This disclosure claims priority to Chinese Patent Application No. 202110883913.2 filed on Aug. 3, 2021 and entitled “Method and Apparatus for Determining Positioning Parameter, Device and Storage Medium”, the disclosure of which is hereby incorporated by reference in its entirety.
The present disclosure relates to the technical field of communications, and in particular, to a method and apparatus for determining a positioning parameter, a device and a storage medium.
With the rapid development of industrial Internet, Internet of Things, and Internet of Vehicles, high-accuracy positioning has become an indispensable key support service for mobile terminals such as intelligent robots and unmanned vehicles. A satellite navigation and positioning technology has the advantages of wide area coverage and good generalizability. However, due to low signal power and weak penetration power, the satellite navigation and positioning technology is mainly used for terminal positioning in open outdoor environments, and cannot provide a navigation and positioning service in sheltered environments and indoor environments.
In order to solve the above problems, in the related art, basic facilities of a wireless communication system or a private wireless positioning base station for deployment is used to position a terminal device. For example, positioning signals sent by the terminal device may be simultaneously measured by using a space-time super-resolution algorithm, so as to determine corresponding positioning parameters, which are Time of Flight (ToF) and Angle of Arrival (AoA), and then positioning information of the terminal device may be determined on the basis of the positioning parameters.
The present disclosure provides a method and apparatus for determining a positioning parameter, and a computer device and a storage medium.
According to a first aspect, the present disclosure provides a method for determining a positioning parameter, including:
According to a second aspect, the present disclosure provides an apparatus for determining a positioning parameter, including:
According to a third aspect, the present disclosure provides a computer device, which includes a memory and a processor, wherein the memory stores a computer program, the processor implements, when executing the computer program, steps of the method in any one of the above embodiments in the first aspect.
According to a fourth aspect, the present disclosure provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, steps of the method in any one of the above embodiments in the first aspect are implemented when the computer program is executed by a processor.
The details of one or more embodiments of the present disclosure are set forth in the drawings and the description below. Other features, objectives, and advantages of the present disclosure will be apparent from the drawings and the claims from the specification.
To make the objectives, technical solutions and advantages of the present disclosure clearer, the present disclosure is further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described here are merely used to explain the present disclosure, and are not used to limit the present disclosure.
With the rapid development of industrial Internet, Internet of Things, and Internet of Vehicles, high-accuracy positioning has become an indispensable key support service for mobile terminals such as intelligent robots and unmanned vehicles. A satellite navigation and positioning technology has the advantages of wide area coverage and good generalizability. However, due to low signal power and weak penetration power, the satellite navigation and positioning technology is mainly used for terminal positioning in open outdoor environments, and cannot provide a navigation and positioning service in sheltered environments and indoor environments.
In order to solve the above problems, one main technical approach is to use basic facilities of a wireless communication system or a private wireless positioning base station for deployment to position a terminal device. Typical positioning technologies include cellular network positioning, Wireless Local Area Network (WLAN) positioning, Bluetooth positioning, Ultra-Wide Band (UWB) positioning, and the like. Systems such as a cellular mobile network, a WLAN, and a UWB generally use a broadband transmission signal and an array antenna, which can simultaneously measure ToF and AoA. In an actual system, due to the impact of processing technic, tooling, and mutual coupling between array elements, there are differences between in-array radiation patterns of array elements in an array. In this case, there are differences in amplitude and phase responses of incident signals from different angles, and the differences are significant at a large AoA. However, existing studies are less informative about the estimation performance of a positioning base station at a large AoA. In addition, in a complex path environment, a real-time positioning requirement for a fast-moving target requires that a positioning algorithm can take both estimation accuracy and real-time performance into consideration.
Based on this, the present disclosure provides a method for determining a positioning parameter, which can take both the accuracy and real-time performance of measuring ToF and AoA into consideration, thereby improving the accuracy of the positioning parameter. The method for determining the positioning parameter provided in the present disclosure is applicable to an application environment shown in
In an embodiment, as shown in
At S202, ToF spectrum data of a positioning signal is determined according to the positioning signal sent via multi-channels by a terminal to be positioned.
The terminal to be positioned may include a mobile terminal device such as a vehicle and an airplane. The positioning signal is a signal including a positioning sequence, may be a 5G signal, a 4G signal, and the like, and is not limited herein. The ToF is a propagation delay, which is the flying time that the signal is propagated from a transmitter end to a receiver end, thus also being called ToF.
For example, when the terminal to be positioned sends the positioning signal to the base station, the base station may receive the positioning signal by means of an antenna array, and perform super-resolution ToF spectrum estimation on the positioning signal after receiving the positioning signal, so as to obtain the ToF spectrum data. The antenna array may be a linear array, or may be a circular array, and is not limited herein. In addition, the antenna array may include a plurality of array elements, and each array element may correspond to one receiving channel.
Further, when the super-resolution ToF spectrum estimation is performed on each receiving channel, a fading coefficient on a delay region of interest is estimated by means of scanning. The process is also called delay spectrum estimation or ToF spectrum estimation. Scan delays corresponding to ToF spectrum peak points represent signal components corresponding to a plurality of paths that the positioning signal is reflected by an obstacle or directly arrives at the antenna array; and a ToF value corresponding to the corresponding ToF spectrum peak point is the ToF of the corresponding path.
Solution may be performed on the ToF spectrum data by means of a single point Least Square (LS) algorithm, an Amplitude and Phase Estimation (APES) algorithm, an Iterative Adaptive Approach (IAA), and a sparse reconstruction algorithm and so on, so as to determine the ToF of the positioning signal.
At S204, an ideal spatial manifold matrix is corrected according to a preset antenna array deviation function, so as to obtain a corrected spatial manifold matrix, wherein each element in the ideal spatial manifold matrix or the spatial manifold matrix represents a response of a corresponding array element in an antenna array to a positioning signal in a preset corresponding angle range, and the antenna array deviation function represents a deviation between a response of a real antenna array to a signal and a response of an ideal antenna array to the signal.
The preset corresponding angle range is an angle range of each portion after an antenna array coverage range [θmin, θmax] is divided into Q portions. The antenna array coverage range [θmin, θmax] may be divided with an equal AoA interval δθ. An antenna array deviation function may be a function of an antenna phase deviation and an amplitude deviation and is obtained in advance through offline measurement. The antenna array deviation function is the deviation between the response of a real antenna array to a signal and the response of an ideal antenna array to the signal.
As at least one alternative embodiment, an ideal spatial manifold matrix is a perfect spatial manifold matrix, but during actual application of the antenna array, due to factors such as antenna planning and mutual coupling between array elements, the antenna array is not in a perfect situation, such that there is an AOA-dependent phase deviation in the antenna array. If an ideal spatial manifold matrix is used to perform direction-finding processing, a large direction-finding deviation occurs due to mismatch between the ideal manifold and the actual manifold. The ideal spatial manifold matrix is corrected by means of the preset antenna array deviation function, and results that are more in line with reality are obtained.
At S206, a positioning parameter of LOS of the positioning signal is determined according to the ToF spectrum data and the corrected spatial manifold matrix, wherein the LOS is the shortest path from the terminal to be positioned to the antenna array.
For example, AoA spectrum estimation may be performed on the ToF spectrum data of the Nth receiving channel on each delay grid point by using a Digital Beam Forming (DBF) method and a MUltiple Signal Classification (MUSIC) algorithm and so on, so as to obtain a ToF-AoA two-dimensional spectrum estimation; and spectrum peak extraction is performed on the obtained ToF-AoA two-dimensional spectrum estimation, so as to obtain estimated values of fading coefficients, AoA, and ToF corresponding to maximum K1 spectrum peaks, which are respectively recorded as {circumflex over (γ)}k, {circumflex over (θ)}k, {circumflex over (τ)}k, k=1, . . . , K1. A LOS component is extracted according to the fading coefficients {circumflex over (γ)}k and ToF values {circumflex over (τ)}k corresponding to the K1 spectrum peak components, that is, from the fading coefficient {circumflex over (γ)}k and the ToF value {circumflex over (τ)}k corresponding to each path, and ToF estimation results and AoA estimation results of the LOS component are outputted. Alternatively, after the AoA estimation result is acquired, fine delay grid points may be then divided, and the idea spatial manifold matrix is corrected; and then fine searching is performed on the corrected spatial manifold matrix, so as to determine a fine AoA result, and there are no limitations herein. Since there are some obstacles in an actual environment, a signal arrives at the antenna array after being reflected and refracted, such that there are a plurality of paths that the signal arrives from a transmitter to the antenna array. The LOS is the shortest path from the terminal to be positioned to the antenna array, which may also be understood as the path that the positioning signal directly arrives at the antenna array without refraction or reflection.
In the method for determining the positioning parameter, the ToF spectrum data of the positioning signal is determined according to the positioning signal sent via multi-channels by the terminal to be positioned; the ideal spatial manifold matrix is corrected according to the preset antenna array deviation function, so as to obtain the corrected spatial manifold matrix; and the positioning parameter of LOS of the positioning signal is determined according to the ToF spectrum data and the corrected spatial manifold matrix. The ideal spatial manifold matrix can be corrected by using the preset antenna array deviation function including a phase and an amplitude, so as to reduce the deviation between the response of a real antenna array to a signal and the response of an ideal antenna array to the signal, and the LOS, which is the shortest path from the terminal to be positioned to the antenna array, is determined, such that the accuracy of measuring the positioning parameter of the positioning signal is improved. In addition, the solution avoids the problem of high computational complexity caused by simultaneous measurement of the ToF and the AoA in the related art.
In the above embodiment, the method for determining the positioning parameter is described, and is mainly to correct, according to the antenna array deviation function, the spatial manifold matrix reflecting the response of receiving the positioning signal by the antenna array. Now, the way of constructing the antenna array deviation function is described by using an embodiment. In an embodiment, as shown in
At S302, an amplitude measurement value set of direction-dependent amplitude responses and a phase measurement value set of phase deviations are acquired, wherein the amplitude measurement value set of direction-dependent amplitude responses is a set of direction-dependent amplitude responses that a simulated real signal arrives at each array element of the antenna array, and the phase measurement value set of phase deviations is a set of direction-dependent amplitude responses that the simulated real signal arrives at each array element of the antenna array.
The simulated real signal is a signal that is transmitted by a signal generator in an anechoic chamber simulating the real signal.
For example, the antenna array is placed on a rotary table in the anechoic chamber, and may be rotated −60° to 60°. Every 5° of rotation is set as a sampling angle. The sampling angles form a discrete AoA set {{umlaut over (θ)}r}r=1R. On arriving each sampling angle, amplitude measurement values of direction-dependent amplitude responses that the simulated real signal arrives at each array element of the antenna array are acquired, and all acquired amplitude measurement values form the amplitude measurement value set; and phase measurement values of phase deviations that the simulated real signal arrives at each array element of the antenna array are acquired, and all acquired phase measurement values form the phase measurement value set. On the discrete AoA set {
At S304, an amplitude pattern function is constructed according to the amplitude measurement value set, and a phase deviation function is constructed according to the phase measurement value set.
As at least one alternative embodiment, according to the measurement sets of the amplitude pattern and phase deviation of each array element n of the antenna, functions ρn(θ) and ϕn(θ) may be estimated by means of polynomial fitting, a support vector machine, or a neural network. For example, the function ϕn(θ) is estimated by using the polynomial fitting method, and the process is described as below. An obtained function fitting result is recorded as {circumflex over (ϕ)}poly,n(θ,g) where g∈RJ×1 is a polynomial weight, J is a polynomial fitting order, the form of {circumflex over (ϕ)}poly,n(θ,g) is {circumflex over (ϕ)}poly,n(θ,g)=Σl=1Jglθl·1, and gl is a r element of a weight vector g. An objective function for polynomial fitting is shown as
In this embodiment, the amplitude measurement value set of direction-dependent amplitude responses that the simulated real signal arrives at each array element of the antenna array, and the phase measurement value set of phase deviations that the simulated real signal arrives at each array element of the antenna array are acquired; and the amplitude pattern function is constructed according to the amplitude measurement value set, and the phase deviation function is constructed according to the phase measurement value set. In this way, the spatial manifold matrix reflecting the response to receiving the positioning signal by the antenna array can be corrected, such that the accuracy of measuring the positioning parameter of the positioning signal is improved.
In the above embodiment, the way of constructing the antenna deviation function is described. For example, the spatial manifold matrix is corrected by using the antenna deviation function with an embodiment. In and embodiment, the ideal spatial manifold matrix includes a coarse ideal spatial manifold matrix and a fine ideal spatial manifold matrix; each element in the coarse ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a first preset corresponding angle range; each element in the fine ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a second preset corresponding angle range; and the first preset corresponding angle range is greater than the second preset corresponding angle range.
The preset corresponding angle range is the corresponding AoA set {θq}q=1Q that is obtained by dividing the antenna array coverage range [θmin, θmax] to Q portions with the equal AoA interval δθ. A coarse result AoA region [{circumflex over (θ)}LOS−Δθ,{circumflex over (θ)}LOS−Δθ]: may be divided by using a uniform grid δθ1, so as to obtain Q1 fine search grid sets, which are recorded as {ψq}q=1Q
For example, the ideal spatial manifold matrix includes a coarse ideal spatial manifold matrix and a fine ideal spatial manifold matrix; each element in the coarse ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a first preset corresponding angle range; each element in the fine ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a second preset corresponding angle range; and the first preset corresponding angle range is greater than the second preset corresponding angle range.
At AoA θ, an ideal array steering vector aθ(θ) is determined by an array structure, and a set of array steering vectors on an AoA set {θq}q=1Q form an ideal manifold matrix of the array, which is recorded as Ae, where Aθ=[aθ(θ1),aθ(θ2), . . . , aθ(θQ)]. The ideal manifold matrix Aθ,fine corresponding to a fine search AoA set is determined, where Aθ,fine=[aθ(ψ1),aθ(ψ2), . . . , aθ(ψQ
In this embodiment, the ideal spatial manifold matrix includes the coarse ideal spatial manifold matrix and the fine ideal spatial manifold matrix; each element in the coarse ideal spatial manifold matrix represents the response of each array element in the antenna array to the positioning signal in the first preset corresponding angle range; and each element in the fine ideal spatial manifold matrix represents the response of each array element in the antenna array to the positioning signal in the second preset corresponding angle range. Since the first preset corresponding angle range is greater than the second preset corresponding angle range, division of different coarseness grid points and correction may be performed on the ideal spatial manifold matrix, so as to guarantee the accuracy of the obtained result to be higher.
In the above embodiment, two ideal coarseness forms of the ideal spatial manifold matrix are introduced. Now, the way of determining the positioning parameter of the LOS of the positioning signal by using the ideal spatial manifold matrix in the two ideal coarseness forms is described with an embodiment. In an embodiment, as shown in
At S402, the coarse ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain a corrected coarse spatial manifold matrix.
For example, the antenna array deviation function is determined according to the amplitude pattern function and the phase deviation function; the antenna array deviation function may be represented as {circumflex over (ζ)}(θq):{circumflex over (ζ)}(θq)|n={circumflex over (ρ)}n(θq)·exp(j{circumflex over (ϕ)}n(θq)); and the antenna phase deviation function {circumflex over (ϕ)}n(θ) and the amplitude pattern function {circumflex over (ρ)}n(θ), n=1, . . . , N are functions obtained in advance through offline measurement. According to an equation
At S404, the fine ideal spatial manifold matrix and ToF corresponding to the LOS are determined according to the corrected coarse spatial manifold matrix and the ToF spectrum data.
The ToF spectrum data may include vectors βn=[βn,1,βn,2, . . . , βn,P]T that are formed by delay τp, p=1, . . . , P corresponding to each scanning grid point, where βn,p is a fading coefficient on each scanning grid point, and n is an nth receiving array element in the antenna array, which is the nth receiving channel.
As at least one alternative embodiment, a delay range [τmin, τmax] of interest is divided into P portions at equal intervals, generally P>>K (the number of paths), and the delays corresponding to P scanning grid points may respectively be τp, p=1, . . . , P. βn,p is recorded, where p=1, . . . , P, βn,p is the fading coefficient on each scanning grid point. When τP={circumflex over (τ)}k, βn,p=αn,k{tilde over (γ)}k, αn,k, where αn,k represents the response of the nth receiving array element to an incident signal of a kth path, and {circumflex over (γ)}k is a fading coefficient of the kth path. On other P-K grid points, βn,P=0. βn=[βn,1,βn,2, . . . , βn,P]T is recorded as a fading coefficient vector on the scanning grid point set, and AT=[aτ(τ1), . . . , aτ(τPp)] is a delay matching matrix on the scanning grid point set. Then hn≈Aτβn+wn, n=1, . . . , N, wherein hn is an nth-column element in a Channel Frequency Response (CFR) matrix that is formed after channel estimation is performed on the received positioning signal, representing the CFR of the nth receiving channel.
As at least one alternative embodiment, for ToF spectrum estimation of the nth channel, an objective function which is solved by the IAA, is
An objective function for spectrum solution using a 1 based sparse reconstruction algorithm is
For example, a pth delay unit may be set, ToF spectrum data vectors of N receiving channels are bp∈CN×1, where bp=[{circumflex over (β)}1,p,{circumflex over (β)}2,p, . . . , {circumflex over (β)}N,p]T; and AoA spectrum estimation is successively performed on the ToF spectrum data vectors bp∈CN×1, p=1, . . . , P, and an AoA spectrum estimation result on a pth ToF unit is recorded as {circumflex over (γ)}p, p=1, . . . , P, γp∈CQ=1. A spectrum estimation method may be a Digital Beam Forming (DBF) method, a MUltiple Signal Classification (MUSIC) algorithm, etc. By using the DBF algorithm as an example, the spectrum estimation result is
Further, as shown in
At S502, ToF of each path of the positioning signal, reference AoA of each path, and an attenuation coefficient of each path are determined according to the corrected coarse spatial manifold matrix and the ToF spectrum data.
As at least one alternative embodiment, two-dimensional positioning parameter spectrum data of the N receiving channels are determined by using an formula
At S504, the LOS is determined from paths according to the attenuation coefficient of each path and the ToF of each path.
As at least one alternative embodiment, by means of a preset spectrum peak intensity threshold λ, K2 components of which energy exceeds the preset spectrum peak intensity threshold λ may be extracted from the K1 spectrum peak components, and then a component with the corresponding ToF being the minimum is extracted from the K2 components as an LOS component, that is, the component corresponding to the LOS. That is, in the spectrum peak components exceeding the preset spectrum peak intensity threshold in the attenuation coefficient of each path, the component with the minimum ToF may be directly determined, according to the solved ToF of the paths, as the ToF corresponding to the LOS.
As at least one alternative embodiment, the LOS component may also be extracted on the basis of basic standards that the LOS is shorter than reflection path propagation time, the LOS is stronger than reflection path energy or the ToF estimation variance and AoA estimation variance of the LOS components between the plurality of frames are smaller.
At S506, dividing is performed according to the reference AoA corresponding to the LOS, so as to obtain the second preset corresponding angle range.
As at least one alternative embodiment, Q1 fine search grid sets, which are recorded as {ψq}q=Q
At S508, the fine ideal spatial manifold matrix is determined according to the second preset corresponding angle range.
As at least one alternative embodiment, the fine search AoA sets may be substituted into a preset ideal manifold matrix, so as to determine the corresponding ideal manifold matrix Aθ,fine, where Aθ,fine=[aθ(ψ1),aθ(ψ2), . . . , aθ(ψQ
At S406, the fine ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain a corrected fine spatial manifold matrix.
As at least one alternative embodiment, a function value, which is the antenna array deviation function {circumflex over (ζ)}(ψq)|n={circumflex over (ρ)}n(ψq)·exp(j{circumflex over (ϕ)}n(ψq))q=1′ . . . , Q1,n=1, . . . , N, of the antenna array deviation function on the fine search grid point is calculated according to the estimated values {circumflex over (ϕ)}n(θ), {circumflex over (ρ)}n(θ), n=1, . . . , N of the antenna phase deviation function and the amplitude pattern function. Then the corrected manifold matrix is Aθ,fine′, and an element at the nth row and qth column of Aθ,fine′ is
At S408, by using a preset angle function, AoA of the LOS is determined according to the corrected fine spatial manifold matrix and the ToF corresponding to the LOS.
As at least one alternative embodiment, bLOS is recorded as the ToF spectrum data of the N receiving channels on a ToF unit where the LOS component is located. The AoA fine estimation is performed on the basis of a beam scanning peak criterion by substituting the corrected fine spatial manifold matrix and the ToF corresponding to the LOS into an angle function corresponding to the beam scanning peak criterion or an angle function corresponding to a criterion such as subspace orthogonality. For example, bLOS. and Aθ,fine′ are substituted into the angle function argθmax Aθ,fine′ HbLOS of the beam scanning peak criterion, so as to determine θ, which is the AoA of the LOS. In addition, bLOS and A, fine may also be substituted into the angle function argθmax|Aθ,fine′ HÛN∥F′ on the basis of the subspace orthogonality criterion, so as to determine a final θ value, which is the AoA of the LOS; ∥X∥F represents a Frobenius norm of a matrix X, and is defined as ∥X∥F=√{square root over (tr(XHX))}. ÛN is an estimation result of a noise subspace obtained according to the vector bLOS.
In this embodiment, the coarse ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain the corrected coarse spatial manifold matrix; the fine ideal spatial manifold matrix and the ToF corresponding to the LOS are determined according to the corrected coarse spatial manifold matrix and the ToF spectrum data; the fine ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain the corrected fine spatial manifold matrix; and by using the preset angle function, the AoA of the LOS is determined according to the corrected fine spatial manifold matrix and the ToF corresponding to the LOS. In this way, an antenna error related to the AoA can be effectively compensated by means of correcting the ideal manifold matrix. Calculation complexity when the ToF and the AoA are simultaneously searched by using two dimensions in the related art is reduced by means of delay spectrum estimation and a multistage cascade signal processing mode of first performing coarse grained searching then fine searching on the AoA of the LOS, such that positioning real-time performance is improved. In addition, a phase error related to the AoA can be accurately compensated, so as to improve direction-finding and positioning accuracy, and in particular, the direction-finding accuracy can be significantly improved when a wireless signal at large AoA.
In the above embodiment, the way of determining the positioning parameter of the LOS of the positioning signal by using the ideal spatial manifold matrix in the two ideal coarseness forms is described. Before the positioning parameter of the LOS of the positioning signal is determined, relevant processing needs to be first performed on the received positioning signal, and then the ToF spectrum data of the positioning signal is determined. Now, the above is described with an embodiment. As shown in
At S602, Fourier transform is performed on the positioning signal sent via multi-channels by the terminal to be positioned, so as to obtain multi-channel frequency-domain signals.
As at least one alternative embodiment, a base station receives the positioning signal with a known sequence, which is sent by the terminal to be positioned, by means of the antenna array.
Since the positioning signal is a time-domain signal, Fast Fourier Transform (FFT) may be first performed on each channel receiving signal, so as to obtain the multi-channel frequency-domain signal. The antenna array may include N array elements, and each array element corresponds to a receiving channel. If the number that a broadband positioning signal occupies sub-bands is M, a frequency-domain positioning signal received by the receiving channel n may be represented as a vector xn=[X1,n,X2,n, . . . , XM,n]T where Xm,n represents the frequency-domain positioning signal, which is received by the nth receiving channel at the mth sub-band. xn∈CM×1, where represents a complex space, and CM×1 represents a M*1-dimensional complex space, which is an M-dimensional complex vector space. In the present disclosure, the vectors all refer to column vectors.
Receiving data matrices of all channels of the base station may be represented as X=[x1,x2, . . . , xN]∈CM×N which is the multi-channel frequency-domain signal. The sequence of the positioning signal sent on M sub-bands is S[m],M=1,2, . . . , M; and a sending signal center carrier frequency is fc, and the corresponding wavelength is λ=c/fc, where c is the speed of light in vacuum. Without losing generality, assuming that the M sub-bands are uniformly distributed, a distribution interval is Δf; and assuming that a receiving antenna array is a Uniform Linear Array (ULA), and an array element interval is d. In addition, assuming that a transmission signal is propagated to the receiving array from K paths; and the ToF, AoA, and fading coefficient of the kth path respectively are {tilde over (τ)}k, {circumflex over (θ)}k, {circumflex over (γ)}k. {circumflex over (θ)}k is defined as an included angle between a signal incident direction and a ULA normal direction. The delay of signal transmission may represent the distance of signal transmission, and the delay and the distance may be mutually transformed by means of the speed of light c. Therefore, the multi-channel receiving signal matrix X may also be represented as X=Σk=1K=[{tilde over (γ)}k·aτ({tilde over (τ)}k)aθ′T({tilde over (θ)}k)]⊙γ+W (1).
In the equation (1), =diag([S[1],S[2], . . . , S[M]]T) is a positioning sequence data matrix of the positioning signal; and the diag(*) operator indicates that a diagonal matrix is obtained by using each element of the vector as the main diagonal element.
In the equation (1), aτ(·)∈T→CM×1 is a delay domain matching vector function, with an input being ToF T, and an output being a delay domain matching vector. For example, T→CM×1 indicates that the action scope of the function is T, a range is an M-dimensional delay domain matching vector, and T is a set of all possible path delay τ, that is, T∈T⊆R, where represents a real number space. The mm element of the delay domain matching vector indicates a phase deviation caused by signal ToF at the mth sub-band, and thus, there is aT({tilde over (τ)}k)|m=(−j2π(m−1)Δf{tilde over (τ)}k), m=1,2, . . . , M, j represents an imaginary unit and is defined as j=√{square root over (−1)}, and the distribution interval is 4.
In the equation (1), aθ′(·)∈Θ→CN×1 represents an actual receiving array steering vector function, with an input being signal AoA θ, and an output being an array steering vector of the corresponding AoA. For example, Θ→CN×1 indicates that an action scope is Θ, a range is an N-dimensional vector, and is a space that is formed by all possible incident signal AoA, that is, θ∈Θ⊆R. Further, aθ′({tilde over (θ)}k)=aθ({circumflex over (θ)}k)⊙({tilde over (θ)}k), where aθ({tilde over (θ)}k) is an ideal array steering vector. When the receiving array is the ULA, the nth element is
In the equation (1), γ∈CM×N: is a broadband response of an analog device such as a front-end amplifier, a filter, and a mixer of the receiving channel of the base station, and the element at the mth row and nth column is a response of the nth receiving channel at the mth sub-band. W∈CM×N is a noise matrix, and the element at the mth row and na column indicates a noise component of the nth receiving channel on the mth sub-band.
At S604, channel estimation is performed on the multi-channel frequency-domain signals, so as to obtain a CFR matrix.
As at least one alternative embodiment, the base station may perform channel estimation by using an LS method according to a frequency-domain receiving signal matrix X, so as to obtain a CFR matrix, which is recorded as H0. For example, assuming that a receiver has known the specific form of the positioning signal in a frequency domain, and has acquired a positioning sequence of the positioning signal, the receiver performs determination according to the positioning sequence, and performs channel estimation by using a classical LS algorithm, H0=S−1X may be obtained. In the equation, H0∈CM×N, the nth column is the CFR matrix of the nth receiving channel, and S−1 is an inverse matrix of a positioning sequence data matrix S=diag([S[1], S[2], . . . , S[M]]T) of the positioning signal. The CFR matrix may also be represented as H0=S−1X=Σk=1K[{tilde over (γ)}k·aτ({tilde over (τ)}k)aθ′T({tilde over (θ)}k)]⊙γ+S−1W.
At S606, the ToF spectrum data is acquired on the basis of the CFR matrix.
As at least one alternative embodiment, super-resolution ToF spectrum estimation is performed on each receiving channel according to the CFR matrix H0. hn, n=1,* is set to be the nth-column element of the matrix H0, representing the CFR of the nth receiving channel. Then hn may be represented as hn≈Σk=1K[αn,k{tilde over (γ)}k·aτ(Δ{tilde over (τ)}k)]+wn. In the equation, αn,k indicates the response of the nth receiving array element to the incident signal of the kth path, and is the nth element of a vector aθ′({tilde over (θ)}k). In the equation, wn∈CM×1 indicates a noise vector of the channel, and is the nth column of a matrix W′. ToF spectrum estimation is performed on the fading coefficient on the delay region of interest by means of scanning, and scanning delay corresponding to the ToF spectrum peak point represents the ToF of a strong path. By dividing a delay range [τmin,τmax] into P portions at equal intervals, generally P>>K (the number of paths), delay corresponding to P scanning grid points may respectively be τpp=1, . . . , P βn,p, p=1, . . . P is recorded as the fading coefficient on each scanning grid point. When τp={tilde over (τ)}k, βn,p=αn,k{tilde over (γ)}k, and on other P-K grid points, βn,p=0. βn=[βn,1,βn,2, . . . , βn,P]T is recorded as a fading coefficient vector on the scanning grid point set, that is, the ToF spectrum data, and Aτ=[aτ(τ1), . . . , aτ(τp)] is a delay matching matrix on the scanning grid point set. Then hn≈Aτβn+wn,n=1, . . . , N is obtained.
The spectrum estimation problem may be solved by using various parameter estimation methods, for example, a single point LS algorithm, an APES algorithm, an IAA, and a sparse reconstruction algorithm. For example, for ToF spectrum estimation of the nth channel, hn, Aτ=[aτ(τ1), . . . , aτ(τP)], and βn,p, p=1, . . . , P are substituted into an objective function
Further as shown in
At S702, a channel calibration coefficient is acquired, and the CFR matrix is corrected according to the channel calibration coefficient, so as to obtain a corrected CFR matrix.
As at least one alternative embodiment, the Y amplitude-phase responses of each receiving channel on each frequency point are different, leading to a term in the equation (1). Generally, the γ matrix may be obtained through measurement before a positioning experiment or obtained through measurement using a special correction channel in the positioning experiment. Assuming that a channel amplitude-phase response matrix obtained through measurement is {circumflex over (γ)}. Since the matrix {circumflex over (γ)} is configured to perform channel correction, the matrix is also generally called a channel calibration coefficient, or simply called a channel coefficient. The CFR matrix obtained through channel amplitude-phase deviation correction is recorded as H, and then the element at the mth row and na column is
At S704, the ToF spectrum data is acquired according to the corrected CFR matrix.
As at least one alternative embodiment, hn, n=1, . . . , N is set to be the nth-column element of the matrix H, representing the CFR of the nth receiving channel. Then hn may be represented as hn≈Σk=1K[αn,k{tilde over (γ)}k·aτ(Δ{tilde over (τ)}k)]+wn. In the equation, αn,k indicates the response of the nth receiving array element to the incident signal of the kth path, and is the nth element of a vector aθ′({tilde over (θ)}k). In the equation, wn∈CM×1 indicates a noise vector of the channel, and is the nth column of a matrix W′. ToF spectrum estimation is performed on the fading coefficient on the delay region of interest by means of scanning, and scanning delay corresponding to the ToF spectrum peak point represents the ToF of a strong path. By dividing the delay range [τmin, τmax] of interest into the P portions at equal intervals, generally P>>K (the number of paths), delay corresponding to the P scanning grid points respectively is τp, p=1, . . . , P βn,p, p=1, . . . , P is recorded as the fading coefficient on each scanning grid point. When τp={tilde over (τ)}k, βn,p=αn,k{tilde over (γ)}k, and on other P-K grid points, βn,p=0. βn=[βn,1,βn,2, . . . , βn,P]T is recorded as a fading coefficient vector on the scanning grid point set, that is, the ToF spectrum data, and Aτ=[aτ(τ1), . . . , aτ(τP)] is a delay matching matrix on the scanning grid point set. Then hn≈Aτβn+wn, n=1, . . . , N is obtained.
The spectrum estimation problem may be solved by using various parameter estimation methods, for example, a single point LS algorithm, an APES algorithm, an IAA, and a sparse reconstruction algorithm. For example, for ToF spectrum estimation of the n*h channel, hn, Aτ=[aτ(τ1), . . . , aτ(τp)], and the unknown βn,p, p=1, . . . , P are substituted into an objective function
In this embodiment, Fourier transform is performed on the positioning signal sent via multi-channels by the terminal to be positioned, so as to obtain the multi-channel frequency-domain signal; channel estimation is performed on the multi-channel frequency-domain signal, so as to obtain the CFR matrix; and the ToF spectrum data is acquired on the basis of the CFR matrix. In this way, the received positioning signal is transformed, facilitating subsequent data analysis. In addition, the higher accuracy of the subsequently-determined ToF spectrum data and the AoA is further achieved by means of correcting the CFR matrix obtained according to the positioning signal.
In the above embodiment, the way of positioning signal processing and the way of determining the ToF spectrum data are described. When the positioning signal is processed, the CFR matrix formed by the positioning signal is corrected. Now, a calibration coefficient during correction is described with an embodiment. In an embodiment, as shown in
At S802, a positioning sequence of each sub-band occupied by the positioning signal is acquired.
As at least one alternative embodiment, since the positioning signal sent by the terminal to be positioned has the known positioning sequence, the sequence of the positioning signal sent on M sub-bands is S[m], m=1,2, . . . , M.
At S804, a positioning sequence matrix is constructed by using the positioning sequence of each sub-band.
As at least one alternative embodiment, a positioning sequence matrix S=diag([S[1],S[2], . . . , S[M]]T) is constructed by using the sequence of the positioning signal sent on the M sub-bands.
At S806, each element in the positioning sequence matrix is used as a main diagonal element, so as to obtain a diagonal matrix for channel estimation; and a channel amplitude-phase response matrix is measured as the channel calibration coefficient.
As at least one alternative embodiment, on the basis of S=diag([S[1],S[2], . . . , S[M]]T) in the positioning sequence matrix, a diag(·) operator indicates that a diagonal matrix is obtained by using each element of the vector as a main diagonal element.
In this embodiment, the positioning sequence of each sub-band occupied by the positioning signal is acquired; the positioning sequence matrix is constructed by using the positioning sequence of each sub-band; and each element in the positioning sequence matrix is used as the main diagonal element, so as to obtain the diagonal matrix for channel estimation; and the channel amplitude-phase response matrix is measured as the channel calibration coefficient. In this way, the channel calibration coefficient for correcting the CFR matrix can be determined, so as to correct the CFR matrix.
For ease of understanding by a person skilled in the art, the method for determining the positioning parameter is further described now with an embodiment. In an embodiment, as shown in
At S902, Fourier transform is performed on the positioning signal sent via multi-channels by the terminal to be positioned, so as to obtain a multi-channel frequency-domain signal.
At S904, a positioning sequence of each sub-band occupied by the positioning signal is acquired.
At S906, a positioning sequence matrix is constructed by using the positioning sequence of each sub-band.
At S908, each element in the positioning sequence matrix is used as a main diagonal element, so as to obtain a diagonal matrix for channel estimation.
At S910, channel estimation is performed on the multi-channel frequency-domain signal, so as to obtain a CFR matrix.
At S912, the CFR is corrected by measuring a channel amplitude response matrix as a channel calibration coefficient, so as to obtain a corrected CFR matrix.
At S914, the ToF spectrum data is acquired according to the corrected CFR matrix.
At S916, an amplitude measurement value set of direction-dependent amplitude responses and a phase measurement value set of phase deviations are acquired, wherein the amplitude measurement value set of direction-dependent amplitude responses is a set of direction-dependent amplitude responses that a simulated real signal arrives at each array element of the antenna array, and the phase measurement value set of phase deviations is a set of phase deviations that the simulated real signal arrives at each array element of the antenna array.
At S918, an amplitude pattern function is constructed according to the amplitude measurement value set, and a phase deviation function is constructed according to the phase measurement value set.
At S920, the coarse ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain a corrected coarse spatial manifold matrix. The ideal spatial manifold matrix includes a coarse ideal spatial manifold matrix and a fine ideal spatial manifold matrix; each element in the coarse ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a first preset corresponding angle range; each element in the fine ideal spatial manifold matrix represents a response of each array element in the antenna array to the positioning signal in a second preset corresponding angle range; and the first preset corresponding angle range is greater than the second preset corresponding angle range.
At S922, ToF of each path of the positioning signal, reference AoA of each path, and an attenuation coefficient are determined according to the corrected coarse spatial manifold matrix and the ToF spectrum data.
At S924, the LOS is determined from all paths according to the attenuation coefficient of each path and the ToF of each path.
At S926, dividing is performed according to the reference AoA corresponding to the LOS, so as to obtain the second preset corresponding angle range.
At S928, the fine ideal spatial manifold matrix is determined according to the second preset corresponding angle range.
At S930, the fine ideal spatial manifold matrix is corrected according to the antenna array deviation function, so as to obtain a corrected fine spatial manifold matrix.
At S932, by using a preset angle function, AoA of the LOS is determined according to the corrected fine spatial manifold matrix and the ToF corresponding to the LOS.
As at least one alternative embodiment, algorithm effectiveness is described by using an indoor positioning experiment based on an FR1 frequency band 5G system as an example. By using a 5G Sounding Reference Signal (SRS) as the positioning signal, the SRS is a broadband OFDM signal. During experiment, the positioning signal is configured to occupy 1632 sub-carriers, and the sub-carriers are spaced 60 kHz apart. During experiment, two 5G RRUs are used as receiving devices. Each RRU is provided with 4 array element ULAs, and the distance between the array elements is 5.8 cm. The array is placed horizontally. Before the positioning experiment starts, estimation of an antenna phase deviation coefficient function and an amplitude pattern function at an offiline phase needs to be completed. Hollow circles shown in
The positions of two RRUs are fixed, and the RRUs are placed in different relative positions of a terminal. Every time the terminal is stationary, 1500 consecutive SRS symbols are collected for positioning parameter estimation. A result that one RRU has large AoA relative to the terminal, and the other RRU has small AoA relative to the terminal is listed here, so as to describe the adaptability of the method provided in the present disclosure to a large AoA signal phase deviation.
SRS data of the two RRUs is processed by using the method provided in the present disclosure. AoA estimation Cumulative Distribution Function (CDF) curves of 1500 SRS symbols are shown by hollow circles in
In this embodiment, the ToF spectrum data of the positioning signal is determined according to the positioning signal sent via multi-channels by the terminal to be positioned; the ideal spatial manifold matrix is corrected according to the preset antenna array deviation function, so as to obtain the corrected spatial manifold matrix; and the positioning parameter of LOS of the positioning signal is determined according to the ToF spectrum data and the corrected spatial manifold matrix. The ideal spatial manifold matrix can be corrected by using the preset antenna array deviation function including a phase and an amplitude, so as to reduce the deviation between the response of a real antenna array to a signal and the response of an ideal antenna array to the signal, and the LOS, which is the shortest path from the terminal to be positioned to the antenna array, is determined, such that the accuracy of measuring the positioning parameter of the positioning signal is improved. In addition, the solution avoids the problem of high computational complexity caused by simultaneous measurement of the ToF and the AoA in the related art.
It is to be understood that, although the various steps in the flowcharts of
In an embodiment, as shown in
The first determination module 141 is configured to determine ToF spectrum data of a positioning signal according to the positioning signal sent via multi-channels by a terminal to be positioned.
The correction module 142 is configured to correct an ideal spatial manifold matrix according to a preset antenna array deviation function, so as to obtain a corrected spatial manifold matrix. Each element in the ideal spatial manifold matrix or the corrected spatial manifold matrix represents a response of each array element in an antenna array to the positioning signal in a preset corresponding angle range, and the antenna array deviation function represents the deviation between a response of a real antenna array to a signal and a response of an ideal antenna array to the signal.
The second determination module 143 is configured to determine a positioning parameter of LOS of the positioning signal according to the ToF spectrum data and the corrected spatial manifold matrix, wherein the LOS is the shortest path from the terminal to be positioned to the antenna array.
In this embodiment, the first determination module determines the ToF spectrum data of the positioning signal according to the positioning signal sent via multi-channels by the terminal to be positioned; the correction module corrects the ideal spatial manifold matrix according to the preset antenna array deviation function, so as to obtain the corrected spatial manifold matrix; and the second determination module determines the positioning parameter of the LOS of the positioning signal according to the ToF spectrum data and the corrected spatial manifold matrix. The ideal spatial manifold matrix can be corrected by using the preset antenna array deviation function including a phase and an amplitude, so as to reduce the deviation between the response of a real antenna array to a signal and the response of an ideal antenna array to the signal, and the LOS, which is the shortest path from the terminal to be positioned to the antenna array, is determined, such that the accuracy of measuring the positioning parameter of the positioning signal is improved.
In addition, the solution avoids the problem of high computational complexity caused by simultaneous measurement of the ToF and the AoA in the related art.
In an embodiment, as shown in
The simulation parameter set module 144 is configured to acquire an amplitude measurement value set of direction-dependent amplitude responses and a phase measurement value set of phase deviations, wherein the amplitude measurement value set of direction-dependent amplitude responses is a set of direction-dependent amplitude responses that a simulated real signal arrives at each array element of the antenna array, and the phase measurement value set of phase deviations is a set of phase deviations that the simulated real signal arrives at each array element of the antenna array.
The deviation function construction module 145 is configured to construct an amplitude pattern function according to the amplitude measurement value set, and construct a phase deviation function according to the phase measurement value set; and determine the antenna array deviation function according to the amplitude pattern function and the phase deviation function.
In an embodiment, as shown in
The first correction unit 1431 is configured to correct the coarse ideal spatial manifold matrix according to the antenna array deviation function, so as to obtain a corrected coarse spatial manifold matrix.
The first determination unit 1432 is configured to determine, according to the corrected coarse spatial manifold matrix and the ToF spectrum data, the fine ideal spatial manifold matrix and ToF corresponding to the LOS.
The second correction unit 1433 is configured to correct the fine ideal spatial manifold matrix according to the antenna array deviation function, so as to obtain a corrected fine spatial manifold matrix.
The second determination unit 1434 is configured to, by using a preset angle function, determine AoA of the LOS according to the corrected fine spatial manifold matrix and the ToF corresponding to the LOS.
In an embodiment, the first determination unit 1432 is configured to: determine, according to the corrected coarse spatial manifold matrix and the ToF spectrum data, ToF of each path of the positioning signal, reference AoA of each path, and an attenuation coefficient of each path; determine the LOS from paths according to the attenuation coefficient of each path and the ToF of each path; divide according to the reference AoA corresponding to the LOS, so as to obtain the second preset corresponding angle range; determine the fine ideal spatial manifold matrix according to the second preset corresponding angle range; and determine the ToF corresponding to the LOS according to the ToF of each path and the attenuation coefficient of each path.
In an embodiment, as shown in
In an embodiment, as shown in
The time-frequency transform unit 1411 is configured to perform Fourier transform on the positioning signal sent via multi-channels by the terminal to be positioned, so as to obtain a multi-channel frequency-domain signal.
The channel estimation unit 1412 is configured to perform channel estimation on the multi-channel frequency-domain signal, so as to obtain a CFR matrix.
The acquisition unit 1413 is configured to acquire the ToF spectrum data on the basis of the CFR matrix.
In an embodiment, the acquisition unit 1413 is configured to: acquire a channel calibration coefficient, and correct the CFR matrix according to the channel calibration coefficient, so as to obtain a corrected CFR matrix; and acquire the ToF spectrum data according to the corrected CFR matrix.
In an embodiment, the channel estimation unit 1412 is configured to: acquire a positioning sequence of each sub-band occupied by the positioning signal; construct a positioning sequence matrix by using the positioning sequence of each sub-band; and use each element in the positioning sequence matrix as a main diagonal element, so as to obtain a diagonal matrix for channel estimation. The acquisition unit 1413 is configured to measure a channel amplitude-phase response matrix as the channel calibration coefficient.
For the specific limitation on the positioning parameter determination apparatus may refer to the limitation on the method for determining the positioning parameter above, and the details are not described herein again. The technical features and beneficial effects thereof set forth in the above embodiments of the method for determining the positioning parameter are all applicable in the embodiments of the positioning parameter determination apparatus, the details of which may be found in the description in the embodiments of the method for determining the positioning parameter of the present disclosure.
Each module in the positioning parameter determination apparatus may be implemented entirely or partly by software, hardware, or a combination thereof. The foregoing modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in the computer device in the form of software, such that the processor calls and executes the operations corresponding to the foregoing modules.
An embodiment provides a computer device. The computer device may be a terminal. An internal structure diagram of the terminal may be shown in
It may be understood by those skilled in the art that the structure shown in
An embodiment further provides a computer device, which includes a memory and a processor. The memory stores a computer program. The processor implements the operations in the foregoing method embodiments when executing the computer program.
An embodiment provides a computer-readable storage medium, which stores a computer program, the computer program, when executed by a processor, implementing the operations in the foregoing method embodiments.
The steps implemented in the above embodiments of the computer device and the computer-readable storage medium correspond to the steps of the foregoing positioning parameter determination method, and the technical features and beneficial effects thereof elaborated in the above embodiments of the method for determining the positioning parameter are applicable to the embodiments of the computer device and the computer-readable storage medium, and the specific limitations may refer to the above limitations for the method for determining the positioning parameter, which are described herein again.
Those of ordinary skill in the art will appreciate that implementing all or part of the processes in the methods described above may be accomplished by instructing associated hardware by a computer program, which may be stored in a non-volatile computer-readable storage medium, which, when executed, may include processes as embodiments of the methods described above. Any reference to the memory, storage, the database, or other media used in the embodiments provided in this application may include at least one of a non-volatile memory or a volatile memory. The non-volatile memory may include a Read-Only Memory (ROM), a magnetic tape, a floppy disk, a flash memory, an optical memory, or the like. The volatile memories may include a Random Access Memory (RAM), or an external cache memory. By way of description and not limitation, the RAM may be in various forms, such as a Static Random Access Memory (SRAM), a Dynamic Random Access Memory (DRAM), or the like.
Various technical features of the above embodiments may be combined arbitrarily. For brevity of description, description is not made to all possible combinations of the various technical features of the above embodiments are described. However, all the combinations of these technical features should be considered to fall within the scope of disclosure contained in the specification as long as there is no contradiction between the combinations of those technical features.
The above embodiments merely illustrate several implementations of the present disclosure, which are specifically described in detail, but are not to be construed as limiting the scope of the present patent for the present disclosure. It should be pointed out that, those of ordinary skill in the art can also make some modifications and improvements without departing from the concept of the present disclosure, and these modifications and improvements all fall within the scope of protection of the present disclosure. Accordingly, the scope of the patent of the present disclosure should be subject to the appended claims.
Number | Date | Country | Kind |
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202110883913.2 | Aug 2021 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2021/139679 | 12/20/2021 | WO |