Method and device for positioning target object

Abstract

The present application provides a method for assisting in locating a target, a method for locating a target, and a device. In an embodiment, the method for assisting in locating a target is applied to a STA, and the method includes: receiving a wireless sensor detection frame containing radar measurement indication information from an AP; sending an uplink data packet to the AP and recording a first sending time, and performing radar measurement on the target according to the radar measurement indication information to obtain a radar measurement result; receiving a downlink data packet from the AP and recording a first receiving time; sending the first sending time, the first receiving time, and the radar measurement result to the AP. According to the technical solution of the embodiment of the present application, during the process of the AP performing FTM on the STA, the STA concurrently performs radar measurement on the target, and the FTM result of the STA can more accurately reflect the actual position of the STA when performing radar measurement on the target; accordingly, the AP can combine the radar measurement results and FTM results of multiple STAs to more accurately locate the target.

Description

[0001] This application is a divisional application. The application number of the original application is 201911140636.5, and the original application date is November 20, 2019. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of communications, and in particular to a method and device for locating a target object. Background Art

[0003] Radar can be used to detect targets, such as detecting one or more of the distance, speed, and direction angle (including azimuth and elevation) of the target relative to the radar. Radar usually includes a transmitting antenna and a receiving antenna. The radar can use its transmitting antenna to transmit radar signals (referred to as transmitting waves) and use its receiving antenna to receive radar signals (referred to as reflected waves) formed by the reflection of the transmitted waves by the target. After that, the radar measurement results can be obtained based on the changes of the reflected waves relative to the transmitted waves, such as the distance, speed and direction angle of the target relative to the radar, or other information used to calculate any one of the distance, speed and direction angle of the target relative to the radar.

[0004] Wireless local area network (WLAN) has been widely deployed and applied as a local area communication network with convenient access and high data transmission rate. In densely deployed WLAN, one access point (AP) is usually connected to multiple stations (STA), and each STA may be used as a radar for detecting targets.

[0005] Typically, an AP can determine, from among the multiple STAs it covers, multiple target STAs that can be used to detect the target under the coordination of the AP; then determine the location information of the multiple target STAs, and coordinate the multiple target STAs to perform radar measurements on the target; thereafter, the AP or a computing device connected to the AP can locate the target based on the location information of the multiple target STAs determined in advance, and the radar measurement results obtained when the multiple target STAs perform radar measurements on the target respectively.

[0006] However, STAs in WLAN are usually mobile, that is, after the location information of the target STA is determined, the target STA may move, resulting in the location information of the target STA not accurately reflecting the real location of the target STA during radar measurement, thereby affecting the positioning result of the target object. Summary of the invention

[0007] The embodiments of the present application provide a method for assisting in locating a target, a method for locating a target, and a device for locating a target, which can more accurately locate the target.

[0008] The embodiments of the present application provide at least the following technical solutions:

[0009] In a first aspect, a method for assisting in positioning a target is provided, which is applied to a STA, and the method includes:

[0010] Receiving a wireless sensor detection frame from an AP, wherein the wireless sensor detection frame includes radar measurement indication information;

[0011] Sending an uplink data packet to the AP, and recording a first sending time of the uplink data packet, and performing radar measurement on the target object according to the radar measurement indication information to obtain a radar measurement result;

[0012] receiving a downlink data packet from the AP, and recording a first receiving time of the downlink data packet;

[0013] The first sending time, the first receiving time, and the radar measurement result are sent to the AP.

[0014] In one possible implementation,

[0015] The performing radar measurement on the target object according to the radar measurement instruction information to obtain the radar measurement result includes:

[0016] sending a first radar signal according to the radar measurement instruction information, and receiving a second radar signal according to the radar measurement instruction information, wherein the second radar signal is formed by a target object reflecting the first radar signal;

[0017] A radar measurement result is determined according to a first starting time corresponding to when the first radar signal is sent, a second starting time corresponding to when the second radar signal is received, and the first radar signal and the second radar signal.

[0018] In one possible implementation,

[0019] The trigger-dependent common information field of the wireless sensor detection frame includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0020] In one possible implementation,

[0021] A user information field of the wireless sensor detection frame includes an application identification field and a trigger-dependent user information field, wherein the application identification field includes an identification of the STA, the trigger-dependent user information field includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0022] In one possible implementation,

[0023] The radar information identification subfield includes a radar duration subfield and a resource control subfield;

[0024] The radar measurement indication information includes radar duration and frequency band information, wherein the radar duration subfield includes the radar duration, and the resource control subfield includes the frequency band information.

[0025] In one possible implementation,

[0026] The sending the first sending time, the first receiving time and the radar measurement result to the AP includes: in response to a wireless sensor report frame sent by the AP to the STA, sending a wireless sensor data frame to the AP, wherein the wireless sensor data frame includes the first sending time, the first receiving time and the radar measurement result.

[0027] In one possible implementation,

[0028] The trigger-dependent common information field of the wireless sensor report frame includes a feedback control subfield;

[0029] The feedback control subfield at least includes a precise time measurement FTM feedback control subfield, and the FTM feedback control subfield includes first indication information, where the first indication information is used to instruct the STA to send the wireless sensor data frame to the AP.

[0030] In one possible implementation,

[0031] The wireless sensor data action field of the wireless sensor data frame includes an FTM result element field;

[0032] The first receiving time and the first sending time are included in the FTM result element field.

[0033] In one possible implementation,

[0034] The wireless sensor data action field of the wireless sensor data frame also includes a wireless sensor data control field, and the wireless sensor data control field includes an FTM control subfield, wherein the FTM control subfield includes second indication information, and the second indication information is used to instruct the AP to obtain the first receiving time and the first sending time from the FTM result element field.

[0035] In a second aspect, a method for positioning a target object is provided, which is applied to an AP. The method is for each STA in a plurality of STAs, and the method includes:

[0036] Sending a wireless sensor detection frame to the STA, wherein the wireless sensor detection frame includes radar measurement indication information;

[0037] receiving an uplink data packet from the STA, and recording a second receiving time of the uplink data packet;

[0038] Sending a downlink data packet to the STA, and recording a second sending time of the downlink data packet;

[0039] receiving a first sending time, a first receiving time, and a radar measurement result from the STA, wherein the first sending time is a time corresponding to when the STA sends the uplink data packet, the first receiving time is a time corresponding to when the STA receives the downlink data packet, and the radar measurement result is a radar measurement result obtained when the STA performs radar measurement on the target object according to the radar measurement indication information;

[0040] Calculate a first distance between the STA and the AP according to the first sending time, the first receiving time, the second sending time, and the second receiving time;

[0041] The target object is positioned according to the first distances and radar measurement results respectively corresponding to the plurality of STAs.

[0042] In one possible implementation,

[0043] The sending of the wireless sensor detection frame to the STA includes: sending the wireless sensor detection frame to the multiple STAs by multicast or broadcast, wherein the multiple user information fields of the wireless sensor detection frame correspond to the multiple STAs one by one, the user information field includes an identifier of the corresponding STA and radar measurement indication information for instructing the corresponding STA to perform radar measurement, and the radar measurement indication information respectively included in the multiple user information fields each includes different frequency band information.

[0044] In one possible implementation,

[0045] The user information field further includes channel information for indicating the corresponding STA to send the uplink data packet, and the channel information respectively included in the plurality of user information fields is different;

[0046] The receiving the uplink data packet from the STA includes: receiving the uplink data packet from the multiple STAs respectively according to the channel information respectively included in each of the user information fields.

[0047] In one possible implementation,

[0048] The sending the downlink data packet to the STA includes: sending the downlink data packet to the multiple STAs in a multicast or broadcast manner.

[0049] In a third aspect, a device for assisting in positioning a target is provided, which is applied to a STA, and the device includes:

[0050] A transceiver unit is used to receive a wireless sensor detection frame from an AP, wherein the wireless sensor detection frame includes radar measurement indication information; send an uplink data packet to the AP; and receive a downlink data packet from the AP;

[0051] A processing unit, configured to record a first sending time of the uplink data packet; record a first receiving time of the downlink data packet; and perform radar measurement on the target object according to the radar measurement indication information to obtain a radar measurement result;

[0052] The transceiver unit is further used to send the first sending time, the first receiving time and the radar measurement result to the AP.

[0053] In one possible implementation,

[0054] The processing unit is specifically configured to trigger the transceiver unit to send a first radar signal according to the radar measurement indication information; and trigger the transceiver unit to receive a second radar signal according to the radar measurement indication information, where the second radar signal is formed by a target object reflecting the first radar signal;

[0055] The processing unit is specifically used to determine the radar measurement result according to a first starting time corresponding to when the transceiver unit sends the first radar signal, a second starting time corresponding to when the transceiver unit receives the second radar signal, and the first radar signal and the second radar signal.

[0056] In one possible implementation,

[0057] The trigger-dependent common information field of the wireless sensor detection frame includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0058] In one possible implementation,

[0059] A user information field of the wireless sensor detection frame includes an application identification field and a trigger-dependent user information field, wherein the application identification field includes an identification of the STA, the trigger-dependent user information field includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0060] In one possible implementation,

[0061] The radar information identification subfield includes a radar duration subfield and a resource control subfield;

[0062] The radar measurement indication information includes radar duration and frequency band information, wherein the radar duration subfield includes the radar duration, and the resource control subfield includes the frequency band information.

[0063] In one possible implementation,

[0064] The processing unit is specifically used to trigger the transceiver unit to send a wireless sensor data frame to the AP in response to the wireless sensor report frame sent by the AP to the STA, wherein the wireless sensor data frame includes the first sending time, the first receiving time and the radar measurement result.

[0065] In one possible implementation,

[0066] The trigger-dependent common information field of the wireless sensor report frame includes a feedback control subfield;

[0067] The feedback control subfield at least includes a precise time measurement FTM feedback control subfield, and the FTM feedback control subfield includes first indication information, where the first indication information is used to instruct the STA to send the wireless sensor data frame to the AP.

[0068] In one possible implementation,

[0069] The wireless sensor data action field of the wireless sensor data frame includes an FTM result element field;

[0070] The first receiving time and the first sending time are included in the FTM result element field.

[0071] In one possible implementation,

[0072] The wireless sensor data action field of the wireless sensor data frame also includes a wireless sensor data control field, and the wireless sensor data control field includes an FTM control subfield, wherein the FTM control subfield includes second indication information, and the second indication information is used to instruct the AP to obtain the first receiving time and the first sending time from the FTM result element field.

[0073] In a fourth aspect, a device for locating a target object is provided, which is applied to an AP, and the device includes:

[0074] A transceiver unit, configured to send a wireless sensor detection frame to each STA in a plurality of STAs, wherein the wireless sensor detection frame includes radar measurement indication information; receive an uplink data packet from the STA; send a downlink data packet to the STA; receive a first sending time, a first receiving time, and a radar measurement result from the STA, wherein the first sending time is a time corresponding to when the STA sends the uplink data packet, the first receiving time is a time corresponding to when the STA receives the downlink data packet, and the radar measurement result is a radar measurement result obtained when the STA performs radar measurement on the target object according to the radar measurement indication information;

[0075] A processing unit is used to record the second receiving time of the uplink data packet; record the second sending time of the downlink data packet; and calculate the first distance between the STA and the AP according to the first sending time, the first receiving time, the second sending time, and the second receiving time; locate the target according to the first distances corresponding to the multiple STAs and the radar measurement results.

[0076] In one possible implementation,

[0077] The processing unit is specifically used to trigger the transceiver unit to send the wireless sensor detection frame to the multiple STAs by multicast or broadcast, wherein the multiple user information fields of the wireless sensor detection frame correspond to the multiple STAs one by one, and the user information field includes an identifier of the corresponding STA and radar measurement indication information for instructing the corresponding STA to perform radar measurement, and the radar measurement indication information respectively contained in the multiple user information fields each includes different frequency band information.

[0078] In one possible implementation,

[0079] The user information field further includes channel information for indicating the corresponding STA to send the uplink data packet, and the channel information respectively included in the plurality of user information fields is different;

[0080] The processing unit is specifically configured to trigger the transceiver unit to receive the uplink data packets respectively from the multiple STAs according to the channel information respectively included in each of the user information fields.

[0081] In one possible implementation,

[0082] The processing unit is specifically used to trigger the transceiver unit to send the downlink data packet to the multiple STAs in a multicast or broadcast manner.

[0083] In a fifth aspect, a computer-readable storage medium is provided for storing instructions, which, when executed by a processor of an STA, enables the STA to implement any of the methods described in the first aspect.

[0084] In a sixth aspect, a computer-readable storage medium is provided for storing instructions, which, when executed by a processor of an AP, enables the AP to implement any of the methods in the second aspect.

[0085] In a seventh aspect, a STA is provided, comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method described in any one of the first aspects is implemented.

[0086] In an eighth aspect, an AP is provided, comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method described in any one of the second aspects is implemented.

[0087] In a ninth aspect, a computer program product is provided, wherein the computer program product comprises a computer program code, and when the computer program code is executed on a computer, the computer executes any one of the methods in the first aspect.

[0088] In a tenth aspect, a computer program product is provided, wherein the computer program product comprises a computer program code, and when the computer program code is executed on a computer, the computer executes any one of the methods in the second aspect.

[0089] In an eleventh aspect, a communication device is provided, wherein the communication device has the functions of the STA in the above-mentioned various aspects. The functions of the STA can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above-mentioned functions.

[0090] In a twelfth aspect, a communication device is provided, wherein the communication device has the functions of the AP in the above aspects. The functions of the AP can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions.

[0091] In a thirteenth aspect, a communication device is provided, which may be the STA described in the above aspects, or a chip set in the STA. The communication device includes a memory, a communication interface, and a processor, wherein the memory is used to store a computer program or instruction, and the processor is coupled to the memory and the communication interface, and when the processor executes the computer program or instruction, the communication device executes any one of the methods described in the first aspect.

[0092] In a fourteenth aspect, a communication device is provided, which may be the AP described in the above aspects, or a chip set in the AP. The communication device includes a memory, a communication interface, and a processor, wherein the memory is used to store a computer program or instruction, and the processor is coupled to the memory and the communication interface, and when the processor executes the computer program or instruction, the communication device executes any one of the methods described in the above second aspect.

[0093] In a fifteenth aspect, a chip system is provided, the chip system including a processor for implementing the functions of the STA described in the above various aspects, for example, receiving or processing the data and / or information involved in the method of the first aspect. In a possible design, the chip system also includes a memory, the memory is used to store program instructions and / or data. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0094] In a sixteenth aspect, a chip system is provided, the chip system including a processor for implementing the functions of the AP described in the above various aspects, for example, receiving or processing the data and / or information involved in the method of the above second aspect. In a possible design, the chip system also includes a memory, the memory is used to store program instructions and / or data. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0095] According to the technical solution of the present application, during the process of AP performing precise time measurement (FTM) on STA, the STA concurrently performs radar measurement on the target object, and the FTM result of the STA can more accurately reflect the actual position of the STA when performing radar measurement on the target object; accordingly, the AP can combine the radar measurement results and FTM results of multiple STAs to more accurately locate the target object. BRIEF DESCRIPTION OF THE DRAWINGS

[0096] The following is a brief introduction to the drawings required for describing the embodiments or prior art.

[0097] Figure 1 Schematic diagram of the frequency change relationship between the first radar signal and the second radar signal in an embodiment of the present application.

[0098] Figure 2 A schematic diagram of an application scenario to which the technical solution provided in an embodiment of the present application is applicable.

[0099] Figure 3 A schematic diagram of a radar coordinate system provided in an embodiment of the present application.

[0100] Figure 4 This is an example of measuring the angle of arrival of an electromagnetic wave by a phase angle measurement method provided in an embodiment of the present application.

[0101] Figure 5 This is a flow chart of a method for assisting in locating a target object provided in an embodiment of the present application.

[0102] Figure 6 A schematic diagram of the structure of a wireless sensor detection frame provided in an embodiment of the present application.

[0103] Figure 7 A schematic diagram of the structure of another wireless sensor detection frame provided in an embodiment of the present application.

[0104] Figure 8 A schematic diagram of the structure of a wireless sensor report frame provided in an embodiment of the present application.

[0105] Fig. 9 A schematic diagram of the structure of a wireless sensor data frame provided in an embodiment of the present application.

[0106] Fig.10 This is a flow chart of a method for locating a target object provided in an embodiment of the present application.

[0107] Fig.11 This is one of the schematic diagrams of the information interaction process between an AP and multiple STAs provided in an embodiment of the present application.

[0108] Fig.12 This is the second schematic diagram of the information interaction process between an AP and multiple STAs provided in an embodiment of the present application.

[0109] Fig.13 This is the third schematic diagram of the information interaction process between an AP and multiple STAs provided in an embodiment of the present application.

[0110] Fig.14A schematic diagram of the structure of a device for assisting in locating a target object provided in an embodiment of the present application.

[0111] Fig.15 A schematic diagram of the structure of a device for locating a target object provided in an embodiment of the present application. DETAILED DESCRIPTION

[0112] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0113] In the embodiment of the present application, the target object includes but is not limited to a human object, and may also include various forms of physical devices.

[0114] In the embodiment of the present application, AP refers to a network device used to connect STA to a wired network. The network coverage of a single AP can usually reach tens of meters, and the communication between the AP and the STA within its coverage is usually based on the IEEE802.11 protocol.

[0115] In the embodiment of the present application, STA may be a wireless communication device with a transmitting antenna and a receiving antenna, and the wireless communication device is usually mobile. Wireless communication devices may also be referred to as mobile devices (MD), user equipment (UE), terminals, mobile stations (MS), and mobile terminals (MT). Specifically, STA includes but is not limited to various forms of mobile phones (or "cellular" phones), laptops, tablet computers, and desktop computers with wireless communication modules. For example, it may also include various forms of Internet of Things terminals, as well as various portable, pocket-sized, handheld, computer-built-in, or vehicle-mounted mobile devices.

[0116] It can be understood that radars can be divided into single-station radars and multi-station radars according to whether their transmitting antennas and receiving antennas have the same address information. Accordingly, if a radar has both a transmitting antenna and a receiving antenna, it can not only be used as a single-station radar, but also cooperate with other radars to serve as a radar signal transmitter of a multi-station radar or as a radar signal receiver of a multi-station radar.

[0117] In the embodiment of the present application, the wireless communication device as STA usually has both a transmitting antenna and a receiving antenna. Therefore, a STA can be used as a single-station radar under the coordination of the AP, or as a radar signal transmitter or radar signal receiver of a multi-station radar under the coordination of the AP.

[0118] When the STA acts as a single-station radar, the STA may first send a first radar signal according to the radar measurement indication information obtained by the STA, and receive a second radar signal according to the radar measurement indication information, where the second radar signal is formed by reflection of the first radar signal by the target object; then determine the radar measurement result according to a first starting time corresponding to when the first radar signal is sent, a second starting time corresponding to when the second radar signal is received, and the first radar signal and the second radar signal.

[0119] Among them, the first radar signal sent by the STA can be a normal continuous wave sent by the STA according to the radar duration and frequency band information, or it can be a frequency modulated continuous wave sent by the STA according to the radar duration and frequency band information, or it can also be a pulse signal sent by the STA according to the radar duration and frequency band information.

[0120] Taking the example that the first radar signal sent by a STA is a frequency modulated continuous wave, the process of the STA performing radar measurement on a target object and obtaining a radar measurement result is described exemplarily below.

[0121] like Figure 1 As shown, in the radar measurement indication information acquired by a STA and used to instruct the STA to perform radar measurement on a target object, the radar duration is 2T, and the frequency band information defines that the frequency band of the first radar signal S1 sent by the STA should be in the frequency band f3-f4.

[0122] First, the STA can send a first radar signal S1 with a period of T and a modulation bandwidth B of (f2-f1) on the frequency modulation band f1~f2 at a first starting time T1, and stop sending the first radar signal S1 at T3; wherein the time difference between T3 and T1 is the radar duration 2T, and the frequency modulation band f1~f2 is located in the frequency band f3~f4.

[0123] Afterwards, the STA may start receiving the second radar signal S2 or S3 on the frequency band f3-f4 at a second starting time T2, and stop receiving the second radar signal S2 or S3 on the frequency band f3-f4 after T4; wherein the time difference between T4 and T2 is the radar duration 2T.

[0124] It can be understood that if the STA and the target object are relatively stationary during the time period T1 to T4, the STA can receive the second radar signal S2 with the same waveform as the first radar signal S1 on the FM band f1 to f2; if the STA and the target object are not relatively stationary during the time period T1 to T4, that is, if the STA and / or the target object moves during the time period T1 to T4, the second radar signal received by the STA may include the Doppler frequency fd generated by the movement of the STA and / or the target object, and the STA may receive the second radar signal S3 including the Doppler frequency fd.

[0125] Further, the STA may obtain a radar measurement result of the STA according to the first starting time T1 of sending the first radar signal, the second starting time T2 of receiving the second radar signal, the first radar signal S1 and the second radar signal S2 / S3.

[0126] Specifically, the STA can usually sample S1, S2 / S3 according to T1 and T2, and then the STA or AP performs fast Fourier transformation (FFT) on the first radar signal S1 and the second radar signal S2 after sampling, so as to obtain the distance between the target and the STA. Among them, the azimuth angle and radial motion speed of the target relative to the STA may also be obtained. Accordingly, the radar measurement results obtained by the STA include but are not limited to the following three forms:

[0127] Before FFT: The STA can mix the first radar signal S1 and the second radar signal S2 / S3 to obtain an intermediate frequency signal according to the first starting time T1 of sending the first radar signal and the second starting time T2 of receiving the second radar signal, convert the intermediate frequency signal into a digital signal through an analog to digital converter (ADC), and sample the digital signal to obtain a sampled digital signal, which can specifically include a sampling frequency, a number of sampling points, and sampling values ​​corresponding to each sampling point. The STA can feed back the sampled digital signal to the AP as the radar measurement result of the STA.

[0128] FFT info: The STA can further perform N-point FFT on the sampled digital signal to obtain the frequency domain graph corresponding to the sampled digital signal. In the frequency domain graph, each point (horizontal axis) corresponds to a frequency point, and the modulus value (vertical axis) of the point is the amplitude characteristic at the frequency point. The STA can feed back the frequency domain graph as the radar measurement result of the STA to the AP.

[0129] FFT result: The STA can further perform range-FFT on the frequency domain graph to obtain the distance of the target relative to the STA, and the STA can feed back the distance between the target and the STA as the radar measurement result of the STA to the AP. Optionally, the STA can also perform doppler-FFT on the frequency domain graph to obtain the radial motion speed of the target relative to the STA, add the radial motion speed to the radar measurement result of the STA and feed it back to the AP. Optionally, the STA can also perform angle-FFT on the frequency domain graph to obtain the direction angle of the target relative to the STA, add the direction angle to the radar measurement result of the STA and feed it back to the AP.

[0130] In a more specific example, the STA or AP may calculate the distance between the target object and the STA according to the following formula 1 or formula 2:

[0131] R=(T2-T1)*c / 2 (1)

[0132]

[0133] Among them, R represents the distance between the target object and the STA, T2 represents the second starting time, T1 represents the first starting time, c represents the speed of light, T represents the frequency modulation period of the first radar signal sent by the STA, B represents the modulation bandwidth of the first radar signal sent by the STA, and f0 represents the frequency of the intermediate frequency signal.

[0134] It should be noted that, when the target object and / or STA moves, the frequency f0 of the intermediate frequency signal can be calculated according to the following formula 3:

[0135]

[0136] Wherein, fa represents the difference frequency of the second radar signal relative to the first radar signal in the positive frequency modulation stage, and fb represents the difference frequency of the second radar signal relative to the first radar signal in the negative frequency modulation stage.

[0137] In a more specific example, the STA or AP may calculate the radial motion speed of the target and the STA according to the following formula 4:

[0138]

[0139] Among them, V R Characterizes the radial motion speed of the target and the STA, f x Indicates the center frequency of the first radar signal sent by the STA.

[0140] It should be noted that when the first radar signal sent by a STA is a common continuous wave, the STA or AP can first calculate the distance between the target and the STA by the above formula 1, and calculate the radial motion speed V between the target and the STA by the following formula 5: R :

[0141]

[0142] Among them, f m Characterizes the frequency of the second radar signal received by the STA, f n Indicates the frequency of the first radar signal sent by the STA.

[0143] It should be noted that for V calculated by the above methods R , when V R When the value of is positive, it indicates that the target is moving towards the direction close to the STA; when V R When the value of is negative, it indicates that the target is moving in the opposite direction away from the STA.

[0144] When the STA acts as a radar signal transmitter of a multi-station radar, the STA may first send a first radar signal according to radar measurement instruction information for instructing the STA to perform radar measurement, and use the first start time of sending the first radar signal and the period, frequency modulation band, and other information of the first radar signal as the radar measurement result. The first radar signal is used to form a second radar signal through reflection from a target object, and another STA corresponding to the STA, which acts as a radar signal receiver of the multi-station radar, may receive the second radar signal.

[0145] When the STA acts as a radar signal receiving end of a multi-station radar, the STA may first receive a second radar signal according to radar measurement instruction information for instructing the STA to perform radar measurement, and use the second starting time of receiving the second radar signal and the second radar signal as the radar measurement result. The second radar signal is formed by the target reflecting the first radar signal, and the first radar signal is sent by another STA corresponding to the STA and serving as a radar signal transmitting end of the multi-station radar.

[0146] It can be understood that the AP can perform comprehensive processing on radar measurement results respectively sent by multiple groups of corresponding STAs to more accurately locate the target object.

[0147] In the embodiment of the present application, positioning the target object includes but is not limited to determining the position information of the target object in a specific coordinate system. For example, it may also include determining the distance between the target object and the AP in the specific coordinate system, and determining the azimuth, pitch angle, radial motion speed, etc. of the target object relative to the AP in the specific coordinate system.

[0148] In the embodiment of the present application, the specific coordinate system includes but is not limited to a geographic coordinate system, for example, it may also be a map coordinate system constructed in combination with actual business needs.

[0149] Figure 2 Schematic diagram of an application scenario to which the technical solution provided in the embodiment of the present application is applicable. Figure 2 As shown, in a densely deployed WLAN, there may be multiple STAs within the coverage of the AP, and the AP may have established connections with multiple STAs within its coverage for communication; for example, the AP may have established connections with STA1 to STA9 at the same time. The AP can poll each STA within its coverage and with which it has established connections, so as to determine the target STA that can be used as a radar to perform radar measurement on the target under the coordination of the AP; then, the AP can further coordinate multiple target STAs to perform radar measurement on the target respectively, and locate the target according to the radar measurement results of each of the multiple target STAs and the position information of each of the multiple STAs in a specific coordinate system.

[0150] For example, when the AP needs to coordinate multiple STAs to perform radar measurements on a target object, the AP can send wireless sensor polling (WiFi sensing poll) frames to STA1~STA9 respectively. If STA1, STA2, STA3, and STA4 automatically or under the trigger of the user determine that they can perform radar measurements on the target object as a radar after receiving the WiFi sensing poll frame from the AP, they can send their own permission to send (clear to send to self) frames to the AP. Correspondingly, if the AP receives clear to send to self frames from STA1, STA2, STA3, and STA4 respectively, and does not receive clear to send to self frames from STA5~STA9, the AP can determine STA1, STA2, STA3, and STA4 as STAs that can perform radar measurements on the target object as radars under the coordination of the AP.

[0151] Take STA1, STA2, STA3, and STA4 as examples of single-station radars that include a receiving antenna and a transmitting antenna. For each STA in STA1, STA2, STA3, and STA4, as mentioned above, the STA can send a radar signal (referred to as a transmitting wave) for detecting a target through its transmitting antenna under the coordination of the AP; the transmitting wave can be reflected by the target, and the radar signal formed by the target reflecting the transmitting wave can be called a reflected wave; the STA can receive the reflected wave through its receiving antenna, and obtain the radar measurement result based on the change of the reflected wave relative to the transmitting wave. Afterwards, the AP or other computing devices connected to the AP can locate the target based on the radar measurement results of STA1, STA2, STA3, and STA4 and the position information of STA1, STA2, STA3, and STA4 in a specific coordinate system.

[0152] In the prior art, the AP needs to determine the location information of multiple STAs before triggering multiple STAs to perform radar measurements on the target object. The mobility of STAs may result in the previously determined location information of STAs not accurately reflecting the actual location of the STA when performing radar measurements on the target object, thereby affecting the accuracy of the positioning results obtained when the target object is subsequently positioned. Figure 2 Taking the application scenario shown as an example, after the position information of STA3 is determined, STA3 may move from the position where STA3 is located to other positions (for example, the position where STA7 is located) before and / or during the radar measurement of the target object. This results in the previously determined position information of STA3 not being able to accurately reflect the actual position of STA3 when performing radar measurement of the target object.

[0153] In view of this, the embodiments of the present application at least provide a method for assisting in locating a target, a method and device for locating a target. During the process of AP performing FTM on a STA, the STA concurrently performs radar measurement on the target. The FTM result of the STA can more accurately reflect the actual position of the STA when performing radar measurement on the target. Accordingly, the AP can combine the radar measurement results and FTM results of multiple STAs to more accurately locate the target.

[0154] It can be understood that AP can perform FTM for multiple STAs based on the IEEE802.11az protocol. During the process of AP performing FTM on a STA, AP can receive uplink data packets from the STA and send downlink data packets to the STA; the FTM result of the STA can at least include: the first sending time t1 when the STA sends an uplink data packet to the AP, the first receiving time t4 when the STA receives a downlink data packet from the AP, the second receiving time t2 when the AP receives an uplink data packet from the STA, and the second sending time t3 when the AP sends a downlink data packet to the STA. Accordingly, AP can calculate the round trip time (RTT) defined by IEEE802.11az as [(t2-t1)+(t4-t3)] based on the FTM result of the STA, and then calculate the distance between the STA and AP as RTT*c / 2; where c represents the speed of light, and its value is usually 3×10 8 m / s.

[0155] It can be understood that if, during the process of AP performing FTM on a STA, the STA concurrently performs radar measurement on a target object; then, the distance between the STA and the AP determined based on the FTM result of the STA can more accurately reflect the actual distance between the STA and the AP when the STA performs radar measurement on the target object. Correspondingly, the position information of the STA determined based on the distance between the STA and the AP can more accurately reflect the actual position of the STA when performing radar measurement on the target object, which is conducive to more accurate positioning of the target object.

[0156] In a possible implementation, before performing FTM on a STA, the AP may send an FTM request to the STA. The FTM request may carry indication information, and the indication information is used to instruct the STA to measure the angle of arrival (including azimuth and elevation) of the electromagnetic waves sent to it by the AP; if the STA is able to measure the angle of arrival of the electromagnetic waves sent to it by the AP, the STA may send the measured angle of arrival to the AP; the AP may determine the position information of the STA by combining its own position information in a specific coordinate system, the angle of arrival measured by the STA, and the distance between the STA and the AP when performing radar measurement on the target object, thereby locating the STA.

[0157] In another possible implementation, the STA may not have the ability to measure the angle of arrival of the electromagnetic waves sent by the AP to it, but the AP can measure the angle of arrival of the electromagnetic waves from the STA. Accordingly, after completing the measurement of the angle of arrival (including the azimuth and elevation) of the electromagnetic waves from a STA, the AP can determine the position information of the STA by combining the position information of the AP in a specific coordinate system, the angle of arrival of the electromagnetic waves from the STA, and the distance between the STA and the AP when performing radar measurement on the target object, so as to locate the STA.

[0158] In an embodiment of the present application, the AP can measure the angle of arrival of the electromagnetic wave from the STA by at least combining any one or more of the amplitude angle measurement method and the phase angle measurement method, so that the AP can determine the position information of the STA based on its own position information in a specific coordinate system, the angle of arrival of the electromagnetic wave from the STA, and the distance between the STA and the AP when the STA performs radar measurement on the target object.

[0159] The following is combined with Figure 3 The radar coordinate system shown in Figure 4 The example of the phase angle measurement method shown is used to exemplarily describe how the AP measures the arrival angle of the electromagnetic wave from the STA through the phase angle measurement method.

[0160] like Figure 3 As shown, the arrival angle of the electromagnetic wave from a STA measured by the AP specifically includes measuring the azimuth angle α and the pitch angle β of the electromagnetic wave; wherein OP represents the distance between the AP and the STA, OB represents the projection of the OP on the horizontal plane, OA represents the reference direction preset based on the geographic coordinate system (for example, the north direction on the horizontal plane), the azimuth angle α is the angle between OA and OB in the horizontal direction, the pitch angle β is the angle between OB and OP in a plumb plane perpendicular to the horizontal plane, and the pitch angle β may also be called the inclination angle, the height angle or the elevation angle.

[0161] like Figure 4 As shown, the AP may include multiple receiving antennas in a "T" shape, and the multiple receiving antennas in a "T" row may be arranged as follows: Figure 4 The array method shown forms a receiving antenna array in the AP. For the convenience of description, it is taken here as an example that the MN direction in the receiving antenna array of the AP is parallel to the pre-set reference direction in the radar coordinate system, and the projection of the STA on the horizontal plane is located on the extension line of MN. The distance between the STA and the AP is usually much larger than the distance between two adjacent receiving antennas in the AP. The electromagnetic waves reaching the two adjacent receiving antennas x and y contained in the AP are approximately plane waves; and, since there is a certain distance between x and y, there is a path difference R between the electromagnetic waves received by x and y respectively; therefore, the electromagnetic waves received by x and y respectively have a phase difference due to the path difference R. Phase Difference The relationship between the wave path difference R and the wave path difference R satisfies the following formula 6:

[0162]

[0163] Wherein, λ represents the wavelength of the electromagnetic wave received by x and y respectively, θ represents the angle between x and y and the electromagnetic wave received by them respectively, and d represents the distance between x and y in the horizontal direction. The phase of the electromagnetic waves received by x and y can be compared by dedicated software and / or hardware (for example, a phase meter) to obtain the phase difference

[0164] Correspondingly, the AP can further determine the elevation angle β of the electromagnetic wave from the STA based on the angle θ between the receiving antenna and the electromagnetic wave received by the AP. Here, the elevation angle β of the electromagnetic wave from the STA can be determined to be (90°-θ).

[0165] In the embodiment of the present application, the azimuth angle α of the electromagnetic wave from the STA can be determined by a method similar to the aforementioned method of measuring the pitch angle β.

[0166] It should be noted that the electromagnetic waves used to measure the angle of arrival in the above examples include but are not limited to the electromagnetic waves corresponding to the uplink data packets received by the AP from the STA. For example, they may also be the electromagnetic waves corresponding to the wireless sensing data (WiFi sensing data) frames sent by the STA to the AP, or the electromagnetic waves corresponding to the location measurement report (LMR, location measurement report) frames sent by the STA to the AP.

[0167] It should be noted that, when the STA is capable of measuring the angle of arrival of the electromagnetic wave sent by the AP to it, the STA may report the angle of arrival measured by the STA to the AP through an LMR frame. The angle of arrival may include the angle of arrival of the electromagnetic wave corresponding to the downlink data packet sent by the AP to the STA.

[0168] The location information of each STA obtained by the aforementioned methods is calculated based on the distance between each STA and the AP during the radar measurement of the target by each STA; the distance between each STA and the AP is calculated based on the FTM result obtained by the AP performing FTM on each STA, which can more accurately reflect the real distance between each STA and the AP when the radar measurement of the target is performed. Accordingly, the location information of each STA obtained by the aforementioned methods can more accurately reflect the real position of each STA when the radar measurement of the target is performed by each STA; the AP or the computing device connected to the AP can more accurately locate the target according to the radar measurement results of multiple STAs and the location information of multiple STAs.

[0169] It is understandable that during the radar measurement of the target by the STA, the STA may move at a relatively low speed. Still taking the example that the first radar signal sent by a STA is a frequency modulated continuous wave, in a possible implementation, the AP can also receive the first radar signal sent by the STA, and calculate the radial movement speed of the STA relative to the AP based on the first radar signal. The radial movement speeds of multiple STAs relative to the AP can be used to assist the AP in locating the target according to the first distances and radar measurement results corresponding to the multiple STAs.

[0170] In the embodiment of the present application, the radial motion speed of the STA relative to the AP can be determined by a method similar to the aforementioned method of measuring the radial motion speed of the target object and the STA.

[0171] In a more specific example, the radial movement speed of the STA relative to the AP can at least be used to correct the first distance of the STA relative to the AP.

[0172] Next, the steps that the AP and the STA need to perform in the process of completing the positioning of the target object are described in detail.

[0173] like Figure 5 As shown, an embodiment of the present application provides a method for assisting in positioning a target object. The method is applied to a STA, and the STA can at least perform the following steps 51-57.

[0174] Step 51: Receive a wireless sensor detection frame from an AP, wherein the wireless sensor detection frame includes radar measurement indication information.

[0175] In the embodiment of the present application, the radar measurement indication information includes but is not limited to radar duration and frequency band information.

[0176] In a possible implementation manner, the wireless sensor detection frame may include a piece of radar measurement indication information, and the STA may obtain the radar measurement indication information from the wireless sensor detection frame.

[0177] In a more specific example, the wireless sensor detection frame may have the following Figure 6 The structure shown. Figure 6As shown, the wireless sensor detection frame may include a medium access control (MAC) header field, a common info field, one or more user information (user info) fields, a padding field, and a frame check sequence (FCS) field. The common info field may at least include a trigger type field, a reserved field, and a trigger-dependent common info field. The trigger dependent common info field may include subfields of WiFi sensing trigger subtype, radar information indication, and reserved. The radar info indication subfield may include subfields of radar duration and resource control. The radar duration subfield may store the radar duration included in the radar measurement indication information used to instruct the STA to perform radar measurement, and the resource control subfield may store the frequency band information included in the radar measurement indication information used to instruct the STA to perform radar measurement.

[0178] It should be understood that when an AP communicates with a STA based on the IEEE802.11 protocol, the trigger frame sent by the AP to the STA to trigger the STA to perform a specific service generally includes: Figure 6 The MAC header field, common info field, one or more user info fields, padding field and FCS field are shown. Among them, the STA can determine the trigger type of the trigger frame according to the value of the trigger type field contained in the common info field of the trigger frame. For example, the trigger frame from the AP is used to instruct the STA to execute the business process related to the trigger type "wireless sensing (WiFi sensing)", and the value of the trigger type field can be 9.

[0179] In an embodiment of the present application, the trigger frame from the AP and used to trigger the STA to execute the business process related to "WiFi sensing" includes but is not limited to the wireless sensor detection frame; for example, it can also include the WiFi sensing poll frame and the wireless sensor report (WiFi sensing report) frame.

[0180] In a more specific example, the AP can instruct the STA to execute various business processes related to the trigger type "WiFi sensing" through the value of the subfield WiFi sensing trigger subtype. Specifically, three reserved values ​​can be selected from the reserved values ​​of the subfield "WiFi Sensing Trigger Subtype" of the trigger type "WiFi Sensing", and the selected three reserved values ​​can be used to instruct the STA to execute the business processes corresponding to the WiFi sensing poll frame, WiFi sensing sounding frame, and WiFi sensing report frame, respectively. For example, refer to the following Table 1:

[0181] Table 1

[0182] WiFi Sensing Trigger Subtype field value Meaning 1 Report 2 Poll 3 Sounding

[0183] As shown in Table 1 above, the reserved values ​​of the "WiFi Sensing Trigger Subtype" subfield of the trigger type "WiFi Sensing" include "1", "2", and "3". When the STA receives a trigger frame from the AP, the STA can first obtain the value of the trigger type field contained in the common info field of the trigger frame. If the value of the trigger type field indicates that the trigger frame is used to trigger the STA to execute a business process related to the trigger type "WiFi sensing", the value of the subfield WiFi Sensing TriggerSubtype contained in the trigger dependent user info field of the trigger frame is further obtained, and various business processes related to the trigger type "WiFi sensing" are executed according to the value of the subfield WiFi Sensing Trigger Subtype. For example, if the value of the WiFi Sensing Trigger Subtype subfield is 2, it means that the trigger frame is a WiFi Sensing poll frame, and the STA can respond to the WiFi Sensing poll frame according to the corresponding business process; if the value of the WiFi Sensing Trigger Subtype subfield is 3, it means that the trigger frame is a WiFi Sensing sounding frame, and the STA can respond to the WiFi Sensingsounding frame according to the corresponding business process; if the value of the WiFi Sensing Trigger Subtype subfield is 1, it means that the trigger frame is a WiFi Sensing report frame, and the STA can respond to the WiFi Sensing report frame according to the corresponding business process.

[0184] In another possible implementation, the wireless sensor detection frame may include multiple radar measurement indication information, and the STA may obtain the radar measurement indication information associated with its own identifier from the wireless sensor detection frame according to its own identifier.

[0185] In a more specific example, the wireless sensor detection frame may have the following Figure 7 The structure shown. Figure 7As shown, the wireless sensor detection frame may include a MAC header field, a common info field, one or more user info fields, a padding field, and an FCS field. For a user info field, the user info field may at least include an application identification (AID) field, a reserved field, and a trigger-dependent user info field; wherein the AID field is used to store an identifier of a STA; the trigger-dependent user info field may at least include a radar info indication subfield, and the radar info indication subfield may include a radar duration subfield and a resource control subfield; wherein the radar duration included in the radar measurement indication information for instructing the STA to perform radar measurement may be stored in the radar duration subfield, and the frequency band information included in the radar measurement indication information for instructing the STA to perform radar measurement may be stored in the resource control subfield.

[0186] Accordingly, when the STA receives a wireless sensor detection frame from the AP, it can first query the AID field contained in one or more user info fields of the wireless sensor detection frame according to its own identifier to determine the target user info field where the AID field containing the identifier of the STA is located; and then obtain the radar duration and frequency band information used to instruct the STA to perform radar measurement from the subfields radarduration and resource control contained in the target user info field.

[0187] Step 53: Send an uplink data packet to the AP, record the first sending time of the uplink data packet, and perform radar measurement on the target object according to the radar measurement indication information to obtain a radar measurement result.

[0188] As described above, when a STA receives a trigger frame from an AP, it can identify whether the trigger frame is a wireless sensor detection frame based on the value of the trigger type field and the value of the WiFi Sensing Trigger Subtype subfield contained in the common info field of the trigger frame. If the trigger frame from the AP is a wireless sensor detection frame, execute step 53.

[0189] In the embodiment of the present application, the STA may concurrently execute sending an uplink data packet to the AP and performing radar measurement on the target according to the radar measurement indication information. Alternatively, the STA may also perform radar measurement on the target according to the radar measurement indication information after completing sending the uplink data packet to the AP.

[0190] In the embodiment of the present application, the uplink data packet may be a null data packet carrying no data content, and the null data packet carrying no data content may also be referred to as an uplink null data packet (UL NDP, uplink null data packet).

[0191] In an embodiment of the present application, STA can act as a single-station radar. After the STA obtains the radar duration and frequency band information from the wireless sensor detection frame, it performs radar measurement on the target object based on the aforementioned method for performing radar measurement on the target object and obtains the corresponding radar measurement result.

[0192] As mentioned above, the radar measurement results obtained by the STA may include three forms: Before FFT, FFT info, and FFT result. Therefore, in a possible implementation, the wireless sensor detection frame from the AP may also include an indication message for indicating the form of the radar measurement results that the STA needs to obtain when performing radar measurement on the target object.

[0193] For a more specific example, see Figure 6 , Figure 7, the subfield radar info indication may also include a feedback control subfield, and the feedback control subfield may include subfields Before FFT control, FFT info control, and FFT result control. The AP may instruct the STA to obtain radar measurement results in a specific form by coordinating the values ​​of the subfields Before FFT control, FFT info control, and FFT result control in the wireless sensor detection frame. Exemplarily, if the AP needs to instruct the STA to obtain radar measurement results in the form of BeforeFFT, the value of Before FFT control contained in the wireless sensor detection frame sent to the STA may be set to 1, and the values ​​of the subfields FFT info control and FFT result control may be set to 0; accordingly, the AP may determine the target subfield (such as Before FFT control) whose value is 1 by querying the subfields Before FFT control, FFT info control, and FFT result control contained in the wireless sensor detection frame; thereafter, the form of the radar result obtained by the STA shall be the form indicated by the target subfield.

[0194] In a possible implementation, the feedback control subfield may also include a channel state information (CSI) control (CSI control) subfield. The AP may indicate whether the STA needs to obtain the CSI for sensing the movement of the target object and add the obtained CSI to the radar measurement result by coordinating the value of the subfield CSI control in the wireless sensor detection frame. Exemplarily, if the value of the subfield CSI control contained in the wireless sensor detection frame received by the STA is 1, the STA needs to obtain the CSI for sensing the movement of the target object and add the obtained CSI to the radar measurement result.

[0195] Step 55: Receive a downlink data packet from the AP, and record the first receiving time of the downlink data packet.

[0196] In the embodiment of the present application, the downlink data packet may be a null data packet carrying no data content, and the null data packet carrying no data content may also be referred to as a downlink null data packet (DL NDP, downlink null data packet).

[0197] It is understandable that before step 55, the STA may also receive a null data packet announcement (NDPA) from the AP. The NDPA is used to reserve the downlink network resources of the STA so that the STA can receive the DL NDP sent to it by the AP.

[0198] Step 57: Send the first sending time, the first receiving time, and the radar measurement result to the AP.

[0199] In the embodiment of the present application, the STA can send the first sending time and the second sending time to the AP through an LMR frame under the coordination of the AP; and send the radar measurement result to the AP through a wireless sensing data frame under the coordination of the AP. Alternatively, the STA can send the first sending time, the first receiving time and the radar measurement result to the AP through a wireless sensing data (WiFi sensing data) frame under the coordination of the AP.

[0200] In a possible implementation, the STA may send a WiFi sensing data frame including a first sending time, a first receiving time, and a radar measurement result to the AP in response to a WiFi sensing report frame sent by the AP to the STA.

[0201] In a more specific example, a WiFi sensing report frame may have the following Figure 8 The structure shown. Figure 8As shown, the WiFi sensing report frame may include a MAC header field, a common info field, one or more user info fields, a padding field, and an FCS field. The common info field may at least include a trigger type field, a reserved field, and a trigger dependent common info field. The trigger dependent common info field may include a WiFi sensing trigger subtype subfield, a reserved subfield, and a feedback control subfield. Among them, the feedback control subfield may at least include an FTM feedback control subfield. The AP may indicate whether the STA needs to feed back a WiFi sensing data frame including a first sending time, a first receiving time, and radar measurement results to the AP by coordinating the value of the FTM feedback control subfield in the WiFi sensing report frame. Exemplarily, after the STA identifies that the trigger frame from the AP is a WiFi sensing report frame, the value of the FTM feedback control subfield contained in the WiFi sensing report frame can be further queried. If the value of the FTM feedback control subfield is the first indication information (for example, 1), a WiFi sensing data frame including the first sending time, the first receiving time and the radar measurement result is fed back to the AP; conversely, if the value of the FTM feedback control subfield is not the first indication information (for example, 0), the STA can feed back a WiFi sensing data frame including the radar measurement result to the AP.

[0202] In a more specific example, the feedback control subfield contained in the WiFi sensing report frame may also include subfields CSI, Before FFT control, FFT info control, and FFT result control. The functions of the subfields CSI control, Before FFT control, FFT info control, and FFT result control are the same as Figure 6 , Figure 7The subfields CSI, BeforeFFT control, FFT info control, and FFT result control included in the WiFi sensing sounding frame shown have the same functions and are not repeated here.

[0203] In a more specific example, a WiFi sensing data frame may include: Fig. 9 The structure shown. Fig. 9 As shown, when an AP communicates with a STA based on the IEEE802.11 protocol, the WiFi sensing data frame sent by the STA to the AP may include the following: Fig. 9 The MAC header field, category field, WiFi sensing action field, WiFi sensing data action field, and FCS field are shown. The WiFi sensing data action field may include a WiFi sensing data control field, a sequence id field, a timestamp field, a sampling frequency field, a CSI field, a Before FFT field, a FFT info field, a FFT result field, and a FTM result element field. The WiFi sensing data control field may include subfields such as sequence id control, timestamp control, sampling frequency control, CSI control, Before FFT control, FFT info control, FFT result control, and FTM control. The FTM result element field may include subfields element id, element id extension, dialog token, time of departure (TOD), time of arrival (TOA), time of departure error (TOD error), time of arrival error (TOA error), and carrier frequency offset (CFO).

[0204] Among them, the STA can indicate to the AP whether the WiFi sensing data frame contains the first receiving time and the first sending time recorded by the STA when the AP performs FTM on the STA by coordinating the value of the FTM control subfield contained in the WiFi sensing data frame. Exemplarily, the AP can first query the value of the FTM control subfield contained in the WiFi sensing data frame. If the value of the FTM control subfield is the second indication information (for example, 1), it means that the WiFi sensing data frame contains the FTM result element field. The AP can obtain the first receiving time and the first sending time recorded by the STA from the FTM result element field under the instruction of the second indication information; specifically, the first receiving time can be stored in the subfield TOA, and the first sending time can be located in the subfield TOD.

[0205] On the contrary, if the AP queries that the value of the FTM control subfield contained in the WiFi sensing data frame is not the second indication information (for example, 0), it means that the WiFi sensing data frame does not contain the FTM result element field, or, it means that the FTM result element field contained in the WiFi sensing data frame does not contain the first receiving time and the first sending time recorded by the STA when the AP performs FTM on the STA.

[0206] Accordingly, when the WiFi sensing data frame fed back by the STA to the AP does not include the first sending time and the first receiving time, in another possible implementation, the STA may send an LMR frame including the first sending time and the first receiving time to the AP in response to a ranging report frame from the AP.

[0207] With Figure 5 Corresponding to the method for assisting in positioning the target shown in the figure, an embodiment of the present application also provides a method for positioning the target, the method is for each STA in a plurality of STAs, the method is applied to the AP, such as Fig.10 As shown, the method for locating a target object may at least include the following steps 101-106.

[0208] Step 101: Send a wireless sensor detection frame to a STA.

[0209] The wireless sensor detection frame includes radar measurement indication information for instructing the STA to perform radar measurement on the target object.

[0210] The multiple STAs are STAs that are determined after the AP polls each STA connected to the AP and can be used as a radar to perform radar measurement on the target object under the coordination of the AP.

[0211] In a possible implementation, the AP may send wireless sensor detection frames to multiple STAs at different times. The wireless sensor detection frames received by each of the multiple STAs may have the following information: Figure 6 In the structure shown, the wireless sensor detection frames received by multiple STAs respectively may contain the same radar measurement indication information.

[0212] In another possible implementation, the AP sends a wireless sensor detection frame to multiple STAs by multicasting or broadcasting. The wireless sensor detection frame may have the following contents: Figure 7 In the structure shown, the radar measurement indication information respectively contained in the multiple user information fields of the wireless sensor detection frame each contains different frequency band information. So that multiple STAs can send the first radar signal and / or receive the second radar signal on different frequency bands in the same time period. In this way, it is helpful to reduce the time overhead required for the information interaction process between the AP and multiple STAs.

[0213] In a possible implementation, when an AP sends a wireless sensor detection frame to multiple STAs by multicast or broadcast, for each of the multiple user information fields contained in the wireless sensor detection frame, the user information field may also include channel information for indicating that the corresponding STA sends an uplink data packet. The channel information respectively contained in the multiple user information fields is different, so that multiple STAs can send uplink data packets to the AP on different channels in the same time period. In this way, the time overhead required for the information interaction process between the AP and multiple STAs can be further reduced.

[0214] Step 102: Receive an uplink data packet from the STA, and record a second receiving time of the uplink data packet.

[0215] In a possible implementation, when the AP sends a wireless sensor detection frame to multiple STAs by multicast or broadcast, it can concurrently receive uplink data packets respectively sent to it by multiple STAs on multiple channels according to the channel information respectively contained in multiple user info fields of the wireless sensor detection frame.

[0216] Step 103: Send a downlink data packet to the STA, and record a second sending time of the downlink data packet.

[0217] Before step 103, the AP may also send the NDPA to each STA respectively by unicast, multicast or broadcast, and reserve the downlink network resources of each STA so that each STA can receive the DL NDP sent by the AP.

[0218] In a possible implementation manner, the AP may send downlink data packets to multiple STAs at different times.

[0219] In another possible implementation, the AP may send downlink data packets to multiple STAs in a multicast or broadcast manner; in this way, the time overhead required for the information interaction process between the AP and the multiple STAs may be further reduced.

[0220] Step 104: Receive a first sending time, a first receiving time, and a radar measurement result from the STA.

[0221] Among them, the first sending time is the time corresponding to when the STA sends the uplink data packet, the receiving time is the time corresponding to when the STA receives the downlink data packet, and the radar measurement result is the radar measurement result obtained when the STA performs radar measurement on the target object according to the radar measurement indication information.

[0222] In a possible implementation, the AP may send WiFi sensing report frames to multiple STAs by multicast or broadcast, so that multiple STAs send WiFi sensing data frames to the AP through different frequency bands / channels in the same time period. Among them, for a STA, the frequency band / channel used by the STA to send the WiFi sensing data frame to the AP may be the frequency band indicated by the frequency band information contained in the radar measurement indication information obtained by the STA, or the channel indicated by the channel information contained in the user info field corresponding to the STA. In this way, the time overhead required for the information interaction process between the AP and multiple STAs can be further reduced.

[0223] Step 105: Calculate a first distance between the STA and the AP according to the first sending time, the first receiving time, the second sending time, and the second receiving time.

[0224] Step 106: Position the target object according to the first distances and radar measurement results respectively corresponding to the plurality of STAs.

[0225] As described above, in step 106, for each STA among the multiple STAs, the AP may determine the location information of the STA according to the first distance between the STA and the AP, the location information of the AP in a specific coordinate system, the arrival angle of the electromagnetic wave from the STA, or the arrival angle of the electromagnetic wave sent by the AP to the STA; wherein, for the arrival angle of the electromagnetic wave from the STA, as described above, at least the following may be combined: Figure 3 The radar coordinate system shown in Figure 4 The example of phase angle measurement method shown in FIG. 1 is measured by the AP through the phase angle measurement method. Then, the AP can locate the target object based on the position information of multiple STAs and the radar measurement results.

[0226] In order to facilitate the description and understanding of the technical solution of the present application, the information interaction process between the AP and multiple STAs is exemplarily described below by taking multiple STAs including STA1, STA2, STA3, and STA4 as an example.

[0227] In one example, if Fig.11 As shown, first, the AP can select an unselected STA from multiple STAs (STA1, STA2, STA3, STA4), and send a WiFi sensing sounding frame to the selected STA. In this way, the STA selected by the AP sends a UL NDP to the AP, sends a first radar signal S1 to the target, and receives a second radar signal S2 formed by the target reflecting the S1 sent by the STA.

[0228] Among them, after receiving the UL NDP sent to it by the selected STA, the AP can re-select an unselected STA from multiple STAs and perform a similar process as described above, so as to send WiFi sensing sounding frames to multiple STAs at different time points.

[0229] When there is no unselected STA among the multiple STAs, the AP can send the NDPA to the multiple STAs in a unicast, multicast or broadcast manner, and notify the multiple STAs through the NDPA to receive the DL NDP that the AP is about to send.

[0230] Then, the AP sends the DL NDP to multiple STAs respectively by unicast, multicast or broadcast.

[0231] Finally, the AP sends WiFi sensing report frames to multiple STAs through unicast, multicast or broadcast, so that multiple STAs send WiFi sensing data frames to the AP respectively.

[0232] In another example, Fig.12 As shown, first, the AP can select an unselected STA from multiple STAs (STA1, STA2, STA3, STA4), and send a WiFi sensing sounding frame to the selected STA. In this way, the STA selected by the AP sends a UL NDP to the AP, sends a first radar signal S1 to the target, and receives a second radar signal S2 formed by the target reflecting the S1 sent by the STA.

[0233] Then, the AP sends the NDPA to the selected STA in a unicast manner, and notifies the selected STA through the NDPA to receive the DL NDP that the AP is about to send.

[0234] Then, the AP sends the DL NDP to the selected STAs in unicast mode.

[0235] Afterwards, the AP may reselect an unselected STA from the multiple STAs and perform a similar process as described above.

[0236] When there are no unselected STAs among multiple STAs, the AP can send WiFi sensing report frames to multiple STAs by unicast, multicast or broadcast, so that multiple STAs send WiFi sensing data frames to the AP respectively.

[0237] In another example, Fig.13 As shown, first, the AP can send WiFi sensing sounding frames to multiple STAs ((STA1, STA2, STA3, STA4)) by multicast or broadcast, so that multiple STAs send UL NDP to the AP on different channels in the same time period, and send the first radar signal S1 and receive the second radar signal S2 on different frequency bands in the same time period.

[0238] Then, the AP may send the NDPA to multiple STAs in a unicast, multicast or broadcast manner, and notify the multiple STAs through the NDPA to receive the DL NDP that the AP is about to send.

[0239] Afterwards, the AP may send the DL NDP to multiple STAs respectively in a unicast, multicast or broadcast manner.

[0240] Finally, the AP can send WiFi sensing report frames to multiple STAs by unicast, multicast or broadcast, so that multiple STAs send WiFi sensing data frames to the AP respectively.

[0241] Based on the same concept as the above method embodiment, Fig.14 As shown, in an embodiment of the present application, a device for assisting in positioning a target object is also provided, which is applied to a STA. The device 140 includes:

[0242] The transceiver unit 141 is configured to receive a wireless sensor detection frame from an AP, wherein the wireless sensor detection frame includes radar measurement indication information; send an uplink data packet to the AP; and receive a downlink data packet from the AP;

[0243] The processing unit 143 is configured to record the first sending time of the uplink data packet; record the first receiving time of the downlink data packet; and perform radar measurement on the target object according to the radar measurement indication information to obtain a radar measurement result;

[0244] The transceiver unit is further used to send the first sending time, the first receiving time and the radar measurement result to the AP.

[0245] In one possible implementation,

[0246] The processing unit 143 is specifically configured to trigger the transceiver unit to send a first radar signal according to the radar measurement indication information; and trigger the transceiver unit to receive a second radar signal according to the radar measurement indication information, where the second radar signal is formed by the target object reflecting the first radar signal;

[0247] The processing unit 141 is specifically used to determine the radar measurement result according to a first starting time corresponding to when the transceiver unit sends the first radar signal, a second starting time corresponding to when the transceiver unit receives the second radar signal, and the first radar signal and the second radar signal.

[0248] In a possible implementation manner, the trigger-dependent common information field of the wireless sensor detection frame includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0249] In a possible implementation, a user information field of the wireless sensor detection frame includes an application identification field and a trigger-dependent user information field, wherein the application identification field includes an identification of the STA, the trigger-dependent user information field includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

[0250] In one possible implementation,

[0251] The radar information identification subfield includes a radar duration subfield and a resource control subfield;

[0252] The radar measurement indication information includes radar duration and frequency band information, wherein the radar duration subfield includes the radar duration, and the resource control subfield includes the frequency band information.

[0253] In a possible implementation, the processing unit 143 is specifically used to trigger the transceiver unit to send a wireless sensor data frame to the AP in response to a wireless sensor report frame sent by the AP to the STA, wherein the wireless sensor data frame includes the first sending time, the first receiving time and the radar measurement result.

[0254] In one possible implementation,

[0255] The trigger-dependent common information field of the wireless sensor report frame includes a feedback control subfield;

[0256] The feedback control subfield at least includes a precise time measurement FTM feedback control subfield, and the FTM feedback control subfield includes first indication information, where the first indication information is used to instruct the STA to send the wireless sensor data frame to the AP.

[0257] In one possible implementation,

[0258] The wireless sensor data action field of the wireless sensor data frame includes an FTM result element field;

[0259] The first receiving time and the first sending time are included in the FTM result element field.

[0260] In a possible implementation, the wireless sensor data action field of the wireless sensor data frame also includes a wireless sensor data control field, and the wireless sensor data control field includes an FTM control subfield, wherein the FTM control subfield includes second indication information, and the second indication information is used to instruct the AP to obtain the first receiving time and the first sending time from the FTM result element field.

[0261] Based on the same concept as the above method embodiment, Fig.15 As shown, an embodiment of the present application further provides a device for locating a target object, which is applied to an AP. The device 150 includes:

[0262] The transceiver unit 151 is used to send a wireless sensor detection frame to each STA in a plurality of STAs, wherein the wireless sensor detection frame includes radar measurement indication information; receive an uplink data packet from the STA; send a downlink data packet to the STA; receive a first sending time, a first receiving time, and a radar measurement result from the STA, wherein the first sending time is a time corresponding to when the STA sends the uplink data packet, the first receiving time is a time corresponding to when the STA receives the downlink data packet, and the radar measurement result is a radar measurement result obtained when the STA performs radar measurement on the target according to the radar measurement indication information;

[0263] The processing unit 153 is used to record the second receiving time of the uplink data packet; record the second sending time of the downlink data packet; and calculate the first distance between the STA and the AP according to the first sending time, the first receiving time, the second sending time, and the second receiving time; and locate the target object according to the first distances corresponding to the multiple STAs and the radar measurement results.

[0264] In a possible implementation, the processing unit 153 is specifically used to trigger the transceiver unit 151 to send the wireless sensor detection frame to the multiple STAs via multicast or broadcast, wherein the multiple user information fields of the wireless sensor detection frame correspond one-to-one to the multiple STAs, and the user information field contains an identifier of the corresponding STA and radar measurement indication information for instructing the corresponding STA to perform radar measurement, and the radar measurement indication information respectively contained in the multiple user information fields each contains different frequency band information.

[0265] In one possible implementation,

[0266] The user information field further includes channel information for indicating the corresponding STA to send the uplink data packet, and the channel information respectively included in the plurality of user information fields is different;

[0267] The processing unit 153 is specifically configured to trigger the transceiver unit to receive the uplink data packets respectively from the multiple STAs according to the channel information respectively included in each of the user information fields.

[0268] In one possible implementation,

[0269] The processing unit 153 is specifically configured to trigger the transceiver unit 151 to send the downlink data packet to the multiple STAs in a multicast or broadcast manner.

[0270] An embodiment of the present application further provides a computer-readable storage medium for storing instructions, which, when executed by a processor of a STA, enables the STA to implement a method for assisting in positioning a target object provided in any embodiment of the present application.

[0271] An embodiment of the present application further provides a computer-readable storage medium for storing instructions, which, when executed by a processor of an AP, enables the AP to implement a method for locating a target object provided in any embodiment of the present application.

[0272] An embodiment of the present application further provides a STA, including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method for assisting in positioning a target provided in any embodiment of the present application is implemented.

[0273] An embodiment of the present application further provides an AP, including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method for locating a target object provided in any embodiment of the present application is implemented.

[0274] An embodiment of the present application further provides a computer program product, which includes a computer program code. When the computer program code is executed on a computer, the computer executes the method for assisting in locating a target object provided in any embodiment of the present application.

[0275] An embodiment of the present application further provides a computer program product, which includes a computer program code. When the computer program code is executed on a computer, the computer executes the method for locating a target object provided in any embodiment of the present application.

[0276] The embodiment of the present application also provides a communication device, which has the functions of STA in the above-mentioned various aspects. The functions of STA can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above-mentioned functions.

[0277] The embodiment of the present application also provides a communication device, which has the functions of the AP in the above aspects. The functions of the AP can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions.

[0278] The embodiment of the present application further provides a communication device, which may be the STA described in the above aspects, or a chip set in the STA. The communication device includes a memory, a communication interface, and a processor, wherein the memory is used to store computer programs or instructions, and the processor is coupled to the memory and the communication interface, and when the processor executes the computer program or instruction, the communication device executes the method for assisting in positioning a target provided in any embodiment of the present application.

[0279] The embodiment of the present application also provides a communication device, which can be the AP described in the above aspects, or a chip set in the AP. The communication device includes a memory, a communication interface and a processor, wherein the memory is used to store computer programs or instructions, and the processor is coupled to the memory and the communication interface. When the processor executes the computer program or instruction, the communication device executes the method for locating a target object provided in any embodiment of the present application.

[0280] The embodiment of the present application also provides a chip system, which includes a processor for the function of the STA described in any embodiment of the present application, for example, receiving or processing the data and / or information involved in the method for assisting in positioning the target provided in any embodiment of the present application. In one possible design, the chip system also includes a memory, which is used to store program instructions and / or data. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0281] The embodiment of the present application also provides a chip system, which includes a processor for implementing the functions of the AP described in any embodiment of the present application, for example, receiving or processing the data and / or information involved in the method for locating a target object provided in any embodiment of the present application. In a possible design, the chip system also includes a memory, which is used to store program instructions and / or data. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0282] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present application.

[0283] It should be understood that in various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0284] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-mentioned network device can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0285] It can be understood that the device embodiments described above are schematic. For example, the division of the modules / units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0286] The above is only a specific implementation of the embodiment of the present application, but the protection scope of the embodiment of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed in the embodiment of the present application, which should be covered within the protection scope of the embodiment of the present application.

[0287] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions provided in the aforementioned embodiments can still be modified, or some of the technical features therein can be replaced by equivalents, and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions provided in the various embodiments of the present application.

Claims

1. A method for assisting in locating a target, characterized in that: Applied to a workstation STA, the method comprises: Receiving a wireless sensor detection frame from an access point AP, wherein the wireless sensor detection frame includes radar measurement indication information; Performing radar measurement on the target object according to the radar measurement instruction information to obtain a radar measurement result; The radar measurement result is sent to the AP.

2. The method according to claim 1, characterized in that: The performing radar measurement on the target object according to the radar measurement instruction information to obtain the radar measurement result includes: sending a first radar signal according to the radar measurement instruction information, and receiving a second radar signal according to the radar measurement instruction information, wherein the second radar signal is formed by a target object reflecting the first radar signal; A radar measurement result is determined according to a first starting time corresponding to when the first radar signal is sent, a second starting time corresponding to when the second radar signal is received, and the first radar signal and the second radar signal.

3. The method according to claim 1, characterized in that The trigger-dependent common information field of the wireless sensor detection frame includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information; or, A user information field of the wireless sensor detection frame includes an application identification field and a trigger-dependent user information field, wherein the application identification field includes an identification of the STA, the trigger-dependent user information field includes a radar information identification subfield, and the radar information identification subfield includes the radar measurement indication information.

4. The method according to claim 3, characterized in that The radar information identification subfield includes a radar duration subfield and a resource control subfield; The radar measurement indication information includes radar duration and frequency band information, wherein the radar duration subfield includes the radar duration, and the resource control subfield includes the frequency band information.

5. The method according to any one of claims 1 to 4, characterized in that: The radar measurement result also includes the direction angle and radial movement speed of the target object relative to the STA.

6. The method according to any one of claims 1 to 4, characterized in that: Sending the radar measurement result to the AP includes: The radar measurement result is sent to the AP via a wireless sensor data frame, wherein the wireless sensor data action field of the wireless sensor data frame includes one or more of the following: a sequence identification field, a timestamp field, and a channel state information field.

7. A method for locating a target object, characterized in that: Applied to an access point AP, the method comprises: Sending a wireless sensor detection frame to a workstation STA, wherein the wireless sensor detection frame includes radar measurement indication information; A radar measurement result is received from the STA, where the radar measurement result is a radar measurement result obtained when the STA performs radar measurement on the target object according to the radar measurement indication information.

8. The method according to claim 7, characterized in that The sending of the wireless sensor detection frame to the STA includes: sending the wireless sensor detection frame to multiple STAs by multicast or broadcast, wherein multiple user information fields of the wireless sensor detection frame correspond to the multiple STAs one by one, and the user information field includes an identifier of the corresponding STA and radar measurement indication information for instructing the corresponding STA to perform radar measurement, and the radar measurement indication information respectively included in the multiple user information fields each includes different frequency band information.

9. The method according to claim 7 or 8, characterized in that: The radar measurement result also includes the direction angle and radial movement speed of the target object relative to the STA.

10. The method according to any one of claims 7 or 8, characterized in that: Receiving the radar measurement result from the STA includes: The radar measurement result is received from the STA via a wireless sensor data frame, wherein the wireless sensor data action field of the wireless sensor data frame includes one or more of the following: a sequence identification field, a timestamp field, and a channel state information field.

11. A device comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method according to any one of claims 1 to 6 is implemented.

12. A device comprising a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, the method according to any one of claims 7 to 10 is implemented.

13. A computer-readable storage medium, used for storing instructions, when the instructions are executed by a processor of a workstation (STA), the STA implements the method according to any one of claims 1 to 6.

14. A computer-readable storage medium, used for storing instructions, when the instructions are executed by a processor of an access point AP, the AP implements the method according to any one of claims 7 to 10.

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