CN107367723B

CN107367723B - Method and equipment for measuring distance

Info

Publication number: CN107367723B
Application number: CN201610319211.0A
Authority: CN
Inventors: 杨晖
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2016-05-13
Filing date: 2016-05-13
Publication date: 2020-04-28
Anticipated expiration: 2036-05-13
Also published as: CN107367723A

Abstract

A method and equipment for measuring distance are used for solving the technical problem that the conventional distance measuring mode is difficult to realize. The method comprises the following steps: receiving a first multi-carrier signal; analyzing the first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase difference is a phase difference between two sub-carriers in the M sub-carriers; calculating a plurality of phase fluctuation values corresponding to the plurality of actual phase differences, wherein the phase fluctuation values are difference values between the actual phase differences and the original phase differences; the original phase difference is the phase difference between two subcarriers in the M subcarriers before the first multicarrier signal is sent; calculating a phase fluctuation average value of the first multi-carrier signal, wherein the phase fluctuation average value is obtained by averaging a plurality of phase fluctuation values; and determining the transmission distance of the first multi-carrier signal according to the mapping relation between the phase fluctuation average value and the transmission distance and the phase fluctuation average value of the first multi-carrier signal.

Description

Method and equipment for measuring distance

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for measuring a distance.

Background

Currently, positioning is a popular application field, and may be used for indoor navigation, item tracking, and the like for users. The positioning is a mainstream positioning method by a distance measuring mode, wherein the distance measuring mode can be that the distances between a node to be positioned and a plurality of anchor nodes are respectively measured, and then the positioning is carried out by utilizing a plurality of groups of distances through positioning algorithms like triangulation positioning and the like.

The existing distance measurement mode generally utilizes time difference to measure distance, for example, the distance between a signal source and a monitoring station can be measured by utilizing the time difference of the signal sent by the signal source reaching different monitoring stations, and obviously, synchronization between the monitoring stations is required by utilizing the time difference. It can be seen that, in the current distance measurement mode, distance measurement is performed by using time difference, so that the requirement for synchronization of devices is high in order to ensure that the measurement accuracy meets the requirement, and strict synchronization between devices is difficult in an actual scene, so that the distance measurement mode using time difference is difficult to implement.

Disclosure of Invention

The embodiment of the invention provides a method and equipment for measuring distance, which are used for solving the technical problem that the conventional distance measuring mode is difficult to realize.

In a first aspect, a method for measuring a distance is provided, and the method may be applied to a receiving device, and the method may include: receiving a first multi-carrier signal sent by sending equipment, and analyzing the received first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase difference is a phase difference between two sub-carriers in the received M sub-carriers, and M is a positive integer greater than 2. A plurality of phase fluctuation values corresponding to a plurality of actual phase differences are calculated, the phase fluctuation values being differences between the actual phase differences of two of the M subcarriers and an original phase difference between the two of the M subcarriers before the first multicarrier signal is transmitted by the transmitting apparatus. And calculating a phase fluctuation average value of the first multi-carrier signal, wherein the phase fluctuation average value is obtained by averaging a plurality of phase fluctuation values, and determining the transmission distance of the first multi-carrier signal according to the mapping relation between the phase fluctuation average value and the transmission distance, and the transmission distance of the first multi-carrier signal is the distance between the sending equipment and the receiving equipment.

Different from the prior art that the distance measurement is performed by using the time difference, the embodiment of the invention provides a brand new distance measurement mode. In the embodiment of the invention, after receiving a first multicarrier signal, a receiving device analyzes the first multicarrier signal to obtain a plurality of actual phase differences of M subcarriers, the actual phase differences are differentiated from the original phase differences of the M subcarriers to obtain phase fluctuation values, and then the phase fluctuation values are averaged to obtain a phase fluctuation average value of the first multicarrier signal, so that the transmission distance of the first multicarrier signal can be determined according to a mapping relation between the preset phase fluctuation average value and the transmission distance. Each receiving device can operate by itself, even if a plurality of receiving devices exist, the receiving devices do not need to be synchronized, the synchronization requirement on the devices is low, and obviously, the distance measuring mode is more beneficial to application in an actual scene.

In addition, the phase of the subcarrier changes, which may be related to the transmission distance, and may also be related to the original phase of the subcarrier.

Alternatively, the multicarrier signal may be a signal obtained by modulating a sequence to be transmitted onto a plurality of subcarriers. In one embodiment, the multi-carrier signal may be, for example, an OFDM signal, although other multi-carrier signals are possible.

Optionally, the mapping relationship may be a relationship between the phase fluctuation average value and the transmission distance, or may be a relationship between other parameters and the transmission distance, for example, a relationship between the phase fluctuation value and the transmission distance, for example, after obtaining a plurality of phase fluctuation values, one transmission distance may be determined according to each phase fluctuation value and the mapping relationship between the phase fluctuation value and the transmission distance, that is, a plurality of transmission distances may be determined, for example, an average value of the plurality of transmission distances is obtained, or the transmission distance of the first multicarrier signal may be obtained. The natural mapping relationship may also be a relationship between other parameters related to the phases of the M subcarriers and parameters related to the transmission distance, and the embodiments of the present invention are not limited.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the mapping relationship may be generated according to a plurality of different transmission distances and a plurality of phase fluctuation average values calculated under the plurality of different transmission distances.

That is, the mapping relation can be set in a case where both the transmission distance and the phase fluctuation average value are known, and the manner is relatively simple. And the mapping relation is preset, so that the distance can be determined according to the mapping relation subsequently, and the ranging process is simplified.

With reference to the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the mapping relationship is generated by obtaining a plurality of phase fluctuation average values according to a plurality of different transmission distances and by calculating under the plurality of different transmission distances, and may be implemented by: setting a plurality of different transmission distances, and establishing a mapping relation according to the plurality of different transmission distances and a plurality of phase fluctuation average values under the plurality of different transmission distances. Wherein, at each of the plurality of different transmission distances, the first receiving device may calculate a plurality of phase fluctuation average values at the plurality of different transmission distances by performing: receiving a second multi-carrier signal sent by the sending equipment, wherein the second multi-carrier signal comprises M sub-carriers, calculating a plurality of phase fluctuation values of the M sub-carriers in the second multi-carrier signal, and calculating a phase fluctuation average value of the second multi-carrier signal.

That is, in the process of setting the mapping relationship, the process of calculating the phase fluctuation value may refer to the process of calculating the phase fluctuation value of the first multicarrier signal, that is, a plurality of transmission distances may be set, and one phase fluctuation average value may be calculated for each transmission distance, so that in the case where both the transmission distance and the phase fluctuation average value are known, the mapping relationship may be generated, and the manner of calculating the phase fluctuation average value in the process of generating the mapping relationship coincides with the manner of calculating the phase fluctuation average value of the multicarrier signal used for ranging, so that the determined distance is accurate.

With reference to the first aspect or the first possible implementation manner or the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, analyzing the received first multicarrier signal to obtain a plurality of actual phase differences of M subcarriers in the first multicarrier signal may be implemented by: selecting a phase difference extraction strategy corresponding to the first multi-carrier signal from a plurality of preset phase difference extraction strategies, and analyzing the first multi-carrier signal according to the phase difference extraction strategy corresponding to the first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal. Correspondingly, the transmission distance of the first multi-carrier signal is determined according to the mapping relation between the phase fluctuation average value and the transmission distance and the phase fluctuation average value of the first multi-carrier signal, and the method can be realized by the following steps: and selecting a mapping relation corresponding to the first multi-carrier signal from the stored mapping relations between the multiple phase fluctuation average values and the transmission distances, and determining the transmission distance of the first multi-carrier signal according to the mapping relation corresponding to the first multi-carrier signal.

That is, a preset phase difference extraction strategy may be adopted to calculate a plurality of actual phase differences of M subcarriers, and a plurality of phase difference extraction strategies may be preset, so that different phase difference extraction strategies may be adopted for different multicarrier signals, or different phase difference extraction strategies may be selected for the same multicarrier signal, and the manner is flexible. For the first multicarrier signal, when the phase difference extraction policy is selected from the multiple phase difference extraction policies, the phase difference extraction policy corresponding to the first multicarrier signal may be selected, that is, the phase difference extraction policy in consideration of the characteristics of the first multicarrier signal, so that the multiple phase differences of the M subcarriers can be calculated more accurately.

Similarly, multiple mapping relationships may be preset, so that different mapping relationships may be used for different multicarrier signals, or different mapping relationships may be selected for the same multicarrier signal, which is more flexible. For the first multi-carrier signal, when the mapping relationship is selected from the multiple mapping relationships, the mapping relationship corresponding to the first multi-carrier signal may be selected, that is, the mapping relationship of the characteristics of the first multi-carrier signal is considered, so that the multiple phase differences of the M sub-carriers can be calculated more accurately.

Optionally, for the first multicarrier signal, the selected phase difference extraction policy and the mapping relationship may also be corresponding, and because the calculation manner of the phase difference extraction policy is consistent with the calculation manner of the actual phase difference when the mapping relationship is set, the corresponding phase difference extraction policy and the mapping relationship are selected, which is beneficial to determining a more accurate transmission distance.

With reference to the first aspect or any possible implementation manner of the first to third possible implementation manners of the first aspect, in a fourth possible implementation manner of the first aspect, the first multicarrier signal may be a pilot signal or a preamble signal.

The pilot signal and the preamble signal are generally known to the devices, and if the first multi-carrier signal is a known signal such as the pilot signal or the preamble signal, the original phase difference of the M sub-carriers can be directly calculated by the first receiving device without being calculated by the sending device and then transmitted to the first receiving device, so that the interaction process between the devices is reduced.

In a second aspect, an apparatus for measuring distance is provided that may include a processor, a memory, a receiver, and a bus. The memory is connected with the processor through the bus, the memory can be used for storing computer instructions, and the processor can be used for executing the computer instructions stored by the memory. When the computer device is running, the processor executes the computer instructions, causing the computer device to perform the following operations: the method comprises the steps of receiving a first multi-carrier signal sent by sending equipment through a calling receiver, and analyzing the first multi-carrier signal received through the receiver to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase difference is the phase difference between two sub-carriers in the received M sub-carriers, and M is a positive integer larger than 2. Calculating a plurality of phase fluctuation values corresponding to a plurality of actual phase differences, wherein the phase fluctuation value is a difference value between an actual phase difference of two subcarriers of the M subcarriers and an original phase difference, the original phase difference is a phase difference between the two subcarriers of the M subcarriers before the first multicarrier signal is sent by the sending equipment, calculating a phase fluctuation average value of the first multicarrier signal, the phase fluctuation average value is obtained by averaging the plurality of phase fluctuation values, determining a transmission distance of the first multicarrier signal according to a mapping relation between the phase fluctuation average value and the transmission distance, and the transmission distance of the first multicarrier signal is a distance between the sending equipment and the receiving equipment.

With reference to the second aspect, in a first possible implementation manner of the second aspect, when the computer device is executed, the processor executes the computer instructions, and further causes the computer device to perform the following operations: and calculating to obtain a plurality of phase fluctuation average values according to a plurality of different transmission distances and under a plurality of different transmission distances, and generating a mapping relation.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, in an aspect that a mapping relationship is generated by calculating a plurality of phase fluctuation average values according to and at a plurality of different transmission distances, the processor executes the computer instructions, so that the computer device performs the following operations: setting a plurality of different transmission distances, and establishing a mapping relation according to the plurality of different transmission distances and a plurality of phase fluctuation average values under the plurality of different transmission distances. Wherein, at each of the plurality of different transmission distances, the processor causes the computer device to calculate a plurality of phase fluctuation averages at the plurality of different transmission distances by executing the computer instructions to: the method comprises the steps of receiving a second multi-carrier signal sent by a sending device through a receiver, calculating a plurality of phase fluctuation values of M sub-carriers in the second multi-carrier signal received by the receiver, and calculating a phase fluctuation average value of the second multi-carrier signal received by the receiver.

With reference to the second aspect or the first possible implementation manner or the second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, in analyzing the received first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, the processor executes the computer instructions to cause the computer device to perform the following operations: selecting a phase difference extraction strategy corresponding to the first multi-carrier signal from a plurality of preset phase difference extraction strategies, and analyzing the first multi-carrier signal according to the phase difference extraction strategy corresponding to the first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal. Accordingly, in determining the transmission distance of the first multicarrier signal based on the mapping of the phase fluctuation average to the transmission distance and the phase fluctuation average of the first multicarrier signal, the processor executes the computer instructions to cause the computer device to perform the following operations: and selecting a mapping relation corresponding to the first multi-carrier signal from the stored mapping relations between the multiple phase fluctuation average values and the transmission distances, and determining the transmission distance of the first multi-carrier signal according to the mapping relation corresponding to the first multi-carrier signal.

With reference to the second aspect or any possible implementation manner of the first possible implementation manner to the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, the first multicarrier signal may be a pilot signal or a preamble signal.

In a third aspect, another apparatus for measuring distance is provided and may include a receiving module, an analyzing module, a calculating module, and a determining module. The receiving module may be configured to receive a first multicarrier signal sent by the sending device, and the analyzing module may be configured to analyze the first multicarrier signal received by the receiving module to obtain a plurality of actual phase differences of M subcarriers in the first multicarrier signal, where the actual phase difference may be a phase difference between two subcarriers in the received M subcarriers, and M is a positive integer greater than 2. The calculation module may be configured to calculate a plurality of phase fluctuation values corresponding to a plurality of actual phase differences, where a phase fluctuation value may be a difference between an actual phase difference of two subcarriers of the M subcarriers and an original phase difference, and the original phase difference may be a phase difference between two subcarriers of the M subcarriers before the first multicarrier signal is transmitted by the transmitting apparatus. The calculation module may be further configured to calculate a phase fluctuation average value of the first multicarrier signal, where the phase fluctuation average value may be obtained by averaging a plurality of phase fluctuation values. The determining module may be configured to determine a transmission distance of the first multicarrier signal according to a mapping relationship between the phase fluctuation average value and the transmission distance, where the transmission distance of the first multicarrier signal may be a distance between the sending device and the receiving device.

With reference to the third aspect, the apparatus may further include means for performing the methods described in the various implementations of the first aspect.

In a fourth aspect, another method for measuring a distance is provided, which may be applied to a receiving device, and which may include: receiving a first multi-carrier signal sent by sending equipment, and analyzing the received first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase difference is a phase difference between two sub-carriers in the received M sub-carriers, and M is a positive integer greater than 2. A plurality of phase fluctuation values corresponding to a plurality of actual phase differences are calculated, the phase fluctuation values being obtained from the phase differences of two of the M subcarriers, the phase fluctuation values being differences between the actual phase differences and the original phase differences, the original phase differences being the phase differences between two of the M subcarriers before the first multicarrier signal is transmitted by the transmitting apparatus. Determining a plurality of transmission distances corresponding to the plurality of phase fluctuation values according to a mapping relation between the phase fluctuation values and the transmission distances, calculating a transmission distance average value, and determining the transmission distance average value as the transmission distance of the first multi-carrier signal, where the transmission distance of the first multi-carrier signal may be the distance between the sending device and the receiving device. Wherein, the transmission distance mean value is obtained by averaging a plurality of transmission distances.

In the embodiment of the present invention, after receiving a first multicarrier signal, a receiving device needs to analyze the first multicarrier signal to obtain a plurality of actual phase differences of M subcarriers, perform a difference between the actual phase differences and original phase differences of the M subcarriers to obtain a phase fluctuation value, obtain a plurality of transmission distances through a mapping relationship between the phase fluctuation value and the transmission distances, and then average the plurality of transmission distances to obtain a transmission distance average value, which can determine the transmission distance average value as the transmission distance of the first multicarrier signal, and the embodiment of the present invention determines that the phase difference between subcarriers carrying the first multicarrier signal is related to the transmission distance of the first multicarrier signal, so that ranging can be completed by calculating the phase difference between subcarriers carrying the first multicarrier signal without using a time difference, and ranging can be completed by using the method provided by the embodiment of the present invention independently no matter how many receiving devices, each receiving device can operate by itself, even if a plurality of receiving devices exist, the receiving devices do not need to be synchronized, the synchronization requirement on the devices is low, and obviously, the distance measuring mode is more beneficial to application in an actual scene.

In addition, since the mapping relation of the fourth aspect is different from the mapping relation of the first aspect, the application manner of the mapping relation is also different. It can be seen that there are many mapping relationships, for example, the mapping relationship between the phase-related parameter and the transmission distance-related parameter can be used as the mapping relationship in the embodiment of the present invention, and then those skilled in the art naturally know how to perform ranging according to different mapping relationships.

Alternatively, the method of the fourth aspect may be performed by the apparatus provided in the second or third aspect.

In a fifth aspect, a computer storage medium is provided, wherein the computer storage medium may store a program, and the program comprises part or all of the steps of any one of the ranging methods described in the first aspect when executed.

The processing method for the phases of the M subcarriers provided by the embodiment of the invention can calculate the phase fluctuation average value, and then can determine the transmission distance of the first multicarrier signal according to the mapping relation between the preset phase fluctuation average value and the transmission distance, without using time difference, and has lower synchronization requirements for equipment.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a possible model of an OFDM communication system;

FIG. 2 is a flow chart of a method for measuring distance according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a possible performance curve between transmission distance and average value of phase fluctuation provided by an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a distance measuring apparatus according to an embodiment of the present invention;

fig. 5 is a block diagram of a possible structure of an apparatus for measuring a distance according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments that can be obtained by a person skilled in the art based on the embodiments of the present invention without any inventive step belong to the scope of the embodiments of the present invention.

The techniques described herein may be used for OFDM communication systems, and may also be applicable to other similar communication systems.

Hereinafter, some terms in the embodiments of the present invention are explained to facilitate understanding by those skilled in the art.

1) The receiving device may comprise, for example, a terminal device, or may further comprise a network device, where the network device may comprise, for example, an access network device, such as a base station, or may further comprise a core network device.

2) The sending device may include, for example, a terminal device, or may also include a network device, where the network device may include, for example, an access network device, such as a base station, or may also include a core network device.

The type of the sending device and the type of the receiving device may be the same or different, for example, both the sending device and the receiving device may be terminal devices, or the sending device may be a network device and the receiving device may be a terminal device, and so on.

3) Terminal device, which refers to a device providing voice and/or data connectivity to a user, may comprise, for example, a handheld device having wireless connection capability, or a processing device connected to a wireless modem. The terminal device may communicate with a core Network via a Radio Access Network (RAN), and exchange voice and/or data with the RAN. The Terminal Device may include a UE, a wireless Terminal Device, a Mobile Terminal Device, a subscription Unit (subscription Unit), a subscription Station (subscription Station), a Mobile Station (Mobile), a Remote Station (Remote Station), an Access Point (Access Point, AP), a Remote Terminal Device (Remote Terminal), an Access Terminal Device (Access Terminal), a User Terminal Device (User Terminal), a User Agent (User Agent), or a User Device (User Device). For example, mobile phones (or so-called "cellular" phones), computers with mobile terminal equipment, dedicated terminal equipment in NB-IoT, portable, pocket, hand-held, computer-included, or car-mounted mobile devices may be included. Examples of such devices include Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), and the like.

4) The OFDM technology is developed from Multi-Carrier Modulation (MCM), and is one implementation of a Multi-Carrier transmission scheme. The main idea of the OFDM technology is to divide a channel into a plurality of orthogonal sub-channels, convert a high-speed data signal into parallel low-speed sub-data streams, and modulate the low-speed sub-data streams onto the orthogonal sub-channels respectively for transmission, that is, to transmit orthogonal signals. The orthogonal signals may be separated by correlation techniques at the receiving end, which may reduce Inter Symbol Interference (ISI) between the subchannels. In addition, the signal bandwidth on each sub-channel is smaller than the coherence bandwidth of the channel, so that each sub-channel can be regarded as flat fading, so that intersymbol interference can be eliminated, and since the bandwidth of each sub-channel is only a small part of the original channel bandwidth, channel equalization becomes relatively easy.

The carriers in OFDM are orthogonal, each carrier has an integral number of carrier periods in a symbol time, and the frequency spectrum zero of each carrier is overlapped with the zero of the adjacent carrier, so that the interference between the carriers is reduced. Because of the partial overlap between the carriers, it improves the Frequency band utilization ratio compared with the traditional Frequency Division Multiple Access (FDMA) technology.

5) The terms "system" and "network" in embodiments of the present invention may be used interchangeably. "plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified.

A possible model of an OFDM communication system is described below with reference to the accompanying drawings.

Referring to fig. 1, when a signal is to be transmitted, a transmitting device performs signal mapping on an original bit sequence, the original bit sequence is a signal to be transmitted, then performs serial-to-parallel conversion, then introduces an Inverse Fast Fourier Transform (IFFT) module, then performs OFDM modulation, changes a parallel sequence into a serial sequence after modulation is completed, adds a protection prefix to the serial sequence, then performs analog-to-digital conversion, low-pass filtering, and up-conversion, and finally transmits the serial sequence to a wireless channel through radio frequency. The receiving equipment receives signals through a wireless channel, performs down-conversion, low-pass filtering and digital/analog conversion on the received signals, removes protective prefixes for the signals to obtain serial sequences, performs serial-to-parallel conversion on the serial sequences to obtain parallel sequences, guides the parallel sequences into a Fast Fourier Transform (FFT) module to perform OFDM demodulation, performs parallel-to-serial conversion on the demodulated results to obtain serial sequences, and performs signal mapping on the serial sequences to obtain original bit sequences, namely transmitted signals. In the receiving process, when a receiver algorithm is involved, different algorithms such as timing synchronization, frequency offset estimation and the like, and frequency offset correction and the like can be added, which are common signal processing modes in the OFDM field, and are not described herein.

The scheme provided by the embodiment of the invention is described in the following with reference to the attached drawings.

Referring to fig. 2, a method for measuring a distance is provided, which may be applied to a receiving device, for example, a receiving device to which the method is applied is hereinafter referred to as a first receiving device, and the first receiving device may be, for example, any one of the terminal devices described above, or any one of the network devices described above. The process of the method is described as follows:

step 201: receiving a first multi-carrier signal sent by sending equipment;

step 202: analyzing the received first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase differences are phase differences between two sub-carriers in the received M sub-carriers, and M is a positive integer greater than 2;

step 203: calculating a plurality of phase fluctuation values corresponding to the plurality of actual phase differences, wherein the phase fluctuation values are the difference values of the actual phase differences and the original phase differences of two subcarriers in the M subcarriers; the original phase difference is the phase difference between two subcarriers in the M subcarriers before the multicarrier signals are sent by the sending equipment;

step 204: calculating a phase fluctuation average value of the first multi-carrier signal, wherein the phase fluctuation average value is obtained by averaging a plurality of phase fluctuation values;

step 205: and determining the transmission distance of the first multi-carrier signal according to the mapping relation between the phase fluctuation average value and the transmission distance, wherein the transmission distance of the first multi-carrier signal is the distance between the sending equipment and the receiving equipment.

The distance measuring method provided by the embodiment of the invention can be applied to indoor distance measurement and outdoor distance measurement, namely, short-distance measurement and long-distance measurement can be completed, and the application range is wider.

In an implementation manner, the method for measuring a distance provided by the embodiment of the present invention may be more suitable for a distance measurement scenario in which a distance to be measured is short, such as indoor distance measurement, for example, the distance to be measured may be smaller than a length corresponding to one period of a phase, the period of the phase is, for example, generally 2 pi, and the length corresponding to 2 pi is related to a subcarrier bandwidth and a subcarrier interval.

In another embodiment, if the method provided by the embodiment of the present invention is applied to distance measurement of an outdoor Global Positioning System (GPS), the distance to be measured is generally longer than a length corresponding to 2 pi, which may involve how many integer multiples of 2 pi are to be estimated, and may be difficult to be estimated, but it can also be implemented if the function of the device for distance measurement is relatively complete.

In an embodiment, the first multicarrier signal may be, for example, an arbitrary OFDM signal (including at least three subcarriers), or in another embodiment, the first multicarrier signal may also be a pilot signal, or in another embodiment, the first multicarrier signal may also be a preamble signal, and so on, and the embodiment of the present invention is not limited. For example, if the first multicarrier signal is a pilot signal or a preamble signal, the sending apparatus may further send another signal, for example, a data signal, to the first receiving apparatus after sending the first multicarrier signal to the first receiving apparatus.

In one embodiment, the first multicarrier signal may be an OFDM signal, for example, a signal received by the receiving device via a wireless channel, such that the first multicarrier signal is carried by a plurality of orthogonal subcarriers, and a phase difference may exist between different subcarriers. For example, the number of subcarriers carrying the first multicarrier signal is M, after the first receiving device receives the first multicarrier signal, the first receiving device may extract a phase difference between M subcarriers carrying the first multicarrier signal according to a preset phase difference extraction policy, that is, extract a phase difference between every two subcarriers of the M subcarriers, where every two subcarriers may be understood as that all the M subcarriers participate in the calculation of the phase difference, some subcarriers may participate in the calculation of obtaining only one phase difference, some subcarriers may participate in the calculation of obtaining a plurality of phase differences, and the first receiving device may extract a plurality of phase differences. In addition, the first receiving device may further obtain a phase difference between every two subcarriers of the M subcarriers before the first multicarrier signal is transmitted, and may also obtain a plurality of phase differences. After obtaining a plurality of actual phase differences and a plurality of original phase differences, the actual phase differences and the original phase differences may be differenced to obtain a plurality of differences. Since a plurality of phase fluctuation values are obtained, an average value of the plurality of phase fluctuation values may be calculated, and in calculating the average value, a general arithmetic average value may be calculated, or a weighted average value may also be calculated, or a squared sum average value may also be calculated, or a weighted average value may also be calculated, and the method for calculating the average value is not limited in the present application. In the embodiment of the present invention, the average value of the phase fluctuation values is referred to as a phase fluctuation average value, and the first receiving device may store a mapping relationship between the phase fluctuation average value and a transmission distance in advance, so that after the phase fluctuation average value of the first multicarrier signal is obtained, the transmission distance of the first multicarrier signal may be determined according to the mapping relationship between the phase fluctuation average value and the transmission distance, where the transmission distance of the first multicarrier signal is the distance between the first receiving device and the transmitting device.

Alternatively, in another embodiment, the mapping relationship may be a relationship between a phase fluctuation value and a transmission distance. For example, after calculating a plurality of phase fluctuation values corresponding to a plurality of actual phase differences, a plurality of transmission distances corresponding to the plurality of phase fluctuation values may be determined according to a mapping relationship between the phase fluctuation values and the transmission distances, a transmission distance average value may be calculated, and the transmission distance average value may be determined as the transmission distance of the first multicarrier signal, where the transmission distance of the first multicarrier signal may be the distance between the transmitting apparatus and the receiving apparatus. The transmission distance average value may be obtained by averaging a plurality of transmission distances. It is to be understood that the mapping relationship may be a mapping table, or may be data stored in other forms in the receiving device.

Optionally, the M subcarriers may be all subcarriers used for carrying the first multicarrier signal, or may also be some subcarriers used for carrying the first multicarrier signal, for example, the number of the subcarriers used for carrying the first multicarrier signal is greater than M, and M subcarriers may be selected from all the subcarriers used for carrying the first multicarrier signal to determine the transmission distance. For example, M subcarriers may be selected from the subcarriers used for carrying the first multicarrier signal according to a preset selection policy, where the preset selection policy may be multiple, for example, M subcarriers apart from a preset interval may be selected, or M subcarriers with the same bandwidth may be selected according to the specification of a protocol or a standard, or may be selected randomly, and the like.

In one embodiment, the original phase difference of the M subcarriers may be calculated by the first receiving device itself. For example, the first multicarrier signal is a known signal to the first receiving device, for example, the first multicarrier signal is a pilot signal, or a preamble signal, etc., then the first receiving device may calculate the original phase difference of the M subcarriers carrying the first multicarrier signal by itself, for example, the first receiving device may simulate that the transmission distance of the first multicarrier signal is 0, so as to calculate the original phase difference of the M subcarriers. That is, if the first multicarrier signal is a signal known to the first receiving device, the first receiving device may calculate the original phase difference by itself, without the participation of the transmitting device, and the interaction process between the devices is reduced.

In another embodiment, the original phase difference of the M subcarriers may be calculated by the transmitting device before transmitting the first multicarrier signal, and the result of the calculation may be transmitted to the first receiving device. For example, if the first multicarrier signal is a signal unknown to the first receiving device, the transmitting device may calculate the original phase differences of the subcarriers after multicarrier modulation of the first multicarrier signal, and transmit the calculated original phase differences to the first receiving device. Through the above two embodiments, the first receiving device can obtain the original phase differences of the M subcarriers no matter whether the first multicarrier signal is a known signal or an unknown signal for the first receiving device, and the application range is wide.

The original phase difference may be a phase difference between subcarriers calculated after the first multicarrier signal is subjected to multicarrier modulation, and the actual phase difference may be a phase difference between subcarriers calculated after the first multicarrier signal is subjected to multicarrier demodulation.

Optionally, the first receiving device calculates an actual phase difference of M subcarriers, and then first refers to extracting phases of the M subcarriers, for example, in the embodiment of the present invention, a subcarrier participating in calculating the actual phase difference is referred to as an actual subcarrier, and similarly, whether the first receiving device or the transmitting device calculates an original phase difference of the M subcarriers, then first refers to extracting phases of the M subcarriers, for example, in the embodiment of the present invention, a subcarrier participating in calculating the original phase difference is referred to as an original subcarrier. Alternatively, the phases of the extracted original subcarriers and the phases of the actual subcarriers may correspond one to one, so that the difference can be obtained.

It should be noted that the actual subcarrier and the original subcarrier are only names of subcarriers carrying the first multicarrier signal at different periods, and for the same subcarrier, after the first multicarrier signal is carried on the subcarrier through multicarrier modulation, the subcarrier is referred to as the original subcarrier, and after the first multicarrier signal carried by the subcarrier is subjected to multicarrier demodulation, the subcarrier is referred to as the actual subcarrier.

Alternatively, the number of subcarriers carrying the first multicarrier signal is M, taking calculating an actual phase difference of M subcarriers as an example, each actual phase difference is a difference between phases of two subcarriers, calculating the actual phase difference relates to how to pair the M subcarriers, that is, to find an actual phase difference according to the phases of two subcarriers, for example, at least one subcarrier spacing number may be set, a unit of the subcarrier spacing number is, for example, a subcarrier, for example, the subcarrier spacing number is 1, which means that the actual phase difference is to be found by two subcarriers apart by one subcarrier, and the actual phase difference may be calculated by two subcarriers apart by the set subcarrier spacing number in the M subcarriers, or, for example, it may be specified that which two subcarriers among the M subcarriers are respectively used to calculate an actual phase difference, or the two modes can be used jointly, for example, the number of subcarrier intervals is preset, how to use the number of subcarrier intervals by M subcarriers can be specified, and the like. Then, how to pair the M subcarriers to obtain the actual phase difference may be determined by the sending device, for example, if the sending device is responsible for calculating the original phase difference, and after the calculation, the plurality of calculated original phase differences may be sent to the first receiving device, and then the first receiving device may calculate the corresponding actual phase difference, or may be predefined by a protocol, so that both the sending device and the first receiving device may know in advance, or may be negotiated by the sending device and the first receiving device in advance. The original phase difference is similar, and the description is omitted. Of course, the original phase difference and the actual phase difference obtained by calculation may correspond to each other one by one, so that the difference can be calculated by pairwise pairing. The method and the device do not limit how to calculate the actual phase difference and the original phase difference.

For ease of understanding, how the first receiving apparatus calculates the multiple phase fluctuation values of the M subcarriers will be described below by way of several examples. It should be noted that the following examples are only used to illustrate the method described in the present application, and the implementation of the method of the present application is not limited to the following examples.

Example 1. In example 1, the first multicarrier signal is an unknown signal to the first receiving device, the phase of the original subcarriers being extracted by the transmitting device, wherein the phase of which original subcarriers and the phase of which actual subcarriers should be extracted can be specified by a protocol. And, the actual phase difference and the original phase difference are calculated by setting the number of subcarrier intervals.

For example, the transmitting device modulates a series of sequences onto K subcarriers by a multicarrier modulation scheme to obtain a first multicarrier signal, where the K subcarriers are, for example, subcarrier 0 to subcarrier 63. The transmitting device extracts therefrom the phase of subcarrier 3, the phase of subcarrier 4, the phase of subcarrier 5, the phase of subcarrier 32, the phase of subcarrier 33 and the phase of subcarrier 34, i.e., M is 6, according to the specifications of the protocol. For example, the set subcarrier spacing numbers include 29, 29, 29, then the transmitting device may obtain the phase difference of the two original subcarriers by the 3 subcarrier spacing numbers, respectively, starting with the extracted first original subcarrier, i.e., subcarrier 3, i.e., the transmitting device may calculate the original phase difference of subcarrier 3 and subcarrier 32, calculate the original phase difference of subcarrier 4 and subcarrier 33, and calculate the original phase difference of subcarrier 5 and subcarrier 34. For example, the transmitting device may transmit the 3 calculated original phase differences to the first receiving device. Alternatively, after extracting the phases of the 6 original subcarriers, the transmitting device may directly transmit the phases of the 6 original subcarriers to the first receiving device, and the first receiving device obtains the 3 original phase differences according to the set number of subcarrier intervals. The sending device sends the first multicarrier signal to the first receiving device, and the sending device sends the calculated original phase difference or sends the extracted phase of the original subcarrier to the first receiving device, and the execution sequence of the two processes can be arbitrary.

The transmitting apparatus transmits the first multicarrier signal to the first receiving apparatus, and after the first receiving apparatus receives the first multicarrier signal, the phase of subcarrier 3, the phase of subcarrier 4, the phase of subcarrier 5, the phase of subcarrier 32, the phase of subcarrier 33, and the phase of subcarrier 34 may be extracted from subcarriers 0 to 63 carrying the first multicarrier signal according to the specification of the protocol. The first receiving apparatus also knows that the set subcarrier spacing numbers include 29, 29, 29, then the first receiving apparatus can obtain the phase difference of two actual subcarriers, respectively, according to the 3 subcarrier spacing numbers, starting with the first actual subcarrier extracted, i.e., subcarrier 3, i.e., the receiving apparatus can calculate the actual phase difference of subcarrier 3 and subcarrier 32, calculate the actual phase difference of subcarrier 4 and subcarrier 33, and calculate the actual phase difference of subcarrier 5 and subcarrier 34.

After obtaining 3 actual phase differences and 3 original phase differences, the first receiving device may calculate differences between the 3 actual phase differences and the 3 original phase differences, that is, calculate phase fluctuation values of M subcarriers, and may obtain 3 phase fluctuation values. Optionally, the actual phase difference and the original phase difference obtained by the first receiving device may correspond to each other one by one, so that it is relatively convenient to calculate the phase fluctuation value. For example, the actual phase difference calculated by the first receiving apparatus includes the phase difference of subcarrier 3 and subcarrier 4 and the phase difference of subcarrier 4 and subcarrier 5, and the original phase difference obtained by the first receiving apparatus may include the phase difference of subcarrier 3 and subcarrier 4 and the phase difference of subcarrier 4 and subcarrier 5, so that when the phase fluctuation value is calculated, the difference between the phase difference of subcarrier 3 and subcarrier 4 in the actual phase difference and the phase difference of subcarrier 3 and subcarrier 4 in the original phase difference, that is, the phase fluctuation value, and the difference between the phase difference of subcarrier 4 and subcarrier 5 in the actual phase difference and the phase difference of subcarrier 4 and subcarrier 5 in the original phase difference, that is, the phase fluctuation value, may be obtained.

Example 2. In example 2, the first multicarrier signal is an unknown signal to the first receiving device, the transmitting device extracts the phases of the original subcarriers, wherein the phases of which original subcarriers and which actual subcarriers should be extracted can be negotiated in advance by the transmitting device and the first receiving device. And, the actual phase difference and the original phase difference are calculated by setting the number of subcarrier intervals.

For example, the sending device modulates a series of sequences onto K subcarriers by a multicarrier modulation method to obtain a first multicarrier signal, where the K subcarriers used for carrying the first multicarrier signal are, for example, subcarrier 0 to subcarrier 63. The transmitting apparatus and the first receiving apparatus have negotiated in advance that the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 are to be extracted therefrom, that is, M is 6, the transmitting apparatus extracts the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 therefrom, and the transmitting apparatus may transmit all the extracted phases of the original subcarriers to the first receiving apparatus.

For example, 5 subcarrier spacing numbers, 3, 3, 3, 3 respectively, are preset, the first receiving device may calculate the phase difference of two original subcarriers according to the 5 subcarrier spacing numbers, starting from the first original subcarrier extracted by the transmitting device, i.e., subcarrier 3, i.e., obtain the original phase difference, i.e., the first receiving device may calculate the original phase difference of subcarrier 3 and subcarrier 6, the original phase difference of subcarrier 6 and subcarrier 9, the original phase difference of subcarrier 9 and subcarrier 12, the original phase difference of subcarrier 12 and subcarrier 15, and the original phase difference of subcarrier 15 and subcarrier 18.

The transmitting device transmits the first multicarrier signal to the first receiving device, and after the first receiving device receives the first multicarrier signal, the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 may be extracted from subcarriers 0 to 63 carrying the first multicarrier signal according to a negotiation in advance with the transmitting device. It is also known that 5 subcarrier spacing numbers, 3, 3, 3, 3, 3 respectively, are preset in the first receiving device, then the receiving device can calculate the phase difference of two actual subcarriers, i.e. calculate the actual phase difference, respectively, according to the 5 subcarrier spacing numbers, starting from the first actual subcarrier, i.e. subcarrier 3, extracted, i.e. the first receiving device can obtain the actual phase difference of subcarrier 3 and subcarrier 6, obtain the actual phase difference of subcarrier 6 and subcarrier 9, obtain the actual phase difference of subcarrier 9 and subcarrier 12, obtain the actual phase difference of subcarrier 12 and subcarrier 15, and obtain the actual phase difference of subcarrier 15 and subcarrier 18.

The first receiving device may calculate the difference between the original phase difference and the actual phase difference, that is, calculate the phase fluctuation value of M subcarriers, after obtaining 5 actual phase differences and 5 original phase differences. Optionally, the actual phase difference and the original phase difference obtained by the first receiving device may correspond to each other one by one, so that it is relatively convenient to calculate the phase fluctuation value.

Example 3. In example 3, the first multicarrier signal is a known signal to the first receiving device, the first receiving device extracting the phases of the original subcarriers, wherein the phases of which original subcarriers and which actual subcarriers should be extracted can be negotiated in advance by the transmitting device and the first receiving device. And, the actual phase difference and the original phase difference are calculated by setting the number of subcarrier intervals.

For example, the sending device modulates a series of sequences onto K subcarriers by a multicarrier modulation method to obtain a first multicarrier signal, where the K subcarriers used for carrying the first multicarrier signal are, for example, subcarrier 0 to subcarrier 63.

The transmitting apparatus transmits the first multicarrier signal to the first receiving apparatus, and after the first receiving apparatus receives the first multicarrier signal, the first receiving apparatus may extract the phases of M subcarriers from K subcarriers according to a negotiation with the transmitting apparatus in advance, for example, if the transmitting apparatus and the first receiving apparatus have negotiated in advance that the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 are to be extracted from K subcarriers, that is, if M is 6, the first receiving apparatus extracts the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 from subcarriers 0 to 63 carrying the first multicarrier signal. For example, 5 subcarrier spacing numbers, 3, 6, 9, 12, 15 respectively, are preset, the first receiving apparatus may calculate the phase difference of two actual subcarriers, respectively, from the extracted first actual subcarrier, i.e., subcarrier 3, according to the 5 subcarrier spacing numbers, i.e., the first receiving apparatus may calculate the actual phase difference of subcarrier 3 and subcarrier 6, the actual phase difference of subcarrier 3 and subcarrier 9, the actual phase difference of subcarrier 3 and subcarrier 12, the actual phase difference of subcarrier 3 and subcarrier 15, and the actual phase difference of subcarrier 3 and subcarrier 18.

For example, the first multicarrier signal is a known signal to the first receiving device, for example, the first multicarrier signal is a pilot signal or a preamble signal, the first receiving device may calculate the original phase difference of the M subcarriers by itself without the transmitting device. Wherein the first receiving device calculates the original phase difference and the actual phase difference, and the execution order of the two processes can be arbitrary. The first receiving apparatus models the transmission distance of the first multicarrier signal as 0, i.e. removes the influence of the distance, which corresponds to the first multicarrier signal not yet transmitted, and thus calculates the original phase difference. The first receiving apparatus extracts the phase of subcarrier 3, the phase of subcarrier 6, the phase of subcarrier 9, the phase of subcarrier 12, the phase of subcarrier 15, and the phase of subcarrier 18 from the M subcarriers according to negotiation in advance with the transmitting apparatus. For example, 5 subcarrier spacing numbers, 3, 6, 9, 12, 15 respectively, are set in advance, the first receiving apparatus may obtain the phase difference of the two original subcarriers, respectively, from the extracted first original subcarrier, that is, subcarrier 3, according to the 5 subcarrier spacing numbers, that is, the first receiving apparatus may calculate the original phase difference of subcarrier 3 and subcarrier 6, the original phase difference of subcarrier 3 and subcarrier 9, the original phase difference of subcarrier 3 and subcarrier 12, the original phase difference of subcarrier 3 and subcarrier 15, and the original phase difference of subcarrier 3 and subcarrier 18.

After calculating 5 actual phase differences and 5 original phase differences, the first receiving device may calculate differences between the 5 actual phase differences and the 5 original phase differences, that is, calculate phase fluctuation values of M subcarriers. Optionally, the actual phase difference and the original phase difference obtained by the first receiving device may correspond to each other one by one, so that it is relatively convenient to calculate the phase fluctuation value.

Of course, the above ways of calculating the phase fluctuation value are only examples, and are not limited to this in practical applications.

Alternatively, after obtaining a plurality of phase fluctuation values, an average value of the plurality of phase fluctuation values, that is, a phase fluctuation average value, is calculated, when calculating the phase fluctuation average value, if the distances between two subcarriers used for obtaining each phase fluctuation value are equal, the phase fluctuation average value may be directly obtained, for example, refer to example 1 and example 2 as before, whereas if the distances between two subcarriers used for obtaining each phase fluctuation value may be unequal, there may be a corresponding method when obtaining the phase fluctuation average value, taking example 3 as an example, example 3, the phase fluctuation values calculated by example 3 correspond to subcarriers 3 and 6, subcarriers 3 and 9, subcarriers 3 and 12, subcarriers 3 and 15, and subcarriers 3 and 18, it is seen that the intervals between the subcarriers corresponding to each phase fluctuation value are different, for example, the phase fluctuation values corresponding to subcarriers 3 and 6 are represented by W, the phase fluctuation values corresponding to subcarriers 3 and 9 are represented by W, the phase fluctuation values corresponding to subcarriers 3 and 12 are represented by W3 and 12, and the subcarrier 3 and subcarrier 18 are represented by W '2, and the phase fluctuation values are represented by W' 2, and W 'are represented by W3 and W' 2, and W 'are represented by W3 and W' 2, so the same subcarrier spacing is calculated as W3 and W6.

Optionally, when determining the transmission distance, the mapping relationship between the phase fluctuation average value and the transmission distance needs to be used, so the mapping relationship between the phase fluctuation average value and the transmission distance may be preset, and the mapping relationship between the phase fluctuation average value and the transmission distance may be set, and this process may be completed by any device, such as a sending device, or may be completed by a first receiving device, or may also be completed by a third-party device, such as a dedicated testing device, as long as the first receiving device can obtain the mapping relationship between the phase fluctuation average value and the transmission distance. How to set the mapping relationship between the phase fluctuation average value and the transmission distance will be described later.

Alternatively, there may be a plurality of mapping relationships between the phase fluctuation average value and the transmission distance, for example, according to the process of calculating the phase fluctuation value as described above, when the number of subcarrier intervals is different, there may be a different mapping relationship between the phase fluctuation average value and the transmission distance, or when two subcarriers for obtaining a phase difference are different, there may be a different mapping relationship between the phase fluctuation average value and the transmission distance, or when the number of M is different, there may be a different mapping relationship between the phase fluctuation average value and the transmission distance, or if the frequency difference between adjacent subcarriers is different, or the channel condition is different, the mapping relationship may be different, and so on. Therefore, when the mapping relationship is preset, at least one mapping relationship may be preset, for example, if only one mapping relationship is set, the mapping relationship that the first receiving device needs to know in advance is less, the storage space of the first receiving device is saved, the whole process is also simpler, and if multiple mapping relationships are set, different mapping relationships may be selected as needed in the process of obtaining the transmission distance, which is more flexible.

Alternatively, a part of the manner for generating the mapping relationship between the phase fluctuation average value and the transmission distance may refer to the manner for calculating the phase fluctuation value as described above, that is, a plurality of phase fluctuation average values may be calculated under a plurality of different transmission distances on the basis of the manner for calculating the phase fluctuation value as described above, where each transmission distance corresponds to one phase fluctuation average value, so that the mapping relationship may be generated according to a plurality of transmission distances and a plurality of phase fluctuation average values, for example, a curve fitting may be performed according to a plurality of phase fluctuation average values and a plurality of transmission distances, so as to obtain the mapping relationship between the phase fluctuation average value and the transmission distance.

Optionally, no matter what kind of mapping relationship between the phase fluctuation average value and the transmission distance is introduced as above, the mapping relationship may be generated in different manners, for example, may be generated in a simulation manner, the generation manner is relatively simple and can be implemented by software, then the process of generating the mapping relationship may be executed by any one device, for example, the mapping relationship may be generated by the sending device or the third-party device through simulation, and the sending device or the third-party device may send the generated mapping relationship to the first receiving device after the mapping relationship is generated, so that the first receiving device may determine the transmission distance through the mapping relationship, or may also generate the mapping relationship through simulation by the first receiving device, thereby saving the process of transmitting the mapping relationship and saving transmission resources. Or, for example, the mapping relationship may also be generated through field experiments, that is, the mapping relationship may be generated by changing the actual distance between the sending device and the first receiving device multiple times, in this case, the first receiving device may receive the second multicarrier signal sent by the testing device to generate the mapping relationship, and the testing device may be, for example, the sending device as described above, or may also be a third-party device, and the correspondence relationship generated by this way may reflect the actual situation and may better conform to the actual application. For ease of understanding, a possible way of generating the mapping relationship by simulation is described below, for example, the simulation process is performed by the first receiving device.

The first receiving device may modulate a string of known sequences l (x) onto M OFDM subcarriers by a multicarrier modulation method through simulation to obtain a second multicarrier signal, where the second multicarrier signal is an OFDM signal obtained by modulating the known sequences onto the OFDM subcarriers after multicarrier modulation, and for example, if the mapping relationship is a mapping relationship corresponding to the first multicarrier signal, the second multicarrier signal and the first multicarrier signal may be the same multicarrier signal. The two multicarrier signals are the same, and may include the same number of subcarriers of the two multicarrier signals, the same information carried by the two multicarrier signals, and the same bandwidth of the subcarriers carrying the two multicarrier signals.

The first receiving apparatus extracts the phase of the original subcarrier of the second multicarrier signal, for example, the extracted original subcarrier is denoted as subcarrier x, and the phase of the extracted original subcarrier is denoted as pi (x), for example, where x ═ 1, …, W are the total number of subcarriers used for carrying the second multicarrier signal, for example, if the mapping relationship is a mapping relationship corresponding to the first multicarrier signal, if W > M, M subcarriers should be selected from the W subcarriers, and if W ═ M, the W subcarriers are taken as M subcarriers. For example, at least one subcarrier spacing number is preset, the at least one subcarrier spacing number is Nb, for example, and the original phase difference of two subcarriers separated by Nb original subcarriers is denoted as q (x), where q (x) is Pi (x + Nb) -Pi (x). For example, the first receiving device may simulate the transmission of the second multicarrier signal over a plurality of transmission distances, respectively, then a plurality of original phase differences may be obtained at each transmission distance. Optionally, the second multicarrier signal may be, for example, a normal OFDM signal, or may be a pilot signal, or may also be a preamble signal, and so on, and the embodiment of the present invention is not limited.

The first receiving device receives the second multicarrier signal by means of simulation at a plurality of transmission distances, respectively, wherein at each transmission distance, the first receiving device extracts the phase of M subcarriers from the W subcarriers used to carry the second multicarrier signal by means of simulation, for example, the extracted subcarriers are referred to as actual subcarriers, which are also denoted as subcarriers x, and at each transmission distance, the first receiving device may obtain the phase difference of the actual subcarriers separated by Nb subcarriers, for example, at each transmission distance, a plurality of actual phase differences may be obtained, where the transmission distance refers to the distance between the first receiving device and the transmitting device. For example, the actual phase difference is denoted as Qi (x), and at each transmission distance, the receiving device may calculate a difference between the actual phase difference and the original phase difference, i.e., calculate a phase fluctuation value, for example, denoted as Δ Qi, where Δ Qi ═ Qi (x) -q (x), and then a plurality of Δ Qi may be obtained according to each transmission distance. The first receiving apparatus may obtain a performance curve between the transmission distances and Δ Qi through simulation based on a plurality of Δ Qi and a plurality of transmission distances, for example, for each transmission distance, the first receiving apparatus may obtain an average value of a plurality of Δ Qi corresponding to the transmission distance, for example, the average value is referred to as a phase fluctuation average value, and a plurality of phase fluctuation average values may be obtained, and then the first receiving apparatus may obtain a performance curve between the transmission distance and the phase fluctuation average value through simulation based on the plurality of phase fluctuation average values and the plurality of transmission distances, for example, referring to fig. 3, which is an example of a performance curve between the transmission distance and the phase fluctuation average value, a horizontal axis in fig. 3 represents the transmission distance, a vertical axis represents the phase fluctuation average value, for example, a frequency difference between two adjacent subcarriers in fig. 3 is 31.25khz, and 256 subcarriers in total, the channel conditions are mode b (modeb) channels as defined in the 802.11n standard. It is proved by experiments that the phase curve is smoother when Nb is 200 subcarriers, and the slope is larger, which means that the resolution is larger, and fig. 3 is taken as an example when Nb is 200. After obtaining the performance curve, for example, a possible performance curve is fig. 3, the first receiving device may obtain a mapping relationship between the average value of the phase fluctuation and the transmission distance through curve fitting, for example, the mapping relationship between the average value of the phase fluctuation and the transmission distance is a linear relationship when Nb is 200 subcarriers, for example, the linear relationship is as follows:

P＝80+(230-80)/20*R (1)

in the formula (1), P represents a phase fluctuation average value, and R represents a transmission distance. The coefficients in equation (1) are obtained by curve fitting, and naturally, the equations will be different if the curves obtained by simulation are different.

The above manner of obtaining the mapping relationship is only an example, and is not limited to this in practical application.

Optionally, as already described above, there may be a plurality of mapping relationships, and it is known that the mapping relationships are associated with the phase difference extraction strategies according to the foregoing description, then correspondingly, a plurality of phase difference extraction strategies may also be preset, for example, one phase difference extraction strategy may correspond to one or more mapping relationships, and for example, one mapping relationship may correspond to one or more phase difference extraction strategies. In addition, different multicarrier signals may correspond to different phase difference extraction strategies and mapping relationships, and thus, it may be considered that multicarrier signals are also related to both phase difference extraction strategies and mapping relationships. For example, after the first receiving apparatus receives the first multicarrier signal, if the first receiving apparatus stores a plurality of preset phase difference extraction policies in advance, the first receiving apparatus may select a phase difference extraction policy corresponding to the first multicarrier signal from the received first multicarrier signal, and correspondingly, if the first receiving apparatus stores a plurality of mapping relationships, the first receiving apparatus may also select a mapping relationship corresponding to the first multicarrier signal from the received first multicarrier signal.

Optionally, in addition to obtaining the transmission distance between the first receiving device and the sending device, the sending device may be located by using the transmission distance, for example, the sending device may be located by using Time Difference of arrival (TDOA). The TDOA technology is developed on the basis Of Time Of Arrival (TOA), the TDOA technology can obtain the distance difference from a signal source to a plurality Of monitoring stations according to the Time difference from the signal source to the plurality Of monitoring stations, the transmission distance from the monitoring stations to the signal source can be obtained directly through the ranging mode provided by the embodiment Of the invention, the ranging is not required to be carried out by utilizing the Time difference, and the monitoring stations are not required to be synchronized, so that the requirement on the error Of synchronization timing is reduced, the requirement on the network is relatively low, and the higher positioning precision can be achieved. In the embodiment of the invention, the monitoring station and the receiving equipment can be in the same concept, and the signal source and the sending equipment can be in the same concept.

By taking the idea of TDOA as a reference, the average value of phase fluctuation between a plurality of receiving devices can be combined to obtain the distance difference between two receiving devices, so as to assist in locating the transmitting device. This can provide the added benefit of TOA to TDOA, reduce the requirement of the network for synchronous timing, and simplify the linear relationship between phase difference and transmission distance.

For example, three receiving devices, namely a first receiving device, a second receiving device and a third receiving device, may be included, and the first receiving device may be the first receiving device as described above. For the purpose of describing more details, the following takes as an example that the receiving device is an Access Point (AP), although the type of the receiving device is not limited thereto. Then, for example, the first receiving device is AP1, the second receiving device is AP2, and the third receiving device is AP3, for example, the transmitting device transmits the first multicarrier signal to AP1, AP2, and AP3, the transmitting device does not need to transmit simultaneously, and AP1, AP2, and AP3 do not need to receive simultaneously. AP1, AP2, and AP3 may all calculate phase fluctuation averages as previously described. For example, the phase fluctuation average value calculated by the AP1 is referred to as a first phase fluctuation average value, for example, denoted as K1, the phase fluctuation average value calculated by the AP2 is referred to as a second phase fluctuation average value, for example, denoted as K2, and the phase fluctuation average value calculated by the AP3 is referred to as a third phase fluctuation average value, for example, denoted as K3. Optionally, the process of locating the transmitting device may be performed by any one of AP1, AP2, and AP3, for example, the AP1 is used to perform locating of the transmitting device. Then the AP1 may request to acquire K2 from the AP2 and may request to acquire K3 from the AP3, or the AP2 may also actively send K2 to the AP1, and the AP3 may also actively send K3 to the AP 1. The AP1 may determine the distance between the transmitting device and the AP1 from K1 and the mapping relationship between the average value of the phase difference fluctuation and the transmission distance, determine the distance between the transmitting device and the AP2 from K2 and the mapping relationship between the average value of the phase difference fluctuation and the transmission distance, determine the distance between the transmitting device and the AP3 from K3 and the mapping relationship between the average value of the phase difference fluctuation and the transmission distance, calculate a distance difference between the distance between the transmitting device and the AP1 and the distance between the transmitting device and the AP2, for example, to represent the distance difference as Δ D12, and calculate a distance between the transmitting device and the AP1 and the distance between the transmitting device and the AP3, for example, to represent the difference as Δ D13, so that the position of the transmitting device may be obtained from Δ D12 and Δ D13.

Alternatively, after obtaining K1, K2 and K3, the AP1 may obtain the difference between K1 and K2 and the difference between K1 and K3, respectively, for example, the difference between K1 and K2 is represented as Δ K12, and the difference between K1 and K3 is represented as Δ K13, the AP1 may determine the distance between the transmitting device and the AP1 and the distance difference between the transmitting device and the AP2 according to Δ K12 and the mapping relationship between the average value of fluctuation of phase difference and the transmission distance, for example, Δ D12, and may determine the distance between the transmitting device and the AP1 and the distance difference between the transmitting device and the AP3 according to Δ K13 and the mapping relationship between the average value of fluctuation of phase difference and the transmission distance, for example, Δ D13, and then the first receiving device may estimate the position of the transmitting device according to Δ D12 and Δ D13, thereby achieving the positioning of the transmitting device.

The following describes the apparatus provided by the embodiment of the present invention with reference to the drawings.

Referring to fig. 4, based on the same inventive concept, there is provided an apparatus for measuring a distance, which may be, for example, the first receiving apparatus as described above, and which may include a memory 401, a processor 402, and a receiver 403.

The method disclosed in the above embodiments of the present invention may be applied to the processor 402 or implemented by the processor 402.

The processor 402 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 402. The processor 402 may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. The general processor can be a microprocessor, a singlechip and other general processors, and can also be any conventional processor and the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor.

The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in the memory 401, and the processor 402 reads the information in the memory 401 and completes the steps of the method in combination with the hardware.

The receiver 403 may belong to a radio frequency system and is used for network communication with an external device, for example, the external device may be communicated with through a network such as ethernet, a wireless access network, a wireless local area network, etc.

The memory 401 and the receiver 403 may be connected to the processor 402 via the bus 400 (as shown in fig. 4 for example), or may be connected to the processor 402 via a dedicated connection.

The device for measuring distance may be adapted to perform the method described above with reference to fig. 2, and may for example be the first receiving device as described above. Therefore, for the functions and the like realized by each unit in the device, reference may be made to the description of the foregoing method portions, which are not repeated herein.

Alternatively, for example, the device may be a dedicated test device, such as some test instruments, or the device may be a general terminal device, such as a handheld device, or a small-sized machine, or a server, or the device may be a network device, such as a base station, or may be a remote sensing device near the base station, or the like. The device may be a stand-alone device or may also be a functional module located in other devices, for example, the device may be implemented by a chip and an antenna, as long as the chip can implement the function of the processor 402 and has a certain storage space, and the antenna can implement the function of the receiver 403. In summary, the embodiment of the present invention does not limit the form of the apparatus, and as long as one apparatus can implement the method for measuring a distance provided by the embodiment of the present invention, the apparatus may be used as the apparatus for measuring a distance in the embodiment of the present invention.

The device can measure the distance between the device and the sending device by calculating the phase fluctuation value of the M subcarriers carrying the first multicarrier signal without synchronizing with other devices, and the synchronization requirement of the device is not high, so that the performance requirement of the device is not high, the device is more beneficial to practical application, and the cost of the device can be saved to a certain extent due to the fact that the performance requirement of the device is not high.

Referring to fig. 5, another apparatus for measuring a distance is provided based on the same inventive concept, and may include a receiving module 501, an analyzing module 502, a calculating module 503, and a determining module 504. Optionally, the apparatus may further comprise a generating module 505.

Wherein, the above-described modules are all shown by fig. 5, then it is obvious that fig. 5 is only a possible structural block diagram of the apparatus, for example, the apparatus may also not include the generating module 505, etc.

In practical applications, the entity device corresponding to the receiving module 501 may be the receiver 403 in fig. 4, and the entity devices corresponding to the analyzing module 502, the calculating module 503, the determining module 504, and the generating module 505 may be the processor 402 in fig. 4.

In the present invention, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the described units or division of units is only one type of division of logical functions, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of some interfaces, devices or units, and may be an electric or other form.

An embodiment of the present invention further provides a computer storage medium, where the computer storage medium may store a program, and when the program is executed, the program includes some or all of the steps of any of the distance measuring methods described in the above method embodiments.

The functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be an independent physical module.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device, such as a personal computer, a server, or a network device, or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a Universal Serial Bus flash drive (usb flash drive), a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above embodiments are only used to describe the technical solutions of the present invention in detail, but the above embodiments are only used to help understanding the method of the embodiments of the present invention, and should not be construed as limiting the embodiments of the present invention. Variations or substitutions that may be readily apparent to one skilled in the art are intended to be included within the scope of the embodiments of the present invention.

Claims

1. A method of measuring distance, the method for a receiving device, comprising:

receiving a first multi-carrier signal sent by sending equipment;

analyzing the received first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, wherein the actual phase differences are phase differences between two sub-carriers in the received M sub-carriers, and M is a positive integer greater than 2;

calculating a plurality of phase fluctuation values corresponding to the plurality of actual phase differences, where the phase fluctuation values are differences between actual phase differences of two subcarriers of the M subcarriers and original phase differences, and the original phase differences are phase differences between two subcarriers of the M subcarriers before the first multicarrier signal is transmitted by the transmitting device;

calculating a phase fluctuation average value of the first multi-carrier signal, wherein the phase fluctuation average value is obtained by averaging the plurality of phase fluctuation values;

and determining the transmission distance of the first multi-carrier signal according to the mapping relation between the phase fluctuation average value and the transmission distance, wherein the transmission distance of the first multi-carrier signal is the distance between the sending equipment and the receiving equipment.

2. The method of claim 1, wherein the method further comprises:

and generating the mapping relation according to a plurality of different transmission distances and a plurality of phase fluctuation average values calculated under the different transmission distances.

3. The method of claim 2, wherein generating the mapping based on a plurality of different transmission distances and a plurality of phase fluctuation averages calculated at the plurality of different transmission distances comprises:

the plurality of different transmission distances are set up,

establishing the mapping relation according to the plurality of different transmission distances and a plurality of phase fluctuation average values under the plurality of different transmission distances;

wherein,

at each of the plurality of different transmission distances, the receiving apparatus calculates a plurality of phase fluctuation average values at the plurality of different transmission distances by performing:

receiving a second multi-carrier signal sent by a test device, wherein the second multi-carrier signal comprises the M sub-carriers;

calculating a plurality of phase fluctuation values for the M subcarriers in the second multicarrier signal;

calculating a phase fluctuation average value of the second multi-carrier signal.

4. A method according to any of claims 1-3, wherein said analyzing said received first multi-carrier signal to obtain a plurality of actual phase differences for M sub-carriers in said first multi-carrier signal comprises:

selecting a phase difference extraction strategy corresponding to the first multicarrier signal from a plurality of preset phase difference extraction strategies;

analyzing the first multi-carrier signal according to the phase difference extraction strategy corresponding to the first multi-carrier signal to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal;

correspondingly, the determining the transmission distance of the first multicarrier signal according to the mapping relationship between the phase fluctuation average value and the transmission distance and the phase fluctuation average value of the first multicarrier signal includes:

selecting a mapping relation corresponding to the first multi-carrier signal from a plurality of stored mapping relations between the phase fluctuation average values and the transmission distances;

and determining the transmission distance of the first multi-carrier signal according to the mapping relation corresponding to the first multi-carrier signal.

5. A method according to any of claims 1-3, wherein the first multi-carrier signal is a pilot signal or a preamble signal.

6. An apparatus for measuring distance, comprising:

the receiving module is used for receiving a first multi-carrier signal sent by sending equipment;

an analyzing module, configured to analyze the received first multicarrier signal to obtain a plurality of actual phase differences of M subcarriers in the first multicarrier signal, where the actual phase difference is a phase difference between two subcarriers in the received M subcarriers, and M is a positive integer greater than 2;

a calculating module, configured to calculate a plurality of phase fluctuation values corresponding to the plurality of actual phase differences, where the phase fluctuation value is a difference between an actual phase difference and an original phase difference of two subcarriers of the M subcarriers; the original phase difference is a phase difference between two subcarriers of the M subcarriers before the first multicarrier signal is transmitted by the transmitting device;

the calculation module is further configured to calculate a phase fluctuation average value of the first multicarrier signal, where the phase fluctuation average value is obtained by averaging the plurality of phase fluctuation values;

a determining module, configured to determine a transmission distance of the first multicarrier signal according to a mapping relationship between the phase fluctuation average value and the transmission distance, where the transmission distance of the first multicarrier signal is a distance between the sending device and the receiving device.

7. The device of claim 6, wherein the device further comprises a generation module to:

8. The apparatus of claim 7, wherein the generation module, in generating the mapping relationship based on a plurality of different transmission distances and a plurality of phase fluctuation averages calculated over the plurality of different transmission distances, is to:

the plurality of different transmission distances are set up,

wherein,

at each of the plurality of different transmission distances, the generation module calculates a plurality of phase fluctuation averages at the plurality of different transmission distances by:

receiving a second multicarrier signal sent by the test equipment through the receiving module, wherein the second multicarrier signal comprises the M subcarriers;

9. The apparatus according to any of claims 6-8, wherein in said analyzing said received first multi-carrier signal to obtain a plurality of actual phase differences for M sub-carriers in said first multi-carrier signal,

the analysis module is configured to:

correspondingly, in the aspect of determining the transmission distance of the first multicarrier signal according to the mapping relationship between the phase fluctuation average value and the transmission distance and the phase fluctuation average value of the first multicarrier signal, the determining module is configured to:

10. The apparatus of any of claims 6-8, wherein the first multi-carrier signal is a pilot signal or a preamble signal.

11. A device for measuring distance, comprising a processor, a memory, a receiver, and a bus, wherein the memory and the processor are connected via the bus; the memory is used for storing computer instructions, and the processor is used for executing the computer instructions stored by the memory; when the computer device is running, the processor executes computer instructions causing the computer device to perform the following operations:

receiving a first multi-carrier signal sent by sending equipment by calling the receiver;

analyzing the first multi-carrier signal received by the receiver to obtain a plurality of actual phase differences of M sub-carriers in the first multi-carrier signal, where the actual phase differences are phase differences between two sub-carriers in the received M sub-carriers, and M is a positive integer greater than 2;

12. The device of claim 11, wherein the processor executes computer instructions that, when executed by the computer device, further cause the computer device to:

13. The apparatus of claim 12, wherein in generating the mapping relationship based on a plurality of different transmission distances and a plurality of phase fluctuation averages calculated over the plurality of different transmission distances, the processor executes computer instructions that cause the computer apparatus to:

the plurality of different transmission distances are set up,

wherein,

at each of the plurality of different transmission distances, the processor causes the computer device to calculate a plurality of phase fluctuation averages at the plurality of different transmission distances by executing computer instructions to:

receiving a second multi-carrier signal sent by test equipment by calling the receiver, wherein the second multi-carrier signal comprises the M sub-carriers;

calculating a plurality of phase fluctuation values of the M subcarriers in the second multicarrier signal received by the receiver;

calculating a phase fluctuation average of the second multi-carrier signal received by the receiver.

14. The apparatus according to any of claims 11-13, wherein in said analyzing said received first multi-carrier signal to obtain a plurality of actual phase differences for M sub-carriers in said first multi-carrier signal,

the processor executes computer instructions that cause the computer device to:

accordingly, in the aspect of determining the transmission distance of the first multicarrier signal according to the mapping relationship between the phase fluctuation average value and the transmission distance and the phase fluctuation average value of the first multicarrier signal, the processor executes computer instructions to make the computer device perform the following operations:

15. The apparatus according to any of claims 11-13, wherein the first multi-carrier signal is a pilot signal or a preamble signal.