CN115460534A

CN115460534A - Positioning method, positioning device and processor-readable storage medium

Info

Publication number: CN115460534A
Application number: CN202110557325.XA
Authority: CN
Inventors: 林益之; 李丹妮; 许江伟
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2021-05-21
Filing date: 2021-05-21
Publication date: 2022-12-09

Abstract

The invention provides a positioning method, a positioning device and a processor readable storage medium, and relates to the technical field of communication. The method comprises the following steps: acquiring first data comprising a plurality of measurement time differences and second data comprising a plurality of distance differences; obtaining position information of the target terminal determined by M times of iteration based on an iteration algorithm according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is the distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M; and positioning the target terminal according to the position information determined by the M times of iteration. The invention can solve the problem of inaccurate terminal positioning in the current positioning method.

Description

Positioning method, positioning device and processor-readable storage medium

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a positioning method, an apparatus, and a processor-readable storage medium.

Background

A terminal can be located based on a plurality of base stations, and the current location method usually uses an Approximate maximum likelihood estimation (AML) method and a Time Difference of Arrival (TDOA) measurement (i.e., a measurement of a Time Difference between signals transmitted from the terminal to different base stations) to solve the location of the terminal. The method for solving the terminal position based on the AML and the TDOA may have a plurality of solutions, if the plurality of solutions of the terminal position are obtained through solving, one solution is selected from the plurality of solutions of the terminal position obtained through solving to carry out the positioning of the terminal, and the method may have the problem of wrong solution selection, so that the positioning of the terminal may be inaccurate.

Disclosure of Invention

The invention provides a positioning method, a positioning device and a processor readable storage medium, which solve the problem of inaccurate terminal positioning in the conventional positioning method.

An embodiment of the present invention provides a positioning method, including:

acquiring first data comprising a plurality of measurement time differences and second data comprising a plurality of distance differences; wherein one of the measured time differences is a measured time difference between transmission of a signal from a target terminal to a first base station and a second base station, and one of the distance differences is a distance difference between the target terminal to the first base station and the second base station; the first base station is a base station in a positioning system, and the second base station is a base station in the positioning system except the first base station;

obtaining position information of the target terminal determined by M times of iteration based on an iteration algorithm according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is a distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M;

and positioning the target terminal according to the position information determined by the M times of iteration.

Optionally, in a case of M =1, obtaining, based on an iterative algorithm, location information of the target terminal determined by M iterations according to the first data and the second data includes:

according to the first data and the second data, position information determined at the (m-1) th time is obtained based on Least Square (LS) estimation, and mth first position information of the target terminal is obtained based on approximate maximum likelihood estimation; wherein the m-1 th determined location information and the mth first location information are both related to the first distance;

and if the value of the first distance calculated by the mth first position information does not meet the positioning condition of the target terminal, determining the position information determined by the mth iteration based on the first distance corresponding to the position information determined at the (m-1) th time, the first data and the second data.

Optionally, in the case that M > 1, the determining, based on an iterative algorithm, location information of the target terminal for M iterations according to the first data and the second data includes:

according to the first data and the second data, estimating and obtaining mth first position information of the target terminal based on an approximate maximum likelihood method; wherein the mth first location information is related to the first distance;

if the value of the first distance calculated by the mth first position information does not meet the positioning condition of the target terminal, determining the position information determined by the mth iteration based on the first distance corresponding to the position information determined at the (m-1) th time, the first data and the second data;

and the position information determined at the m-1 th iteration is the position information determined at the m-1 st iteration obtained based on the iterative algorithm.

Optionally, obtaining, according to the first data and the second data, mth first position information of the target terminal based on an approximate maximum likelihood estimation method, including:

determining a first maximum likelihood error function from the first data and the second data;

and determining the mth first position information according to the first maximum likelihood error function.

Optionally, determining the mth first location information according to the first maximum likelihood error function includes:

determining a first equivalent formula corresponding to the derivative being zero according to the derivative of the first maximum likelihood error function relative to theta; wherein θ is preset position information of the target terminal;

and determining the mth first position information according to the first equivalent formula.

Optionally, the first maximum likelihood error function J _d Comprises the following steps:

wherein, T _d Is the first data; d (θ) is the second data; c is the transmission speed of the signal; q _d Is based on T _d The determined covariance matrix.

Optionally, the first equivalent formula is: 2 Φ D θ = Φ v;

wherein the content of the first and second substances,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

v ₁ ＝[(Δ ₂₁ ² +k ₁ -k ₂ )…(Δ _N1 ² +k ₁ -k _N )] ^T ；Ψ＝2[Δ ₂₁ …Δ _N1 ] ^T ；

wherein the position information of the ith second base station in the N-1 second base stations is (x) _i ，y _i ) I =2, \ 8230;, N; n is the number of base stations in the positioning system; r is _i Is the distance, k, from the target terminal to the ith second base station _i ＝x _i ² +y _i ² (ii) a The location information of the first base station is (x) ₁ ，y ₁ )；r ₁ Is the distance, k, from the target terminal to the first base station ₁ ＝x ₁ ² +y ₁ ² ；Δ _i1 And measuring the distance difference between the target terminal and the first base station and the ith second base station.

Optionally, if the value of the first distance calculated from the mth first location information does not satisfy the location condition of the target terminal, determining the location information determined in the mth iteration based on the first distance corresponding to the location information determined in the m-1 th iteration, the first data, and the second data includes:

if two values of the first distance calculated by the mth first position information satisfy a preset condition, determining that the first distance r calculated by the mth first position information satisfies the preset condition ₁ The value of (2) does not meet the positioning condition of the target terminal; wherein, the two values meet the preset conditions as follows: the two numerical values are both positive real numbers, or the two numerical values are both negative real numbers, or the two numerical values are both complex numbers;

and determining the position information determined by the mth iteration based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data.

Optionally, determining the position information determined in the mth iteration based on the first distance, the first data, and the second data corresponding to the position information determined in the (m-1) th iteration includes:

determining a second maximum likelihood error function according to a first distance corresponding to the m-1 th determined position information, the first data, the second data and third data containing a plurality of measuring times; wherein one of the measurement times is a measurement time for a signal transmitted from the target terminal to a base station in the positioning system;

and determining the position information determined by the mth iteration according to the second maximum likelihood error function.

Optionally, determining a second maximum likelihood error function according to a first distance, the first data, the second data, and third data including a plurality of measurement times corresponding to the m-1 th determined location information includes:

determining fourth data according to a first distance corresponding to the position information determined at the (m-1) th time, the transmission speed of the signal and the first data;

determining fifth data according to the first distance corresponding to the position information determined at the (m-1) th time and the second data;

determining a second maximum likelihood error function based on the third data, the fourth data, and the fifth data.

Optionally, the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data, and the fourth data,

T _d ＝[t ₂₁ …t _N1 ] ^T ，t _i1 measuring time difference for signal transmission from the target terminal to the first base station and an ith second base station, i =2, \8230; n is the number of base stations in the positioning system; r is a radical of hydrogen _1,m-1 A first distance corresponding to the position information determined for the (m-1) th time;

r _d (θ) is the fifth data, r _d (θ)＝[r _1,m-1 ,d(θ)] ^T ，d(θ)＝[d ₂₁ …d _N1 ] ^T ，d _i1 Obtaining the distance difference between the target terminal and the first base station and the ith second base station;

c is the transmission speed of the signal; q is a covariance matrix determined based on the third data.

Optionally, positioning the target terminal according to the position information determined by M iterations includes:

determining a maximum likelihood error value corresponding to the position information determined by each iteration;

determining target position information according to the minimum maximum likelihood error value corresponding to the position information determined by the M times of iteration;

and determining the target position information as the positioning position of the target terminal.

The embodiment of the invention provides a positioning device, which comprises a memory, a transceiver and a processor;

wherein the memory is used for storing computer programs; the transceiver is used for transceiving data under the control of the processor; the processor is used for reading the computer program in the memory and executing the following operations:

acquiring first data comprising a plurality of measurement time differences and second data comprising a plurality of distance differences; wherein one of the measured time differences is a measured time difference between transmission of a signal from a target terminal to a first base station and a second base station, and one of the distance differences is a distance difference between the target terminal to the first base station and the second base station; the first base station is one base station in a positioning system, and the second base station is a base station in the positioning system other than the first base station;

Optionally, in case m =1, the processor is configured to read the computer program in the memory and perform the following operations:

obtaining the position information determined at the (m-1) th time based on least square method estimation according to the first data and the second data, and obtaining the mth first position information of the target terminal based on approximate maximum likelihood method estimation; wherein the m-1 th determined location information and the mth first location information are both related to the first distance;

and if the value of the first distance calculated by the mth first position information does not meet the positioning condition of the target terminal, determining the position information determined by the mth iteration based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data.

Optionally, in case m > 1, the processor is configured to read the computer program in the memory and perform the following operations:

Optionally, the processor is configured to read the computer program in the memory and perform the following operations:

Optionally, the first equivalent formula is: 2 Φ D θ = Φ v;

wherein the content of the first and second substances,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

wherein the position information of the ith second base station in the N-1 second base stations is (x) _i ，y _i ) I =2, \8230;, N; n is the number of base stations in the positioning system; r is a radical of hydrogen _i Is the distance, k, from the target terminal to the ith second base station _i ＝x _i ² +y _i ² (ii) a The location information of the first base station is (x) ₁ ，y ₁ )；r ₁ Is the distance, k, from the target terminal to the first base station ₁ ＝x ₁ ² +y ₁ ² ；Δ _i1 For the target terminal to theA difference in measured distances of the first base station and the ith second base station.

determining a second maximum likelihood error function according to a first distance corresponding to the position information determined at the (m-1) th time, the first data, the second data and third data comprising a plurality of measuring times; wherein one of the measurement times is a measurement time for a signal transmitted from the target terminal to a base station in the positioning system;

Optionally, the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data that is the fourth data,

T _d ＝[t ₂₁ …t _N1 ] ^T ，t _i1 i =2, \8230fora measurement time difference of a signal transmitted from the target terminal to the first base station and an ith second base station; n is the number of base stations in the positioning system; r is _1,m-1 A first distance corresponding to the position information determined for the (m-1) th time;

determining target position information according to the minimum maximum likelihood error value corresponding to the position information determined by M times of iteration;

An embodiment of the present invention further provides a positioning apparatus, including:

an acquisition unit configured to acquire first data including a plurality of measurement time differences and second data including a plurality of distance differences; wherein one of the measured time differences is a measured time difference between transmission of a signal from a target terminal to a first base station and a second base station, and one of the distance differences is a distance difference between the target terminal to the first base station and the second base station; the first base station is a base station in a positioning system, and the second base station is a base station in the positioning system except the first base station;

the processing unit is used for obtaining the position information of the target terminal determined by M times of iteration based on an iteration algorithm according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is a distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M;

and the positioning unit is used for positioning the target terminal according to the position information determined by the M times of iteration.

An embodiment of the present invention further provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is configured to enable the processor to execute the steps in the positioning method described above.

The technical scheme of the invention has the beneficial effects that:

in the scheme, according to first data comprising a plurality of measurement time differences transmitted by a signal from a target terminal to different base stations and second data comprising a plurality of distance differences from the target terminal to different base stations, position information of the target terminal determined by M times of iteration is obtained based on an iterative algorithm; the first distance is the distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M; and positioning the target terminal according to the position information determined by the M times of iteration. In this way, the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data, so that the problem of inaccurate positioning when one of the positions of the plurality of target terminals obtained by solving is selected for positioning the target terminal in the conventional positioning method can be solved.

Drawings

FIG. 1 shows a flow chart of a positioning method of an embodiment of the invention;

FIG. 2 is a flow chart of a root selection method of an embodiment of the present invention;

FIG. 3 is a schematic diagram of a first positioning scenario in accordance with an embodiment of the present invention;

FIG. 4 is a schematic diagram of an error CDF in a positioning scenario according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating a second positioning scenario according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an error CDF in the second positioning scenario according to the embodiment of the present invention;

FIG. 7 is a graph showing an error distribution using a conventional positioning method;

FIG. 8 is a graph showing an error profile of a positioning method using an embodiment of the present invention;

FIG. 9 is a schematic diagram of errors between a positioning method according to an embodiment of the present invention and a conventional positioning method;

FIG. 10a is a schematic diagram of an error CDF using a conventional positioning method and a positioning method according to an embodiment of the present invention;

FIG. 10b is a second schematic diagram of an error CDF of the conventional positioning method and the positioning method according to the embodiment of the present invention;

FIG. 11 shows one of the block diagrams of a positioning device according to an embodiment of the invention;

fig. 12 shows a second block diagram of a positioning apparatus according to an embodiment of the invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments. In the following description, specific details are provided, such as specific configurations and components, merely to facilitate a thorough understanding of embodiments of the invention. Thus, it will be apparent to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In various embodiments of the present invention, it should be understood that the sequence numbers of the following processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

The term "and/or" in the embodiments of the present invention describes an association relationship of associated objects, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

In the embodiments of the present application, the term "plurality" means two or more, and other terms are similar thereto.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The embodiment of the application provides a positioning method and a positioning device, which are used for solving the problem of inaccurate terminal positioning in the conventional positioning method.

The method and the device are based on the same application concept, and because the principles of solving the problems of the method and the device are similar, the implementation of the device and the method can be mutually referred, and repeated parts are not described again.

As shown in fig. 1, an embodiment of the present invention provides a positioning method, including:

step 11: first data including a plurality of measurement time differences and second data including a plurality of distance differences are obtained.

Wherein one of said measured time differences is a measured time difference for a signal transmitted from a target terminal to a first base station and a second base station, and one of said range differences is a range difference from said target terminal to said first base station and said second base station; the first base station is a base station in a positioning system and the second base station is a base station in the positioning system other than the first base station.

Optionally, the positioning system includes at least three base stations, for example, the positioning system includes 3 base stations (base station a, base station B, and base station C). The base station a is a first base station (i.e., a reference base station), and the base stations B and C are both second base stations; the first data includes: a difference between a first measurement time when a signal is transmitted from the target terminal to the base station B and a second measurement time when the signal is transmitted from the target terminal to the base station a (i.e., a measurement time difference), and a difference between a third measurement time when the signal is transmitted from the target terminal to the base station C and a second measurement time when the signal is transmitted from the target terminal to the base station a (i.e., a measurement time difference). The second data includes: a difference between a first distance from the target terminal to base station B and a second distance from the target terminal to base station a (i.e., a distance difference), and a difference between a third distance from the target terminal to base station C and a second distance from the target terminal to base station a (i.e., a distance difference).

Here, the distance from the target terminal to the base station may be understood as an actual distance, for example, the position coordinates of the target terminal are preset to be (x, y), and the position coordinates of each base station are known, for example, the position of the base station is (x) _i ,y _i ) Thus, according to the position coordinates of the target terminal and the position coordinates of each base station, the actual distance (or called real distance) from the target terminal to each base station can be determined based on the distance formula. The distance difference can be understood as the difference between the actual distances, and for example, the distance difference from the target terminal to the base station a and the base station B is: actual distance from target terminal to base station A and actual distance from target terminal to base station BIs measured in the measurement area.

Step 12: and obtaining the position information of the target terminal determined by M times of iteration based on an iterative algorithm according to the first data and the second data.

The position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is the distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M.

Alternatively, when m > 1, the m-1 st determined location information may be understood as location information determined at the m-1 st iteration based on an iterative algorithm; when m =1, the position information determined at the m-1 st time may be an initial value determined based on a preset algorithm (e.g., the position information of the target terminal is determined based on the LS estimation and taken as the initial value).

Alternatively, the iterative process based on the iterative algorithm may be: the position information of the target terminal is obtained based on the LS estimation, the position information determined based on the LS is used as an initial value, the first iteration processing is performed, the subsequent iteration can be performed based on the position information determined by the last iteration of the current iteration as an input, and multiple iterations (for example, 5 iterations) are performed in the same way.

Step 13: and positioning the target terminal according to the position information determined by the M times of iteration.

In the scheme, according to first data comprising a plurality of measurement time differences transmitted by a signal from a target terminal to different base stations and second data comprising a plurality of distance differences from the target terminal to different base stations, position information of the target terminal determined by M times of iteration is obtained based on an iterative algorithm; the first distance is a distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M; and positioning the target terminal according to the position information determined by the M times of iteration. In this way, the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data, so that the problem of inaccurate positioning when one of the positions of the plurality of target terminals obtained by solving is selected for positioning the target terminal in the conventional positioning method can be solved.

For example: the position information θ (x, y) estimated based on LS may be represented by the first distance r1, and based on this, a distance formula based on the first distance r1 may be solved to obtain a value of r1, and based on the solved value of r1 and the position information θ estimated based on LS, the final position information (e.g., position coordinates) of the target terminal may be determined.

Similarly, the position information θ (x, y) estimated by the AML method may be represented by the first distance r1, and then a distance formula based on the first distance r1 may be solved to obtain the value of r 1. If the value of r1 obtained by solving based on the AML method does not satisfy the location condition, it is necessary to determine one value of r1 satisfying the location condition among the values of r1 obtained by solving based on the AML method based on the first distance, the first data, and the second data corresponding to the position information determined by solving based on the m-1 th time (here, the final position information of the target terminal determined based on the LS estimation), so as to determine the position information of the target terminal determined by the m-th iteration, that is, the position information (e.g., position coordinates) of the target terminal determined by the first iteration, according to the determined one value of r1 satisfying the location condition and the position information θ obtained by estimating based on the AML method.

Optionally, in a case that M > 1, the determining, based on an iterative algorithm, location information of the target terminal for M iterations according to the first data and the second data includes:

For example: the position information θ (x, y) estimated based on the AML method can be represented by the first distance r1, and on this basis, a distance formula based on the first distance r1 can be solved to obtain the value of r 1. If the values of r1 obtained by solving based on the AML method do not satisfy the positioning condition, determining one value of r1 satisfying the positioning condition from the values of r1 obtained by solving based on the AML method based on the first distance, the first data and the second data corresponding to the position information determined by the (m-1) th iteration, and determining the position information of the target terminal determined by the mth iteration, namely the position information of the target terminal determined by the mth iteration, according to the determined one value of r1 satisfying the positioning condition and the position information θ obtained by estimating based on the AML method.

Optionally, obtaining, according to the first data and the second data, mth first location information of the target terminal based on an approximate maximum likelihood estimation method, includes:

For example: based on the first maximum likelihood error function, mth first location information estimated based on the AML method can be determined. The position information of the target terminal estimated based on LS, that is, the position information of the target terminal determined m-1 times when m =1, may also be determined based on the first maximum likelihood error function.

determining a first equivalent formula corresponding to the derivative being zero according to the derivative of the first maximum likelihood error function relative to theta; the theta is preset position information of the target terminal; if the position information of the target terminal is preset to be the coordinate theta (x, y).

wherein, T _d Is the first data; d (θ) is the second data; c is the transmission speed of the signal; q _d Is based on T _d Determined covariance matrices, e.g. Q _d ＝E{T _d T _d ^T }，Q _d ^-1 Is Q _d The inverse matrix of (c).

For example: based on the first maximum likelihood error function J _d And obtaining a first equivalent formula by simplifying transformation relative to theta derivation.

Optionally, the first equivalent formula is: 2 Φ D θ = Φ v;

wherein the content of the first and second substances,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

wherein N is the number of base stations in the positioning system, and the position information of the ith second base station in the N-1 second base stations is (x) _i ，y _i )，i＝2,…,N；r _i Is the distance, k, from the target terminal to the ith second base station _i ＝x _i ² +y _i ² 。

The location information of the first base station is (x) ₁ ，y ₁ )；r ₁ Is the distance from the target terminal to the first base station (which can be understood as the actual distance or the real distance from the target terminal to the first base station), k ₁ ＝x ₁ ² +y ₁ ² 。

Δ _i1 Measuring a difference in distance, e.g. Δ, for the target terminal to the first base station and the ith second base station _i1 ＝c*t _i1 ,t _i1 Is the measured time difference between the transmission of the signal from the target terminal to the first base station and the ith second base station.

For example: based on the first equivalent formula, let Φ = I, I be an identity matrix, and solve to obtain the location information θ (x, y) of the target terminal, that is, determine the location information of the target terminal obtained based on LS estimation. The position information of the target terminal obtained based on the LS estimation is used as an initial value, the initial value is used as the input of the first iteration, the position information theta (x, y) of the target terminal is obtained through solving based on the first equivalent formula, namely the position information of the target terminal obtained based on the AML method estimation is determined, the position information theta (x, y) of the target terminal determined through the previous iteration of the next iteration is used as the input, the position information of the target terminal obtained through the next estimation based on the AML method can be determined, and the like, and the description is omitted.

For example: the position information θ (x, y) estimated based on the AML method can be represented by the first distance r1, and on this basis, a distance formula based on the first distance r1 can be solved to obtain the value of r 1. If two values of r1 (namely, two roots of r1 obtained by determining a quadratic equation based on r1 through a distance formula based on theta and r1 represented by r1 and obtained by solving the quadratic equation based on the r 1) are both positive real numbers, or two values of r1 are both negative real numbers, or two values of r1 are complex numbers, then if the first maximum likelihood error function J corresponding to each of the two values based on r1 is determined _d To select a value of r1 and determine the position information determined in the final mth iteration, which may result in inaccurate terminal positioning, i.e. not meeting the positioning condition of the target terminal.

According to the embodiment of the invention, a maximum likelihood error function can be reconstructed based on the first distance, the first data and the second data corresponding to the position information determined in the (m-1) th time, so that the maximum likelihood error of the mirror image solution and the abnormal solution obtained by solving is increased, the probability of selecting the wrong solution is reduced, an accurate solution of the r1 is determined, and the position information of the target terminal determined by the mth iteration is determined based on the determined accurate solution of the r1, so that the accuracy of terminal positioning is ensured.

Alternatively, the positioning system includes 3 base stations (base station a, base station B, and base station C) for example. The base station a is a first base station (i.e., a reference base station), and the base stations B and C are both second base stations; the third data includes: a first measurement time for a signal to be transmitted from the target terminal to base station a, a second measurement time for a signal to be transmitted from the target terminal to base station B, and a third measurement time for a signal to be transmitted from the target terminal to base station C.

In this embodiment, a second maximum likelihood error function is reconstructed based on a first distance corresponding to the position information determined in the (m-1) th time and third data including a plurality of measurement times, and based on the reconstructed second maximum likelihood error function, when the value of the first distance r1 calculated from the mth first position information does not satisfy the positioning condition, the maximum likelihood error of the mirror solution and the abnormal solution obtained by solving r1 may be increased based on the reconstructed second maximum likelihood error function to reduce the probability of selecting an erroneous solution, so that an accurate value is selected from two values of the first distance that do not satisfy the positioning condition, thereby ensuring the accuracy of the position information of the target terminal determined by the final iteration.

In this embodiment, reconstructing the first data based on the first distance corresponding to the position information determined in the (m-1) th time, that is, updating the first data to obtain fourth data; e.g. fourth data T _d ' is:

T _d ＝[t ₂₁ …t _N1 ] ^T wherein T is _d Is the first data, r _1,m-1 And the first distance corresponds to the position information determined for the (m-1) th time.

Reconstructing the second data based on the first distance corresponding to the m-1 th determined position information, i.e. updating the second data to obtain fifth data, e.g. fifth data r _d (θ) is: r is a radical of hydrogen _d (θ)＝[r _1,m-1 ,d(θ)] ^T ，d(θ)＝[d ₂₁ …d _N1 ] ^T Where d (θ) is the second data.

Determining a covariance matrix based on the third data according to the third data, wherein the covariance matrix Q based on the third data is: q = E { T } ^T Where T is the third data.

Optionally, the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data, and the fourth data,

r _d (θ) is the fifth data, r _d (θ)＝[r _1,m-1 ,d(θ)] ^T ，d(θ)＝[d ₂₁ …d _N1 ] ^T ，d _i1 The distance difference between the target terminal and the first base station and the ith second base station is obtained;

c is the transmission speed of the signal; q is a covariance matrix determined based on the third data, Q- ¹ Is the inverse matrix of Q.

For example: and determining the position information of the target terminal determined by M times of iteration based on an iterative algorithm, for example, iterating for 5 times to obtain the position information of 5 target terminals. For the position information of the target terminal determined by the secondary iteration, the corresponding maximum likelihood error value can be determined based on the first maximum likelihood error function, and the position information with the minimum maximum likelihood error value is selected from the position information and used as the final positioning information of the target terminal, so that the positioning of the target terminal is realized, and the accuracy of the positioning result is ensured.

The root selection method of the embodiment of the present invention is described below with reference to fig. 2:

based on the maximum likelihood error function as J _d Determining a first equivalent formula, and determining the position information of the target terminal obtained based on LS estimation according to the first equivalent formula, wherein the position information corresponds to a first distance r1; and determining the position information of the target terminal estimated based on the AML method according to the first equivalent formula, where the position information is represented by the first distance r1, which can be referred to in the above embodiments and is not described herein again.

Step 21: and solving to obtain two solutions of the r1 based on the position information of the target terminal estimated by the AML method and a distance formula of the first distance r 1.

Step 22: whether both solutions are real and are positive-negative is judged.

Step 23: if both solutions are real and both positive or negative, or both solutions are complex, step 24 is performed.

Step 24: reconstructing the maximum likelihood error function to obtain a second maximum likelihood error function J _d ′：

Wherein, T _d ' is the fourth data that is the fourth data,

T _d ＝[t ₂₁ …t _N1 ] ^T ，t _i1 measuring time difference for signal transmission from the target terminal to the first base station and an ith second base station, i =2, \8230; n is the number of base stations in the positioning system; r is _1,m-1 A first distance corresponding to the position information determined for the (m-1) th time; r is _d (θ) is the fifth data, r _d (θ)＝[r _1,m-1 ,d(θ)] ^T ，d(θ)＝[d ₂₁ …d _N1 ] ^T ，d _i1 The distance difference between the target terminal and the first base station and the ith second base station is obtained; c is the transmission speed of the signal; q is a covariance matrix determined based on the third data.

Step 25: the reconstructed second maximum likelihood error function is J _d ', determining J corresponding to the two solutions _d The smaller of the' values serves as an accurate solution for r 1.

Step 26: if after step 22 it is determined that both solutions are real and one is positive and one is negative, then the solution with r1 being positive is determined to be the correct solution and J is based on the first maximum likelihood error function _d Determining J corresponding to the exact solution _d The value of (c).

Step 27: determining an accurate solution for r1 and corresponding J _d And outputting the result.

It should be noted that, if the position information of the target terminal estimated based on the AML method is the first iteration, it is determined in the second iteration that both solutions of r1 obtained by solving exist in the case of positive real number/negative real number/complex number, and J may be reconstructed based on the r1 value corresponding to the output result obtained by the first iteration _d ′。

Such that the reconstructed second maximum likelihood error function is J _d ' to define a correct interval of the first iteration solution in the hyperbolic curve two solutions, thereby continuously reducing the error in the iteration process, so as to reduce the probability of selecting a wrong solution under the non-ideal condition, and further reduce the positioning error. Meanwhile, the method can be continuously updated along with iteration and becomes more accurate so as to ensure rapid convergence.

The following describes the effect of the positioning method according to the embodiment of the present invention with reference to specific scenarios:

scene one: taking the classical indoor positioning scenario shown in fig. 3 as an example: the target UE sends an uplink Sounding Reference Signal (SRS) Signal, and the base stations TRP at 6 different positions complete the Signal reception and distance measurement. A Local Management Function (LMF) server collects distance measurement information of all TRPs, position Location and tracking are completed by using TDOA and TRP coordinates, and the Location is resolved based on the Location method of the embodiment of the invention, except for measurement errors, resolving errors caused by that r1 is a positive real number or a negative real number or no solution (complex number) are reduced. If the target UE moves in the TRP coverage range, the measurement error is Gaussian truncation error with the amplitude of 1m. Each TRP is independent of each other, the total error of TDOA is within 5m, the final position error is within 5m, and the statistical result of the distribution function (CDF) of the error is shown in fig. 4.

Scene two: for a scenario where the terminal side uses downlink signal positioning, as shown in fig. 5, base stations TRP at 4 different positions transmit downlink Phase-tracking reference signal (PTRS) signals, and the target UE completes signal reception and distance measurement. Position location and tracking are accomplished using TDOA and TRP coordinates. Traversing the position coordinates of the target UE in the coverage range of the trapezoid formed by the TRP connecting lines, wherein the measurement error is a Gaussian truncation error and the amplitude is 0.5m. All TRPs are independent, the total error of the TDOA is within 2m, and the CDF statistical result of the error is shown in figure 6.

In general, since the base stations are generally distributed irregularly in an actual station distribution scenario, 4 BSs are the minimum number of base stations that satisfy the stable positioning condition. The boundary problem is more obvious in the scene, and the positioning error at the boundary can be reduced to be within a normal range by adopting the embodiment of the invention. The embodiment of the invention can be applied to different base station distribution scenes and the number of the base stations, and can well solve the problems of no solution and wrong solution of the position calculation algorithm of the existing positioning method at the coverage boundary of the base station.

The following description is made in conjunction with a scenario in which positioning measurement is performed based on 6 base stations in rectangular distribution, and the effect of the positioning method according to the embodiment of the present invention is:

fig. 7 is an error distribution diagram of a conventional positioning method, and fig. 8 is an error distribution diagram of a positioning method according to an embodiment of the present invention, in which the measurement error is a gaussian truncation error with a magnitude of 0.5m, the number of iterations of the AML algorithm is 5, the measurement error of all positions within the observation rectangle is 0.2 m in coordinate resolution, the vertical axis represents the position settlement error (unit: m), and 1m represents an error greater than 5m. As can be seen from fig. 7 and 8, the conventional positioning method has a large resolving error near the rectangular boundary and the four-corner base station; the positioning method of the embodiment of the invention has larger errors only at four corners, but all the errors are within 5m, and the average settlement error is smaller than that of the traditional positioning method. It can be seen that the positioning method of the embodiment of the invention can limit the solution range through the first LS estimation when the error is large or the position is close to the base station (when two solutions are probably generated), ensure iterative convergence, and avoid selecting the wrong solution, thereby reducing the solution error.

The terminal moves from the leftmost end to the rightmost end in the rectangular range, the measurement error is a gaussian truncation error with the amplitude of 1m, and the other configurations are the same as above, and the error of the positioning method adopting the embodiment of the invention is compared with the error of the traditional positioning method, as shown in fig. 9.

Referring to fig. 10a, a schematic diagram of the error CDF statistics of the positioning method of the present invention and the conventional positioning method based on AML algorithm is shown, and it can be seen from fig. 10a that the positioning method using the embodiment of the present invention has no error maxima at both ends of the rectangle. The traditional positioning method is easy to select a wrong mirror image solution when the position is not good or the measurement error is large, so that the maximum resolving error can reach 80m, and the maximum positioning method adopting the embodiment of the invention is only about 10 m.

Fig. 10b is a schematic diagram showing the error CDF statistics of the positioning method of the present invention and the conventional positioning method based on chan algorithm. Because the traditional positioning method based on the chan algorithm uses two LS solutions, and the final result is based on the first measuring base station, the mirror image solution can not occur, but the error is larger than 20m due to poor positions at the two ends of the rectangle, and the accuracy is higher than that of the traditional positioning method due to 5 maximum iterations by adopting the positioning method of the embodiment of the invention.

In the above description, the positioning method of the present invention is described, and the following embodiment will further describe the positioning device corresponding to the positioning method with reference to the accompanying drawings.

Specifically, as shown in fig. 11, the positioning apparatus 1100 according to the embodiment of the present invention includes:

an obtaining unit 1110 configured to obtain first data including a plurality of measurement time differences and second data including a plurality of distance differences; wherein one of said measured time differences is a measured time difference for a signal transmitted from a target terminal to a first base station and a second base station, and one of said range differences is a range difference from said target terminal to said first base station and said second base station; the first base station is one base station in a positioning system, and the second base station is a base station in the positioning system other than the first base station;

a processing unit 1120, configured to obtain, based on an iterative algorithm, position information of the target terminal determined by M iterations according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is a distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M;

a positioning unit 1130, configured to position the target terminal according to the position information determined by the M iterations.

Optionally, in case m =1, the processing unit 1120 is further configured to:

Optionally, in the case that m > 1, the processing unit 1120 is further configured to:

and the m-1 determined position information is the m-1 iteratively determined position information obtained based on an iterative algorithm.

Optionally, the processing unit 1120 is further configured to:

determining a first equivalence formula corresponding to the derivative being zero according to the derivative of the first maximum likelihood error function relative to theta; the theta is preset position information of the target terminal;

Optionally, the first equivalent formula is: 2 Φ D θ = Φ v;

wherein, the first and the second end of the pipe are connected with each other,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

wherein the position information of the ith second base station in the N-1 second base stations is (x) _i ，y _i ) I =2, \ 8230;, N; n is the number of base stations in the positioning system; r is a radical of hydrogen _i Is the distance, k, from the target terminal to the ith second base station _i ＝x _i ² +y _i ² (ii) a The location information of the first base station is (x) ₁ ，y ₁ )；r ₁ Is the distance, k, from the target terminal to the first base station ₁ ＝x ₁ ² +y ₁ ² ；Δ _i1 And measuring the distance difference between the target terminal and the first base station and the ith second base station.

Optionally, the processing unit 1120 is further configured to:

determining a second maximum likelihood error function from the third data, the fourth data, and the fifth data.

Optionally, the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data that is the fourth data,

T _d ＝[t ₂₁ …t _N1 ] ^T ，t _i1 measuring time difference for signal transmission from the target terminal to the first base station and an ith second base station, i =2, \8230; n is the number of base stations in the positioning system; r is _1,m-1 A first distance corresponding to the position information determined for the (m-1) th time;

Optionally, the positioning unit 1130 is further configured to:

It should be noted that the division of the unit in the embodiment of the present application is schematic, and is only a logic function division, and there may be another division manner in actual implementation. In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.

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

It should be noted that, the apparatus provided in the embodiment of the present invention can implement all the method steps implemented by the method embodiment and achieve the same technical effect, and detailed descriptions of the same parts and beneficial effects as the method embodiment in this embodiment are omitted here.

To better achieve the above objects, as shown in fig. 12, a positioning apparatus according to an embodiment of the present invention includes a memory 1220, a transceiver 1210, a processor 1200; wherein the memory 1220 is used for storing computer programs; a transceiver 1210 for transceiving data under the control of the processor 1200; such as a transceiver 1210 for receiving and transmitting data under the control of the processor 1200; the processor 1200 is configured to read the computer program in the memory and perform the following operations:

acquiring first data comprising a plurality of measurement time differences and second data comprising a plurality of distance differences; wherein one of said measured time differences is a measured time difference for a signal transmitted from a target terminal to a first base station and a second base station, and one of said range differences is a range difference from said target terminal to said first base station and said second base station; the first base station is a base station in a positioning system, and the second base station is a base station in the positioning system except the first base station;

Optionally, in case m =1, the processor 1200 is configured to read the computer program in the memory and perform the following operations:

according to the first data and the second data, obtaining the position information determined at the (m-1) th time based on least square method estimation, and obtaining the mth first position information of the target terminal based on approximate maximum likelihood method estimation; wherein the m-1 th determined location information and the mth first location information are both related to the first distance;

Alternatively, in case m > 1, the processor 1200 is configured to read the computer program in the memory and perform the following operations:

Optionally, the processor 1200 is configured to read the computer program in the memory and execute the following operations:

Optionally, the first equivalent formula is: 2 Φ D θ = Φ v;

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

Optionally, the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data, and the fourth data,

Where, in fig. 12, the bus architecture may include any number of interconnected buses and bridges, in particular one or more processors, represented by processor 1200, and various circuits, represented by memory 1220, linked together. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 1210 may be a plurality of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium including wireless channels, wired channels, fiber optic cables, and the like. The processor 1200 is responsible for managing the bus architecture and general processing, and the memory 1220 may store data used by the processor 1200 in performing operations.

The processor 1200 may be a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or a Complex Programmable Logic Device (CPLD), and may also have a multi-core architecture.

An embodiment of the present invention further provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is configured to enable the processor to execute the steps in the positioning method.

The processor-readable storage medium can be any available medium or data storage device that can be accessed by a processor, including, but not limited to, magnetic memory (e.g., floppy disks, hard disks, magnetic tape, magneto-optical disks (MOs), etc.), optical memory (e.g., CDs, DVDs, BDs, HVDs, etc.), and semiconductor memory (e.g., ROMs, EPROMs, EEPROMs, non-volatile memories (NAND FLASH), solid State Disks (SSDs)), etc.

The terminal device referred to in the embodiments of the present application may refer to a device providing voice and/or data connectivity to a user, a handheld device having a wireless connection function, or another processing device connected to a wireless modem. In different systems, the names of the terminal devices may be different, for example, in a 5G system, the terminal device may be referred to as a User Equipment (UE). A wireless terminal device, which may be a mobile terminal device such as a mobile phone (or called a "cellular" phone) and a computer having a mobile terminal device, for example, a portable, pocket, hand-held, computer-included or vehicle-mounted mobile device, may communicate with one or more Core Networks (CNs) via a Radio Access Network (RAN), and may exchange languages and/or data with the RAN. 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. The wireless terminal device may also be referred to as a system, a subscriber unit (subscriber unit), a subscriber station (subscriber station), a mobile station (mobile station), a remote station (remote station), an access point (access point), a remote terminal (remote terminal), an access terminal (access terminal), a user terminal (user terminal), a user agent (user agent), and a user device (user device), which is not limited in this embodiment.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer-executable instructions. These computer-executable instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be stored in a processor-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the processor-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These processor-executable instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Furthermore, it is to be noted that in the device and method of the invention, it is obvious that the individual components or steps can be decomposed and/or recombined. These decompositions and/or recombinations are to be regarded as equivalents of the present invention. Also, the steps of performing the series of processes described above may naturally be performed chronologically in the order described, but need not necessarily be performed chronologically, and some steps may be performed in parallel or independently of each other. It will be understood by those skilled in the art that all or any of the steps or elements of the method and apparatus of the present invention may be implemented in any computing device (including processor, storage medium, etc.) or network of computing devices, in hardware, firmware, software, or any combination thereof, which can be implemented by those skilled in the art using their basic programming skills after reading the description of the present invention.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of positioning, comprising:

acquiring first data comprising a plurality of measurement time differences and second data comprising a plurality of distance differences; wherein one of said measured time differences is a measured time difference for a signal transmitted from a target terminal to a first base station and a second base station, and one of said range differences is a range difference from said target terminal to said first base station and said second base station; the first base station is one base station in a positioning system, and the second base station is a base station in the positioning system other than the first base station;

2. The method according to claim 1, wherein in case of M =1, obtaining the location information of the target terminal determined by M iterations based on an iterative algorithm according to the first data and the second data comprises:

and if the value of the first distance calculated by the mth first position information does not meet the positioning condition of the target terminal, determining the position information determined by the iteration determined by the mth iteration based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data.

3. The method according to claim 1, wherein in case M > 1, said determining location information of the target terminal for M iterations based on an iterative algorithm according to the first data and the second data comprises:

4. The method according to claim 2 or 3, wherein the obtaining the mth first location information of the target terminal based on the approximate maximum likelihood estimation according to the first data and the second data comprises:

5. The method of claim 4, wherein determining the mth first location information according to the first maximum likelihood error function comprises:

determining a first equivalent formula corresponding to the derivative being zero according to the derivative of the first maximum likelihood error function relative to theta; the theta is preset position information of the target terminal;

6. The method according to claim 5, characterized in that the first maximum likelihood error function J _d Comprises the following steps:

7. The method according to claim 5, wherein the first equivalent formula is: 2 Φ D θ = Φ v;

wherein the content of the first and second substances,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

wherein, the ith second base station in the N-1 second base stationsThe location information of the base station is (x) _i ，y _i ) I =2, \ 8230;, N; n is the number of base stations in the positioning system; r is a radical of hydrogen _i Is the distance, k, from the target terminal to the ith second base station _i ＝x _i ² +y _i ² (ii) a The location information of the first base station is (x) ₁ ，y ₁ )；r ₁ Is the distance, k, from the target terminal to the first base station ₁ ＝x ₁ ² +y ₁ ² ；Δ _i1 And measuring the distance difference from the target terminal to the first base station and the ith second base station.

8. The method according to claim 2 or 3, wherein if the value of the first distance calculated from the mth first location information does not satisfy the location condition of the target terminal, determining the location information determined in the mth iteration based on the first distance, the first data, and the second data corresponding to the location information determined in the (m-1) th iteration comprises:

9. The method according to claim 8, wherein determining the position information determined at the mth iteration based on the first distance corresponding to the position information determined at the (m-1) th iteration, the first data and the second data comprises:

10. The method of claim 9, wherein determining a second maximum likelihood error function according to a first distance corresponding to the m-1 th determined location information, the first data, the second data, and a third data comprising a plurality of measurement times comprises:

11. The method of claim 10, wherein the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data, and the fourth data,

T _d ＝[t ₂₁ …t _N1 ] ^T ，t _i1 measuring time difference for signal transmission from the target terminal to the first base station and an ith second base station, i =2, \8230; n is the positioning systemThe number of the middle base stations; r is _1,m-1 A first distance corresponding to the position information determined for the (m-1) th time;

12. The method according to claim 1, wherein locating the target terminal according to the position information determined by M iterations comprises:

13. A positioning device comprising a memory, a transceiver, a processor;

obtaining position information of the target terminal determined by M times of iteration based on an iteration algorithm according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is the distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M;

14. The positioning apparatus according to claim 13, wherein in case of m =1, the processor is configured to read the computer program in the memory and perform the following operations:

15. The positioning apparatus according to claim 13, wherein in case m > 1, the processor is configured to read the computer program in the memory and perform the following operations:

16. The positioning apparatus according to claim 14 or 15, wherein the processor is configured to read the computer program stored in the memory and perform the following operations:

17. The positioning apparatus of claim 16, wherein the processor is configured to read the computer program in the memory and perform the following operations:

18. The positioning apparatus of claim 17, wherein the first maximum likelihood error function J is _d Comprises the following steps:

19. The positioning apparatus of claim 17, wherein the first equivalent formula is: 2 Φ D θ = Φ v;

wherein the content of the first and second substances,

Φ＝WΛ，V＝v ₁ +r ₁ Ψ；

20. The positioning apparatus according to claim 14 or 15, wherein the processor is configured to read the computer program stored in the memory and perform the following operations:

if two values of the first distance calculated by the mth first position information satisfy a preset condition, determining that the first distance r calculated by the mth first position information satisfies the preset condition ₁ The value of (2) does not meet the positioning condition of the target terminal; wherein, the two numerical values meet the preset conditions that: both values are positiveReal numbers, or both of the two numerical values are negative real numbers, or both of the two numerical values are complex numbers;

21. The positioning apparatus of claim 20, wherein the processor is configured to read the computer program in the memory and perform the following operations:

22. The positioning apparatus of claim 21, wherein the processor is configured to read the computer program in the memory and perform the following operations:

23. The positioning apparatus of claim 22, wherein the second maximum likelihood error function is J _d ′：

Wherein, T _d ' is the fourth data, and the fourth data,

24. The positioning apparatus of claim 13, wherein the processor is configured to read the computer program in the memory and perform the following operations:

25. A positioning device, comprising:

an acquisition unit configured to acquire first data including a plurality of measurement time differences and second data including a plurality of distance differences; wherein one of the measured time differences is a measured time difference between transmission of a signal from a target terminal to a first base station and a second base station, and one of the distance differences is a distance difference between the target terminal to the first base station and the second base station; the first base station is one base station in a positioning system, and the second base station is a base station in the positioning system other than the first base station;

the processing unit is used for obtaining the position information of the target terminal determined by M times of iteration based on an iterative algorithm according to the first data and the second data; the position information determined by the mth iteration is determined based on the first distance corresponding to the position information determined by the (m-1) th iteration, the first data and the second data; the first distance is a distance from the target terminal to the first base station; m and M are positive integers, and M is more than or equal to 1 and less than or equal to M;

26. A processor-readable storage medium, characterized in that the processor-readable storage medium stores a computer program for causing a processor to perform the steps in the positioning method of any one of claims 1 to 12.