TDOA positioning method and system based on channel estimation and channel equalization, and electronic equipment

Abstract

The invention provides a TDOA (time difference of arrival) positioning method, which comprises the following steps of: positioning an unmanned aerial vehicle by using K receiving base stations, receiving signals in a measurement range of each receiving base station by each receiving base station, and generating first target data if pilot signals are received; obtaining pilot frequency information of the pilot frequency signal based on the first target data; obtaining an estimation channel time domain response based on the pilot frequency information; obtaining a tap coefficient of a relative channel equalizer corresponding to the receiving base station based on the estimation channel time domain response; based on the tap coefficient, performing equalization processing on the received signal to obtain an equalized signal; performing generalized cross-correlation calculation on all the balanced signals to obtain TDOA information among all the receiving base stations; and determining the position of the unmanned aerial vehicle based on the TDOA information among all the receiving base stations. According to the method, the influence of the multipath effect is reduced through equalization processing, and a signal main path and a reflection path do not need to be separated, so that the scheme of the invention has lower calculation overhead while the signal processing complexity is lower.

Description

Technical Field

[0001] The present invention relates to the field of multi-station positioning, and in particular to a TDOA positioning method, system and electronic equipment based on channel estimation and channel equalization. Background Art

[0002] Multi-station positioning systems are widely used in specific applications such as military reconnaissance and surveillance, agriculture and environmental monitoring due to their high accuracy, reliability and wide coverage.

[0003] However, in actual use, signal transmission has a multipath effect. The multipath effect is caused by the reflection of wireless signals from obstacles (such as buildings, trees, walls, etc.) during the propagation process, which makes the signal propagation path longer, thereby generating multiple paths for the signal to reach the receiving point. Positioning technology in a multipath environment needs to consider the delay and strength differences of the signal reaching the receiving base station through different paths, and improve positioning accuracy and stability through complex signal processing and complex optimization algorithms.

[0004] Therefore, how to reduce the complexity of signal processing and algorithms required for positioning technology in a multipath environment has become a technical problem that urgently needs to be solved in the industry. Summary of the invention

[0005] The present invention provides a TDOA positioning method, system and electronic device based on channel estimation and channel equalization, which solves the technical problem of how to reduce the complexity of signal processing and algorithm required for positioning technology in a multipath environment.

[0006] According to a first aspect of the present invention, an embodiment of the present invention provides a TDOA positioning method based on channel estimation and channel equalization, which uses K receiving base stations to locate the UAV, where K is an integer greater than or equal to 2;

[0007] The multi-station positioning method includes:

[0008] Each receiving base station receives a signal within its measurement range, and generates first target data if a pilot signal is received, wherein the first target data includes time domain information of the pilot signal;

[0009] Based on the first target data, obtaining pilot information of the pilot signal;

[0010] Based on the pilot information, obtaining an estimated channel time domain response;

[0011] Based on the estimated channel time domain response, obtaining tap coefficients of a relative channel equalizer corresponding to a receiving base station;

[0012] Based on the tap coefficients, performing equalization processing on the received signal to obtain an equalized signal;

[0013] Performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations;

[0014] Based on the TDOA information between all the receiving base stations, the position of the drone is determined.

[0015] Optionally, determining whether a pilot signal is received includes:

[0016] Obtaining received signal data of signals within the measurement range;

[0017] Based on the received signal data, obtaining a duration of the pilot signal and a sending time interval of the pilot signal;

[0018] Based on the duration and the sending time interval, it is determined whether the pilot signal is received.

[0019] Optionally, performing equalization processing on the received signal based on the tap coefficient to obtain an equalized signal includes:

[0020] Based on the tap coefficients, construct a relative channel equalizer of a corresponding receiving base station;

[0021] The received signal is equalized based on the relative channel equalizer to obtain an equalized signal.

[0022] Optionally, the relative channel equalizer is a linear equalizer.

[0023] Optionally, performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations includes:

[0024] calculating a generalized cross-correlation function between the equalized signals;

[0025] Performing inverse Fourier transform processing on all the generalized cross-correlation functions to obtain corresponding time-domain generalized cross-correlation functions;

[0026] Based on the maximum values ​​of all the time-domain generalized cross-correlation functions, the TDOA information between all receiving base stations is obtained.

[0027] Optionally, determining the position of the drone based on the TDOA information between all the receiving base stations includes:

[0028] Establishing a rectangular coordinate system with any point in space as the center origin, and obtaining the coordinates of each receiving base station in the rectangular coordinate system;

[0029] Based on the coordinates of each receiving base station in the rectangular coordinate system and the TDOA information between all the receiving base stations, the position coordinates of the drone in the rectangular coordinate system are determined.

[0030] According to a second aspect of the present invention, an embodiment of the present invention provides a TDOA positioning system based on channel estimation and channel equalization, including:

[0031] K receiving base stations each receive signals within their measurement range, where K is an integer greater than or equal to 2;

[0032] A first target data generating module, configured to generate first target data upon receiving a pilot signal, wherein the first target data includes time domain information of the pilot signal;

[0033] A pilot information acquisition module, configured to obtain pilot information of the pilot signal based on the first target data;

[0034] An estimated channel time domain response acquisition module, used to obtain an estimated channel time domain response based on the pilot information;

[0035] A tap coefficient acquisition module, used to obtain the tap coefficients of the relative channel equalizer corresponding to the receiving base station based on the estimated channel time domain response;

[0036] An equalized signal acquisition module, used to perform equalization processing on the received signal based on the tap coefficients to obtain an equalized signal;

[0037] A TDOA information acquisition module, used to perform generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations;

[0038] A positioning module is used to determine the position of the drone based on the TDOA information between all the receiving base stations.

[0039] Optionally, a pilot signal acquisition module is further included, and the pilot signal acquisition module includes:

[0040] A received signal data acquisition unit, used to obtain received signal data of signals within the measurement range;

[0041] A pilot signal information acquisition module, used to obtain the duration of the pilot signal and the sending time interval of the pilot signal based on the received signal data;

[0042] The judging module is used to judge whether the pilot signal is received based on the duration and the sending time interval.

[0043] Optionally, the equalized signal acquisition module includes:

[0044] A relative channel equalizer construction unit, used to construct a relative channel equalizer of a corresponding receiving base station based on the tap coefficients;

[0045] The equalization processing module performs equalization processing on the received signal based on the relative channel equalizer to obtain an equalized signal.

[0046] According to a third aspect of the present invention, an embodiment of the present invention provides an electronic device, comprising a TDOA positioning system as described in any one of the second aspects of the present invention.

[0047] Compared with the prior art, the technical solution of the embodiment of the present invention has the following beneficial effects:

[0048] In the TDOA positioning method, system and electronic device of the technical solution of the present invention, K receiving base stations are used to locate the UAV, and each receiving base station receives the signal within its measurement range. If a pilot signal is received, the first target data is generated; based on the first target data, the pilot information of the pilot signal is obtained; based on the pilot information, the estimated channel time domain response is obtained; based on the estimated channel time domain response, the tap coefficient of the relative channel equalizer of the corresponding receiving base station is obtained; based on the tap coefficient, the received signal is equalized to obtain an equalized signal; generalized cross-correlation calculation is performed on all equalized signals to obtain TDOA information between all receiving base stations; based on the TDOA information between all receiving base stations, the position of the UAV is determined. The present invention reduces the influence of multipath effect by equalization processing, and there is no need to separate the main path and the reflection path of the signal, so that the solution of the present invention has a lower signal processing complexity and a smaller calculation overhead, and has strong robustness to TDOA in multipath environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 is a schematic diagram of a system model of a TDOA positioning method in an embodiment of the present invention;

[0051] Figure 2 is a schematic flow chart of a multi-station positioning method in one embodiment of the present invention;

[0052] Figure 3 is a schematic diagram of a time domain signal of received signal data in one embodiment of the present invention;

[0053] Figure 4 is a schematic diagram of positioning of a drone in one embodiment of the present invention;

[0054] Figure 5is a block diagram of a TDOA positioning system in one embodiment of the present invention;

[0055] Figure 6 is a block diagram of an equalized signal acquisition module in one embodiment of the present invention;

[0056] Description of reference numerals:

[0057] 81-receiving base station;

[0058] 82-first target data generating module;

[0059] 83-pilot information acquisition module;

[0060] 84- channel time domain response estimation acquisition module;

[0061] 85-tap coefficient acquisition module;

[0062] 86-balanced signal acquisition module;

[0063] 87-TDOA information acquisition module;

[0064] 88- positioning module;

[0065] 861-relative channel equalizer construction unit;

[0066] 862-Equalization processing module. DETAILED DESCRIPTION

[0067] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0069] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0070] As described in the background art, it is difficult for the prior art to reduce the complexity of signal processing and the complexity of algorithms required for positioning technology in a multipath environment, which will be described in detail below.

[0071] Currently, the common positioning methods in multipath environments are mainly the following:

[0072] 1.) TDOA positioning:

[0073] TDOA locates by measuring the arrival time difference of the signal between different receiving base stations. Using these time differences, the location of the signal source can be determined through geometric relationships. TDOA needs to deal with multipath effects and separate direct paths from reflected paths. TDOA multipath algorithm solutions represented by beamforming, polarization methods, sparse reconstruction methods, etc. usually have the disadvantage of high computational complexity. In addition, this method requires the clocks of each receiving base station to be highly synchronized, which places high demands on hardware equipment.

[0074] 2) Received signal strength (RSS) positioning:

[0075] RSS measures the signal strength received by each receiver, estimates the distance to the receiving base station using the signal attenuation model, and then determines the location of the signal source through geometric methods. Compared with TDOA positioning, RSS does not require clock synchronization, only needs to measure signal strength, and is suitable for low-cost applications. However, due to the existence of multipath effects, RSS positioning may have large errors.

[0076] 3) Angle of Arrival (AOA) Positioning

[0077] AOA performs positioning by measuring the angle at which the signal reaches each receiver. Using this angle information, the location of the signal source can be determined through geometric relationships. In a multipath environment, AOA positioning requires the use of antenna arrays and advanced beamforming technology to distinguish between direct signals and multipath signals. This method is suitable for multiple receiving base stations to work together and does not rely on clock synchronization.

[0078] 4) Frequency Differential Oscillating (FDOA) Positioning:

[0079] Frequency Differential of Arrival (FDOA) uses the frequency offset of the signal at different receivers for positioning. The frequency offset is caused by the Doppler effect. By measuring the frequency offset and combining it with the known geometric position, the location of the signal source can be calculated. FDOA positioning requires frequency estimation and filtering technology to distinguish between direct signals and multipath signals in a multipath environment.

[0080] 5) Hybrid positioning:

[0081] The hybrid positioning method combines the advantages of the above-mentioned technologies and improves positioning accuracy and robustness through the combination of multi-sensor fusion and multiple signal processing algorithms. For example, combining TDOA and AOA positioning methods can simultaneously use time and angle information for more accurate positioning.

[0082] In summary, the positioning technology in multipath environment uses a combination of multidisciplinary technical means such as radio communication, signal processing, and optoelectronic sensing. The above technologies all have the problem of high signal processing complexity and high algorithm complexity.

[0083] In view of this, an embodiment of the present invention provides a TDOA positioning method, which uses K receiving base stations to locate the UAV, and each receiving base station receives the signal within its measurement range. If a pilot signal is received, the first target data is generated; based on the first target data, the pilot information of the pilot signal is obtained; based on the pilot information, the estimated channel time domain response is obtained; based on the estimated channel time domain response, the tap coefficients of the relative channel equalizer of the corresponding receiving base station are obtained; based on the tap coefficients, the received signal is equalized to obtain an equalized signal; generalized cross-correlation calculations are performed on all equalized signals to obtain TDOA information between all receiving base stations; based on the TDOA information between all receiving base stations, the position of the UAV is determined. The present invention reduces the influence of multipath effects through equalization processing, and there is no need to separate the main path and the reflection path of the signal, so that the solution of the present invention has a lower signal processing complexity and a smaller calculation overhead, and has strong robustness to TDOA in multipath environments.

[0084] In order to make the above-mentioned objects, features and beneficial effects of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0085] The embodiment of the present invention provides a TDOA positioning method based on channel estimation and channel equalization, which uses K receiving base stations to locate the UAV, where K is an integer greater than or equal to 2;

[0086] As an example, the system model of the TDOA positioning method of the present invention can be as follows: Figure 1 As shown, where i is the index of the receiving base station and 0≤i≤K-1.

[0087] Please refer to Figure 2 , the multi-station positioning method includes:

[0088] S1: Each receiving base station receives a signal within its measurement range, and if a pilot signal is received, generates first target data, where the first target data includes time domain information of the pilot signal;

[0089] S2: obtaining pilot information of the pilot signal based on the first target data;

[0090] S3: Obtaining an estimated channel time domain response based on the pilot information;

[0091] S4: based on the estimated channel time domain response, obtaining tap coefficients of a relative channel equalizer corresponding to a receiving base station;

[0092] S5: performing equalization processing on the received signal based on the tap coefficients to obtain an equalized signal;

[0093] S6: performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations;

[0094] S7: Determine the location of the UAV based on the TDOA information between all the receiving base stations.

[0095] The equalization processing of the received signal can be understood as equalization processing of the overall signal received within the measurement range of each receiving base station, where the overall signal includes the pilot signal and the signal carrying information after the pilot signal.

[0096] In summary, the present invention makes full use of equalization technology to achieve accurate TDOA positioning in a multipath environment, estimates the relative channel information at this time through pilot information, uses equalization technology to eliminate the influence of the reflection path, and further eliminates the TDOA estimation error caused by the multipath effect. On this basis, the system uses generalized cross correlation (GCC) to estimate the TDOA information at this time, which is more accurate. It can be seen that the method provided by the present invention is suitable for TDOA in a multipath environment and has strong robustness.

[0097] The method of the present invention is now further described.

[0098] Please refer to Figure 2 as well as Figure 3 , execute step S1,

[0099] S1: Each receiving base station receives a signal within its measurement range. If a pilot signal is received, first target data is generated. The first target data includes time domain information of the pilot signal.

[0100] In one implementation, determining whether a pilot signal is received includes:

[0101] Obtaining received signal data of signals within the measurement range;

[0102] Specifically, the schematic diagram of the time domain signal s(t) of the received signal data can be as follows: Figure 3 As shown, in Figure 3 In the example, the front end of each signal carries a repeated pilot signal p(t), where T p Represents the duration of each pilot signal, T s It is the time interval between two adjacent pilot signals.

[0103] Based on the received signal data, obtaining a duration of the pilot signal and a sending time interval of the pilot signal;

[0104] Based on the duration and the sending time interval, it is determined whether the pilot signal is received.

[0105] The first target data is now described:

[0106] In a multipath environment, the signal received by the receiving base station i can be expressed as

[0107]

[0108] This signal can be regarded as the first target data, including the time domain information of the pilot signal, where h i (t) represents the time domain channel response at the receiving base station i, n i (t) represents the time domain Gaussian white noise at the receiving base station i, Γ i is the set of path delays of receiving base station i.

[0109] Affected by the path delay, the received signal of the receiving base station in a certain period of time is independent of the transmitted signal. Then the received signal data at base station i is

[0110]

[0111] Among them, τ i is the actual delay of the direct path at receiving base station i, n i (t) represents the time domain Gaussian white noise at the receiving base station i, Γ' i is the set of relative delays between each path and the direct path at the receiving base station i; g i (t) = h i (t+τ i ) is the relative channel response in the time domain after the shift, h i (t) represents the time domain channel response at the receiving base station i, i is an integer, and 0≤i≤K-1.

[0112] Please refer to Figure 2 , execute step S2,

[0113] S2: Based on the first target data, obtain pilot information of the pilot signal.

[0114] Specifically, based on the first target data r i (t), obtain the pilot information p of the pilot signal i (t).

[0115] Please refer to Figure 2 , execute step S3,

[0116] S3: Based on the pilot information, obtain an estimated channel time domain response.

[0117] Due to receiving r i The pilot information p received in (t) i (t) can be written as:

[0118] p i (t) = p(t)*g i (t)

[0119] Therefore, in a specific implementation manner, step S3 includes:

[0120] Based on the pilot information p i (t) and the pilot signal p(t), and obtain the estimated channel time domain response g i (t).

[0121] Please refer to Figure 2 , execute step S4,

[0122] S4: Based on the estimated channel time domain response, obtain tap coefficients of a relative channel equalizer corresponding to a receiving base station.

[0123] Specifically, based on the estimated channel time domain response g i (t), directly obtain the tap coefficient c of the relative channel equalizer of the corresponding receiving base station i (t).

[0124] It should be understood that the present invention will receive g i (t) is adjusted to correspond to the tap coefficient c of the relative channel equalizer of the receiving base station i (t).

[0125] Therefore, the present invention solves the problem of multiple peaks and ambiguity of correlation peaks when directly performing GCC delay estimation on the signal received by the base station.

[0126] Please refer to Figure 2 , execute step S5,

[0127] S5: Based on the tap coefficients, perform equalization processing on the received signal to obtain an equalized signal.

[0128] In one implementation, a method for performing equalization processing on a received signal based on the tap coefficients to obtain an equalized signal includes:

[0129] Based on the tap coefficients, construct a relative channel equalizer of a corresponding receiving base station;

[0130] Performing equalization processing on the received signal based on the relative channel equalizer to obtain an equalized signal;

[0131] Specifically, the equalized signal y corresponding to base station i i (t) = r i (t)*c i (t).

[0132] In a specific implementation manner, the relative channel equalizer is a linear equalizer. The present invention utilizes the application advantages of the linear equalizer, such as simple structure and small amount of calculation, to reduce the amount of calculation during positioning.

[0133] Please refer to Figure 2 , execute step S6,

[0134] S6: Perform generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations.

[0135] In one implementation, performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations includes:

[0136] calculating a generalized cross-correlation function between the equalized signals;

[0137] As an example, the generalized cross-correlation function between receiving base station i and receiving base station j is

[0138]

[0139] Where i, j represents the index of the base station (i, j = 0, .. K-1), X i (f), X j (f) is the Fourier transform of the received signal, (·) * Indicates conjugation.

[0140] Performing inverse Fourier transform processing on all the generalized cross-correlation functions to obtain corresponding time-domain generalized cross-correlation functions;

[0141] Specifically, for the generalized cross-correlation function R ij (f) Perform inverse Fourier transform to obtain the generalized cross-correlation function r in the time domain ij (τ), where

[0142] Based on the maximum values ​​of all the time-domain generalized cross-correlation functions, obtaining TDOA information between all receiving base stations;

[0143] Specifically, the generalized cross-correlation function r is obtained ij The maximum value of (τ) corresponds to the delay τ ij , and then obtain the time difference of signal arrival, where τ ij = argmax[r ij (τ)].

[0144] Please refer to Figure 1 as well as Figure 2 , execute step S7,

[0145] S7: Determine the location of the UAV based on the TDOA information between all the receiving base stations.

[0146] In one embodiment, the method for determining the position of the drone based on the TDOA information between all receiving base stations includes:

[0147] Establishing a rectangular coordinate system with any point in space as the center origin, and obtaining the coordinates of each receiving base station in the rectangular coordinate system;

[0148] Based on the coordinates of each receiving base station in the rectangular coordinate system and the TDOA information between all the receiving base stations, the position coordinates of the drone in the rectangular coordinate system are determined.

[0149] Specifically, Figure 1 Taking the four base stations in the figure as an example, by introducing the known three-dimensional coordinates of each base station and the coordinates of the unknown signal source, three nonlinear equations related to the distance can be listed, among which the coordinates of base station A are (x A ,y A ,z A ), the coordinates of base station B are (x B ,y B ,z B ), the coordinates of base station C are (x C ,y C ,z C ), the coordinates of base station D are (x D ,y D ,z D ), the coordinates of the drone are (x, y, z).

[0150] The distances from base station A to other base stations B, C, and D are c*TDOA AB 、c*TDOA AC 、c*TDOA AD In the case of, the three nonlinear equations related to distance are:

[0151] Equation 1:√((xx B )2+(yy B )2+(zz B )2)-√((xx A )2+(yy A )2+(zz A )2)=c*TDOA AB

[0152] Equation 2:√((xx C )2+(yy C )2+(zz C )2)-√((xx A )2+(yy A )2+(zz A )2)=c*TDOA AC

[0153] Equation 3:√((xx D )2+(yy D )2+(zz D )2)-√((xx A )2+(yy A )2+(zz A )2)=c*TDOA AD

[0154] Where c is the speed of light.

[0155] By solving these three equations using numerical methods, such as nonlinear least squares method, the position coordinates of the drone in the rectangular coordinate system can be determined.

[0156] It should be understood that the present invention is not limited to this, and of course other TDOA positioning methods may also be used. Since the TDOA positioning method is a relatively common prior art, the present invention will not be described in detail here.

[0157] Please combine Figure 2 as well as Figure 4 , the positioning effect of the present invention is further described:

[0158] Figure 4 The schematic diagram of the positioning of the UAV is shown. Figure 4 In the example, four receiving base stations are used for positioning, and the positioning area is enlarged, where:

[0159] The circle symbol can be understood as the location of the base station;

[0160] The cross symbol can be understood as the real position;

[0161] The cross symbol can be understood as the location of the drone using existing technology;

[0162] The diamond symbol can be understood as the positioning position of the UAV by the method of the present invention.

[0163] It can be seen that the closer the position of the equalized TDOA positioning (cross symbol) is to the real position of the drone (cross symbol), the better the positioning performance.

[0164] In summary, the present invention reduces the impact of multipath effects through equalization processing, without separating the main signal path and the reflection path, so that the solution of the present invention has lower signal processing complexity and smaller computational overhead, has stronger robustness to TDOA in multipath environments, and the corresponding hardware cost is also lower.

[0165] In addition, please refer to Figure 5 The embodiment of the present invention further provides a TDOA positioning system based on channel estimation and channel equalization, including:

[0166] K receiving base stations 81 each receive a signal within its measurement range, where K is an integer greater than or equal to 2;

[0167] A first target data generating module 82, configured to generate first target data upon receiving a pilot signal, wherein the first target data includes time domain information of the pilot signal;

[0168] A pilot information acquisition module 83, configured to obtain pilot information of the pilot signal based on the first target data;

[0169] An estimated channel time domain response acquisition module 84 is used to obtain an estimated channel time domain response based on the pilot information;

[0170] A tap coefficient acquisition module 85, used to obtain the tap coefficients of the relative channel equalizer corresponding to the receiving base station 81 based on the estimated channel time domain response;

[0171] An equalized signal acquisition module 86, configured to perform equalization processing on the received signal based on the tap coefficients to obtain an equalized signal;

[0172] A TDOA information acquisition module 87, configured to perform generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations 81;

[0173] The positioning module 88 is used to determine the position of the UAV based on the TDOA information between all the receiving base stations 81.

[0174] In one implementation, please refer to Figure 6 , the equalized signal acquisition module 86 includes:

[0175] A relative channel equalizer construction unit 861, configured to construct a relative channel equalizer of the corresponding receiving base station 81 based on the tap coefficients;

[0176] The equalization processing module 862 performs equalization processing on the received signal based on the relative channel equalizer to obtain an equalized signal.

[0177] It can be seen that the acquisition module of the present invention reduces the influence of the multipath effect through equalization processing, and there is no need to separate the main path of the signal and the reflection path. This makes the solution of the present invention have lower signal processing complexity and smaller calculation overhead, and has strong robustness to TDOA in multipath environment.

[0178] In a preferred implementation, the TDOA positioning system further includes a pilot signal acquisition module, and the pilot signal acquisition module includes:

[0179] A received signal data acquisition unit, used to obtain received signal data of signals within the measurement range;

[0180] A pilot signal information acquisition module, used to obtain the duration of the pilot signal and the sending time interval of the pilot signal based on the received signal data;

[0181] The judging module is used to judge whether the pilot signal is received based on the duration and the sending time interval.

[0182] In addition, an embodiment of the present invention further provides an electronic device, including the above-mentioned TDOA positioning system. As an example, the electronic device can be an antenna base station, etc. Of course, the present invention is not limited to this, and can also be other devices that require TDOA positioning.

[0183] In summary, the embodiment of the present invention uses K receiving base stations to locate the UAV, and each receiving base station receives the signal within its measurement range. If a pilot signal is received, the first target data is generated; based on the first target data, the pilot information of the pilot signal is obtained; based on the pilot information, the estimated channel time domain response is obtained; based on the estimated channel time domain response, the tap coefficients of the relative channel equalizer of the corresponding receiving base station are obtained; based on the tap coefficients, the received signal is equalized to obtain an equalized signal; generalized cross-correlation calculations are performed on all equalized signals to obtain TDOA information between all receiving base stations; based on the TDOA information between all receiving base stations, the position of the UAV is determined. The present invention reduces the influence of multipath effects through equalization processing, and there is no need to separate the main path of the signal and the reflection path, so that the solution of the present invention has a lower signal processing complexity and a smaller computational overhead, and has strong robustness to TDOA in multipath environments.

[0184] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A TDOA positioning method based on channel estimation and channel equalization, characterized in that: Use K receiving base stations to locate the drone, where K is an integer greater than or equal to 2; The multi-station positioning method includes: Each receiving base station receives a signal within its measurement range, and generates first target data if a pilot signal is received, wherein the first target data includes time domain information of the pilot signal; Based on the first target data, obtaining pilot information of the pilot signal; Based on the pilot information, obtaining an estimated channel time domain response; Based on the estimated channel time domain response, obtaining tap coefficients of a relative channel equalizer corresponding to a receiving base station; Based on the tap coefficients, performing equalization processing on the received signal to obtain an equalized signal; Performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations; Based on the TDOA information between all the receiving base stations, the position of the drone is determined.

2. The TDOA positioning method according to claim 1, characterized in that: Determining whether a pilot signal is received includes: Obtaining received signal data of signals within the measurement range; Based on the received signal data, obtaining a duration of the pilot signal and a sending time interval of the pilot signal; Based on the duration and the sending time interval, it is determined whether the pilot signal is received.

3. The TDOA positioning method according to claim 1, characterized in that: Based on the tap coefficients, the received signal is equalized to obtain an equalized signal, including: Based on the tap coefficients, construct a relative channel equalizer of a corresponding receiving base station; The received signal is equalized based on the relative channel equalizer to obtain an equalized signal.

4. The TDOA positioning method according to claim 3, characterized in that: The relative channel equalizer is a linear equalizer.

5. The TDOA positioning method according to claim 1, characterized in that: Performing generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations, including: calculating a generalized cross-correlation function between the equalized signals; Performing inverse Fourier transform processing on all the generalized cross-correlation functions to obtain corresponding time-domain generalized cross-correlation functions; Based on the maximum values ​​of all the time-domain generalized cross-correlation functions, the TDOA information between all receiving base stations is obtained.

6. The TDOA positioning method according to claim 1, characterized in that: Determining the position of the UAV based on the TDOA information between all the receiving base stations includes: Establishing a rectangular coordinate system with any point in space as the center origin, and obtaining the coordinates of each receiving base station in the rectangular coordinate system; Based on the coordinates of each receiving base station in the rectangular coordinate system and the TDOA information between all the receiving base stations, the position coordinates of the drone in the rectangular coordinate system are determined.

7. A TDOA positioning system based on channel estimation and channel equalization, characterized in that: include: K receiving base stations each receive signals within their measurement range, where K is an integer greater than or equal to 2; A first target data generating module, configured to generate first target data upon receiving a pilot signal, wherein the first target data includes time domain information of the pilot signal; A pilot information acquisition module, configured to obtain pilot information of the pilot signal based on the first target data; An estimated channel time domain response acquisition module, used to obtain an estimated channel time domain response based on the pilot information; A tap coefficient acquisition module, used to obtain the tap coefficients of the relative channel equalizer corresponding to the receiving base station based on the estimated channel time domain response; An equalized signal acquisition module, used to perform equalization processing on the received signal based on the tap coefficients to obtain an equalized signal; A TDOA information acquisition module, used to perform generalized cross-correlation calculation on all the equalized signals to obtain TDOA information between all receiving base stations; A positioning module is used to determine the position of the drone based on the TDOA information between all the receiving base stations.

8. The TDOA positioning system according to claim 7, characterized in that: It also includes a pilot signal acquisition module, the pilot signal acquisition module includes: A received signal data acquisition unit, used to obtain received signal data of signals within the measurement range; A pilot signal information acquisition module, used to obtain the duration of the pilot signal and the sending time interval of the pilot signal based on the received signal data; The judging module is used to judge whether the pilot signal is received based on the duration and the sending time interval.

9. The TDOA positioning system according to claim 7, characterized in that: The equalized signal acquisition module comprises: A relative channel equalizer construction unit, used to construct a relative channel equalizer of a corresponding receiving base station based on the tap coefficients; The equalization processing module performs equalization processing on the received signal based on the relative channel equalizer to obtain an equalized signal.

10. An electronic device, characterized in that: Comprising the TDOA positioning system as described in any one of claims 7 to 9.

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