Method and apparatus for estimating angle of arrival of signals from a mixed field source

Abstract

The application provides a signal arrival angle estimation method and device for a mixed field source, the method comprising: for a mixed field source in an indoor single base station scenario, constructing a fourth-order cumulant matrix that has eliminated the influence of the distance of the source; constructing a MUSIC spectrum function based on the fourth-order cumulant matrix, and applying the MUSIC spectrum function to obtain an estimated value of the signal arrival angle of the mixed field source to the antenna array for 5G positioning. The application can be effectively applied to an indoor single base station positioning scenario, and can estimate the signal arrival angle of the mixed field source containing the mixed field source in the far field region and the near field region of the antenna array, can improve the reliability and effectiveness of the signal arrival angle estimation process of the mixed field source, and can effectively improve the estimation accuracy of the signal arrival angle in the mixed field source scenario.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of 5G positioning technology, and in particular to a signal angle of arrival estimation method and device for mixed field sources. BACKGROUND

[0002] Single base station positioning using a 5G base station requires estimation of the angle of arrival (AOA) of a signal. The multiple signal classification (MUSIC) algorithm is a commonly used subspace-based signal angle of arrival estimation algorithm that uses the orthogonality of the received signal steering vector and the noise subspace of its covariance matrix to estimate the angle of arrival of a signal.

[0003] Currently, in the existing MUSIC-based signal angle of arrival estimation method, the received signal needs to be operated on a cross-correlation matrix, and then a MUSIC spectrum is constructed based on the cross-correlation matrix, and the estimated value of the angle of arrival of the signal to the antenna array is solved. Although this method can accurately estimate the angle of arrival of a far-field signal to an antenna array, it does not improve the signal angle of arrival estimation for sources in the near-field region of the antenna array in an indoor positioning scenario. That is, the traditional MUSIC method only assumes the source to be a far-field source, and if it is applied to a near-field source, there will be a large signal angle of arrival estimation error. Therefore, there is an urgent need for a signal angle of arrival estimation method for mixed field sources suitable for indoor single base station positioning scenarios. SUMMARY

[0004] In view of this, the embodiments of the present application provide a signal angle of arrival estimation method and device for mixed field sources to eliminate or improve one or more defects in the prior art.

[0005] One aspect of the present application provides a signal angle of arrival estimation method for mixed field sources, comprising:

[0006] For mixed field sources in an indoor single base station scenario, a fourth-order cumulant matrix that has eliminated the influence of the distance of the source is constructed.

[0007] A MUSIC spectrum function is constructed based on the fourth-order cumulant matrix, and the MUSIC spectrum function is applied to obtain an estimated value of the angle of arrival of the signal of the mixed field source to the antenna array for 5G positioning.

[0008] In some embodiments of the present application, the fourth-order cumulant matrix that has eliminated the influence of the distance of the source for mixed field sources in an indoor single base station scenario comprises:

[0009] The signal of the mixed field source is received, and the nonlinear component affected by the distance of the source in the phase of the received signal is eliminated by using the symmetry of the fourth-order cumulant to construct the fourth-order cumulant matrix of the mixed field source in the indoor single base station scene.

[0010] In some embodiments of the present application, the signal of the mixed field source is received, and the nonlinear component affected by the distance of the source in the phase of the received signal is eliminated by using the symmetry of the fourth-order cumulant to construct the fourth-order cumulant matrix of the mixed field source in the indoor single base station scene, comprising:

[0011] Obtaining a definition function of the fourth-order cumulant;

[0012] Determining the nonlinear component affected by the distance of the source in the phase of the received signal in the definition function;

[0013] Replacing the nonlinear component affected by the distance of the source in the phase of the received signal in the definition function by using the symmetry of the fourth-order cumulant to obtain the fourth-order cumulant matrix of the mixed field source in the indoor single base station scene which has eliminated the influence of the distance of the source.

[0014] In some embodiments of the present application, the MUSIC spectrum function is constructed based on the fourth-order cumulant matrix, and the angle of arrival estimation value of the signal of the mixed field source arriving at the antenna array is obtained by applying the MUSIC spectrum function to be used for 5G positioning, comprising:

[0015] Decomposing the fourth-order cumulant matrix to obtain a corresponding decomposition result;

[0016] Constructing the MUSIC spectrum function according to the decomposition result;

[0017] Obtaining the angle of arrival estimation value of the signal of the mixed field source arriving at the antenna array based on the MUSIC spectrum function;

[0018] Outputting the angle of arrival estimation value for 5G positioning.

[0019] In some embodiments of the present application, the fourth-order cumulant matrix is decomposed to obtain a corresponding decomposition result, comprising:

[0020] Performing singular value decomposition on the fourth-order cumulant matrix to obtain a decomposition result containing a signal subspace and a noise subspace;

[0021] Constructing the MUSIC spectrum function according to the decomposition result;

[0022] Obtaining the angle of arrival estimation value of the signal of the mixed field source arriving at the antenna array based on the MUSIC spectrum function.

[0023] In some embodiments of the present application, the constructing the MUSIC spectrum function according to the decomposition result comprises:

[0024] The MUSIC spectrum function is constructed according to the direction vector of the mixed-field source and the orthogonality of the noise subspace.

[0025] In some embodiments of the present application, the obtaining the angle of arrival estimation value of the signal of the mixed-field source to the antenna array based on the MUSIC spectrum function comprises:

[0026] The MUSIC spectrum function is searched for a spectrum peak to obtain the angle of arrival estimation value of the signal of the mixed-field source to the antenna array.

[0027] Another aspect of the present application provides a device for estimating the angle of arrival of a signal of a mixed-field source, comprising:

[0028] A distance influence elimination module is configured to construct a fourth-order cumulant matrix with eliminated distance influence of a source for a mixed-field source in an indoor single-base station scenario.

[0029] An angle of arrival estimation module is configured to construct a MUSIC spectrum function based on the fourth-order cumulant matrix, and to obtain an angle of arrival estimation value of a signal of a mixed-field source to an antenna array by applying the MUSIC spectrum function, so as to perform 5G positioning.

[0030] Another aspect of the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for estimating the angle of arrival of a signal of a mixed-field source when executing the computer program.

[0031] Another aspect of the present application provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executable on a processor to implement the method for estimating the angle of arrival of a signal of a mixed-field source.

[0032] The signal arrival angle estimation method of the mixed field source provided by the application is suitable for the mixed field source in the indoor single base station positioning scene, has obvious advantages, can provide a high-precision signal arrival angle estimation method for the TOA+AOA positioning method in the 5G positioning method, can estimate the signal arrival angle of the mixed field source containing the far field region and the near field region of the antenna array, can improve the reliability and effectiveness of the signal arrival angle estimation process of the mixed field source, and can effectively improve the estimation precision of the signal arrival angle in the mixed field source scene.

[0033] Additional advantages, objects, and features of the application will be set forth in part in the description which follows, and will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0034] It will be understood by those skilled in the art that the objects and advantages of the present application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0035] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. The components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the application. For purposes of clarity and understanding, portions of some portions may have been exaggerated or simplified, and portions of some portions may be shown in section, while, for purposes of brevity and clarity, portions of other portions may be omitted. In the drawings:

[0036] Figure 1 The flow chart of the first MUSIC-based signal arrival angle estimation method.

[0037] Figure 2 The first flowchart of the signal arrival angle estimation method of the mixed field source in an embodiment of the application.

[0038] Figure 3 The second flowchart of the signal arrival angle estimation method of the mixed field source in an embodiment of the application.

[0039] Figure 4A third flowchart of a signal angle of arrival estimation method for a mixed field source in an embodiment of the present application.

[0040] Figure 5 A structure diagram of a signal angle of arrival estimation device for a mixed field source in another embodiment of the present application.

[0041] Figure 6 A flowchart of a signal angle of arrival estimation method for a mixed field source provided by an application example of the present application. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and drawings. Herein, the illustrative embodiments of the present application and the descriptions thereof are used to explain the present application, but not to limit the present application.

[0043] It should be noted that, in order to avoid the present application being obscured by unnecessary details, only the structures and / or processing steps closely related to the solutions according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0044] It should be emphasized that the term "comprise / comprising" is used herein to mean that a feature, element, step or component is present, but not to the exclusion of one or more other features, elements, steps or components.

[0045] It should be noted that, herein, the term "connected" can mean not only direct connection, but also indirect connection with an intermediate object, if not specially stated.

[0046] Hereinafter, the embodiments of the present application will be described with reference to the drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0047] Traditional positioning technologies mainly rely on satellite navigation systems for positioning, but are limited by the propagation of satellite signals, and thus it is difficult for these positioning technologies to perform high-precision positioning indoors. Therefore, how to solve the "last mile" problem of positioning has attracted a large number of experts and scholars to conduct research. They have proposed a variety of indoor positioning technologies, such as Wi-Fi positioning, Bluetooth positioning, Radio Frequency Identification (RFID) positioning, Ultra-Wideband (UWB) positioning, etc. However, the above positioning methods have the defect of requiring a large number of nodes to cover the area to be positioned, which undoubtedly increases the positioning cost.

[0048] With the 5G mobile communication network put into use, its large-scale multiple-input multiple-output (Massive MIMO) technology, ultra-dense networking (UDN) technology and millimeter wave (mmWave) technology bring new opportunities for high-precision indoor positioning.

[0049] According to the 3rd Generation Partnership Project (3GPP) TR38.913 agreement, 5G base stations are mainly divided into two types: one is a macro base station mainly deployed in an outdoor open area; the other is a micro base station mainly deployed in a densely populated urban area or indoors. The distribution of base stations with higher density makes it more likely for indoor mobile terminals to be within the communication range of at least one line of sight (LOS) base station, so that indoor positioning using a single base station is possible. At the same time, positioning using a single base station can reduce the non-line of sight (NLOS) error caused by multi-base station positioning methods. However, in order to use a 5G base station for single-base station positioning, the angle of arrival (AOA) of the signal needs to be estimated.

[0050] Multiple signal classification (MUSIC) algorithm is a commonly used subspace-based signal angle of arrival estimation algorithm, which uses the orthogonality of the received signal steering vector and the noise subspace of its covariance matrix to estimate the angle of arrival of the signal.

[0051] First, consider using the first MUSIC-based signal angle of arrival estimation method, the process of which is shown in Figure 1 First, the received signal is subjected to cross-correlation matrix operation, then the matrix is subjected to eigenvalue decomposition, which is decomposed into signal subspace and noise subspace. The steering vector of the signal subspace is orthogonal to the noise subspace, and the MUSIC spectrum is calculated using this principle. The peak value of the MUSIC spectrum is searched, and the angle corresponding to the peak value is the estimated value of the angle of arrival of the signal to the antenna array. The specific process is described as follows:

[0052] In a signal angle of arrival estimation process, it is assumed that there are K signal sources, the transmitted signal is s k (t), and the antenna array receives the signal as:

[0053]

[0054] where am (θ k ) is the response of the mth array element to the kth far-field signal, n m (t) is the received noise at the mth array element. Matrix the (1) as follows:

[0055] x(t)=A(θ)s(t)+n(t) (2)

[0056] where is called the direction matrix, a(θ k )=[a -N (θ k ),…,a N (θ k )] T is the array response vector.

[0057] Calculate the covariance matrix of the received signal:

[0058] R=E[xx H ] (3)

[0059] Eigenvalue decomposition of the covariance matrix can be decomposed into signal subspace and noise subspace:

[0060]

[0061] where U S is the signal subspace of the received signal, U n is the noise subspace of the received signal, Λ S is a diagonal matrix composed of K larger eigenvalues, and Λ n is a diagonal matrix composed of the remaining smaller eigenvalues. Using the orthogonality, we have:

[0062]

[0063] The MUSIC algorithm in the first way uses the following spectral function to search for spectral peaks to estimate the transmission delay:

[0064]

[0065] The estimated value of the transmission delay is:

[0066]

[0067] The MUSIC algorithm has superior resolution capability for signal angle of arrival estimation, which can improve the angle measurement capability of 5G signals.

[0068] However, although the above-mentioned manner can estimate the angle of arrival of the far-field signal to the antenna array more accurately, it does not improve the estimation of the angle of arrival of the signal for the case that the signal source in the indoor positioning scene may be in the near-field region of the antenna array. The MUSIC method in the first manner only assumes the signal source to be a far-field source, and a large error in the estimation of the angle of arrival of the signal will exist if it is applied to a near-field source.

[0069] Based on this, the present application considers to improve another method for estimating the angle of arrival of the signal of the mixed-field source different from the first method, by constructing a fourth-order cumulant matrix eliminating the influence of the distance of the signal source for the mixed-field source in the indoor single base station scene, and constructing a MUSIC spectrum function based on the fourth-order cumulant matrix, and applying the MUSIC spectrum function to obtain the estimation value of the angle of arrival of the signal of the mixed-field source to the antenna array for 5G positioning, which can be effectively applied to the indoor single base station positioning scene, has obvious advantages, can provide a high-precision signal angle of arrival estimation algorithm for the TOA+AOA positioning method in the 5G positioning method, can estimate the angle of arrival of the signal of the mixed-field source containing the far-field region and the near-field region of the antenna array, can improve the reliability and effectiveness of the signal angle of arrival estimation process of the mixed-field source, and can effectively improve the estimation accuracy of the angle of arrival of the signal in the mixed-field source scene.

[0070] In one or more embodiments of the present application, GNSS (Global Navigation Satellite System) refers to a global navigation satellite system.

[0071] In one or more embodiments of the present application, GPS (Global Positioning System) refers to a global positioning system.

[0072] In one or more embodiments of the present application, DL-TDOA (Down Link Time Difference of Arrival) refers to downlink time difference of arrival.

[0073] In one or more embodiments of the present application, AOA (Angle of Arrival) refers to the angle of arrival.

[0074] In one or more embodiments of the present application, MUSIC (Multiple Signal Classification) refers to a multiple signal classification algorithm.

[0075] In one or more embodiments of the present application, TOA (Time of Arrival) refers to the time of arrival.

[0076] In one or more embodiments of the present application, ESPRIT (Estimating Signal Parameter via Rotational Invariance Techniques) refers to signal parameter estimation based on rotational invariance techniques.

[0077] Based on this, in order to solve the problem that the prior art does not estimate the angle of arrival of signals for the mixed field source in the indoor single base station positioning scene, the present application provides a signal angle of arrival estimation method for a mixed field source, as shown in Figure 2 The signal angle of arrival estimation method for the mixed field source specifically includes the following contents:

[0078] Step 100: For the mixed field source in the indoor single base station scene, a fourth-order cumulant matrix that has eliminated the distance influence of the source is constructed.

[0079] Step 200: Based on the fourth-order cumulant matrix, a MUSIC spectrum function is constructed, and the MUSIC spectrum function is applied to obtain the angle of arrival estimation value of the signal of the mixed field source to the antenna array for 5G positioning.

[0080] It can be understood that the MUSIC algorithm has superior resolution capability for signal angle of arrival estimation, which can improve the angle measurement capability of 5G signals.

[0081] From the above description, it can be seen that the signal angle of arrival estimation method for the mixed field source provided by the embodiments of the present application can effectively be applied to the indoor single base station positioning scene, and has obvious advantages, which can provide a high-precision signal angle of arrival estimation algorithm for the TOA+AOA positioning method in the 5G positioning method, can estimate the signal angle of arrival of the mixed field source containing the far field region and the near field region of the antenna array, can improve the reliability and effectiveness of the signal angle of arrival estimation process of the mixed field source, and can effectively improve the estimation accuracy of the signal angle of arrival in the mixed field source scene.

[0082] In order to improve the reliability and effectiveness of constructing the fourth-order cumulant matrix that has eliminated the distance influence of the source for the mixed field source, in the signal angle of arrival estimation method for the mixed field source provided by the embodiments of the present application, as shown in Figure 3 The step 100 in the signal angle of arrival estimation method for the mixed field source specifically includes the following contents:

[0083] Step 110: receiving the signal of the mixed-field source, eliminating the nonlinear component in the phase of the received signal affected by the distance of the source by using the symmetry of the fourth-order cumulant, so as to construct the fourth-order cumulant matrix of the mixed-field source in the indoor single base station scene.

[0084] From the above description, it can be known that the method for estimating the signal direction of arrival of the mixed-field source provided by the embodiment of the application eliminates the nonlinear component in the phase of the received signal affected by the distance of the source by using the symmetry of the fourth-order cumulant, and provides a specific implementation mode for constructing the fourth-order cumulant matrix of the mixed-field source which has eliminated the influence of the distance of the source, and can effectively improve the reliability and effectiveness of constructing the fourth-order cumulant matrix of the mixed-field source which has eliminated the influence of the distance of the source.

[0085] In order to improve the reliability and effectiveness of eliminating the nonlinear component in the phase of the received signal affected by the distance of the source by using the symmetry of the fourth-order cumulant, in the method for estimating the signal direction of arrival of the mixed-field source provided by the embodiment of the application, referring to Figure 4 , the step 110 in the method for estimating the signal direction of arrival of the mixed-field source further specifically includes the following contents:

[0086] Step 111: obtaining the definition function of the fourth-order cumulant;

[0087] Step 112: determining the nonlinear component in the phase of the received signal affected by the distance of the source in the definition function;

[0088] Step 113: replacing the nonlinear component in the phase of the received signal affected by the distance of the source in the definition function by using the symmetry of the fourth-order cumulant, so as to obtain the fourth-order cumulant matrix of the mixed-field source which has eliminated the influence of the distance of the source in the indoor single base station scene.

[0089] Specifically, according to the definition of the fourth-order cumulant, there are:

[0090]

[0091] Wherein m, n, p, q represent the array element label. And there are:

[0092]

[0093] It can be seen from the formula (9) that there is a nonlinear component in the phase, and the component is related to the direction of arrival and the distance of the near-field source. When estimating the parameters of the near-field source, the distance information can no longer be concerned, and only the angle information is concerned. Therefore, if n=-m and q=-p, the fourth-order cumulant matrix is constructed as follows:

[0094]

[0095] where i = M + 1 + m, j = M + 1 + n, and m, n ∈ [-N, N].

[0096] As can be seen from the above description, the method for estimating the signal angle of arrival of the mixed-field source provided in the embodiments of the present application can effectively improve the reliability and effectiveness of eliminating the nonlinear components in the received signal phase affected by the source distance by obtaining the definition function of the fourth-order cumulant, determining the nonlinear components in the received signal phase affected by the source distance in the definition function, and replacing the nonlinear components in the received signal phase affected by the source distance in the definition function by using the symmetry of the fourth-order cumulant, and further improve the reliability and effectiveness of constructing the fourth-order cumulant matrix of the mixed-field source which has eliminated the influence of the source distance.

[0097] In order to improve the reliability and effectiveness of constructing the MUSIC spectrum function, in the method for estimating the signal angle of arrival of the mixed-field source provided in the embodiments of the present application, referring to Figure 3 , the step 200 of the method for estimating the signal angle of arrival of the mixed-field source specifically includes the following content:

[0098] Step 210: decompose the fourth-order cumulant matrix to obtain a decomposition result for application;

[0099] Step 220: construct a MUSIC spectrum function according to the decomposition result;

[0100] Step 230: obtain an angle of arrival estimation value of the signal of the mixed-field source arriving at the antenna array based on the MUSIC spectrum function;

[0101] Step 240: output the angle of arrival estimation value for 5G positioning.

[0102] As can be seen from the above description, the method for estimating the signal angle of arrival of the mixed-field source provided in the embodiments of the present application can effectively improve the reliability and effectiveness of constructing the MUSIC spectrum function by first decomposing the fourth-order cumulant matrix to obtain a decomposition result for application, and then constructing a MUSIC spectrum function according to the decomposition result, and further improve the accuracy and effectiveness of obtaining the angle of arrival estimation value of the signal of the mixed-field source arriving at the antenna array based on the MUSIC spectrum function.

[0103] In order to improve the effectiveness and reliability of spatial decomposition, in the method for estimating the signal angle of arrival of the mixed-field source provided in the embodiments of the present application, referring to Figure 4 , the step 210 of the method for estimating the signal angle of arrival of the mixed-field source specifically includes the following content:

[0104] Step 211: singular value decomposition is performed on the fourth-order cumulant matrix to obtain a decomposition result containing a signal subspace and a noise subspace;

[0105] Step 212: a MUSIC spectrum function is constructed according to the decomposition result;

[0106] Step 213: an angle of arrival estimation value of a mixed-field signal source to an antenna array is obtained based on the MUSIC spectrum function.

[0107] Specifically, by definition, formula (10) can be rewritten as:

[0108]

[0109] wherein C 4s = diag{c1,…,c k ,…,c K}, the kth column of matrix A1 and A2 is respectively:

[0110]

[0111]

[0112] singular value decomposition is performed on C1, and there are

[0113]

[0114] wherein Σ s is a diagonal matrix composed of K large singular values, Σ n is a diagonal matrix composed of M-K small singular values; U s is a signal subspace spanned by left singular vectors corresponding to the K large singular values, U n is a noise subspace spanned by left singular vectors corresponding to the M-K small singular values; V s is a signal subspace spanned by right singular vectors corresponding to the K large singular values, V n is a noise subspace spanned by right singular vectors corresponding to the M-K small singular values.

[0115] As can be seen from the above description, the angle of arrival estimation method of the mixed-field signal source provided in the embodiments of the present application can realize signal subspace and noise subspace decomposition by singular value decomposition of the fourth-order cumulant when performing signal subspace and noise subspace decomposition, which can effectively improve the effectiveness and reliability of spatial decomposition, and further improve the signal angle of arrival estimation precision in the mixed-field signal source scene in an indoor scene.

[0116] In order to improve the application reliability and effectiveness of the MUSIC spectrum function, in the angle of arrival estimation method of the mixed-field signal source provided in the embodiments of the present application, referring toFigure 4 The step 220 in the method for estimating the angle of arrival of signals of the mixed-field source further specifically includes the following content:

[0117] Step 221: Construct a MUSIC spectrum function according to the direction vector of the mixed-field source and the orthogonality of the noise subspace.

[0118] Specifically, the noise subspace of signals is obtained by formula (14), and the array spatial spectrum function is constructed by using the orthogonality of the source direction vector and the noise subspace, which is similar to the classical MUSIC algorithm:

[0119]

[0120] Wherein, U n is the noise subspace matrix of signals, P MUSIC is the spectrum function.

[0121] From the above description, it can be seen that the method for estimating the angle of arrival of signals of the mixed-field source provided by the embodiments of the present application can effectively improve the application reliability and effectiveness of the MUSIC spectrum function by constructing the MUSIC spectrum function according to the direction vector of the mixed-field source and the orthogonality of the noise subspace, and further improve the estimation accuracy of the angle of arrival of signals in the mixed-field source scene in the indoor scene.

[0122] In order to improve the reliability and accuracy of the estimated value of the angle of arrival of signals of the mixed-field source to the antenna array, in the method for estimating the angle of arrival of signals of the mixed-field source provided by the embodiments of the present application, referring to Figure 4 The step 230 in the method for estimating the angle of arrival of signals of the mixed-field source further specifically includes the following content:

[0123] Step 231: Perform spectrum peak searching on the MUSIC spectrum function to obtain the estimated value of the angle of arrival of signals of the mixed-field source to the antenna array.

[0124] Specifically, the angle corresponding to the peak value of P MUSIC is searched as the estimated value of the angle of arrival of signals of the mixed-field source, that is:

[0125]

[0126] After the above process, the estimated value of the angle of arrival of signals of the mixed-field source can be obtained.

[0127] From the above description, the mixed field source signal angle of arrival estimation method provided by the embodiments of the present application can highlight the spectral function peak value corresponding to the signal angle of arrival by using the calculation method of the MUSIC spectral function constructed by the present application when the MUSIC algorithm is used to estimate the signal angle of arrival, which can effectively improve the reliability and accuracy of the obtained signal angle of arrival estimation value of the mixed field source to the antenna array, and further improve the signal angle of arrival estimation precision in the mixed field source scene in the indoor scene.

[0128] From the software level, the present application further provides a mixed field source signal angle of arrival estimation device for executing all or part of the mixed field source signal angle of arrival estimation method, which is described in detail with reference to Figure 5 , and the mixed field source signal angle of arrival estimation device specifically includes the following contents:

[0129] The distance influence elimination module 10 is used for constructing a fourth-order cumulant matrix with eliminated distance influence of the signal source for the mixed field source in the indoor single base station scene.

[0130] The angle of arrival estimation module 20 is used for constructing a MUSIC spectral function based on the fourth-order cumulant matrix, and obtaining the angle of arrival estimation value of the mixed field source to the antenna array by using the MUSIC spectral function for 5G positioning.

[0131] The embodiments of the mixed field source signal angle of arrival estimation device provided by the present application can be specifically used for executing the processing flow of the embodiments of the mixed field source signal angle of arrival estimation method in the above embodiments, and the functions thereof will not be repeated here, and the detailed description can be referred to the above embodiments of the mixed field source signal angle of arrival estimation method.

[0132] The part of the mixed field source signal angle of arrival estimation device for the mixed field source signal angle of arrival estimation can be executed in the server, and in another actual application situation, all operations can be completed in the client device. Specifically, the processing capacity of the client device and the use scene of the user can be selected, and the present application is not limited thereto. If all operations are completed in the client device, the client device can further include a processor for specific processing of the mixed field source signal angle of arrival estimation.

[0133] The client device described above can have a communication module (i.e., a communication unit) that can be in communication connection with a remote server to realize data transmission with the server. The server can include a server of a task scheduling center side, and in other implementation scenarios, it can also include a server of an intermediate platform, such as a server of a third-party server platform that is in communication link with the server of the task scheduling center. The server can include a single computer device, or a server cluster composed of multiple servers, or a server structure of a distributed device.

[0134] The server and the client device can use any suitable network protocol to communicate, including a network protocol that has not been developed as of the filing date of the present application. The network protocol can include, for example, a TCP / IP protocol, a UDP / IP protocol, an HTTP protocol, an HTTPS protocol, and the like. Of course, the network protocol can also include, for example, a RPC protocol (Remote Procedure Call Protocol) used on top of the above-mentioned protocols, a REST protocol (Representational State Transfer), and the like.

[0135] As can be known from the above description, the signal arrival angle estimation device for mixed field sources provided by the embodiments of the present application can be used for mixed field sources in an indoor single base station scenario, construct a fourth-order cumulant matrix that has eliminated the influence of source distance, construct a MUSIC spectrum function based on the fourth-order cumulant matrix, and apply the MUSIC spectrum function to obtain an estimated value of the signal arrival angle of the mixed field source to the antenna array for 5G positioning. This can effectively be applied to an indoor single base station positioning scenario, has obvious advantages, can provide a high-precision signal arrival angle estimation algorithm for the TOA+AOA positioning method in the 5G positioning method, can estimate the signal arrival angle of mixed field sources containing far-field regions and near-field regions of the antenna array, can improve the reliability and effectiveness of the signal arrival angle estimation process of the mixed field source, and can effectively improve the estimation accuracy of the signal arrival angle in the mixed field source scenario.

[0136] To further illustrate the present scheme, the present application also provides a specific application example of a signal arrival angle estimation method for mixed field sources. Referring to Figure 6Firstly, the nonlinear component in the phase of the received signal affected by the distance of the signal source is eliminated by using the symmetry of the fourth-order cumulant, and a fourth-order cumulant matrix is constructed. Then, the fourth-order cumulant matrix is singular value decomposed, and is decomposed into a signal subspace and a noise subspace. By using the orthogonality between the signal source direction vector and the noise subspace, a MUSIC spectrum function is constructed, a spectral peak search is performed, and the angle of arrival estimation value of the mixed field signal source is obtained. The signal angle of arrival estimation method of the mixed field source is described in detail below. The signal angle of arrival estimation method of the mixed field source specifically includes the following contents:

[0137] (I) Construction of the fourth-order cumulant matrix

[0138] According to the definition of the fourth-order cumulant, there is:

[0139]

[0140] Where m, n, p, q represent the element number. And there is:

[0141]

[0142] It can be seen from equation (9) that there is a nonlinear component in the phase, and the component is related to the direction of arrival and the distance of the near-field signal source. When estimating the parameters of the near-field signal source, the distance information can no longer be concerned, and only the angle information is concerned. Therefore, if n=-m and q=-p, the fourth-order cumulant matrix is constructed as follows:

[0143]

[0144] Where i=M+1+m, j=M+1+n, and m, n∈[-N, N].

[0145] (II) Singular value decomposition calculation of the fourth-order cumulant matrix

[0146] According to the definition, equation (10) can be rewritten as:

[0147]

[0148] Where, 4s =diag{c1,…,c k ,…,c K}, the kth column of matrix A1 and A2 is respectively:

[0149]

[0150]

[0151] The singular value decomposition of C1 is performed, and there is

[0152]

[0153] where Σ s is a diagonal matrix composed of K large singular values, Σ n is a diagonal matrix composed of M-K small singular values; U s is a signal subspace spanned by the left singular vectors corresponding to the K large singular values, U n is a noise subspace spanned by the left singular vectors corresponding to the M-K small singular values; V s is a signal subspace spanned by the right singular vectors corresponding to the K large singular values, V n is a noise subspace spanned by the right singular vectors corresponding to the M-K small singular values.

[0154] (III) MUSIC spectrum calculation and peak search

[0155] The noise subspace of the signal is obtained from formula (14), and the orthogonality between the source direction vector and the noise subspace is used to construct the array space spectrum function, similar to the classical MUSIC algorithm:

[0156]

[0157] where U n is the noise subspace matrix of the signal, P MUSIC is the spectrum function. The peak value of P MUSIC corresponding to the angle is taken as the estimation value of the signal arrival angle of the mixed field source, that is:

[0158]

[0159] After the above process, the estimation value of the signal arrival angle of the mixed field source can be obtained.

[0160] In summary, the above method provided by the application examples eliminates the non-linear components affected by the source distance before using the MUSIC algorithm to estimate the signal arrival angle. When performing signal subspace and noise subspace decomposition, the fourth-order cumulant is decomposed by singular value decomposition to realize signal subspace and noise subspace decomposition. When using the MUSIC algorithm to estimate the signal arrival angle, the calculation method of the spectrum function proposed in the application is used to highlight the spectrum function peak value corresponding to the signal arrival angle. In the indoor single base station positioning scene, there is obvious advantage, which provides a high-precision signal arrival angle estimation algorithm for the TOA+AOA positioning method in the 5G positioning method, which can effectively improve the signal arrival angle estimation precision in the mixed field source scene in the indoor scene. At the same time, the technical details of the signal arrival angle estimation are given.

[0161] The embodiments of the present application also provide a computer device (i.e., an electronic device), which can include a processor, a memory, a receiver and a transmitter. The processor is configured to execute the method for estimating the signal angle of arrival of the mixed-field source mentioned in the above embodiments. The processor and the memory can be connected through a bus or other means. The receiver can be connected to the processor and the memory through wired or wireless means. The computer device is connected to the device for estimating the signal angle of arrival of the mixed-field source to receive real-time motion data from the sensor in the wireless multimedia sensor network and to receive the original video sequence from the video acquisition device.

[0162] The processor can be a central processing unit (CPU). The processor can also be other general-purpose processors, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, or a combination of the above.

[0163] The memory is a non-transitory computer readable storage medium, which can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as the program instructions / modules corresponding to the method for estimating the signal angle of arrival of the mixed-field source in the embodiments of the present application. The processor executes various functions and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory, i.e., implements the method for estimating the signal angle of arrival of the mixed-field source in the above method embodiments.

[0164] The memory can include a program storage area and a data storage area. The program storage area can store an operating system and at least one application required by a function. The data storage area can store data created by the processor and the like. In addition, the memory can include a high-speed random access memory, and can also include a non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state memory device. In some embodiments, the memory can optionally include a memory remotely arranged with respect to the processor, and these remote memories can be connected to the processor through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof.

[0165] The one or more modules are stored in the memory and, when executed by the processor, perform a signal direction of arrival estimation method for a hybrid field source in embodiments.

[0166] In some embodiments of the present application, the user equipment can include a processor, a memory, and a transceiver which can include a receiver and a transmitter, the processor, the memory, the receiver and the transmitter can be connected through a bus system, the memory is configured to store computer instructions, and the processor is configured to execute the computer instructions stored in the memory to control the transceiver to transceive signals.

[0167] As an implementation manner, the functions of the receiver and the transmitter in the present application can be implemented by a transceiving circuit or a transceiving dedicated chip, and the processor can be implemented by a dedicated processing chip, a processing circuit or a general-purpose chip.

[0168] As another implementation manner, the server provided by the embodiments of the present application can be implemented by using a general-purpose computer. That is, program codes for implementing the functions of the processor, the receiver and the transmitter are stored in the memory, and the general-purpose processor implements the functions of the processor, the receiver and the transmitter by executing the codes in the memory.

[0169] The embodiments of the present application further provide a computer readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the steps of the signal direction of arrival estimation method for a hybrid field source. The computer readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0170] Those of ordinary skill in the art should understand that the example components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Whether the implementation is in hardware or software depends on the specific application and design constraints imposed on the overall system. Skilled artisans can employ different elements in different combinations to implement the described functions, without departing from the scope of the present application. When implemented in hardware, the functions can be implemented in, for example, an electronic circuit, a special-purpose integrated circuit (ASIC), suitable firmware, a plug-in, a functional card, or the like. When implemented in software, the elements of the present application are the program or code segments to perform the necessary tasks. The program or code segments can be stored in a machine-readable medium, or transmitted by a data signal in a carrier wave over a transmission medium or a communication link.

[0171] It is to be expressly understood that the application is not limited to the described and illustrated particular configurations and processes. For the sake of clarity, detailed descriptions of known methods are omitted. In the above described embodiments, several specific steps are described and illustrated as examples. However, the method processes of the application are not limited to the specific steps described and illustrated, and the skilled person can make various changes, modifications and additions, or change the order of the steps, after having understood the spirit of the application.

[0172] In this application, features described and / or illustrated with respect to one embodiment can be used in the same or similar manner in one or more other embodiments and / or combined with or substituted for features of other embodiments.

[0173] The above only describes the preferred embodiments of the application, and is not intended to limit the application. The skilled in the art can make various changes and modifications to the embodiments of the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A method for estimating the angle of arrival of a signal from a mixed field source, characterized in that: include: For mixed-field signal sources in indoor single-base station scenarios, a fourth-order cumulant matrix is ​​constructed to eliminate the influence of signal source distance. Constructing a MUSIC spectrum function based on the fourth-order cumulant matrix, and applying the MUSIC spectrum function to obtain an estimated value of the arrival angle of the signal of the mixed field source arriving at the antenna array for 5G positioning; The method of constructing a fourth-order cumulant matrix that eliminates the influence of source distance for a mixed-field signal source in an indoor single-base station scenario includes: Receive signals containing mixed-field sources in the far-field and near-field regions of the antenna array, and use the symmetry of fourth-order cumulants to eliminate the nonlinear component of the received signal phase affected by the source distance, thereby constructing a fourth-order cumulant matrix for the mixed-field source in an indoor single-base station scenario. The method of constructing a MUSIC spectrum function based on the fourth-order cumulant matrix and applying the MUSIC spectrum function to obtain an estimated value of the arrival angle of a signal from a mixed field source arriving at an antenna array for 5G positioning includes: Performing singular value decomposition on the fourth-order cumulant matrix to obtain a decomposition result including a signal subspace and a noise subspace; Constructing a MUSIC spectrum function according to the direction vector of the mixed field signal source and the orthogonality of the noise subspace; Obtaining an estimated value of the arrival angle of the signal of the mixed field source arriving at the antenna array based on the MUSIC spectrum function; Outputting the arrival angle estimate value for use in 5G positioning; The receiving device includes a signal of a mixed field source located in the far field region and the near field region of the antenna array, and utilizes the symmetry of the fourth-order cumulant to eliminate the nonlinear component of the received signal phase affected by the source distance, so as to construct a fourth-order cumulant matrix for the mixed field source in an indoor single base station scenario, including: Get the definition function of the fourth-order cumulant; Determining, in the defined function, a nonlinear component of the received signal phase that is affected by the distance to the source; Utilizing the symmetry of the fourth-order cumulants, the nonlinear component of the received signal phase affected by the source distance is replaced in the defined function to obtain a fourth-order cumulant matrix that eliminates the influence of the source distance for an indoor single-base station scenario; The obtaining, based on the MUSIC spectrum function, an estimated value of an arrival angle of a signal from a mixed field signal source arriving at an antenna array includes: A spectrum peak search is performed on the MUSIC spectrum function to obtain an estimated value of an arrival angle of the signal of the mixed field signal source arriving at the antenna array.

2. A device for estimating the angle of arrival of a signal from a mixed field signal source, characterized in that: include: The distance effect elimination module is used to construct a fourth-order cumulant matrix that has eliminated the source distance effect for mixed-field signal sources in indoor single-base station scenarios; An arrival angle estimation module is used to construct a MUSIC spectrum function based on the fourth-order cumulant matrix, and apply the MUSIC spectrum function to obtain an arrival angle estimate of the signal of the mixed field source arriving at the antenna array for 5G positioning; The method of constructing a fourth-order cumulant matrix that eliminates the influence of source distance for a mixed-field signal source in an indoor single-base station scenario includes: Receive signals containing mixed-field sources in the far-field and near-field regions of the antenna array, and use the symmetry of fourth-order cumulants to eliminate the nonlinear component of the received signal phase affected by the source distance, thereby constructing a fourth-order cumulant matrix for the mixed-field source in an indoor single-base station scenario. The method of constructing a MUSIC spectrum function based on the fourth-order cumulant matrix and applying the MUSIC spectrum function to obtain an estimated value of the arrival angle of a signal from a mixed field source arriving at an antenna array for 5G positioning includes: Performing singular value decomposition on the fourth-order cumulant matrix to obtain a decomposition result including a signal subspace and a noise subspace; Constructing a MUSIC spectrum function according to the direction vector of the mixed field signal source and the orthogonality of the noise subspace; Obtaining an estimated value of the arrival angle of the signal of the mixed field source arriving at the antenna array based on the MUSIC spectrum function; Outputting the arrival angle estimate value for use in 5G positioning; The receiving device includes a signal of a mixed field source located in the far field region and the near field region of the antenna array, and utilizes the symmetry of the fourth-order cumulant to eliminate the nonlinear component of the received signal phase affected by the source distance, so as to construct a fourth-order cumulant matrix for the mixed field source in an indoor single base station scenario, including: Get the definition function of the fourth-order cumulant; Determining, in the defined function, a nonlinear component of the received signal phase that is affected by the distance to the source; Utilizing the symmetry of the fourth-order cumulants, the nonlinear component of the received signal phase affected by the source distance is replaced in the defined function to obtain a fourth-order cumulant matrix that eliminates the influence of the source distance for an indoor single-base station scenario; The obtaining, based on the MUSIC spectrum function, an estimated value of an arrival angle of a signal from a mixed field signal source arriving at an antenna array includes: A spectrum peak search is performed on the MUSIC spectrum function to obtain an estimated value of an arrival angle of the signal of the mixed field signal source arriving at the antenna array.

3. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the method for estimating the signal arrival angle of a mixed-field signal source according to claim 1 is implemented.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for estimating the signal arrival angle of a mixed-field signal source according to claim 1 is implemented.

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