Ranging methods, devices, communication equipment and readable storage media

Abstract

This application discloses a ranging method, apparatus, communication device, and readable storage medium, belonging to the field of communication technology. The ranging method of this application includes: a first device sending a first signal to a second device through a first communication module; the first communication module communicating based on a first communication protocol; receiving a second signal from the second device through a second communication module; the second signal being obtained by backscattering the first signal; the second communication module communicating based on a second communication protocol; the second communication module and the first communication module being different communication modules in the first device; and the second communication protocol and the first communication protocol being communication protocols with different protocol specifications; obtaining the phase information of the second signal; and determining the distance between the first device and the second device based on the phase information of the second signal.

Description

Technical Field

[0001] This application belongs to the field of communication technology, specifically relating to a ranging method, apparatus, communication equipment, and readable storage medium. Background Technology

[0002] In backscatter communication systems, the terminal device receiving the backscattered signal typically needs to provide a radio frequency carrier to excite the tag device and also needs to receive the backscattered signal transmitted by the tag device. After receiving the backscattered signal, the terminal device can perform ranging based on the backscattered signal. However, due to limitations in the terminal device's radio frequency link, the number of antennas, or its half-duplex operation, the transmitting and receiving links of the terminal device usually need to be switched. This results in a limited receiving window for the backscattered echo, and the phase reference continuity between the transmitted and received signals is difficult to guarantee, leading to lower ranging accuracy. Summary of the Invention

[0003] This application provides a ranging method, apparatus, communication device, and readable storage medium, which can solve the problem of low ranging accuracy when using backscattered signals in related technologies.

[0004] Firstly, a ranging method is provided, the method comprising:

[0005] The first device sends a first signal to the second device through a first communication module; wherein the first communication module communicates based on a first communication protocol.

[0006] The first device receives a second signal from the second device through the second communication module; wherein the second signal is obtained by backscattering the first signal, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules in the first device; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications;

[0007] The first device obtains the phase information of the second signal and determines the distance between the first device and the second device based on the phase information of the second signal.

[0008] Secondly, a ranging method is provided, which includes:

[0009] The second device receives a first signal from the first device; wherein the first signal is sent through a first communication module in the first device, and the first communication module communicates based on a first communication protocol;

[0010] The second device performs a backscattering operation on the first signal to obtain the second signal;

[0011] The second device sends the second signal to the first device; wherein the second signal is received through a second communication module in the first device, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; the phase information of the second signal is used to determine the distance between the first device and the second device.

[0012] Thirdly, a ranging device is provided, comprising:

[0013] A first communication module is used to send a first signal to a second device; wherein the first communication module communicates based on a first communication protocol;

[0014] The second communication module is used to receive a second signal from the second device; wherein the second signal is obtained by backscattering the first signal, the second communication module communicates based on a second communication protocol, the second communication module and the first communication module are different communication modules in the first device, and the second communication protocol and the first communication protocol are communication protocols with different protocol specifications;

[0015] An acquisition module is used to obtain the phase information of the second signal;

[0016] The determining module is used to determine the distance between the first device and the second device based on the phase information of the second signal.

[0017] Fourthly, a ranging device is provided, comprising:

[0018] A receiving module is configured to receive a first signal from a first device; wherein the first signal is transmitted through a first communication module in the first device, and the first communication module communicates based on a first communication protocol;

[0019] The processing module is used to perform a backscattering operation on the first signal to obtain a second signal;

[0020] A transmitting module is used to transmit the second signal to the first device; wherein the second signal is received by a second communication module in the first device, the second communication module communicates based on a second communication protocol, the second communication module and the first communication module are different communication modules, and the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; the phase information of the second signal is used to determine the distance between the first device and the second device.

[0021] Fifthly, a communication device is provided, comprising a processor and a memory, the memory storing a program or instructions executable on the processor, the program or instructions, when executed by the processor, implementing the steps of the method as described in the first aspect, or implementing the steps of the method as described in the second aspect.

[0022] In a sixth aspect, a readable storage medium is provided, on which a program or instructions are stored, which, when executed by a processor, implement the steps of the method described in the first aspect, or implement the steps of the method described in the second aspect.

[0023] In a seventh aspect, a chip is provided, the chip including a processor and a communication interface coupled to the processor, the processor being configured to run a program or instructions to implement the steps of the method described in the first aspect, or to implement the steps of the method described in the second aspect.

[0024] The solution of this application embodiment can realize cross-communication protocol signal interaction between the first device and the second device based on different communication modules in the first device. That is, it realizes cross-communication protocol backscatter communication based on the collaborative work of different communication modules in the first device. In this way, when ranging based on backscatter signals, it can solve the problem of limited receiving window of backscatter echo caused by the need to switch between the transmitting link and the receiving link in related technologies, thereby improving ranging accuracy and meeting ranging requirements. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1A and Figure 1B A schematic diagram illustrating two types of impedance modulation methods applicable to embodiments of this application is shown;

[0027] Figure 2 This is a schematic diagram of the architecture of the backscatter communication system in the embodiments of this application;

[0028] Figure 3 This is one of the flowcharts of the ranging method provided in the embodiments of this application;

[0029] Figure 4 This is the second flowchart of the ranging method provided in the embodiments of this application;

[0030] Figure 5This is a schematic diagram of the signal interaction architecture across communication protocols in the implementation of this application;

[0031] Figure 6 This is a flowchart of the signal interaction process across communication protocols in the implementation of this application;

[0032] Figure 7 This is a schematic diagram of a WiFi frame structure implemented in this application;

[0033] Figure 8 This is a schematic diagram of a Bluetooth data packet structure implemented in this application;

[0034] Figure 9 This is one of the structural schematic diagrams of the ranging device provided in the embodiments of this application;

[0035] Figure 10 This is a second schematic diagram of the ranging device provided in the embodiments of this application;

[0036] Figure 11 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0037] Figure 12 This is a schematic diagram of the structure of a terminal provided in an embodiment of this application. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0039] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0040] To facilitate understanding of the embodiments of this application, the following will be described first.

[0041] Backscatter communication is a communication technology whose core principle is to modulate and transmit information using existing radio frequency signals in the environment. Backscatter communication devices adjust their internal load impedance... To control the reflection coefficient of the modulation circuit This alters the amplitude, frequency, and phase of the incident signal, thus achieving signal modulation. Reflection coefficient It can be characterized as:

[0042]

[0043] in, The characteristic impedance of the antenna. This is the load impedance. To represent a complex number, Represents phase. Assume the incident signal is represented as... The output signal can then be expressed as Therefore, by reasonably controlling the reflection coefficient, corresponding amplitude modulation, frequency modulation, or phase modulation can be achieved. Based on this, backscatter communication devices can be tags in traditional Radio Frequency Identification (RFID), or passive or semi-passive Internet of Things (IoT) devices. Backscatter communication devices can also be ambient-powered IoT (AIoT) devices.

[0044] Based on their implementation mechanism, impedance modulation techniques can be divided into two categories: one is analog modulation, which changes the load impedance by adjusting the built-in analog circuit. ,like Figure 1A As shown. For example, varactor diodes are deployed in tag devices. By adjusting the bias voltage of the varactor diodes, the equivalent reactance of the load network is continuously changed, thereby modulating the carrier signal. Another type is digital impedance modulation, which uses a controller to change the load impedance. ,like Figure 1B As shown. For example, tag devices construct discrete impedance networks based on radio frequency switch arrays and switch preset impedance states through a digital controller. The advantage of this type of modulation method lies in its ultra-low power consumption at the microwatt level.

[0045] An example of a backscatter communication system applicable to the embodiments of this application is as follows: Figure 2 As shown. This backscatter communication system includes a reader, tags, and a host computer. The tags use a backscatter modulation mechanism for data transmission: when an object with a tag enters the effective range of the reader, the reader first sends a query command to it; after the tag chip is activated, it modulates its own information onto the carrier wave and sends it back to the reader; finally, the reader demodulates the signal and transmits the processed data to the host computer.

[0046] The ranging method, apparatus, communication device, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through some embodiments and application scenarios.

[0047] Please see Figure 3 , Figure 3 This is a flowchart of a ranging method provided in an embodiment of this application. The method is executed by a first device, such as... Figure 3 As shown, the method includes the following steps:

[0048] Step 31: The first device sends a first signal to the second device through the first communication module; the first communication module communicates based on the first communication protocol;

[0049] Step 32: The first device receives a second signal from the second device through the second communication module; the second signal is obtained by backscattering the first signal; the second communication module communicates based on the second communication protocol; the second communication module and the first communication module are different communication modules in the first device; the second signal is the backscattered signal of the first signal; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications.

[0050] Step 33: The first device obtains the phase information of the second signal and determines the distance between the first device and the second device based on the phase information of the second signal.

[0051] In this embodiment, the first device can be one of the following: a terminal device, a relay device, a network device such as a base station, a repeater, an integrated access and backhaul (IAB) device, etc. The terminal device may include, but is not limited to, mobile phones, computers, tablets, embedded boards, general-purpose software-defined radio devices, multi-protocol communication devices, etc. The first device can be configured with corresponding communication modules according to actual needs to support signal transmission and reception of different communication protocols. The first device can be understood as a positioning device.

[0052] The first communication module can be used to generate and transmit a first signal. The first communication module can satisfy at least one of the following: (a) it has a signal generation function for generating a first signal with a first signal structure that can be received by a second device; (b) it has a signal transmission function for transmitting the first signal to the second device for the second device to perform backscattering operation; (c) it includes at least one of a radio frequency signal generation unit, a baseband processing unit, a modulation unit, and a transmission front-end unit; (d) it includes at least one of a WiFi communication module, a Bluetooth communication module, a ZigBee communication module, a Starfleet communication module, a Long Range (LoRa) radio communication module, an Ultra-Wideband (UWB) communication module, and a sidelink communication module; (e) all or part of the parameters of the first signal generated by the first communication module are known or obtainable for subsequent signal analysis or distance estimation.

[0053] The second communication module can be used to receive a second signal. The second communication module can satisfy at least one of the following: (a) having a signal receiving function for receiving a second signal generated by the second device and transmitted in a backscattering manner; (b) having a signal identification, parsing, or processing function for identifying, parsing, or processing the second signal; (c) including at least one of a radio frequency receiving unit, a baseband processing unit, a demodulation unit, and a signal processing unit; (d) including at least one of a WiFi communication module, a Bluetooth communication module, a ZigBee communication module, a StarScan communication module, a LoRa communication module, a UWB communication module, and a sidelink communication module; (e) the second communication module and the first communication module are communication modules that support different communication protocols.

[0054] The second device is specifically a backscattering device, which may possess impedance modulation capabilities and signal reflection capabilities. The second device can be understood as the device to be located, and may include an antenna, impedance switching network, and control unit. The second device can be selected as a low-power passive tag, a semi-passive tag, or an active tag.

[0055] The first and second communication protocols are communication protocols with different protocol specifications.

[0056] In some embodiments, the first communication protocol may include, but is not limited to, at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarScan communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, Sidelink communication protocol, etc.

[0057] In some embodiments, the second communication protocol may include, but is not limited to, at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarScan communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, Sidelink communication protocol, etc.

[0058] In some embodiments, the first communication protocol is a WiFi communication protocol and the second communication protocol is a Bluetooth communication protocol; or, the first communication protocol is a Bluetooth communication protocol and the second communication protocol is a WiFi communication protocol; or, the first communication protocol is a Zigbee communication protocol and the second communication protocol is a Bluetooth communication protocol; or, the first communication protocol is a WiFi communication protocol and the second communication protocol is a Zigbee communication protocol; and so on.

[0059] In some embodiments, the first communication protocol is used to define the physical layer signal structure characteristics of the first signal, and the characteristics of the first communication protocol may include at least one of the following:

[0060] (a) Modulation characteristics, including at least one of the following: amplitude modulation, frequency modulation, phase modulation, etc.;

[0061] (b) Frequency structure characteristics, including at least one of the following: single-frequency structure, multi-frequency structure, frequency hopping structure, continuous spectrum structure, and multi-carrier structure, etc.;

[0062] (c) Phase characteristics, including continuous phase change characteristics or discrete phase modulation characteristics;

[0063] (d) Temporal structure characteristics, including at least one of the following: continuous signal, periodic signal, frame structure signal, time slot structure signal, etc.;

[0064] (e) Physical layer packet structure features, including at least one of the following: preamble, synchronization field, access address, header, payload, check field, and Constant Tone Extension (CTE) field.

[0065] In some embodiments, the second communication protocol is used to define or describe the physical layer signal structure characteristics of the second signal, and the characteristics of the second communication protocol may include at least one of the following:

[0066] (a) Modulation characteristics, including at least one of the following: amplitude modulation, frequency modulation, phase modulation, etc.;

[0067] (b) Frequency structure characteristics, including at least one of the following: single-frequency structure, multi-frequency structure, frequency hopping structure, continuous spectrum structure, and multi-carrier structure, etc.;

[0068] (c) Phase characteristics, including continuous phase change characteristics or discrete phase modulation characteristics;

[0069] (d) Temporal structure characteristics, including at least one of the following: continuous signal, periodic signal, frame structure signal, time slot structure signal, etc.;

[0070] (e) Physical layer packet structure features, including at least one of the following: preamble, synchronization field, access address, header, payload, check field, constant tone extension field;

[0071] (f) The second communication protocol is used to support the second communication module in identifying, parsing and / or processing the second signal.

[0072] It is understandable that the signal structure features specified or described by the first and second communication protocols may differ in at least one of the following: modulation method, frequency structure, phase, timing structure, physical layer data packet structure, etc.

[0073] In some embodiments, the first signal may have a first signal structure, which is a signal structure conforming to the specifications of a first communication protocol; or, the first signal structure is a signal structure having preset characteristics in at least one of the time domain, frequency domain, phase domain, modulation scheme, and data packet structure, i.e., the first signal is a signal that does not fully conform to the specifications of the standard communication protocol, but can be transmitted through the first communication module. The preset characteristics may include at least one of the following related to the first communication protocol: modulation scheme characteristics, frequency structure characteristics, phase characteristics, timing structure characteristics, physical layer data packet structure characteristics, etc.

[0074] In some embodiments, when the first signal structure does not conform to the signal structure specified by the first communication protocol, the first signal may satisfy at least one of the following:

[0075] (1) The first signal is a single-frequency signal;

[0076] (2) The first signal is a single-tone signal;

[0077] (3) The first signal is a polyphonic signal;

[0078] (4) The first signal is a single-carrier signal;

[0079] (5) The first signal is a multi-carrier signal.

[0080] (6) The first signal has multiple discrete frequency components, and the frequency interval between the multiple discrete frequency components is fixed or approximately fixed; wherein, the fixed frequency interval between the multiple discrete frequency components can be understood as: the frequency interval between any two adjacent discrete frequency components is the same fixed value, which can be set according to actual needs, etc. The approximately fixed frequency interval between the multiple discrete frequency components can be understood as: the difference between different frequency intervals is less than a certain value, which can be set according to actual needs, etc.

[0081] (7) The first signal has a signal structure consisting of a preset time sequence, a preset code sequence, a preset spread spectrum sequence, a preset pilot sequence and / or a preset training sequence.

[0082] In some embodiments, the parameter characteristics of the first signal can be pre-configured. The parameter characteristics of the first signal may include at least one of the following:

[0083] (a) Time-domain related parameters, including at least one of the following: signal duration, frame length, symbol length, time slot length, transmission period, etc.;

[0084] (b) Frequency domain related parameters, including at least one of the following: center frequency, bandwidth, number of frequency points, frequency spacing, frequency hopping mode, etc.;

[0085] (c) Modulation-related parameters, including at least one of the following: modulation method, modulation rate, frequency offset, phase state, amplitude state, etc.;

[0086] (d) Encoding-related parameters, including at least one of the following: encoding method, spreading sequence, pilot sequence, training sequence, pseudo-random sequence, etc.;

[0087] (e) Data frame related parameters, including parameters corresponding to at least one of the following: preamble field, synchronization field, access address field, header field, payload field, check field, constant tone extension field, etc.

[0088] In some embodiments, the function of the first signal may include, but is not limited to, at least one of the following:

[0089] (a) As an incident signal that can be received by the second device, so that the second device can perform a backscattering operation;

[0090] (b) As an excitation signal for the second device to perform backscattering operation;

[0091] (c) The base signal for generating the second signal by the second device;

[0092] (d) As a reference signal when the first device performs analytical processing on the second signal;

[0093] (e) The phase reference, frequency reference and / or timing reference used when the first device obtains distance information.

[0094] In some embodiments, the second signal may have a second signal structure, which is a signal structure conforming to the specifications of a second communication protocol; or, the second signal structure is a signal structure having preset characteristics in at least one of the time domain, frequency domain, phase domain, modulation scheme, and data packet structure, i.e., the second signal is a signal that does not fully conform to the specifications of the standard communication protocol, but can be recognized, parsed, or processed by the second communication module. The preset characteristics may include at least one of the following related to the second communication protocol: modulation scheme characteristics, frequency structure characteristics, phase characteristics, timing structure characteristics, physical layer data packet structure characteristics, etc.

[0095] In some embodiments, the parameter characteristics of the second signal can be pre-configured. The parameter characteristics of the second signal may include at least one of the following:

[0096] (a) Time-domain related parameters, including at least one of the following: signal duration, frame length, symbol length, time slot length, transmission period, sequence length, etc.;

[0097] (b) Frequency domain related parameters, including at least one of the following: center frequency, bandwidth, number of frequency points, frequency spacing, frequency offset, frequency hopping mode, number of discrete frequency components, etc.;

[0098] (c) Modulation-related parameters, including at least one of the following: modulation method, modulation rate, frequency offset, phase state, amplitude state, phase change method, etc.;

[0099] (d) Encoding-related parameters, including at least one of the following: encoding method, spreading sequence, pilot sequence, training sequence, synchronization sequence, pseudo-random sequence, etc.;

[0100] (e) Data frame related parameters, including parameters corresponding to at least one of the following: preamble field, synchronization field, access address field, header field, payload field, check field, constant tone extension field, etc.

[0101] (f) Parameters used to characterize that the second signal can be recognized, parsed or processed by the second communication module.

[0102] In some embodiments, the function of the second signal may include, but is not limited to, at least one of the following:

[0103] (a) As a backscattered signal, it is generated by the second device based on the first signal through a backscattering operation;

[0104] (b) The signal to be identified, parsed, or processed received by the first device through the second communication module;

[0105] (c) The basic signal used by the first device to obtain distance information;

[0106] (d) Serves as a carrier for the first device to extract phase information, frequency information, timing information and / or structural information;

[0107] (e) as a received signal for enabling cross-communication protocol signal interaction and distance estimation.

[0108] In some embodiments, the backscattering operation is a backscattering process performed by the second device after receiving the first signal, based on the signal structure characteristics of the first signal. When the first signal has a signal structure conforming to a first communication protocol, the second device performs the backscattering operation based on the signal structure characteristics corresponding to the first communication protocol. When the first signal has a signal structure conforming to a non-standard protocol, the second device performs the backscattering process based on the signal structure corresponding to the non-standard protocol.

[0109] In some embodiments, the backscattering operation includes at least one of the following: (1) backscattering modulation: the second device modulates the first signal by controlling the load impedance switching or changing the equivalent reflection coefficient to generate the second signal, that is, mapping the signal structure corresponding to the first signal to the structural features corresponding to the second signal; the backscattering modulation may include processing the first signal in the time domain, frequency domain, phase domain and / or amplitude domain; (2) fixed coefficient reflection: the second device directly reflects the first signal with a preset reflection coefficient, that is, it maintains the existing signal structure features of the first signal and reflects it without modulating the first signal, and the reflected signal is used as the second signal.

[0110] In some embodiments, the phase information of the second signal can be single-frequency phase information or multi-frequency phase information, without limitation. When determining the distance between the first device and the second device based on the phase information of the second signal, the distance can be calculated based on the relationship between single-frequency phase and signal propagation distance, or based on the relationship between multi-frequency phase difference and signal propagation distance.

[0111] The solution of this application embodiment can realize cross-communication protocol signal interaction between the first device and the second device based on different communication modules in the first device. That is, it realizes cross-communication protocol backscatter communication based on the collaborative work of different communication modules in the first device. In this way, when ranging based on backscatter signals, it can solve the problem of limited receiving window of backscatter echo caused by the need to switch between the transmitting link and the receiving link in related technologies, thereby improving ranging accuracy and meeting ranging requirements.

[0112] Furthermore, the solution in this embodiment does not require changes to the hardware structure of the first device, nor does it require the second device to have active radio frequency transmission capability. It can achieve mapping of different signal structures through impedance modulation, and can also generate backscattered signals through direct reflection with a fixed coefficient, thereby reducing the complexity of the second device. Moreover, the second device does not need to actively transmit signals, making it suitable for low-power or even passive device scenarios. Based on this, distance estimation can also be achieved using the phase information of the second signal, and stable ranging can be supported under different signal structures such as single-carrier and multi-frequency, improving system robustness and scalability.

[0113] Understandably, after receiving the second signal, the first device needs to perform operations such as identification, parsing, and processing of the second signal. Specifically, the first device can perform parsing and processing of the second signal based on the signal structure characteristics of the second communication protocol, including at least one of the following: 1) demodulating the second signal based on the modulation method; 2) performing frequency separation or spectrum analysis of the second signal based on the frequency structure characteristics; 3) performing phase extraction or phase tracking of the second signal based on the phase characteristics; (4) performing frame synchronization, symbol synchronization, and / or sequence detection of the second signal based on the timing structure characteristics. After completing the parsing of the second signal, the data or information included in the second signal can be extracted, and the second signal can be processed based on the second communication protocol.

[0114] In some embodiments, the first device may perform protocol sensing or identification on the second signal to determine the second communication protocol corresponding to the second signal, including at least one of the following: 1) determining the second communication protocol corresponding to the second signal based on signal characteristics; 2) determining the second communication protocol corresponding to the second signal based on preset rules or prior information; 3) determining the second communication protocol corresponding to the second signal based on signaling or mapping relationships; 4) jointly determining the second communication protocol corresponding to the second signal based on at least two of the signal's modulation method, frequency structure, phase characteristics, and / or timing structure; 5) determining the second communication protocol corresponding to the second signal by matching the signal structure characteristics of the second signal.

[0115] In some embodiments, when obtaining the phase information of the second signal, the fixed phase error of the second signal can be eliminated or calibrated, for example, eliminating or calibrating the effects of at least one of the initial phase of the first signal, the fixed phase deviation of the transmit / receive link of the first device, and the fixed phase deviation introduced by the backscattering operation of the second device.

[0116] In some embodiments, the second signal is a signal carried by a single target subcarrier, that is, the second signal is obtained by backscattering a first signal corresponding to a single target subcarrier. Determining the distance between the first device and the second device based on the phase information of the second signal includes:

[0117] The first device calculates the phase difference between the phase of the second signal and the reference phase based on the phase information of the second signal and the pre-acquired reference phase.

[0118] The first device calculates the distance between the first device and the second device based on the phase difference value.

[0119] It should be noted that the reference phase can be pre-configured, or it can be the phase of the backscattered signal received from the second device by the first device, given that the reference distance between the first and second devices is known. This backscattered modulation signal is obtained by modulating the signal sent by the first device through a backscattering operation, which includes backscattering modulation or direct backscattering. Therefore, the distance between the first and second devices can be calculated using a reference calibration method.

[0120] For example, with a known reference distance Next, the first device receives the second signal reflected back from the second device and extracts the reference phase. In actual ranging, the first device extracts the current phase of the second signal, which is exactly the same as the one used during calibration. The phase difference is obtained through phase difference: Since the same signal is used, the change in phase in distance calculation is only related to the change in distance and is independent of frequency. Therefore, this phase difference mainly corresponds to the change in current distance relative to reference distance.

[0121] set up , To actually measure the distance, under the round-trip propagation model, the phase difference... It can be represented as:

[0122]

[0123] Therefore, the change in distance can be expressed as: .

[0124] Due to reference distance Given that the distance between the first device and the second device can be expressed as: Therefore, the first device can eliminate or reduce the effect of fixed phase deviation by reference calibration under the condition of a single target subcarrier, thereby obtaining the distance between the first device and the second device.

[0125] It should be noted that the single-carrier phase ranging scheme is more suitable for scenarios where the first device enables only one target subcarrier, and the second device generates a second signal based solely on that target subcarrier.

[0126] In some embodiments, the second signal includes multiple signals carried by multiple target subcarriers, and determining the distance between the first device and the second device based on the phase information of the second signal includes:

[0127] The first device calculates at least one phase difference value based on the phase information of the plurality of signals, wherein the phase difference value is the phase difference between two signals among the plurality of signals;

[0128] The first device calculates the distance between itself and the second device based on the at least one phase difference value. This allows for distance calculation based on multi-frequency phase differences, thereby improving the accuracy of the calculated distance.

[0129] For example, suppose the first device is at a frequency and Phase observations were obtained on each side. and Then we have:

[0130] ;

[0131] .

[0132] in, and These represent the observable initial phases when the first signal is transmitted. and These are the fixed phase deviations introduced by the reflection coefficient of the second device. and These are the fixed system phase deviations introduced by the transmit and receive links of the first device, respectively. Under the condition of adjacent target subcarriers or similar operating frequencies, the fixed phase deviations introduced by the transmit and receive links of the first device and the reflection state of the second device can be approximated as a common term. In this case, subtracting the phase observations corresponding to the two frequency points yields:

[0133] .

[0134] Therefore, the distance between the first device and the second device can be expressed as:

[0135] .

[0136] Optionally, to further improve ranging accuracy, multiple measurements can be averaged, or three or more target subcarriers can be enabled, allowing the first device to obtain phase observations corresponding to multiple frequency points and fit the relationship between phase and frequency. For example, the phase observations can be expressed as: . This represents the common fixed phase deviation term. The first device can utilize multiple ( The data points are fitted using least squares to obtain the slope of the phase-frequency relationship, and the distance between the first and second devices is estimated from this slope. .

[0137] In some embodiments, the first signal includes a first signal portion, and the second signal is obtained by backscattering modulation of the first signal portion; obtaining the phase information of the second signal includes:

[0138] The first device identifies the second signal portion of the second signal and determines the phase information of the second signal based on the phase information of the second signal portion. The second signal portion has a signal structure conforming to the second communication protocol specification and can be directly identified and parsed by the second communication module of the first device. Therefore, the second device does not need to identify and demodulate the first signal, but only needs to identify the first signal portion of the first signal and perform backscatter modulation on it, thus saving overhead. Similarly, the first device also does not need to identify and demodulate the second signal, but only needs to identify the second signal portion of the second signal, thus saving overhead.

[0139] It should be noted that the first signal portion of the first signal can be carried by the target field in the first signal, and the target field can be determined according to the signal structure of the first signal. For example, if the first signal is a WiFi signal, the target field can be selected as a payload field; or, if the first signal is a BLE signal, the target field can be selected as a CTE field.

[0140] The second signal portion of the second signal can be carried by a target field within the second signal, which can be determined based on the signal structure of the second signal. For example, if the second signal is a WiFi signal, the target field can be a payload field; or, if the second signal is a BLE signal, the target field can be a CTE field.

[0141] In some embodiments, the first signal includes a third signal portion, the third signal portion having a signal structure conforming to a second communication protocol specification; the second signal is obtained by direct backscattering of the third signal portion. Obtaining the phase information of the second signal includes:

[0142] The first device identifies the fourth signal portion of the second signal and determines the phase information of the second signal based on the phase information of the fourth signal portion. The fourth signal portion has a signal structure conforming to the second communication protocol specification and can be directly identified and parsed by the second communication module of the first device. Therefore, the second device does not need to identify and demodulate the first signal, but only needs to identify the third signal portion of the first signal and directly backscatter it, thus saving overhead. Similarly, the first device also does not need to identify and demodulate the second signal, but only needs to identify the fourth signal portion of the second signal, thus saving overhead.

[0143] It should be noted that the third signal portion of the first signal can be carried by the target field in the first signal, and the target field can be determined according to the signal structure of the first signal. For example, if the first signal is a WiFi signal, the target field can be selected as a payload field; or, if the first signal is a BLE signal, the target field can be selected as a CTE field.

[0144] The fourth signal portion of the second signal can be carried by the target field in the second signal, which can be determined according to the signal structure of the second signal. For example, if the second signal is a WiFi signal, the target field can be selected as a payload field; or, if the second signal is a BLE signal, the target field can be selected as a CTE field.

[0145] Please see Figure 4 , Figure 4 This is a flowchart of a ranging method provided in an embodiment of this application. The method is executed by a second device, such as... Figure 4 As shown, the method includes the following steps:

[0146] Step 41: The second device receives a first signal from the first device; the first signal is sent through a first communication module in the first device, and the first communication module communicates based on a first communication protocol;

[0147] Step 42: The second device performs a backscattering operation on the first signal to obtain the second signal;

[0148] Step 43: The second device sends a second signal to the first device; the second signal is received through the second communication module in the first device, the second communication module communicates based on the second communication protocol, and the second communication module and the first communication module are different communication modules; the phase information of the second signal is used to determine the distance between the first device and the second device.

[0149] In this embodiment, the first device can be one of the following: a terminal device, a relay device, a network device such as a base station, a repeater, an IAB device, etc. The first device can be configured with corresponding communication modules according to actual needs to support signal transmission and reception of different communication protocols. The first device can be understood as a positioning device.

[0150] The second device is specifically a backscattering device, which may possess impedance modulation capabilities and signal reflection capabilities. The second device can be understood as the device to be located, and may include an antenna, impedance switching network, and control unit. The second device can be selected as a low-power passive tag, a semi-passive tag, or an active tag.

[0151] The first and second communication protocols are communication protocols with different protocol specifications.

[0152] In some embodiments, the first communication protocol may include, but is not limited to, at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarScan communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, Sidelink communication protocol, etc.

[0153] In some embodiments, the second communication protocol may include, but is not limited to, at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarScan communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, Sidelink communication protocol, etc.

[0154] In some embodiments, the first signal may have a first signal structure, which is a signal structure conforming to the specifications of a first communication protocol; or, the first signal structure is a signal structure having preset characteristics in at least one of the time domain, frequency domain, phase domain, modulation scheme, and data packet structure, i.e., the first signal is a signal that does not fully conform to the specifications of the standard communication protocol, but can be transmitted through the first communication module. The preset characteristics may include at least one of the following related to the first communication protocol: modulation scheme characteristics, frequency structure characteristics, phase characteristics, timing structure characteristics, physical layer data packet structure characteristics, etc.

[0155] In some embodiments, the second signal may have a second signal structure, which is a signal structure conforming to the specifications of a second communication protocol; or, the second signal structure is a signal structure having preset characteristics in at least one of the time domain, frequency domain, phase domain, modulation scheme, and data packet structure, i.e., the second signal is a signal that does not fully conform to the specifications of the standard communication protocol, but can be recognized, parsed, or processed by the second communication module. The preset characteristics may include at least one of the following related to the second communication protocol: modulation scheme characteristics, frequency structure characteristics, phase characteristics, timing structure characteristics, physical layer data packet structure characteristics, etc.

[0156] In some embodiments, the backscattering operation is a backscattering process performed by the second device after receiving the first signal, based on the signal structure characteristics of the first signal. When the first signal has a signal structure conforming to a first communication protocol, the second device performs the backscattering operation based on the signal structure characteristics corresponding to the first communication protocol. When the first signal has a signal structure conforming to a non-standard protocol, the second device performs the backscattering process based on the signal structure corresponding to the non-standard protocol.

[0157] It should be noted that for specific descriptions of the first communication module, the second communication module, the first communication protocol, the second communication protocol, the first signal, and the second signal, please refer to the above embodiments, and they will not be repeated here. For the method of determining the distance between the first device and the second device based on the phase information of the second signal, please refer to the above embodiments, and they will not be repeated here.

[0158] The solution of this application embodiment can realize cross-communication protocol signal interaction between the first device and the second device based on different communication modules in the first device. That is, it realizes cross-communication protocol backscatter communication based on the collaborative work of different communication modules in the first device. In this way, when ranging based on backscatter signals, it can solve the problem of limited receiving window of backscatter echo caused by the need to switch between the transmitting link and the receiving link in related technologies, thereby improving ranging accuracy and meeting ranging requirements.

[0159] In some embodiments, the backscattering operation on the first signal described above to obtain the second signal includes any of the following:

[0160] The second device modulates the first signal by backscattering through controlling the load impedance switching or changing the equivalent reflection coefficient to obtain the second signal; for example, it can control the load impedance switching or changing the equivalent reflection coefficient periodically, or it can control the load impedance switching or changing the equivalent reflection coefficient non-periodically, or it can control the load impedance switching or changing the equivalent reflection coefficient by preset encoding sequence / preset timing.

[0161] The second device uses a fixed reflection coefficient to directly backscatter the first signal to obtain the second signal. That is, it maintains the existing signal structure characteristics of the first signal and reflects it without modulating the first signal; the reflected signal is used as the second signal.

[0162] In some embodiments, the first signal includes a first signal portion, and the backscattering operation on the first signal to obtain the second signal includes:

[0163] The second device performs backscatter modulation on the first signal portion to obtain a second signal. The second signal includes a second signal portion used to determine the distance between the first and second devices. The second signal portion has a signal structure conforming to the second communication protocol specification and can be directly recognized and parsed by the second communication module of the first device. Therefore, the second device does not need to recognize and demodulate the first signal, but only needs to recognize the first signal portion and perform backscatter modulation on it, thus saving overhead. Similarly, the first device also does not need to recognize and demodulate the second signal, but only needs to recognize the second signal portion, thus saving overhead.

[0164] It should be noted that the first signal portion of the first signal can be carried by a target field in the first signal, which can be determined according to the signal structure of the first signal. Similarly, the second signal portion of the second signal can be carried by a target field in the second signal, which can be determined according to the signal structure of the second signal.

[0165] In some embodiments, the first signal includes a third signal portion, the third signal portion having a signal structure conforming to a second communication protocol specification; the backscattering operation on the first signal to obtain the second signal includes:

[0166] The second device directly backscatters the third signal portion using a fixed coefficient to obtain a second signal. This second signal includes a fourth signal portion used to determine the distance between the first and second devices. This fourth signal portion has a signal structure conforming to the second communication protocol specification and can be directly recognized and parsed by the second communication module of the first device. Therefore, the second device does not need to identify and decode the first signal individually; it only needs to identify the third signal portion and directly backscatter it, thus saving overhead. Similarly, the first device also does not need to identify and decode the second signal individually; it only needs to identify the fourth signal portion, thus saving overhead.

[0167] It should be noted that the third signal portion of the first signal can be carried by a target field in the first signal, which can be determined according to the signal structure of the first signal. Similarly, the fourth signal portion of the second signal can be carried by a target field in the second signal, which can be determined according to the signal structure of the second signal.

[0168] In some embodiments of this application, see Figure 5 and Figure 6 As shown, the cross-communication protocol signal interaction process between the first device and the second device may include the following steps:

[0169] Step 0: The first and second devices perform positioning-related processes such as registration, pairing, and adjustment of transmission signal parameters.

[0170] Step 1: The first device generates a first signal based on the first information and sends the first signal through the first communication module.

[0171] Optionally, the first information may include at least one of the following: (1) information related to the first communication protocol; (2) signal structure parameter information of the first signal, such as at least one of the following: modulation method, frequency structure, phase characteristics, timing structure, data packet structure, etc.; (3) signal parameter information of the first signal, such as at least one of the following: encoding method, frequency offset, bandwidth, center frequency, number of frequency points, pilot sequence, etc.; (4) time domain resource information, such as at least one of the following: frame length, subframe length, symbol length, signal duration, transmission period, etc.; (5) frequency domain resource information, such as at least one of the following: bandwidth, frequency interval, number of frequency points, frequency hopping mode, frequency modulation mode, etc.

[0172] Step 2: The second device receives the first signal based on the second information and identifies the signal structure of the first signal. It should be noted that the second information may include some of the instructions in the first information described above, and / or information used to guide the second device in receiving, detecting, and identifying the first signal and determining the key parameters required to perform the backscattering operation.

[0173] Step 3: The second device generates a second signal based on the third information and sends the second signal to the first device in a backscattering manner.

[0174] Optionally, the third information may include at least one of the following: (1) information related to the second communication protocol, used to instruct the second device to generate the second signal; (2) backscatter modulation parameter information, used to guide the second device to perform backscatter modulation, the parameter information may include at least one of the following: modulation method, frequency offset and frequency shift control, load impedance or equivalent reflection coefficient setting, switch switching rate and transmission data information, etc.; (3) fixed coefficient reflection parameter information, used to guide the second device to perform fixed coefficient backscatter, the parameter information may include at least one of the following: preset reflection coefficient, amplitude and phase adjustment, possible amplification coefficient, impedance matching information, etc.; (4) signal parameters and resource information of the second signal, which may include at least one of the following: time domain characteristics, frame / subframe length, symbol length, signal duration, frequency domain characteristics, number of frequency points, frequency interval, pilot sequence, etc.

[0175] Step 4: The first device receives the second signal based on the fourth information and performs protocol sensing / identification.

[0176] Step 5: The first device analyzes the second signal based on the fourth information, extracts the phase information of the second signal, and determines the distance between the first device and the second device based on the phase information. It should be noted that the fourth information may include some of the indications in the third information described above, used to guide the first device in receiving, recognizing, or analyzing the second signal. Furthermore, the fourth information can be used to assist the first device in extracting phase information, frequency information, timing information, and / or structural information, and can also be used to assist the first device in obtaining reference information, calibration information, and / or ranging information for distance information, etc.

[0177] It should be noted that the signal structure mapping relationship and related parameter information corresponding to the first signal and the second signal can be determined by explicit signaling, preset rules and / or implicit methods.

[0178] The present application will now be described in conjunction with specific embodiments.

[0179] Example 1

[0180] In this first embodiment, a specific implementation method is given for structural mapping of WiFi signals to BLE signals based on backscattering and for performing phase ranging.

[0181] Specifically, the first device is a terminal device or software-defined radio device with WiFi signal transmission capability and BLE signal reception and processing capability, which may include, but is not limited to, mobile phones, tablets, embedded boards, general-purpose software-defined radio devices, multi-protocol communication devices, etc. The first device includes a first communication module and a second communication module. The first communication module is used to generate and transmit a first signal with a WiFi physical layer structure, and the first communication module communicates based on a wireless local area network communication protocol. The second communication module is used to receive and parse backscattered signals with BLE physical layer characteristics, and the second communication module communicates based on a Bluetooth Low Energy (BLE) communication protocol. Optionally, the first communication module can configure fields or subcarriers in the WiFi data packets.

[0182] The second device is a backscattering device with impedance modulation capability, which may include an antenna, an impedance switching network, and a control unit. The second device does not actively generate a radio frequency carrier; instead, it modulates the first signal through backscattering by controlling the load impedance or equivalent reflection coefficient to generate a second signal with the characteristics of the target communication protocol. The second device may include, but is not limited to, low-power passive tags and active tags.

[0183] It should be noted that, since the second device typically does not possess a complete BLE radio frequency transmission link and protocol stack capability, the second signal with BLE communication protocol characteristics in this embodiment mainly refers to its physical layer signal structure or data frame structure conforming to or substantially conforming to BLE signal characteristics. As long as the second signal can be recognized, parsed, or processed by a mobile phone, Bluetooth receiver module, or other terminal device with BLE receiving capability, it can be considered a signal with BLE communication protocol characteristics.

[0184] In this first embodiment, the first device sends a first signal with a WiFi physical layer structure through a first communication module. The second device performs backscatter modulation based on the target field in the first signal to generate a second signal with some BLE physical layer characteristics, and sends the second signal to the first device. The first device receives the second signal through a second communication module and performs analysis and ranging. The specific process is as follows:

[0185] Step 1: The first device generates a first signal based on the first information and sends the first signal through the first communication module.

[0186] In this step, the first information is used to instruct the first device to generate and transmit a WiFi signal. The first information may include at least one of the following: WiFi frame structure information, target field information, target subcarrier information, frequency domain resource information, time domain resource information, and phase reference information.

[0187] Optionally, the first signal is an Orthogonal Frequency Division Multiplexing (OFDM) signal with a WiFi physical layer structure and a complete WiFi data packet structure, including, for example, a preamble, synchronization field, signal field, header field, and payload field. Figure 7 As shown. The preamble, synchronization field, and header field maintain the WiFi physical layer packet structure, used to maintain the frame structure, synchronization structure, and timing structure of WiFi packets. The payload field is configured as a backscatter modulation field to provide the incident signal to the second device.

[0188] Within the payload field, the first device can configure OFDM subcarrier resources based on the first information. Specifically, the first device enables only one or a few target subcarriers and disables, zeros, or suppresses other subcarriers, thereby forming a single-carrier or narrowband signal structure in the frequency domain dominated by the target subcarrier. Let the target subcarrier be the first... There are 1 subcarrier with the following frequencies: . The center frequency of the WiFi operating channel. This refers to the OFDM subcarrier spacing.

[0189] In one specific implementation, the first device may generate the first signal using a programmable WiFi transmitting platform, a software radio platform, or a configurable baseband transmitting module. For example, while maintaining the original structure of the WiFi data packet's preamble, synchronization field, and header field, the target subcarrier is enabled only in the payload field. Therefore, the signal portion within the payload field can be represented as: .in, The amplitude of the target subcarrier, The initial or observable phase of the target subcarrier.

[0190] Through the above process, on the one hand, the first signal retains the overall frame structure of the WiFi data packet; on the other hand, a single-carrier incident signal suitable for the second device to perform backscatter modulation is formed within the payload field. In other words, this embodiment does not rely on the frequency selective response of the second device to passively filter out a single frequency component from the multi-subcarrier signal, but rather the first device actively configures the target subcarrier within the target field of the first signal, so that the second device receives the incident signal dominated by the target subcarrier within that field.

[0191] Step 2: The second device receives the first signal based on the second information and performs backscatter modulation.

[0192] In this step, the second information is used to instruct the second device to receive the first signal and determine the timing for executing backscatter modulation. The second information may include at least one of the following: target field location, target subcarrier frequency, payload modulation window, synchronization method, backscatter start time, and duration.

[0193] Specifically, after receiving the first signal sent by the first device, the second device can determine the payload field or other preset target field in the first signal based on the second information, and perform backscatter modulation within the time window corresponding to the target field. Since the first device has already enabled only the target subcarrier within the payload field... Therefore, when the second device performs backscatter modulation, it does not need to demodulate the complete WiFi multi-subcarrier signal, nor does it need to select a frequency from multiple subcarriers. Instead, it directly performs backscatter modulation on the target subcarrier carrying the target field.

[0194] The second device can perform backscattering processing on the target subcarrier component in the first signal by controlling the load impedance switching or changing the equivalent reflection coefficient. Specifically, the second device can control the impedance modulation network to switch between different load states according to a preset Bluetooth data bit sequence or ranging auxiliary sequence, thereby adjusting the reflection coefficient. According to the preset timing changes, the target subcarrier is thus changed. The corresponding signal portion is modulated into a backscattered signal with characteristics of the BLE physical layer.

[0195] In one implementation, the second device does not need to recognize the entire content of the WiFi data packet. Instead, it only needs to determine the starting position of the payload field based on preset rules, energy detection, field timing, or external synchronization information, and perform impedance switching within that payload field. Therefore, the processing complexity of the second device mainly focuses on reflection coefficient control, without requiring full WiFi demodulation capabilities.

[0196] Step 3: The second device generates a second signal based on the third information and returns the second signal.

[0197] In this step, the third information is used to instruct the second device to generate a second signal with BLE physical layer characteristics. The third information may include at least one of the following: BLE bit sequence, preamble information, access address information, header information, payload information, CTE field information, ranging auxiliary sequence, modulation scheme, frequency offset, impedance state, reflection coefficient, switching rate, and timing control information. The second device generates a reflection control sequence based on the third information. The reflection control sequence is used to control the impedance modulation network of the second device, enabling the second device to modulate the target subcarrier. The incident signal is backscattered and modulated within the corresponding payload modulation window.

[0198] In some implementations, the second device can generate a reflection control sequence according to the following BLE physical layer data packet bit structure:

[0199] The preamble is fixed as: 0xAA (10101010).

[0200] Access Address, for example: 0x8E89BED6 (10001110 10001001 1011111011010110);

[0201] Header: Used to indicate data length or type information;

[0202] The payload is primarily based on a preset or ranging-aided sequence;

[0203] The Constant Tone Extension (CTE) field can be composed of consecutive bits with the same value, such as an all-1 field or an all-0 field.

[0204] The preamble, access address, and header fields are primarily used to enable the first device to complete signal detection, synchronization, and structure identification. The payload field carries preset data or ranging assistance information. The CTE field is mainly used to provide a phase extraction window for the first device after the second signal is identified, allowing the first device to acquire stable phase observations within this CTE field for subsequent distance estimation. Optionally, the above data packet structure may also include a CRC field for data verification.

[0205] In some implementations, the Bluetooth data packet structure can be as follows: Figure 8 As shown, it includes a preamble, an access address field, a protocol data unit, a cyclic redundancy check field, and a constant tone extension field. The protocol data unit includes a header and a payload field.

[0206] The second device can map the BLE bit sequence to a reflection coefficient control sequence. For each bit... The second device controls the change of the reflection coefficient according to the preset modulation rules.

[0207] In some implementations, the second device can operate in two impedance states. and Switching between the two impedance states causes the reflection coefficient to change between them. The reflection phases corresponding to the two impedance states can satisfy: Therefore, by means of reflection phase reversal, periodic impedance switching, or preset timing control, the target subcarrier can be... A backscattered signal with frequency-shift keying characteristics or approximately GFSK characteristics is formed nearby. The second signal can be represented as:

[0208]

[0209] in, This is the time-varying reflectance coefficient. Because... According to the BLE bit timing change, the second signal has a BLE data packet structure in the time domain, a frequency offset or sideband component introduced by backscatter modulation in the frequency domain, and retains the phase information introduced by the target subcarrier propagation path in the phase domain.

[0210] It should be noted that the second signal in this embodiment is not required to fully comply with all physical layer constraints of the standard BLE protocol, but rather to have BLE physical layer characteristics in at least one or more of the following: preamble structure, access address structure, bit timing, frequency offset, phase continuity, and data packet structure, and to be recognizable, parsed, and used for phase measurement by the BLE receiving module of the first device.

[0211] Step 4: The first device receives the second signal based on the fourth information and performs distance measurement.

[0212] In this step, the fourth information is used to instruct the first device to receive and process the second signal. The fourth information may include at least one of the following: BLE signal listening window, target frequency band, target subcarrier information, BLE structure identification rules, synchronization rules, phase measurement window, reference phase information, fixed phase deviation calibration information, and ranging parameter information.

[0213] Specifically, the first device receives the second signal generated by the backscattering of the second device through the second communication module, and can perform at least one of the following: self-interference suppression, target frequency band extraction, BLE structure identification, frequency demodulation, phase extraction, fixed phase deviation calibration, and distance estimation.

[0214] Because the first device has transmission leakage or direct component when transmitting the first signal, the second signal received by the first device can be represented as: .in, The leakage component of the signal emitted by the first device itself; This is the backscattered signal from the second device; The propagation attenuation coefficient; It is noise.

[0215] because Therefore, the backscattered signal is correlated with the original signal. To reduce the influence of self-interference signals, the first device can construct a local reference signal using the known first signal. And the leakage component is suppressed by subtraction, correlation cancellation, or linear elimination:

[0216]

[0217] in, To estimate the coefficients, the value is fitted by repeatedly transmitting the same reference signal in advance, ultimately resulting in: .

[0218] After self-interference suppression, the first device can... Filtering, down-conversion, and frequency domain extraction are performed to obtain the narrowband signal near the target subcarrier and its modulation components.

[0219] Optionally, the first device can synchronize and identify the second signal based on the preamble, access address, preset sequence, and / or ranging auxiliary field, and demodulate, match, and extract the phase of the second signal according to its frequency offset, symbol timing, and phase changes. When the second signal contains a CTE field, the first device can determine the location of the CTE field after completing the detection, synchronization, and structure identification of the second signal, and extract phase observations within the time window corresponding to the CTE field. Since the CTE field has a continuous or nearly continuous signal structure, it can be used as a phase measurement field, thereby improving the stability of phase extraction. Subsequent single-carrier phase ranging or multi-frequency phase ranging can be performed based on the phase observations extracted from the CTE field.

[0220] In one implementation, the first device enables a single target subcarrier within the payload field of the first signal. The second device performs backscatter modulation based on the target subcarrier and generates a second signal. At this time, the first device extracts the phase observation from the second signal. It can be represented as:

[0221]

[0222] in:

[0223] The initial or reference phase that can be observed when the first signal is transmitted;

[0224] The propagation phase is introduced by the round-trip propagation distance between the first and second devices;

[0225] A fixed phase deviation is introduced for the reflection coefficient of the second device;

[0226] The fixed system phase deviation introduced for the transmit and receive links of the first device.

[0227] Since it is difficult to eliminate a fixed phase deviation using only frequency differential under single target subcarrier conditions, a reference calibration method can be used for ranging. Specifically, given a known reference distance... Next, the first device receives the second signal reflected back from the second device and extracts the reference phase. In actual ranging, the first device transmits a signal that is exactly the same as the reference calibration signal and extracts the current phase of the returned signal. The phase difference is obtained through phase difference: Since the same signal is used, the change in phase in distance calculation is only related to the change in distance and is independent of frequency. Therefore, this phase difference mainly corresponds to the change in current distance relative to reference distance.

[0228] set up , To actually measure the distance, under the round-trip propagation model, the phase difference... It can be represented as:

[0229]

[0230] Therefore, the change in distance can be expressed as: .

[0231] Due to reference distance Given that the distance between the first device and the second device can be expressed as: Therefore, the first device can eliminate or reduce the effect of fixed phase deviation by reference calibration under the condition of a single target subcarrier, thereby obtaining the distance between the first device and the second device.

[0232] It should be noted that the single-carrier phase ranging scheme is more suitable for scenarios where the first device enables only one target subcarrier, and the second device generates a second signal based solely on that target subcarrier. In this case, the instantaneous frequency offset generated by bit modulation within a single BLE data packet is mainly used for signal identification, synchronization, and / or data parsing, and is usually not directly used as multiple stable carrier frequencies in multi-frequency phase ranging.

[0233] In another implementation, the first device may enable two or more target subcarriers within the payload field of the first signal, or sequentially change the target subcarrier number, target subcarrier frequency, or WiFi operating channel within multiple ranging cycles, causing the second device to perform backscatter modulation based on target subcarriers of different frequencies. In this case, the first device can obtain phase observations corresponding to multiple frequencies and perform distance estimation based on the multi-frequency phase difference.

[0234] Assume the first device is at frequency and Phase observations were obtained on each side. and Then we have:

[0235] ;

[0236] .

[0237] Under the condition of adjacent target subcarriers or similar operating frequencies, the fixed phase deviation introduced by the transmit and receive links of the first device and the reflection state of the second device can be approximated as a common term, or compensated for through pre-calibration. In this case, subtracting the phase observations corresponding to the two frequencies yields:

[0238] .

[0239] Therefore, the distance between the first device and the second device can be expressed as:

[0240] .

[0241] Optionally, to further improve ranging accuracy, multiple measurements can be averaged, or three or more target subcarriers can be enabled, allowing the first device to obtain phase observations corresponding to multiple frequency points and fit the relationship between phase and frequency. For example, the phase observations can be expressed as: . This represents the common fixed phase deviation term. The first device can utilize multiple ( The data points are fitted using least squares to obtain the slope of the phase-frequency relationship, and the distance between the first and second devices is estimated from this slope. .

[0242] Therefore, the multi-frequency phase ranging scheme can eliminate or reduce the influence of common fixed phase deviation by using the phase difference between different target subcarriers or different operating frequencies, and alleviate the periodic ambiguity problem in single-frequency phase ranging. This scheme is suitable for scenarios where the first device can enable multiple target subcarriers within the same payload field, or can switch between different target subcarriers or different operating channels within multiple ranging periods.

[0243] Example 2

[0244] In this second embodiment, a specific implementation method is given for structural mapping of BLE signals to WiFi-like signals based on backscattering and for performing phase ranging.

[0245] Specifically, the first device transmits a first signal with a BLE physical layer structure through a first communication module. The second device performs backscatter modulation within a preset stable field of the first signal. By periodically controlling the load impedance or equivalent reflection coefficient, the ground reflection signal is made to form multiple discrete frequency components in the frequency domain, thereby generating a second signal with WiFi-like multi-subcarrier distribution characteristics. The first device then receives the second signal through the second communication module and performs distance estimation based on the phase information of the multiple frequency components of the second signal.

[0246] It should be noted that, since the second device is a passive or low-power backscattering device, it constructs the signal solely by modulating the reflection coefficient of the incident signal. Lacking an independent RF oscillator and broadband modulation capabilities, it is difficult to directly generate an Orthogonal Frequency Division Multiplexing (OFDM) signal structure that fully conforms to the physical layer specifications of the Wireless Local Area Network (WiFi) protocol, particularly in terms of subcarrier orthogonality preservation, precise baseband modulation, and power spectrum control. Therefore, this second embodiment does not directly construct a standard WiFi signal. Instead, it periodically modulates the reflection coefficient to generate a WiFi-like signal with multi-subcarrier distribution and phase relationship characteristics in the frequency domain. This allows for cross-communication protocol signal structure mapping and subsequent ranging processing while satisfying the backscattering implementation constraints.

[0247] Optionally, the first device is a terminal device with BLE signal transmission capability and WiFi-like signal reception and processing capability, which may include, but is not limited to, mobile phones, tablets, embedded boards, general-purpose software radio devices, etc. The first device includes a first communication module and a second communication module. The first communication module is used to generate and transmit BLE signals, and the first communication module communicates based on the Bluetooth Low Energy communication protocol. The second communication module is used to receive and parse backscattered signals with some WiFi physical layer characteristics. The second communication module communicates based on the physical layer structure characteristics (WiFi-like signals) of the wireless local area network communication protocol.

[0248] The second device is a backscattering device with impedance modulation capability, which may include an antenna, an impedance switching network, and a control unit. The second device does not have active radio frequency transmission capability; it achieves backscattering processing of the first signal by modulating the reflection coefficient of the incident signal, thereby generating a second signal with the characteristics of the target communication protocol. The second device may include, but is not limited to, low-power passive tags and active tags.

[0249] It should be noted that WiFi-like signals are not required to strictly conform to all physical layer constraints in the standard WiFi protocol, but rather to possess the structural characteristics of multi-subcarrier signals in wireless local area networks in at least one of the following dimensions:

[0250] (1) It has multiple discrete subcarrier components in the frequency domain, and each subcarrier is distributed around the center frequency;

[0251] (2) Each subcarrier has a fixed or nearly fixed frequency interval;

[0252] (3) It has the characteristic of multi-subcarrier superposition in signal structure, and can be represented as a set of discrete spectral lines in the frequency domain;

[0253] (4) In the phase domain, each subcarrier has extractable phase information, and this phase information is related to the propagation path.

[0254] In this second embodiment, the first device sends a first signal with a BLE physical layer structure through a first communication module. The second device performs periodic backscatter modulation based on a preset stable field in the first signal to generate a second signal with WiFi-like multi-frequency structure characteristics. The first device then receives the second signal through the second communication module and performs frequency domain analysis and ranging. The specific process includes the following steps:

[0255] Step 1: The first device generates a first signal based on the first information and sends the first signal through the first communication module.

[0256] In this step, the first information is used to instruct the first device to generate and transmit a BLE signal. The first information may include at least one of the following: BLE physical layer frame structure information, operating frequency information, CTE field information, time domain resource information, frequency reference information, and phase reference information.

[0257] Optionally, the first signal conforms to the BLE physical layer specification and has a complete BLE physical layer data packet structure, including a preamble, access address, protocol data unit, cyclic check field, and constant tone extension (CTE) field. The preamble and access address are used by the receiver for signal detection, synchronization, and access identification. The protocol data unit carries header and payload information. The cyclic check field is used for data verification. The CTE field is located at the end of the data packet and provides a stable or near-stable backscatter modulation window for the second device. The data packet structure of the first signal can be referenced. Figure 8 As shown.

[0258] The parameters of the first signal may include, but are not limited to, at least one of the following: operating frequency, data packet duration, CTE field length, CTE start position, CTE stability range, transmit power, modulation scheme, and modulation parameters. In the BLE physical layer, the first signal may employ Gaussian Frequency Shift Keying (GFSK) modulation. The modulation parameters may include bit rate, modulation index, and / or frequency offset parameters. The frequency offset parameter characterizes the direction and magnitude of the offset of the instantaneous frequency corresponding to different data bits relative to the nominal carrier frequency. For the CTE field, since it consists of continuous identical values ​​or a preset repetitive pattern, the instantaneous frequency within the CTE field tends to stabilize or approximately stabilize after the initial transition, thereby forming an incident reference signal suitable for backscatter modulation.

[0259] The CTE field consists of a sequence of bits with consecutive identical values ​​or a preset repetition pattern, and its duration is determined by the first information. Since the CTE field is mainly used to provide a continuous or near-continuous observation window, rather than primarily to carry rapidly changing data bits, the first signal can serve as the incident signal for the second device to perform periodic backscatter modulation within the stable range of the CTE field.

[0260] Within the stable range of the CTE field, the first signal can be approximated as: .in, The amplitude of the incident signal, The equivalent frequency within the CTE stability range. This refers to the initial or observable phase corresponding to the CTE stable interval.

[0261] Step 2: The second device receives the first signal based on the second information and performs backscatter modulation.

[0262] In this step, the second information is used to instruct the second device to receive the first signal and determine the timing for executing backscatter modulation. The second information may include at least one of the following: BLE packet timing information, CTE field position, preset modulation window, synchronization mode, backscatter start time, stabilization wait time, and modulation duration.

[0263] Specifically, after receiving the first signal sent by the first device, the second device can determine the modulation window corresponding to the CTE field or other preset stable fields based on the second information, and perform backscatter modulation within the modulation window. The second information can be sent by the first device through explicit signaling, or it can be pre-agreed by the first and second devices, or it can be determined by the second device based on energy detection, simplified correlation detection, field timing, preset delay, or external synchronization information.

[0264] In other words, this second embodiment does not require the second device to completely demodulate the BLE packets or parse the BLE payload bit by bit. The second device only needs to determine a stable time window suitable for backscatter modulation and perform periodic backscattering processing on the incident signal within that time window.

[0265] Optionally, the second device sets a preset stabilization wait time in the initial phase after the CTE field begins. This avoids instantaneous frequency changes caused by modulation filter transition response or field switching. Subsequently, the second device performs backscatter modulation within the stable range of the CTE field. This stable range can be represented as: .in, The duration of the CTE field or the preset end time of the modulation window.

[0266] The backscatter modulation includes a second device controlling the load impedance to switch or change the equivalent reflection coefficient, thereby adjusting the reflection coefficient. The signal changes according to a preset periodic pattern. Through periodic reflection control, the second device expands the incident signal within the CTE stable range into multiple discrete frequency components, thus providing a basis for generating WiFi-like signals.

[0267] Step 3: The second device generates a second signal based on the third information and sends the second signal.

[0268] In this step, the third information is used to instruct the second device to generate a second signal with WiFi-like multi-frequency structure characteristics. The third information may include at least one of the following: WiFi-like frequency spacing information, number of discrete frequency components, periodic reflection control parameters, impedance state parameters, reflection coefficient parameters, switching rate, duty cycle, multi-level impedance control method, and timing control information. The second device generates a reflection control sequence based on the third information. The reflection control sequence is used to control the impedance modulation network of the second device, enabling the second device to perform periodic backscatter modulation of the first signal within the CTE stable range.

[0269] In this embodiment, the second signal is a backscattered signal with WiFi-like multi-frequency structure characteristics. The frequency domain structure of the second signal includes multiple frequencies surrounding the equivalent incident frequency. The frequency components are distributed discretely, with a preset frequency interval between adjacent frequency components. The preset frequency interval can be set to be the same as or approximately the same as the WiFi subcarrier interval, for example: Therefore, the discrete frequency components in the second signal can be expressed as:

[0270] .

[0271] in, It can be an integer or a preset sequence number.

[0272] In some implementations, the second device can periodically switch between two impedance states to adjust the reflection coefficient. It exhibits periodic changes. Let the periodic reflection control function be... Then we have: Among them, the period satisfy: .

[0273] Taking an ideal symmetrical square wave with a duty cycle of 50% as an example, the periodic reflection control function can be expanded into a Fourier series, whose spectrum includes the fundamental frequency and odd harmonic components. Therefore, when the second device performs the above-mentioned periodic backscatter modulation on the incident signal, the second signal can be expressed as: .

[0274] because It is a periodic square wave function. It can be expanded into a Fourier series form:

[0275]

[0276] in, The DC component, Let be odd-order harmonic coefficients, and let the harmonic frequencies satisfy: , .

[0277] As can be seen from the time-domain multiplication corresponding to the frequency-domain convolution, the first signal will generate multiple discrete frequency components near the incident carrier frequency, including: , This forms a WiFi-like signal structure with equally spaced multi-frequency components. Consequently, the second signal exhibits a discrete frequency distribution characteristic similar to a WiFi multi-subcarrier signal in the frequency domain. It should be noted that the WiFi-like signal in this embodiment does not require strict adherence to all subcarrier distributions, orthogonality constraints, and baseband modulation methods in the standard WiFi physical layer. Rather, it refers to having multiple equally spaced discrete frequency components in the frequency domain, exhibiting a spectral structure characteristic similar to a wireless local area network multi-subcarrier signal. The aforementioned square wave reflection control is merely an exemplary implementation. In other embodiments, the second device can also adjust the duty cycle, employ multi-level impedance states, preset periodic control sequences, or other periodic reflection control functions to include more preset harmonic components in the reflection coefficient, thereby forming a richer set of discrete frequency components. Therefore, the WiFi-like signal in this embodiment is not limited to containing only odd-order harmonic components.

[0278] Optionally, the hardware implementation of the second device includes, but is not limited to, the following:

[0279] (1) Impedance modulation network: It is composed of MOSFET switch array or other controllable load network, and the reflection coefficient is periodically changed by switching different impedance states.

[0280] (2) Control unit: It consists of a low-power digital controller, state machine or timing control circuit, and is used to output periodic control signals.

[0281] (3) Timing control unit: used to determine the backscatter modulation window, switching period, duty cycle and / or multi-stage impedance state.

[0282] In summary, the second device can perform periodic backscatter modulation on the first signal, giving the second signal multiple discrete frequency components with fixed or approximately fixed intervals in the frequency domain. The second signal is not required to strictly meet the subcarrier orthogonality, coding modulation, and protocol stack requirements of standard WiFi; instead, it reflects some structural characteristics of the multi-subcarrier distribution in the WiFi physical layer and retains phase information related to the propagation path.

[0283] Step 4: The first device receives the second signal based on the fourth information and performs distance measurement.

[0284] In this step, the fourth information is used to instruct the first device to receive and process the second signal. The fourth information may include at least one of the following: a WiFi-like signal listening window, a target frequency band, a preset frequency interval, discrete frequency component search rules, an amplitude threshold, a phase measurement window, fixed phase deviation calibration information, and ranging parameter information. The first device receives the second signal generated by the backscattering of the second device through the second communication module and can perform at least one of the following: self-interference suppression, carrier frequency-near-frequency leakage component suppression, frequency domain analysis, discrete frequency component extraction, WiFi-like structure identification, phase extraction, phase unrolling, multi-frequency fusion, and distance estimation. For details regarding self-interference suppression, reference signal cancellation, and fixed phase deviation processing after the first device receives the second signal, please refer to the relevant descriptions in Embodiment 1 above.

[0285] In this second embodiment, since the second signal is generated by periodic backscatter modulation and is located at the incident frequency... The nearby DC reflection component and the leakage component of the first signal may be significantly stronger than other discrete frequency components. Therefore, the first device can determine the incident frequency. Nearby DC and leakage components are suppressed, eliminated, or band-stop filtered to improve the extraction stability of other types of WiFi discrete frequency components.

[0286] After completing self-interference suppression, the first device can perform frequency domain analysis on the second signal. For example, the first device can analyze the processed second signal... Performing a Fast Fourier Transform yields: Then, the first device operates according to the preset frequency interval in the fourth information. At the incident frequency A search is conducted in the vicinity for discrete frequency components that satisfy the amplitude threshold, resulting in a set of candidate frequency points. .

[0287] For each candidate frequency point The first device extracts its corresponding complex spectrum: Based on this complex spectrum, the corresponding phase can be obtained: .

[0288] Since the second signal in this embodiment contains multiple stable or nearly stable discrete frequency components, the first device can perform multi-frequency phase ranging based on the phase observations corresponding to the multiple frequency components. That is, based on the phase difference between two or more target frequency components, the common fixed phase deviation is eliminated or reduced, and the distance between the first device and the second device is estimated according to the relationship between phase and frequency.

[0289] In one alternative implementation, the first device can perform phase unrolling on the phase sequence corresponding to multiple frequency components in ascending order of frequency to reduce the impact of phase jumps on distance estimation. Specifically, for adjacent frequency components... and Calculate the phase difference: .

[0290] like Then execute: ;

[0291] like Then execute: .

[0292] Through the above process, a more continuous phase-frequency relationship can be obtained. Based on the phase difference and frequency difference between different subcarriers, the measured distance between the first and second devices can be expressed as: .

[0293] Optionally, when the first device extracts three or more discrete frequency components, it can process multiple ( The data points are linearly fitted to obtain the slope of the phase change with frequency, and the distance between the first device and the second device is estimated based on the slope.

[0294] Understandably, in this second embodiment, the first device does not need to parse the second signal into standard WiFi data packets. Instead, based on the frequency domain characteristics of the second signal identified by the second communication module, it extracts multiple stable frequency components and their phase information according to the discrete frequency distribution characteristics of WiFi-like signals, and obtains distance information using a multi-frequency phase ranging method. The multi-frequency structure of the second signal is generated by the periodic backscatter modulation of the second device, but each frequency component still carries phase information introduced by the propagation path, and therefore can be used for phase-based distance estimation.

[0295] Example 3

[0296] In this third embodiment, a specific implementation method is given for mapping BLE signals to Zigbee-like signal structures based on backscattering and performing phase ranging.

[0297] Specifically, the first device transmits a first signal with a BLE physical layer structure through a first communication module. The second device performs chip-level backscatter modulation within a preset stable field of the first signal, and generates a second signal with Zigbee-like spread spectrum structure characteristics by controlling the load impedance or equivalent reflection coefficient to change according to a preset spread spectrum sequence. The first device then receives the second signal through a second communication module and performs distance estimation based on the relevant despread phase information.

[0298] It should be noted that, since the second device is a passive or low-power backscattering device, it is usually difficult to directly generate OQPSK signals that strictly conform to the ZigBee or IEEE 802.15.4 physical layer specifications. Therefore, the Zigbee-like signal in this embodiment is not required to meet all physical layer constraints in the standard ZigBee protocol. Instead, it has a discrete modulation structure driven by chip sequences, with one information unit mapped to the spread spectrum sequence characteristics of multiple chips, and can be matched using known sequences, thereby supporting subsequent signal analysis and phase ranging.

[0299] Optionally, the first device is a terminal device or software-defined radio device with BLE signal transmission capability and Zigbee-like signal reception and processing capability, which may include, but is not limited to, mobile phones, tablets, embedded boards, general-purpose software-defined radio devices, or multi-protocol communication devices. The first device includes a first communication module and a second communication module. The first communication module is used to generate and transmit a first signal with a BLE physical layer structure, and the first communication module communicates based on the Bluetooth Low Energy communication protocol. The second communication module is used to receive and parse a second signal generated by backscattering from the second device, which has Zigbee-like spread spectrum sequence structure characteristics. The second communication module communicates based on the signal structure with spread spectrum sequence structure characteristics. Optionally, the first communication module may transmit a BLE signal containing a CTE field to provide a stable or near-stable chip-level backscatter modulation window for the second device.

[0300] The second device is a backscattering device with impedance modulation capability, which may include an antenna, an impedance switching network, and a control unit. The second device does not actively generate a radio frequency carrier; instead, it controls the load impedance or equivalent reflection coefficient to backscatter and modulate the first signal according to a preset chip sequence, thereby generating a second signal with the characteristics of the target communication protocol. The second device includes, but is not limited to, low-power passive tags, active tags, or semi-passive backscattering nodes.

[0301] It should be noted that Zigbee-like signals are not required to strictly conform to all physical layer constraints in the standard ZigBee (IEEE 802.15.4) protocol, but rather to possess the structural characteristics of ZigBee signals in at least one of the following dimensions:

[0302] (1) It has a modulation structure driven by a high-speed discrete sequence in the time domain;

[0303] (2) In terms of signal structure, it has the spread spectrum sequence feature of mapping one information unit to multiple chips;

[0304] (3) In the frequency domain, it exhibits characteristics of bandwidth expansion or spectrum broadening;

[0305] (4) Phase information related to the propagation path can be extracted in the phase domain.

[0306] In this third embodiment, the first device transmits a first signal with a BLE physical layer structure through a first communication module. The second device performs chip-level backscatter modulation based on a preset stabilization field in the first signal to generate a second signal with Zigbee-like spread spectrum sequence structure characteristics. The first device then receives the second signal through the second communication module and performs related despreading and ranging. The specific process includes the following steps:

[0307] Step 1: The first device generates a first signal based on the first information and sends the first signal through the first communication module.

[0308] It should be noted that the first signal is a signal conforming to the BLE physical layer specification, preferably a BLE data packet containing a Constant Tone Extension (CTE) field. The CTE field is mainly used to provide a stable or near-stable chip-level backscatter modulation window for the second device. The second device can perform impedance modulation on the first signal within the stable interval corresponding to the CTE field, according to a preset spreading sequence, thereby generating a second signal with Zigbee-like spreading sequence structural characteristics. For a related explanation of the first information, please refer to Embodiment 2 above, which will not be repeated here.

[0309] Within the stable interval corresponding to the CTE field, the first signal can be approximated as: Where A is the amplitude of the first signal. The equivalent frequency within the CTE stability range. This refers to the initial or observable phase corresponding to the CTE stable interval.

[0310] Step 2: The second device receives the first signal based on the second information and performs backscatter modulation.

[0311] In this step, the second information is used to instruct the second device to receive the first signal and determine the timing for executing backscatter modulation. The second information may include at least one of the following: BLE packet timing information, CTE field position, preset modulation window, synchronization method, backscatter start time, chip period, chip sequence length, and modulation duration. After receiving the first signal from the first device, the second device can determine the modulation window corresponding to the CTE field or other preset stable fields and perform backscatter modulation within that modulation window. The second information can be sent by the first device via explicit signaling, pre-agreed upon by the first and second devices, or determined by the second device based on energy detection, simplified correlation detection, field timing, preset delay, or external synchronization information.

[0312] In other words, this third embodiment does not require the second device to completely demodulate the BLE packets or parse the BLE payload bit by bit. The second device only needs to determine a stable time window suitable for backscatter modulation and perform backscatter modulation on the incident signal according to a preset chip sequence within that time window.

[0313] The aforementioned backscatter modulation includes a second device controlling the load impedance or equivalent reflection coefficient to adjust the reflection coefficient. The chip timing is discretely varied according to a preset timing sequence. Through chip-level backscatter modulation, the second device modulates the incident signal within the CTE stable range into a second signal with spread spectrum sequence structure characteristics.

[0314] Step 3: The second device generates a second signal based on the third information and sends the second signal.

[0315] In this step, the third information is used to instruct the second device to generate a second signal with Zigbee-like spread spectrum structure characteristics. The third information may include at least one of the following: the information bits to be transmitted, the spread spectrum codebook, the chip sequence, the chip period, the chip sequence length, impedance state parameters, reflection coefficient parameters, reflection phase state, synchronization sequence, and ranging auxiliary sequence. The second device generates a reflection control sequence based on the third information. The reflection control sequence is used to control the impedance modulation network of the second device, causing the second device to perform backscatter modulation of the first signal according to a preset chip sequence within the CTE stable range.

[0316] In one specific implementation, the second device maps the information bits to be transmitted into a spreading sequence based on a preset mapping rule. Let the information bits to be transmitted be: .

[0317] For each information bit The second device maps it to a length of according to a preset mapping rule. chip sequence: .in: Indicates the first The corresponding bit One chip; Desirable or Equal discrete values.

[0318] Optionally, the chip sequence can be a pseudo-random sequence, orthogonal sequence, quasi-orthogonal sequence, synchronization sequence in a preset codebook, or a fixed-length sequence constructed with reference to the ZigBee direct sequence spread spectrum concept. Through the above mapping process, one information bit no longer directly corresponds to one reflection state, but corresponds to a group of multiple chips arranged in a preset order, thereby forming a spread spectrum sequence structure.

[0319] In some implementations, if the second device only needs to send a fixed identifier, synchronization information, or ranging auxiliary sequence, the spread spectrum sequence can also be a fixed preset sequence without relying on real-time information bits. In this case, the second device can output the fixed spread spectrum sequence cyclically or all at once within the modulation window.

[0320] The second device can map the chip sequence to an impedance switching sequence. For each The second device controls the impedance modulation network to switch to the corresponding impedance state: .

[0321] In some implementations, when At that time, corresponding to the first impedance state ;when At that time, corresponding to the second impedance state .

[0322] The reflection coefficient is determined by the relationship between the load impedance and the antenna characteristic impedance, which can be expressed as: .in, Given the current load impedance, This is the characteristic impedance of the antenna.

[0323] Based on this, the different reflection coefficients corresponding to the two impedance states can be expressed as: , .in, It is a complex constant with a basically constant amplitude.

[0324] Equivalently, the reflection coefficient can also be expressed as: .

[0325] It should be noted that the above and − It does not restrict the reflection coefficient to a real number with positive or negative values, but rather indicates that the amplitudes of the two reflection states are approximately equal, and the phase difference is approximately... Therefore, the two reflection coefficients mentioned above can also be written as: , .

[0326] Therefore, this embodiment preferably employs two reflection states, one with equal amplitude and the other with opposite phase, rather than a "total reflection / total absorption" on / off control method. The reason for this design is as follows:

[0327] (1) The amplitude of the reflected signal is basically the same under both reflection states, which is conducive to maintaining stable backscattered signal energy;

[0328] (2) The phase difference between the two reflection states is approximately It can achieve phase-flip modulation of the incident signal;

[0329] (3) The chip sequence can be directly mapped to the second signal through reflection phase flipping, thereby providing a linear correspondence for subsequent correlation despreading and improving the reliability of correlation despreading and phase extraction.

[0330] In some implementations, the two reflection states described above can be approximated by setting a near-open-circuit state and a near-short-circuit state respectively. Specifically, when the load impedance is close to an open circuit, its reflection coefficient approaches +1; when the load impedance is close to a short circuit, its reflection coefficient approaches -1. Therefore, by switching between the near-open-circuit and near-short-circuit states, a phase difference of approximately [missing value] can be approximately obtained. The two states of reflection.

[0331] In some implementations, non-uniform amplitude reflection or multi-level impedance states can also be used. In this case, the first device can obtain an equivalent spread spectrum despreading result by pre-calibrating the reflection coefficients corresponding to different chips and performing weighted compensation during relevant despreading.

[0332] Optionally, within the CTE modulation window, the second device operates according to a preset chip cycle. The impedance state is switched. Let the duration for each chip be... Then for the first Each chip, and its corresponding time interval is: During this time interval, the second device maintains its corresponding impedance state unchanged, and the reflection coefficient can be expressed as: , Therefore, the second device can sequentially output the impedance states corresponding to multiple chips within the CTE stable range, enabling the second signal to exhibit a chip-level discrete switching structure in the time domain. Since the chip switching rate is higher than the original information bit rate, the second signal exhibits bandwidth expansion or spectral broadening characteristics in the frequency domain.

[0333] It should be noted that since the incident signal is approximately stable during the CTE duration, the chip cycle, chip boundary, and impedance switching time mentioned above can be independently controlled by the second device according to the preset timing, without the need for complex alignment with the original bit boundaries of the ordinary BLE payload.

[0334] The Zigbee-like signal in this third embodiment does not require complete reproduction of the standard ZigBee's OQPSK modulation, I / Q splitting, and half-symbol offset structures. Instead, it retains the spread spectrum sequence structure characteristics that are more suitable for backscattering implementation. That is, one information bit is mapped to multiple chips, and a spread spectrum modulation structure is formed through chip-level timing control. Correlation or matching processing can be performed at the receiving end using a known sequence.

[0335] The second signal can be represented as: .in, This is the first signal within the CTE stable range. This is the chip-level time-varying reflectance coefficient. Because... Within the CTE stability range, it can serve as a relatively stable incident reference, while The second signal changes according to a preset chip sequence, so the main structural features of the second signal are determined by the chip sequence.

[0336] Step 4: The first device receives the second signal based on the fourth information and performs distance measurement.

[0337] In this step, the fourth information is used to instruct the first device to receive and process the second signal. The fourth information may include at least one of the following: a Zigbee-like signal listening window, a spreading codebook, chip period, chip sequence length, synchronization sequence, correlation despreading rules, phase measurement window, reference phase information, fixed phase deviation calibration information, and ranging parameter information. The first device receives the second signal generated by the backscattering of the second device through the second communication module and performs at least one of the following: self-interference suppression, target frequency band extraction, Zigbee-like spreading structure identification, chip synchronization, correlation despreading, phase extraction, fixed phase deviation calibration, and distance estimation. For details regarding self-interference suppression, reference signal cancellation, and fixed phase deviation processing after the first device receives the second signal, please refer to the relevant descriptions in Embodiment 1 above.

[0338] In this third embodiment, the first device performs correlation despreading on the second signal based on a known chip sequence and extracts phase information from the despreading result. Before performing correlation despreading, the first device needs to determine the chip boundary or select a complete spread spectrum sequence window. Specific methods may include at least one of the following:

[0339] (1) Synchronization is performed using a preset synchronization sequence;

[0340] (2) Determine the starting position by sliding the correlation search to find the maximum correlation peak;

[0341] (3) Detect chip switching points based on energy change or phase reversal characteristics;

[0342] (4) Determine the chip boundary based on the preset chip period and modulation window position in the fourth information.

[0343] Let the distance between the first device and the second device be . Then, after the first signal propagates back and forth through "first device - second device - first device", a propagation phase is introduced. :

[0344]

[0345] No. The second signal within a chip cycle can be represented as:

[0346]

[0347] in, The propagation attenuation coefficient, This refers to noise and residual self-interference terms.

[0348] The first device is for the first The second signal within a chip cycle By performing down-conversion, integration, matched filtering, and sampling, the corresponding complex observations are obtained. The complex observations , is the discrete complex sampling result obtained after baseband processing of the received signal in the i-th chip cycle. Further, in the i-th chip cycle, if the reflection state of the second device remains the same as... Given the corresponding impedance state, and the incident signal and propagation phase being approximately stable within this time window, then... It can be represented as: .in, This includes a fixed reference phase term that comprises the initial phase of the first signal, the device link phase, and the reflection fixed phase. This refers to the noise and residual interference items after receiving and processing.

[0349] The first device performs correlation accumulation on a complete spread spectrum sequence period based on a known chip sequence, and obtains: .Will Substituting, we get: .

[0350] because Therefore =1. Then: .

[0351] Therefore, after relevant processing, the spread spectrum sequence modulation term The signal energy is eliminated and increased by N times, resulting in an equivalent complex correlation output, while retaining the phase information introduced by the propagation path in its phase. .

[0352] After despreading the second signal, the first device can extract the phase of the relevant output result, which is represented as a combination of a fixed reference phase term and a propagation phase term: .

[0353] Assuming a known reference distance Below, the reference phase is measured. Then we have: .

[0354] Since the reference distance is known Therefore, it can be achieved through multiple corrections. An approximation can also be obtained by measuring the reference phase. Then, at the distance to be measured The current phase is measured below. : .

[0355] Subtracting the two equations eliminates the fixed phase deviation term. ,get: .

[0356] In the above formula, only the distance d to be measured is unknown, so it can be solved as follows: .

[0357] Optionally, The effects of phase jumps, noise, and residual fixed biases on distance estimation can be reduced by phase unrolling, reference calibration, or averaging of multiple measurements.

[0358] Understandably, the first device can eliminate the influence of symbol changes introduced by the spreading sequence by performing correlation despreading on the Zigbee-like signal (the second signal), thereby obtaining processing gain while retaining propagation phase information.

[0359] Example 4

[0360] In this fourth embodiment, a specific implementation method is given for generating target protocol signals based on Cross-Technology Communication (CTC) and using backscattering with a fixed reflection coefficient to achieve ranging.

[0361] Unlike the previous embodiments where the target communication protocol features were primarily constructed by the second device through impedance modulation, this fourth embodiment shifts the focus of cross-protocol target structure generation to the first device. Specifically, the first device generates and transmits a first signal with some BLE physical layer characteristics through its first communication module. After being reflected back by the second device with a fixed coefficient, the first signal can be detected, synchronized, identified, analyzed, and used for phase sampling at the physical layer by the second communication module of the first device. Upon receiving the first signal, the second device does not perform complex backscatter modulation but reflects the first signal back with a fixed or approximately fixed reflection coefficient, forming a second signal. The first device then receives the second signal through its second communication module and obtains distance information based on its phase information.

[0362] It should be noted that the BLE-like signal in this embodiment is not required to strictly conform to all physical layer constraints or protocol stack requirements of the standard BLE protocol. Instead, it must possess BLE physical layer characteristics in at least one of the following: time domain, frequency domain, phase domain, modulation scheme, and data packet structure, and be detectable, synchronized, identified, parsed, and used to extract phase information by the BLE receiving link. In this way, the first device can achieve cross-communication protocol signal interaction and ranging without relying on the second device to perform complex cross-protocol modulation.

[0363] Optionally, the first device is a terminal device, infrastructure node, software-defined radio device, or multi-protocol communication device with heterogeneous communication capabilities, and may include, but is not limited to, mobile phones, tablets, embedded terminals, general-purpose software-defined radio devices, or multi-protocol gateways. The first device includes a first communication module and a second communication module. The first communication module generates and transmits a first signal, and the second communication module receives a second signal reflected back by the second device with a fixed coefficient, and performs processing operations such as detection, synchronization, identification, phase extraction, and distance estimation on the second signal. The first and second communication modules support different communication protocols. The first communication protocol is the communication protocol supported by the first communication module, and may be selected as the WiFi communication protocol. The second communication protocol is the communication protocol supported by the second communication module, and may be selected as the BLE communication protocol.

[0364] In some implementations, the first communication module is a configurable WiFi transmitting module, a software-defined radio platform, a test mode, a WiFi transmitting link, and a communication module capable of configuring OFDM subcarrier mapping content. The second communication module is a BLE receiving module. The first communication module is used to generate and transmit a first signal with BLE-like physical layer characteristics, and the equivalent carrier frequency, frequency offset, or target frequency band of the first signal is configured to fall within the receivable frequency band of the second communication module, so that the second communication module can perform physical layer detection, synchronization, identification, and phase sampling on the second signal reflected back from the second device.

[0365] The second device is a backscattering device, including an antenna and a load network. The second device can be a passive tag, a semi-passive tag, a low-power backscattering node, or other backscattering terminal that does not have active radio frequency transmission capabilities. The second device does not undertake the main cross-protocol structure generation task; instead, it configures the load network to a fixed or nearly fixed reflection state, reflecting the first signal back to form the second signal using a fixed-coefficient reflection method.

[0366] It should be noted that the BLE-like physical layer structure of the first signal is generated by the first device, while the second device only maintains a fixed reflection state. The second signal is essentially a return signal of the first signal after scaling, phase rotation, and propagation delay by a fixed reflection coefficient. Therefore, the second signal retains the existing BLE-like physical layer structure of the first signal and carries phase information related to the propagation path for subsequent identification, analysis, and distance estimation by the first device.

[0367] In this fourth embodiment, the first device generates and transmits a first signal with BLE-like physical layer characteristics through a first communication module. The second device performs a fixed-coefficient reflection on the first signal to form a second signal that maintains the BLE-like physical layer structure. The first device then receives the second signal through the second communication module and performs identification, phase extraction, and ranging. The specific process includes the following steps:

[0368] Step 1: The first device generates a first signal based on the first information and sends the first signal through the first communication module.

[0369] In this step, the first information is used to instruct the first device to generate and transmit the first signal. The first information may include at least one of the following: receiving frequency information of the second communication module, BLE-like target structure information, target field configuration, phase measurement segment configuration, WiFi / OFDM transmit chain constraint information, subcarrier mapping information, frequency compensation information, and time-domain resource information. Specifically, the first device first determines the BLE-like physical layer structure of the first signal based on the receiving requirements of the second communication module. This BLE-like physical layer structure enables the second communication module to detect, synchronize, identify, and use for phase sampling at the physical layer after the second signal is reflected back by the second device. In a preferred embodiment, the BLE-like physical layer structure includes:

[0370] (1) The leading identification section is used to enable the second communication module to complete energy detection, correlation detection and / or start position determination;

[0371] (2) Target field section, used to enable the second communication module to complete structure recognition, synchronization and / or target window positioning;

[0372] (3) Phase measurement section, used to enable the second communication module to extract phase-related information within a preset time window.

[0373] Optionally, the phase measurement segment may be a CTE field, a continuous constant symbol field, a single-frequency or approximately single-frequency field, or other fields that are continuous in time and have relatively stable frequency offset patterns. This segment is mainly used to provide a stable phase observation window, rather than primarily for transmitting complex service data.

[0374] After determining the BLE-like physical layer structure, the first device can generate a target frequency trajectory based on the target bit sequence or target symbol sequence. Since the BLE physical layer typically uses frequency shift keying modulation, the first device can set different target frequency offsets in different directions or with different amplitudes according to different target bit states, and smooth the frequency trajectory to reduce abrupt changes at adjacent bit boundaries.

[0375] Let the first The target frequency offset corresponding to each sampling point is The sampling period is Then the target phase trajectory can be expressed as: .

[0376] Furthermore, the first device can generate the target complex baseband waveform: .in, For preset amplitude, The target phase trajectory.

[0377] Through the above process, the first device first constructs a target-class BLE time-domain waveform in the digital domain. It should be noted that in this step, the first device does not directly generate WiFi data packets, but first obtains the target-class BLE waveform.

[0378] Since the first communication module in this embodiment is preferably a WiFi transmitting module or an OFDM transmitting link, it typically cannot directly output arbitrary target time-domain waveforms. Therefore, the first device can further reverse-map the BLE-like target waveform to content that the WiFi / OFDM transmitting link can transmit. Specifically, the first device can map the BLE-like target waveform according to the OFDM symbol length. It is divided into multiple consecutive time-domain segments, each segment corresponding to an effective symbol segment of one or more OFDM symbols. For the first... For each target time-domain segment, the first device inversely calculates a set of complex symbols for frequency-domain subcarriers. This allows the time-domain signal after IFFT transformation to approximate the target time-domain segment within the target window: And within the valid symbol segment, the following conditions must be met: The approximation can be achieved through least squares, iterative optimization, or inversion under preset constraints.

[0379] The above approximation can be achieved by meeting a preset error threshold within the preamble identification section, target field section, or phase measurement section, without requiring the entire WiFi / OFDM transmission waveform to be strictly equivalent to the standard BLE waveform at all time points.

[0380] Optionally, after obtaining the complex symbols of the initial subcarrier, the first device may also perform corrections and compensations based on the actual transmission constraints of the first communication module, such as including at least one of the following:

[0381] (1) Amplitude constraint correction: Normalize, limit or control the power of the complex symbols of the subcarriers to meet the transmit power limit;

[0382] (2) Phase quantization correction: Discretize or quantize the subcarrier phase to adapt to the actual modulation capability of the first communication module;

[0383] (3) Boundary continuity correction: The phase relationship at the boundary of adjacent OFDM symbols is adjusted to reduce the phase abruptness caused by symbol switching;

[0384] (4) Cyclic prefix compensation: Align the BLE target segment as much as possible with the OFDM effective symbol segment, or compensate for the time-domain repetition structure caused by the cyclic prefix;

[0385] (5) Frequency compensation: Based on the monitoring channel of the second communication module, the equivalent carrier frequency, frequency offset and / or target frequency band of the first signal are compensated so that the second signal reflected back by the second device falls into the receivable frequency band of the second communication module.

[0386] (6) Redundancy or repeated construction: The target structure is repeatedly constructed in multiple OFDM symbols or multiple transmission cycles to improve the stability of the second communication module in detecting, identifying and extracting the phase of the returned signal.

[0387] In other words, this fourth embodiment does not simply use the WiFi module to directly send ordinary WiFi data packets, nor does it require the WiFi transmission chain to strictly generate a standard BLE waveform. Instead, it first determines the BLE-like physical layer structure required by the receiving side of the second communication module, and then combines the subcarrier mapping, cyclic prefix, power limitation and frequency constraint of the WiFi / OFDM transmission chain to perform reverse solution and compensation on the target waveform, thereby generating a first signal that can be actually transmitted by the first communication module.

[0388] After completing the above construction, the first device transmits a first signal through the first communication module. On the one hand, the first signal serves as the incident signal received by the second device; on the other hand, it also forms the structural basis of the second signal. Since the second device in this embodiment only performs fixed-coefficient reflection, the first signal, when transmitted, should possess sufficient BLE-like physical layer structural features to support the subsequent detection, identification, parsing, and phase extraction of the second communication module.

[0389] Step 2: The second device receives the first signal based on the second information and performs a reflection operation with a fixed coefficient.

[0390] In this step, the second information is used to instruct the second device to receive the first signal and determine the execution mode of the fixed-coefficient reflection. The second information may include at least one of the following: reflection working window, fixed impedance state, preset reflection coefficient, reflection duration, operating frequency band, start-up time, and reflection state configuration information. After receiving the first signal sent by the first device, the second device performs the reflection operation with a fixed coefficient. That is, the second device does not perform symbol-by-symbol, bit-by-bit, or field-by-field modulation on the first signal, but instead configures the load network to a fixed or approximately fixed impedance state, so that the reflection coefficient remains fixed or approximately fixed within the reflection working window.

[0391] Let the equivalent characteristic impedance of the antenna port of the second device be... The load impedance is Then the reflection coefficient can be expressed as: .in, Indicates the amplitude of reflection. This indicates the fixed reflection phase introduced by the fixed reflection state of the second device.

[0392] In some implementations, the second device can set the load network to a near-open-circuit state, a near-short-circuit state, or a preset complex impedance state, so that it forms a fixed or approximately fixed reflection coefficient. For fixed-coefficient reflections, the second device does not undertake the main task of cross-protocol structure generation, but instead retains the existing BLE-like physical layer structure in the first signal through the fixed reflection state, and returns the reflected echo (second signal) carrying propagation path information to the first device.

[0393] Step 3: The second device generates a second signal based on the third information and sends the second signal.

[0394] In this step, the third information is used to indicate the second signal formed after the second device reflects the signal with a fixed coefficient. The third information may include at least one of the following: fixed reflection coefficient, reflection amplitude, reflection phase, reflection window, propagation delay, target structure preservation rule, and ranging auxiliary parameters. Since the second device does not perform complex modulation, the second signal is essentially a return signal of the first signal after being scaled by a fixed reflection coefficient, phase rotated, and propagated with a delay.

[0395] Let the incident complex envelope of the first signal at the second device be... The second signal can then be represented as: .in, This represents the combined amplitude attenuation coefficient resulting from propagation loss and scattering loss. For a fixed reflection coefficient, For round-trip propagation delay.

[0396] Therefore, the second signal is not reconstructed by the second device, but rather is the first signal reflected by a fixed coefficient. Thus, the second signal retains the existing BLE-like physical layer structure of the first signal, and the corresponding changes may include at least one of the following:

[0397] (1) Amplitude attenuation is determined by propagation loss, reflection loss and receiving link loss;

[0398] (2) Fixed phase deviation is introduced by the fixed reflection coefficient phase, the device link phase and the system processing link;

[0399] (3) The propagation phase change is introduced by the round-trip propagation distance between the first device and the second device.

[0400] Understandably, the role of the second device is not to regenerate the BLE-like structure, but to maintain the existing target structure in the first signal and reflect it back, so that the second signal can be detected, identified, parsed and used for phase extraction by the second communication module of the first device.

[0401] Step 4: The first device receives the second signal based on the fourth information and performs distance measurement.

[0402] In this step, the fourth information is used to instruct the first device to receive and process the second signal. The fourth information may include at least one of the following: the listening window of the second communication module, the target frequency band, BLE-like structure identification rules, the location of the phase measurement segment, reference phase information, fixed phase deviation calibration information, emission leakage suppression parameters, and ranging parameter information. The first device receives the second signal reflected back by the second device with a fixed coefficient through the second communication module and performs at least one of the following: emission leakage suppression, target frequency band extraction, BLE-like signal detection, synchronization, structure identification, phase sampling, fixed phase deviation calibration, and distance estimation.

[0403] Since the second communication module may simultaneously receive internal leakage signals, direct components, or environmental reflection components from the first device when the first device sends the first signal through the first communication module, the first device can utilize known first signals, local reference signals, listening window control, bandpass filtering, etc., to reduce the impact of leakage signals and direct components on the reception of the second signal.

[0404] After completing the emission leakage suppression or target frequency band extraction, the first device can detect and identify the second signal. Specifically, the first device can perform energy detection, correlation detection, or start position determination based on the preamble identification segment in the second signal, as well as perform structure identification, synchronization, and target window positioning based on the target field segment, and extract phase observations based on the phase measurement segment.

[0405] In a preferred embodiment, the first device can extract phase observations from the IQ samples corresponding to the phase measurement segment. The phase measurement segment can be a CTE field, a continuous constant symbol field, a single-frequency or approximately single-frequency field, or other fields with relatively stable frequency offsets. The first device can select a preset sampling point, a preset sampling window, or the average phase of the entire segment within this segment as the phase observation corresponding to the second signal, denoted as... .

[0406] Since the second device only performs fixed-coefficient reflection, the second signal typically corresponds to a single stable operating frequency or a narrow frequency range. Therefore, the first device performs single-carrier phase ranging. Specifically, the phase observation can be expressed as:

[0407]

[0408] in, This indicates the fixed phase deviation term. This represents the propagation phase term caused by the round-trip propagation distance between the first device and the second device. The first device can determine the fixed phase deviation using a reference distance calibration method, as described in Embodiment 1 above, and will not be repeated here.

[0409] Optionally, to improve the accuracy of distance estimation, the first device may further suppress the effects of fixed bias and random error by employing at least one of the following methods:

[0410] (1) Perform multiple calibrations at the same reference distance and average the multiple extracted reference phases to obtain a more stable fixed phase deviation estimate.

[0411] (2) In actual distance measurement, the phase observations corresponding to multiple sampling points in the phase measurement section are averaged to reduce the impact of noise;

[0412] (3) When the measured phase undergoes a periodic jump, the phase is unfolded to reduce the error caused by phase ambiguity;

[0413] (4) Re-perform the reference distance calibration under different environments or different working conditions to compensate for the fixed phase drift caused by changes in system state.

[0414] In summary, in this fourth embodiment, the first device first generates and transmits a first signal with BLE-like physical layer characteristics through the first communication module. The second device returns the first signal using a fixed-coefficient reflection method. The first device then uses the second communication module to detect, identify, extract the phase of, and perform reference calibration ranging on the returned second signal. This embodiment shifts the focus of cross-protocol target structure generation to the first device, allowing the second device to participate in cross-communication protocol interaction and phase-based distance estimation without performing complex impedance modulation, simply through fixed reflection.

[0415] It should be noted that the cross-communication protocol backscattering ranging method proposed in this application can be extended to various heterogeneous wireless communication systems. The first device can be a terminal device, infrastructure node, or software-defined radio device with multiple communication modules or configurable radio frequency capabilities, including but not limited to smartphones, tablets, wearable devices, embedded development boards, multi-protocol gateways, access points, or test equipment. The second device can be a low-power or passive backscattering device, including but not limited to tags, smart cards, sensor nodes, asset identification nodes, and environmentally powered IoT nodes.

[0416] Regarding the combination of communication protocols, the solution in this application is not limited to signal interaction between WiFi, BLE and ZigBee communication protocols, but can also be extended to combinations of StarFlash, LoRa, UWB, Sidelink or other wireless communication protocols.

[0417] The solution in this application can be used in scenarios such as cross-protocol device access, low-power IoT communication, asset management, indoor positioning, short-range ranging, intelligent sensing, and heterogeneous wireless system collaboration. It is especially suitable for application environments with high requirements for power consumption, cost, device complexity, and system compatibility.

[0418] It should be noted that the ranging method provided in this application can be executed by a ranging device or a control module within the ranging device for executing the ranging method. This application uses the example of a ranging device executing the ranging method to illustrate the ranging device provided in this application.

[0419] Please see Figure 9 , Figure 9 This is a structural diagram of a ranging device provided in an embodiment of this application, as shown below. Figure 9 As shown, the ranging device 90 includes:

[0420] The first communication module 91 is used to send a first signal to the second device; wherein the first communication module communicates based on a first communication protocol;

[0421] The second communication module 92 is used to receive a second signal from the second device; wherein the second signal is obtained by backscattering the first signal, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules in the first device; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications;

[0422] Acquisition module 93 is used to obtain the phase information of the second signal;

[0423] The determination module 94 is used to determine the distance between the first device and the second device based on the phase information of the second signal.

[0424] Optionally, the first signal has a first signal structure, which is a signal structure that conforms to the first communication protocol specification; or, the first signal structure is a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure.

[0425] Alternatively, the second signal may have a second signal structure, which is a signal structure that conforms to the second communication protocol specification; or, the second signal structure may be a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure.

[0426] Optionally, when the first signal structure does not conform to the signal structure specified in the first communication protocol, the first signal satisfies at least one of the following:

[0427] The first signal is a single-frequency signal;

[0428] The first signal is a single-tone signal;

[0429] The first signal is a multi-tone signal;

[0430] The first signal is a single-carrier signal;

[0431] The first signal is a multi-carrier signal.

[0432] The first signal has multiple discrete frequency components, and the frequency interval between the multiple discrete frequency components is fixed or approximately fixed.

[0433] Optionally, the first communication protocol includes at least one of the following: Wi-Fi communication protocol, Bluetooth communication protocol, StarFlash communication protocol, Zigbee communication protocol, LoRa long-range radio communication protocol, cellular communication protocol, UWB communication protocol, and Sidelink access technology;

[0434] And / or, the second communication protocol includes at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarScan communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, and Sidelink communication protocol.

[0435] Optionally, the second signal is a signal carried by a single target subcarrier, and the determining module 94 is specifically used to: calculate the phase difference between the phase of the second signal and the reference phase based on the phase information of the second signal and a pre-acquired reference phase; and calculate the distance between the first device and the second device based on the phase difference.

[0436] Optionally, the second signal includes multiple signals carried by multiple target subcarriers, and the determining module 94 is specifically used to: calculate at least one phase difference value based on the phase information of the multiple signals, wherein the phase difference value is the phase difference value between two signals among the multiple signals; and calculate the distance between the first device and the second device based on the at least one phase difference value.

[0437] Optionally, the first signal includes a first signal portion, and the second signal is obtained by backscattering modulation of the first signal portion; the acquisition module 93 is specifically used to: identify the second signal portion of the second signal, and determine the phase information of the second signal based on the phase information of the second signal portion.

[0438] Optionally, the first signal includes a third signal portion, the third signal portion having a signal structure conforming to the second communication protocol specification; the second signal is obtained by direct backscattering of the third signal portion;

[0439] The acquisition module 93 is specifically used for: the first device identifying the fourth signal portion of the second signal, and determining the phase information of the second signal based on the phase information of the fourth signal portion.

[0440] The ranging device in this application embodiment can be a device, or a component, integrated circuit, or chip in a terminal. The device can be a mobile electronic device or a non-mobile electronic device. For example, mobile electronic devices can be mobile phones, tablets, laptops, PDAs, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc., while non-mobile electronic devices can be servers, network-attached storage (NAS), personal computers (PCs), televisions (TVs), ATMs, or self-service machines, etc. This application embodiment does not impose specific limitations.

[0441] The ranging device in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit the specific operating system used.

[0442] The ranging device 90 provided in this embodiment can achieve... Figure 3 The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0443] Please see Figure 10 , Figure 10 This is a structural diagram of another ranging device provided in the embodiments of this application, such as... Figure 10 As shown, the ranging device 100 includes:

[0444] The receiving module 101 is used to receive a first signal from the first device; wherein the first signal is sent through a first communication module in the first device, and the first communication module communicates based on a first communication protocol;

[0445] Processing module 102 is used to perform a backscattering operation on the first signal to obtain a second signal;

[0446] The transmitting module 103 is used to transmit the second signal to the first device; wherein the second signal is received by a second communication module in the first device, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; the phase information of the second signal is used to determine the distance between the first device and the second device.

[0447] Optionally, the first signal has a first signal structure, which is a signal structure that conforms to the first communication protocol specification; or, the first signal structure is a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure.

[0448] Alternatively, the second signal may have a second signal structure, which is a signal structure that conforms to the second communication protocol specification; or, the second signal structure may be a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure.

[0449] Optionally, the processing module 102 is specifically used for any of the following:

[0450] The second signal is obtained by backscattering modulation of the first signal by controlling the load impedance switching or changing the equivalent reflection coefficient;

[0451] The second signal is obtained by directly backscattering the first signal using a fixed reflection coefficient.

[0452] Optionally, the first signal includes a first signal portion, and the processing module 102 is specifically used to: perform backscatter modulation on the first signal portion to obtain the second signal; the second signal includes a second signal portion, which is used to determine the distance between the first device and the second device.

[0453] Optionally, the first signal includes a third signal portion, the third signal portion having a signal structure conforming to the second communication protocol specification; the processing module 102 is specifically used to: perform direct backscattering on the third signal portion using a fixed coefficient to obtain the second signal; wherein, the second signal includes a fourth signal portion, the fourth signal portion being used to determine the distance between the first device and the second device.

[0454] The ranging device 100 provided in this embodiment can achieve... Figure 4The various processes implemented in the method embodiments achieve the same technical effect, and will not be described again here to avoid repetition.

[0455] Optionally, such as Figure 11 As shown, this application embodiment also provides a communication device 110, including a processor 111 and a memory 112. The memory 112 stores a program or instructions that can run on the processor 111. When the program or instructions are executed by the processor 111, they implement the various steps of the above-described ranging method embodiment and can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0456] Figure 12 A schematic diagram of the hardware structure of a terminal to implement an embodiment of this application.

[0457] The terminal 1200 includes, but is not limited to, at least some of the following components: radio frequency unit 1201, network module 1202, audio output unit 1203, input unit 1204, sensor 1205, display unit 1206, user input unit 1207, interface unit 1208, memory 1209, and processor 1210.

[0458] Those skilled in the art will understand that the terminal 1200 may also include a power supply (such as a battery) for supplying power to various components. The power supply may be logically connected to the processor 1210 through a power management system, thereby enabling functions such as managing charging, discharging, and power consumption through the power management system. Figure 12 The terminal structure shown does not constitute a limitation on the terminal. The terminal may include more or fewer components than shown, or combine certain components, or have different component arrangements, which will not be elaborated here.

[0459] The terminal 1200 can be a mobile phone, tablet computer, laptop computer, notebook computer, personal digital assistant (PDA), handheld computer, netbook, ultra-mobile personal computer (UMPC), mobile internet device (MID), augmented reality (AR), virtual reality (VR) device, robot, wearable device, flight vehicle, vehicle user equipment (VUE), shipboard equipment, pedestrian user equipment (PUE), smart home (home devices with wireless communication capabilities, such as refrigerators, televisions, washing machines, or furniture), game console, personal computer (PC), ATM, or self-service machine, etc.

[0460] The radio frequency unit 1201 is used to send a first signal to a second device through a first communication module; the first communication module communicates based on a first communication protocol; and receives a second signal from the second device through a second communication module; the second signal is obtained by backscattering the first signal; the second communication module communicates based on a second communication protocol; the second communication module and the first communication module are different communication modules in the terminal 1200. The second communication protocol and the first communication protocol are communication protocols with different protocol specifications.

[0461] The processor 1210 is configured to obtain phase information of the second signal and determine the distance between the terminal 1200 and the second device based on the phase information of the second signal.

[0462] The solution of this application embodiment can realize cross-communication protocol signal interaction between terminal 1200 and the second device based on different communication modules in terminal 1200. That is, cross-communication protocol backscatter communication can be realized based on the collaborative work of different communication modules in terminal 1200, thereby improving the ranging accuracy and meeting the ranging requirements when ranging is based on backscatter signals.

[0463] It is understood that the implementation process of each implementation method mentioned in this embodiment can refer to the above. Figure 3The relevant descriptions of the method embodiments shown herein, which achieve the same or corresponding technical effects, will not be repeated here to avoid duplication.

[0464] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described ranging method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0465] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0466] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described ranging method embodiments and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0467] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0468] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0469] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0470] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A distance measurement method, characterized in that, include: The first device sends a first signal to the second device through a first communication module; wherein the first communication module communicates based on a first communication protocol. The first device receives a second signal from the second device through the second communication module; wherein the second signal is obtained by backscattering the first signal, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules in the first device; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; The first device obtains the phase information of the second signal and determines the distance between the first device and the second device based on the phase information of the second signal.

2. The method according to claim 1, characterized in that, The first signal has a first signal structure, which is a signal structure that conforms to the first communication protocol specification; or, the first signal structure is a signal structure that has a preset feature in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure. or, The second signal has a second signal structure, which is a signal structure that conforms to the second communication protocol specification, or the second signal structure is a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method and data packet structure.

3. The method according to claim 2, characterized in that, When the first signal structure does not conform to the signal structure specified in the first communication protocol, the first signal satisfies at least one of the following: The first signal is a single-frequency signal; The first signal is a single-tone signal; The first signal is a multi-tone signal; The first signal is a single-carrier signal; The first signal is a multi-carrier signal; The first signal has multiple discrete frequency components, and the frequency interval between the multiple discrete frequency components is fixed or approximately fixed.

4. The method according to any one of claims 1 to 3, characterized in that, The first communication protocol includes at least one of the following: Wi-Fi communication protocol, Bluetooth communication protocol, StarFlash communication protocol, Zigbee communication protocol, LoRa long-range radio communication protocol, cellular communication protocol, UWB communication protocol, and Sidelink access technology; And / or, The second communication protocol includes at least one of the following: WiFi communication protocol, Bluetooth communication protocol, StarFlash communication protocol, Zigbee communication protocol, LoRa communication protocol, cellular communication protocol, UWB communication protocol, and Sidelink communication protocol.

5. The method according to any one of claims 1 to 4, characterized in that, The second signal is a signal carried by a single target subcarrier. Determining the distance between the first device and the second device based on the phase information of the second signal includes: The first device calculates the phase difference between the phase of the second signal and the reference phase based on the phase information of the second signal and a pre-acquired reference phase. The first device calculates the distance between the first device and the second device based on the phase difference value.

6. The method according to any one of claims 1 to 4, characterized in that, The second signal includes multiple signals carried by multiple target subcarriers. Determining the distance between the first device and the second device based on the phase information of the second signal includes: The first device calculates at least one phase difference value based on the phase information of the plurality of signals, wherein the phase difference value is the phase difference value between two signals among the plurality of signals; The first device calculates the distance between the first device and the second device based on the at least one phase difference value.

7. The method according to any one of claims 1 to 6, characterized in that, The first signal includes a first signal portion, and the second signal is obtained by backscattering modulation of the first signal portion; The first device obtains the phase information of the second signal, including: The first device identifies the second signal portion of the second signal and determines the phase information of the second signal based on the phase information of the second signal portion.

8. The method according to any one of claims 1 to 6, characterized in that, The first signal includes a third signal portion, which has a signal structure that conforms to the second communication protocol specification; The second signal is obtained by direct backscattering of the third signal portion; The first device obtains the phase information of the second signal, including: The first device identifies the fourth signal portion of the second signal and determines the phase information of the second signal based on the phase information of the fourth signal portion.

9. A distance measurement method, characterized in that, include: The second device receives a first signal from the first device; wherein the first signal is sent through a first communication module in the first device, and the first communication module communicates based on a first communication protocol; The second device performs a backscattering operation on the first signal to obtain the second signal; The second device sends the second signal to the first device; wherein the second signal is received through a second communication module in the first device, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; the phase information of the second signal is used to determine the distance between the first device and the second device.

10. The method according to claim 9, characterized in that, The first signal has a first signal structure, which is a signal structure that conforms to the first communication protocol specification; or, the first signal structure is a signal structure that has a preset feature in at least one of the time domain, frequency domain, phase domain, modulation method, and data packet structure. or, The second signal has a second signal structure, which is a signal structure that conforms to the second communication protocol specification, or the second signal structure is a signal structure that has preset features in at least one of the time domain, frequency domain, phase domain, modulation method and data packet structure.

11. The method according to claim 9, characterized in that, The second device performs a backscattering operation on the first signal to obtain a second signal, including any one of the following: The second device modulates the first signal by backscattering through controlling the load impedance switching or changing the equivalent reflection coefficient to obtain the second signal; The second device uses a fixed reflection coefficient to directly backscatter the first signal to obtain the second signal.

12. The method according to any one of claims 9 to 11, characterized in that, The first signal includes a first signal portion, and the second device performs a backscattering operation on the first signal to obtain a second signal, including: The second device performs backscatter modulation on the first signal portion to obtain the second signal; wherein the second signal includes a second signal portion, which is used to determine the distance between the first device and the second device.

13. The method according to any one of claims 9 to 11, characterized in that, The first signal includes a third signal portion, which has a signal structure that conforms to the second communication protocol specification; The second device performs a backscattering operation on the first signal to obtain a second signal, including: The second device performs direct backscattering of the third signal portion using a fixed coefficient to obtain the second signal; wherein, the second signal includes a fourth signal portion, the fourth signal portion being used to determine the distance between the first device and the second device.

14. A ranging device, characterized in that, include: A first communication module is used to send a first signal to a second device; wherein the first communication module communicates based on a first communication protocol; The second communication module is used to receive a second signal from the second device; wherein the second signal is obtained by backscattering the first signal, the second communication module communicates based on a second communication protocol, and the second communication module and the first communication module are different communication modules in the first device; the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; An acquisition module is used to obtain the phase information of the second signal; The determining module is used to determine the distance between the first device and the second device based on the phase information of the second signal.

15. A ranging device, characterized in that, include: A receiving module is configured to receive a first signal from a first device; wherein the first signal is transmitted through a first communication module in the first device, and the first communication module communicates based on a first communication protocol; The processing module is used to perform a backscattering operation on the first signal to obtain a second signal; A transmitting module is used to transmit the second signal to the first device; wherein the second signal is received through a second communication module in the first device, the second communication module communicates based on a second communication protocol, the second communication module and the first communication module are different communication modules, and the second communication protocol and the first communication protocol are communication protocols with different protocol specifications; the phase information of the second signal is used to determine the distance between the first device and the second device.

16. A communication device, characterized in that, It includes a processor and a memory, the memory storing a program or instructions that can run on the processor, the program or instructions being executed by the processor to implement the steps of the ranging method as described in any one of claims 1 to 8, or to implement the steps of the ranging method as described in any one of claims 9 to 13.

17. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions that, when executed by a processor, implement the steps of the ranging method as described in any one of claims 1 to 8, or implement the steps of the ranging method as described in any one of claims 9 to 13.

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