Target 116 Reflected signal 118 Leak Signal 120 Receiver Module 122 Analog-to-Digital Converter 124 Channel Estimation 126 distance 128 directions 130 Mapping 132 Correlation 133 Synchronization 134 Reference signal 136 Other Targets 138 Other Wireless Devices 415 Other Applications 418 Other Data 602 Processor 604 Memory 606 Communication Interface 608 Display Devices 610 Other Input / Output (I / O) Devices 612 Mass Storage Devices 614 System Bus 710 Wireless Wide Area Network (WWAN) Transceiver 712 Receiver 714 Transmitter 716 Antenna 718 Signal 720 Wireless Local Area Network (WLAN) Transceiver 722 Receiver 724 Transmitter 726 Antenna 728 signal 730 Satellite Positioning System (SPS) Receiver 732 Processing System 734 Data Bus 736 Antenna 738 SPS signal 740 Memory Components 742 Sensing Components 744 Sensors 746 User Interface 750 Wireless Wide Area Network (WWAN) Transceiver 752 Receiver 754 Transmitter 756 Antenna 758 signal 760 WLAN Transceiver 762 Receiver 764 Transmitter 766 Antenna 768 signal 770 SPS Receiver 776 Antenna 778 SPS signal 780 Network Interface 782 Data Bus 784 Processing System 786 Memory Components 788 Sensing Components

Claims

1. 1. A method of operating a wireless device, comprising: transmitting a physical layer protocol data unit on one or more channels, said physical layer protocol data unit comprising: a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit; a second portion including a plurality of Wi-Fi sensing fields, a sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, a number of transmit antennas used to transmit the physical layer protocol data unit, and a stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream; A method comprising:

2. receiving a reflected signal associated with the physical layer protocol data unit, the reflected signal including the second portion of the physical layer protocol data unit reflected from a target object; receiving a leakage signal associated with the physical layer protocol data unit, the leakage signal including the second portion of the physical layer protocol data unit and not reflected from the target object; determining a distance to and a direction of the target object based at least in part on the reflected signal and the leakage signal; generating a map including an approximate location of the target object based at least in part on the distance to the target object and the direction of the target object; The method of claim 1, further comprising:

3. the first portion of the physical layer protocol data unit comprising: Short Training Field (STF) and Long Training Field (LTF) and Signal length field and Further comprising: the first portion of the physical layer protocol data unit conforms to an 802.11a standard, an 802.11n standard, an 802.11ac standard, an 802.11ax standard, and an 802.11be standard; The method of claim 1.

4. The time domain sequence is Zadoff-Chu based series, or Orthogonal Frequency Division Multiplexing (OFDM) based sequences The method of claim 1 , further comprising one of:

5. transmitting the physical layer protocol data unit on the one or more channels, transmitting the first portion of the physical layer protocol data unit at a first power level; transmitting the second portion of the physical layer protocol data unit at a second power level that is less than the first power level; 2. The method of claim 1, comprising:

6. determining an average Wi-Fi sensing field value of the plurality of Wi-Fi sensing fields, the average Wi-Fi sensing field value having an increased signal-to-noise ratio relative to an individual Wi-Fi sensing field of the plurality of Wi-Fi sensing fields; The method of claim 1, further comprising:

7. 1. A wireless device comprising: means for transmitting a physical layer protocol data unit on one or more channels, said physical layer protocol data unit comprising: a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit; a second portion including a plurality of Wi-Fi sensing fields, a sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, a number of transmit antennas used to transmit the physical layer protocol data unit, and a stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream; Including, wireless devices.

8. A memory; At least one transceiver; at least one processor communicatively coupled to the memory and to the at least one transceiver; and wherein the at least one processor further comprises: configured to transmit the physical layer protocol data units (PPDUs) on one or more channels using the at least one transceiver, the physical layer protocol data units comprising: the first portion including a signal length field indicating the duration of the transmission of the physical layer protocol data unit; the second portion including the plurality of Wi-Fi sensing fields, the sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, the number of transmit antennas used to transmit the physical layer protocol data unit, and the stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream; 8. The wireless device of claim 7, comprising:

9. A receiving antenna array; A receiving module, receiving a reflected signal associated with the physical layer protocol data unit, the reflected signal including the second portion of the physical layer protocol data unit reflected from a target object; receiving a leakage signal associated with the physical layer protocol data unit, the leakage signal including the second portion of the physical layer protocol data unit and not reflected from the target object; A receiving module configured to Further equipped with one or more processors, determining a distance to the target object based at least in part on the reflected signal and the leakage signal; determining a direction of the target object based at least in part on the reflected signal and the leakage signal; generating a map including an approximate location of the target object based at least in part on the distance to the target object and the direction of the target object; A processor configured to: The wireless device of claim 8 , further comprising:

10. A non-transitory computer-readable storage medium having computer executable code stored thereon, code for transmitting a physical layer protocol data unit (PPDU) on one or more channels, the physical layer protocol data unit comprising: a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit; a second portion including a plurality of Wi-Fi sensing fields, a sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, a number of transmit antennas used to transmit the physical layer protocol data unit, and a stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream; A non-transitory computer readable storage medium comprising:

11. 1. A method of operating a first wireless device, comprising: receiving a physical layer protocol data unit on one or more channels from a second wireless device, the physical layer protocol data unit comprising: a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit; a second portion including a plurality of Wi-Fi sensing fields, a sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, a number of transmit antennas used to transmit the physical layer protocol data unit, and a stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream; and scheduling data transmission based on the physical layer protocol data unit; A method comprising:

12. scheduling the data transmission based on the physical layer protocol data unit, determining a transmission time based at least in part on the signal length field; scheduling said data transmission after said physical layer protocol data unit has completed transmission; 12. The method of claim 11, comprising:

13. determining an amount of time to cease transmission based at least in part on the signal length field; ceasing transmission for at least said amount of time.

12. The method of claim 11, further comprising:

14. A first wireless device, 1. A means for receiving a physical layer protocol data unit on one or more channels, the physical layer protocol data unit comprising: a first portion including a signal length field indicating a duration of transmission of the physical layer protocol data unit; and a second portion including a plurality of Wi-Fi sensing fields, a sequence type field for indicating that each Wi-Fi sensing field of the plurality of Wi-Fi sensing fields includes either a time domain sequence or a frequency domain sequence, a number of transmit antennas used to transmit the physical layer protocol data unit, and a stream type field for indicating that the plurality of Wi-Fi sensing fields includes either a single stream or a multiple-input multiple-output (MIMO) stream. and means for scheduling data transmission based on said physical layer protocol data units; a first wireless device comprising:

15. means for determining a transmission time based at least in part on the signal length field; means for scheduling said data transmission after said physical layer protocol data unit has completed transmission; The first wireless device of claim 14, further comprising:

Images