Broadband signal incoming wave direction estimation method and system based on bandwidth internal frequency domain interference

Abstract

The invention provides a broadband signal incoming wave direction estimation method and system based on bandwidth internal frequency domain interference, and the method comprises the steps: carrying out the frequency domain conversion of a broadband signal received by an antenna array element, and employing the principle that the phase difference of each array element signal on the same frequency component in the frequency domain is correspondingly related to the incoming wave direction, a phase-frequency feature sequence and a feature matrix of the signal are constructed, and then the sequence is subjected to spatial spectrum calculation of an incoming wave signal by adopting a spectrum estimation method to realize estimation of the incoming wave direction of the signal. According to the method, the array element spacing is not limited by half-wavelength in a traditional method, and long-baseline unambiguous direction finding can be realized only by at least two antenna array elements under the condition of ensuring the ambiguous constraint; moreover, the method can achieve the decoupling of the observation signal source number and the antenna array element number, can achieve the estimation of multi-source signals with the number larger than the array element number, and is not limited by the coherence of the multi-source signals.

Description

Technical Field

[0001] This invention relates to the field of radio signal direction finding technology, and in particular to a method and system for estimating the direction of arrival of broadband signals based on frequency domain interferometry within the bandwidth. Background Technology

[0002] Direction of arrival (DOA) estimation for radio signals has always been a crucial technology and research hotspot in the field of radio signal detection. Typically, array antennas are used. For narrowband signals, the linear relationship between the phase difference of the received signals between array elements and the angle of arrival is utilized through interferometry or spectral estimation methods to measure the DOA and thus trace the signal source. However, for the more commonly used broadband signals, this correspondence is not constant, and conventional narrowband direction-finding methods are not applicable. DOA estimation for broadband signals has always been a core algorithm in the fields of radio communication signal reception and radar, widely used in radiation source localization, target perception, and many other areas. It has significant application value in civilian and military fields such as communication, reconnaissance, and electronic warfare.

[0003] For broadband signal direction of arrival (OCA) estimation, common solutions include splitting the broadband signal into multiple sub-bands, applying narrowband estimation methods to each sub-band, and finally combining the sub-band results to achieve broadband OCA estimation; or using the "frequency focusing" approach, constructing a focusing matrix to align or focus different frequency components of the signal onto a reference frequency in the signal subspace, and then processing them using narrowband estimation methods. However, to ensure the ambiguity of the estimation results, these traditional broadband OCA estimation methods are limited by the element spacing to the signal carrier (center) frequency. Higher signal frequencies require lower element spacing, making the elements susceptible to coupling interference. Sub-band division or the construction of a focusing matrix requires significant computation, and the sub-band division process results in a loss of sampling snapshots. Furthermore, to improve estimation accuracy, traditional OCA estimation methods generally require a large number of elements to participate in the measurement to ensure sufficient array aperture. These shortcomings limit the system complexity of broadband signal OCA estimation equipment and the timeliness of signal detection, measurement, and tracing. Summary of the Invention

[0004] This invention provides a method and system for estimating the direction of arrival (ROA) of a broadband signal based on frequency domain interferometry within the bandwidth. This method addresses the shortcomings of existing technologies by utilizing the principle that the phase difference of the signals of each array element in the frequency domain corresponds to the ROA. It calculates the unambiguous spacing between the array elements using the principle that the ROA corresponds to the direction of arrival. Based on the calculation results, the element spacing is designed. Then, the ROA is obtained by constructing the phase-frequency characteristic sequence, phase-frequency characteristic matrix, and phase-frequency characteristic steering vector of the signal. Finally, the ROA is obtained by estimating the spatial spectrum of the phase-frequency characteristic matrix.

[0005] In a first aspect, the present invention provides a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth, comprising: Based on the relationship between the phase difference of each array element signal in the frequency domain and the direction of arrival, the unambiguous spacing of the bandwidth direction-finding array element is calculated, and the calculation result of the unambiguous spacing of the bandwidth direction-finding array element is obtained. The element spacing of the antenna array is determined based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements. The incoming wave signal is received by an antenna array with a predetermined element spacing, and the incoming wave signal received by each element is transformed into the frequency domain to obtain the element frequency domain signal. Phase-frequency feature sequences are constructed using the frequency domain signals of array elements, and phase-frequency feature matrices are constructed from the phase-frequency feature sequences. Construct phase-frequency characteristic steering vectors based on phase-frequency characteristic matrices; Based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, the spatial spectrum of the incoming wave direction is estimated, and the position of the spectral peak is determined as the direction of arrival of the broadband signal.

[0006] According to the present invention, a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth is provided. Based on the correspondence between the phase difference of the signals of each array element of the antenna at the same frequency component in the frequency domain and the direction of arrival, the method calculates the unambiguous spacing of the bandwidth direction-finding array elements, obtaining the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements, including: Using the antenna array baseline as a reference, and the counterclockwise direction as the positive direction, the direction of arrival is determined as follows: , and These are the upper and lower frequency boundaries of the broadband signal, with a bandwidth of [missing information]. ; The distance between any two adjacent antennas is The frequencies are respectively and ,satisfy Then the phase differences of the received signals of any two adjacent antennas at the same frequency point are as follows:

[0007]

[0008] and They are respectively and The corresponding wavelength; For bandwidth Different frequency components within the range are obtained as follows:

[0009] Determine the signal sampling rate The sampling length is ,get:

[0010] Then we have:

[0011]

[0012] according to The element spacing constraint condition for unambiguous estimation of broadband incoming wave direction is obtained: .

[0013] According to the present invention, a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth is provided, which constructs a phase-frequency characteristic sequence using the frequency domain signals of array elements, including: Based on the frequency domain signals of the array elements of any two adjacent two lines and Construct phase-frequency feature sequences: .

[0014] According to the present invention, a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth is provided, which constructs a phase-frequency feature matrix from a phase-frequency feature sequence, including:

[0015] in, The phase-frequency characteristic matrix, , This indicates rounding down to the nearest integer.

[0016] According to the present invention, a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth is provided, which constructs a phase-frequency characteristic steering vector based on the phase-frequency characteristic matrix, including: For any direction , Construct phase-frequency characteristic steering vector : .

[0017] According to the present invention, a method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within the bandwidth is provided. This method estimates the spatial spectrum of the direction of arrival based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, determining the spectral peak position as the direction of arrival of the broadband signal. The method includes: Determine the phase-frequency characteristic matrix covariance matrix :

[0018] in, Represents the conjugate transpose of a matrix; Combined with phase-frequency characteristic steering vector The spatial spectrum of the incoming wave direction is obtained. :

[0019] Since the direction of the wave spatial spectrum The spectral peak position is the direction of arrival of the broadband signal.

[0020] Secondly, the present invention also provides a broadband signal direction of arrival estimation system based on intra-bandwidth frequency domain interferometry, comprising: The calculation module is used to calculate the unambiguous spacing of the bandwidth direction-finding array elements based on the phase difference of the signals of each array element in the frequency domain and the correspondence with the direction of arrival, and to obtain the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements. The determination module is used to determine the element spacing of the antenna array based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements; The transformation module is used to receive incoming wave signals from an antenna array with a predetermined element spacing, and transform the incoming wave signals received by each element to the frequency domain to obtain the element frequency domain signal. The first construction module is used to construct a phase-frequency feature sequence using the frequency domain signal of the array element, and to construct a phase-frequency feature matrix from the phase-frequency feature sequence. The second construction module is used to construct the phase-frequency characteristic steering vector based on the phase-frequency characteristic matrix; The estimation module is used to estimate the spatial spectrum of the incoming wave direction based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, and to determine the position of the spectral peak as the incoming wave direction of the broadband signal.

[0021] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry as described above.

[0022] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry as described above.

[0023] The present invention provides a broadband signal direction-of-arrival estimation method and system based on intra-bandwidth frequency domain interferometry. The element spacing is not subject to the unambiguous limitation of half-wavelength of the signal center frequency, allowing for greater freedom under new unambiguous constraints and effectively avoiding coupling interference between antennas. Unlike traditional broadband direction-finding methods that require sub-band division and sub-band-by-sub-band direction-of-arrival estimation, this method results in no loss of snapshots. It eliminates the need to construct a focusing matrix, reducing computational complexity. Effective direction-of-arrival estimation can be achieved with just two elements, greatly simplifying the hardware system and reducing site requirements. It decouples the number of observed signal sources from the number of antenna elements, enabling estimation of multi-source signals with fewer antenna elements without virtual element expansion. The direction-of-arrival estimation is unaffected by the coherence interference of multi-source signals, eliminating the need for decoherence processing. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a flowchart illustrating the broadband signal direction of arrival estimation method based on frequency domain interferometry within the bandwidth provided by the present invention. Figure 2 This is a schematic diagram of the signal arrival model of adjacent array elements of the antenna array provided by the present invention; Figure 3 This is a graph showing the relationship between the phase difference between adjacent array elements at the upper and lower boundary frequencies of a 200kHz bandwidth and the direction of arrival and the spacing between array elements, provided by the present invention. Figure 4 This is a graph showing the relationship between the phase difference between adjacent array elements at the upper and lower boundary frequencies of a 400kHz bandwidth and the direction of arrival and the spacing between array elements, provided by the present invention. Figure 5 This is a graph showing the relationship between the phase difference between adjacent array elements and the direction of arrival and the spacing between array elements when the fixed signal bandwidth is B=400kHz, as provided by the present invention. Figure 6 This invention provides a graph showing the relationship between the phase difference between adjacent array elements at the upper and lower boundary frequencies and the direction of incoming waves under the conditions of an array element spacing of 150m and a signal bandwidth of 400kHz. Figure 7 The carrier frequency provided by this invention is fc =100MHz, bandwidth is B A pulse signal of 2MHz, when the sampling rate is... fs =10MHz, usage duration is T =100us, L=Tfs= Time-domain waveform of a 1000 signal; Figure 8 The carrier frequency provided by this invention is fc =100MHz, bandwidth is B A pulse signal of 2MHz, when the sampling rate is... fs =10MHz, usage duration is T Spectrum diagram of a signal with a value of 100µs; Figure 9 The carrier frequency provided by this invention is fc =100MHz, bandwidth is B A pulse signal of 2MHz, when the sampling rate is... fs =10MHz, usage duration is T =100us, direction of incoming wave The designed array spacing is Capon spatial spectrum of array signal when 8-element uniform array is used; Figure 10 The signal parameters and array element spacing provided by this invention are... Figure 9 Under the same conditions, using the broadband signal direction estimation method based on the principle of frequency domain interference within the bandwidth described in this invention, we take... n Capon space spectrum at =150; Figure 11 The center frequency provided by this invention is fc A linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B The real part waveform of a signal with a sampling rate of 10MHz and a sampling duration of 100us, and a signal-to-noise ratio of 10dB; Figure 12 The center frequency provided by this invention is fc A linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B The signal spectrum of a signal with a sampling rate of 10MHz and a sampling duration of 100us, and a signal-to-noise ratio of 10dB; Figure 13 The center frequency provided by this invention is fc A linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B With a sampling rate of 10MHz and a sampling duration of 100µs, and a signal-to-noise ratio of 10dB, the element spacing is taken as... The Capon spatial spectrum of the 8-element array signal was obtained; Figure 14 This invention provides the same as Figure 13 Under the same signal parameters and element spacing conditions, take n Capon space spectrum when =100; Figure 15 The center frequency provided by this invention is fc A linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B =2MHz sampling rate 10MHz, sampling duration 100us, when a set of coherent signals with the same time domain waveforms come from 30°, 80° and 150° respectively, and the signal-to-noise ratio is 15dB, the real part waveforms of the three signals in the time domain are shown. Figure 16 This invention provides a solution for... Figure 15 Under multi-source coherent signal conditions, the array element spacing is taken Capon spatial spectrum of 8-element array signal; Figure 17 This invention provides the same as Figure 16 Under the same signal parameters and element spacing, take n Capon space spectrum when =100; Figure 18 This is a schematic diagram of the structure of the broadband signal direction of arrival estimation system based on frequency domain interferometry within the bandwidth provided by the present invention; Figure 19 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0027] To address the shortcomings of existing technologies, this invention proposes a broadband signal arrival direction estimation method based on frequency domain interferometry within bandwidth. This method utilizes the bandwidth characteristic of signals and the principle that the phase difference of signals from each array element at the same frequency component corresponds to the arrival direction. Under ambiguity-free constraints, the phase-frequency characteristic sequence of the array signal is obtained by dividing the frequency domain converted from the received signals of two array elements. Based on this, a characteristic matrix and a phase-frequency steering vector are constructed. The broadband signal arrival direction is estimated by calculating the spatial spectrum of the phase-frequency characteristic sequence. This method is not limited by the half-wavelength limitation of traditional methods in antenna element spacing. Under ambiguity constraints, only two antenna elements are required to achieve long-baseline ambiguity-free direction finding. It decouples the number of observed signal sources from the number of antenna elements, allowing for the estimation of multi-source signals with more than the number of elements. Furthermore, it is not limited by the coherence of multi-source signals, effectively reducing the complexity, hardware cost, and site requirements of radio direction finding systems. This method has significant application value for radio signal reception, measurement, tracing, and electronic countermeasures activities.

[0028] Figure 1 This is a flowchart illustrating the broadband signal direction-of-arrival estimation method based on intra-bandwidth frequency domain interferometry provided in an embodiment of the present invention, as shown below. Figure 1 As shown, it includes: Step 100: Based on the relationship between the phase difference of the signals of each array element in the frequency domain and the direction of arrival, calculate the unambiguous spacing of the bandwidth direction-finding array elements and obtain the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements. Step 200: Determine the element spacing of the antenna array based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements; Step 300: The antenna array with the determined element spacing receives the incoming wave signal, and transforms the incoming wave signal received by each element into the frequency domain to obtain the element frequency domain signal; Step 400: Construct a phase-frequency feature sequence using the frequency domain signal of the array elements, and construct a phase-frequency feature matrix from the phase-frequency feature sequence; Step 500: Construct the phase-frequency characteristic steering vector based on the phase-frequency characteristic matrix; Step 600: Based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, perform spatial spectrum estimation of the incoming wave direction to determine the position of the spectral peak as the incoming wave direction of the broadband signal.

[0029] Specifically, such as Figure 2 As shown, for the signal model of adjacent elements of an antenna array, for the direction of arrival of the wave... (With the antenna array baseline as a reference, the counter-clockwise direction is the positive direction), the bandwidth is Target signal ( and (These are the upper and lower frequency boundaries of the broadband signal, respectively). When the distance between two adjacent antennas is... At that time, if the speed of light is ,Pick Then, for two adjacent array elements, the phase difference of their received signals at the same frequency point should be: (1) Using traditional interferometric estimation methods for the direction of arrival, it is possible to utilize The direction of incoming wave can be determined. : (2) However, for the two frequency components within the signal bandwidth Then we can obtain: (3) If the sampling rate of the signal is The sampling length is L， Then we can obtain: (4) Then we have: (5) Then, using the same interference method, using... The direction of incoming waves can also be determined. : (6) Obviously, in this case, compared with the traditional interferometric direction finding method of Equation (2), the present invention utilizes the correlation between the phase difference of the signals of each array element at the same frequency component in the frequency domain and the direction of arrival of the wave, and adopts the direction of arrival estimation method of Equation (6) without using the signal and The exact value, but only the frequency difference needs to be known. And measured That's all.

[0030] To ensure that the phase difference estimation results are not ambiguous, the following should be true: Because the measurement system should ensure Therefore, the element spacing constraint condition for the method of the present invention without ambiguity estimation of the broadband direction of arrival is: (7) Step 2: Design the element spacing based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements; It should be noted that the element spacing must meet the element spacing constraint of the present invention for ambiguity estimation of broadband incoming wave direction.

[0031] Step 3: Use this antenna array to receive signals and transform the signals of each array element to the frequency domain; Step 4: Construct the phase-frequency feature sequence and phase-frequency feature matrix using the frequency domain signals of the array elements; It should be noted that after the received signals of two adjacent antenna elements are transformed into the frequency domain, the two signal sequences can be... and The phase-frequency feature sequence can be constructed as follows: (8) Based on this phase-frequency characteristic sequence, a characteristic matrix can then be constructed: (9) in, The phase-frequency characteristic matrix, , This indicates rounding down to the nearest integer.

[0032] Step 5: Construct the phase-frequency characteristic steering vector based on the signal phase-frequency characteristic matrix construction method; It should be noted that any direction ( The method for constructing the phase-frequency characteristic steering vector is as follows: (10) Step 6: Estimate the spatial spectrum of the incoming wave direction based on the signal phase-frequency characteristic matrix and steering vector; It should be noted that, based on The covariance matrix can be obtained. : (11) Combined with guide vector A typical Capon spatial spectrum is represented as: in, Represents the conjugate transpose of a matrix; (12) The position of its spectral peak is the corresponding direction of the incoming wave.

[0033] Of course, for this step, in addition to the Capon spatial spectrum, based on and Alternatively, other spectral estimation methods such as MUSIC can be used to obtain the angle of arrival of the incoming wave, which still does not deviate from the basic principle of the method described in this invention.

[0034] Based on the above embodiments, the present invention uses multiple simulation embodiments to illustrate the technical solution of the present invention.

[0035] When the direction of the incoming wave is At that time, take For broadband signals with B=200kHz and B=400kHz, then m = m. Distribution, such as Figure 3 and Figure 4 As shown, it is clear that for a fixed range of angles of arrival and element spacing, the distribution characteristics of the phase difference remain constant, and its magnitude is modulated by the signal bandwidth. When the fixed signal bandwidth is B = 400 kHz, as... Figure 5 As shown, obviously Spacing between true elements Maintain a linear relationship.

[0036] When the array element spacing is fixed When the signal bandwidth is B=400kHz, such as Figure 6 As shown, obviously Angle of arrival of the incoming wave The cosine mapping relationship is maintained. At this time, such a single unambiguous mapping characteristic is independent of the carrier frequency or center frequency of the signal, but it is consistent with the inter-element phase difference-direction of arrival characteristic in the narrowband signal direction of arrival estimation. This means that by taking advantage of the fact that the signal has a certain bandwidth, the direction of arrival estimation of broadband signals can be transformed into the same mode as the direction of arrival estimation of narrowband signals without sub-band segmentation and focusing matrix by estimating the difference between the phase differences between antenna elements at different frequency points.

[0037] More specifically, for a carrier frequency of fc =100MHz, bandwidth is B A pulse signal of 2MHz, when the sampling rate is... fs =10MHz, usage duration is T When = 100us, L=Tfs= 1000, the designed array spacing is When using an 8-element uniform array, the time-domain signal waveform and spectrum after mixing to baseband can be obtained as follows: Figure 7 and Figure 8 As shown, for Given the direction of arrival of the wave, under ideal conditions with no noise interference, the spatial spectrum can be obtained using classic array signal Capon spectrum estimation as follows: Figure 9 As shown, it is obvious that because the spacing between array elements is much larger than half the carrier wavelength, the spatial spectrum becomes significantly blurred, making it difficult to effectively estimate the direction of arrival. However, when using the broadband signal direction of arrival estimation method based on the principle of frequency domain interference within the bandwidth described in this invention, under the same signal conditions, only the signals from two adjacent array elements are used to obtain... n =150, then the Capon space spectrum can be obtained as follows Figure 10 As shown, it can be seen that the spatial spectrum has a unique peak and is located in the correct position. The direction of arrival can be estimated using only two antennas, and the angular ambiguity caused by the excessive spacing between array elements is overcome.

[0038] For a center frequency of fcA linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B When the sampling rate is 10MHz and the sampling duration is 100us, and the signal-to-noise ratio is 15dB, the real part of the signal and its spectrum are as follows: Figure 11 and Figure 12 As shown. At this time, the element spacing is taken as... The spatial spectrum of an 8-unit array can be obtained as follows: Figure 13 As shown, it is difficult to form a single sharp spectral peak. Clearly, for broadband signals where the signal bandwidth is not far from the center frequency, the array spatial spectrum not only becomes blurred, but it is also difficult to form an effective sharp pattern for a single spectral peak, making effective spectrum estimation difficult using the array antenna. However, when using the method described in the invention, utilizing the signal bandwidth and employing two adjacent antennas for direction finding, taking... n =100, then a sharper single Capon peak can be obtained, such as Figure 14 As shown, the position of the spectral peak corresponds to the angle of arrival of the incoming wave.

[0039] For multi-source coherent signals, an example is a signal with a center frequency of... fc A linear frequency modulated continuous wave with a frequency of 4 MHz and a bandwidth of [missing information] B =2MHz sampling rate, 10MHz sampling time, 100us sampling duration. When a set of coherent signals with the same time-domain waveforms come from 30°, 80°, and 150° respectively, the array element spacing is taken as... With a signal-to-noise ratio of 15dB, the real part waveforms of the three signals in the time domain are as follows: Figure 15 As shown, the Capon spatial spectrum of its array signal is as follows: Figure 16 As shown, multiple spectral peaks were formed, but they did not correspond to the source signal, resulting in direction finding failure. However, when direction finding was performed using two adjacent antennas with the signal bandwidth according to the method described in the invention, the results were satisfactory. n =100, then sharp Capon peaks can be obtained, such as Figure 17 As shown, the positions of the three spectral peaks indicate the correct direction of arrival of the incoming wave, enabling effective direction finding of multi-source coherent signals. Furthermore, it decouples the number of observed signal sources from the number of antenna array elements, allowing the measurement of three incoming wave directions using only two antennas without the need for virtual array expansion.

[0040] The following describes the broadband signal direction of arrival estimation system based on intra-bandwidth frequency domain interferometry provided by the present invention. The broadband signal direction of arrival estimation system based on intra-bandwidth frequency domain interferometry described below can be referred to in correspondence with the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry described above.

[0041] Figure 18 This is a schematic diagram of the structure of a broadband signal direction-of-arrival estimation system based on intra-bandwidth frequency domain interferometry provided in an embodiment of the present invention, as shown below. Figure 18As shown, it includes: a calculation module 1801, a determination module 1802, a transformation module 1803, a first construction module 1804, a second construction module 1805, and an estimation module 1806, wherein: The calculation module 1801 is used to calculate the unambiguous spacing of the bandwidth direction-finding array elements based on the correspondence between the phase difference of the signals of each array element in the frequency domain and the direction of arrival, and obtain the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; the determination module 1802 is used to determine the element spacing of the antenna array based on the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; the transformation module 1803 is used to receive the incoming wave signal from the antenna array with the determined element spacing, and transform the incoming wave signal received by each array element to the frequency domain to obtain the array element frequency domain signal; the first construction module 1804 is used to construct the phase-frequency feature sequence using the array element frequency domain signal, and construct the phase-frequency feature matrix from the phase-frequency feature sequence; the second construction module 1805 is used to construct the phase-frequency feature steering vector based on the phase-frequency feature matrix; the estimation module 1806 is used to perform spatial spectrum estimation of the direction of arrival based on the phase-frequency feature matrix and the phase-frequency feature steering vector, and determine the position of the spectral peak as the direction of arrival of the broadband signal.

[0042] Figure 19 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 19 As shown, the electronic device may include: a processor 1910, a communications interface 1920, a memory 1930, and a communications bus 1940, wherein the processor 1910, the communications interface 1920, and the memory 1930 communicate with each other through the communications bus 1940. Processor 1910 can call logic instructions in memory 1930 to execute a broadband signal arrival direction estimation method based on frequency domain interferometry within the bandwidth. This method includes: calculating the unambiguous spacing of the bandwidth direction-finding array elements based on the correspondence between the phase difference of the signals of each array element in the frequency domain and the arrival direction, obtaining the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; determining the element spacing of the antenna array based on the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; receiving the arrival signal from the antenna array with the determined element spacing, transforming the arrival signal received by each element to the frequency domain, obtaining the element frequency domain signal; constructing a phase-frequency feature sequence using the element frequency domain signal, and constructing a phase-frequency feature matrix from the phase-frequency feature sequence; constructing a phase-frequency feature steering vector based on the phase-frequency feature matrix; and performing spatial spectrum estimation of the arrival direction based on the phase-frequency feature matrix and the phase-frequency feature steering vector to determine the spectral peak position as the broadband signal arrival direction.

[0043] Furthermore, the logical instructions in the aforementioned memory 1930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0044] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the broadband signal arrival direction estimation method based on bandwidth frequency domain interference provided by the above methods. The method includes: calculating the unambiguous spacing of the bandwidth direction-finding array elements according to the correspondence between the phase difference of the signals of each array element in the frequency domain and the arrival direction, and obtaining the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; determining the element spacing of the antenna array based on the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements; receiving the arrival signal by the antenna array with the determined element spacing, transforming the arrival signal received by each array element to the frequency domain, and obtaining the array element frequency domain signal; constructing a phase-frequency feature sequence using the array element frequency domain signal, and constructing a phase-frequency feature matrix from the phase-frequency feature sequence; constructing a phase-frequency feature steering vector based on the phase-frequency feature matrix; and performing spatial spectrum estimation of the arrival direction based on the phase-frequency feature matrix and the phase-frequency feature steering vector to determine the spectral peak position as the broadband signal arrival direction.

[0045] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the broadband signal arrival direction estimation method based on bandwidth-interval frequency domain interferometry provided by the above methods. The method includes: calculating the unambiguous spacing of the bandwidth-direction-finding array elements according to the correspondence between the phase difference of the signals of each array element in the frequency domain and the arrival direction, and obtaining the calculation result of the unambiguous spacing of the bandwidth-direction-finding array elements; determining the element spacing of the antenna array based on the calculation result of the unambiguous spacing of the bandwidth-direction-finding array elements; receiving the arrival signal by the antenna array with the determined element spacing, transforming the arrival signal received by each array element to the frequency domain, and obtaining the array element frequency domain signal; constructing a phase-frequency feature sequence using the array element frequency domain signal, and constructing a phase-frequency feature matrix from the phase-frequency feature sequence; constructing a phase-frequency feature steering vector based on the phase-frequency feature matrix; and performing spatial spectrum estimation of the arrival direction based on the phase-frequency feature matrix and the phase-frequency feature steering vector to determine the spectral peak position as the broadband signal arrival direction.

[0046] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0047] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0048] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating the direction of arrival of a broadband signal based on frequency domain interferometry within its bandwidth, characterized in that, include: Based on the relationship between the phase difference of each array element signal in the frequency domain and the direction of arrival, the unambiguous spacing of the bandwidth direction-finding array element is calculated, and the calculation result of the unambiguous spacing of the bandwidth direction-finding array element is obtained. The element spacing of the antenna array is determined based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements. The incoming wave signal is received by an antenna array with a predetermined element spacing, and the incoming wave signal received by each element is transformed into the frequency domain to obtain the element frequency domain signal. Phase-frequency feature sequences are constructed using the frequency domain signals of array elements, and phase-frequency feature matrices are constructed from the phase-frequency feature sequences. Construct phase-frequency characteristic steering vectors based on phase-frequency characteristic matrices; Based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, the spatial spectrum of the incoming wave direction is estimated, and the position of the spectral peak is determined as the direction of arrival of the broadband signal.

2. The broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry according to claim 1, characterized in that, Based on the relationship between the phase difference of the signals of each array element in the frequency domain and the direction of arrival, the unambiguous spacing of the bandwidth direction-finding array elements is calculated, and the calculation results of the unambiguous spacing of the bandwidth direction-finding array elements are obtained, including: Using the antenna array baseline as a reference, and the counterclockwise direction as the positive direction, the direction of arrival is determined as follows: , and These are the upper and lower frequency boundaries of the broadband signal, with a bandwidth of [missing information]. ; The distance between any two adjacent antennas is The frequencies are respectively and ,satisfy Then the phase differences of the received signals of any two adjacent antennas at the same frequency point are as follows: and They are respectively and The corresponding wavelength; For bandwidth Different frequency components within the range are obtained as follows: Determine the signal sampling rate The sampling length is ,get: Then we have: according to The element spacing constraint condition for unambiguous estimation of broadband incoming wave direction is obtained: 。 3. The broadband signal direction of arrival estimation method based on frequency domain interferometry within bandwidth according to claim 1, characterized in that, Constructing phase-frequency feature sequences using array element frequency domain signals includes: Based on the frequency domain signals of the array elements of any two adjacent two lines and Construct phase-frequency feature sequences: 。 4. The broadband signal direction of arrival estimation method based on frequency domain interferometry within bandwidth according to claim 3, characterized in that, Constructing a phase-frequency feature matrix from phase-frequency feature sequences includes: in, The phase-frequency characteristic matrix, , This indicates rounding down to the nearest integer.

5. The broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry according to claim 1, characterized in that, Construct the phase-frequency characteristic steering vector based on the phase-frequency characteristic matrix, including: For any direction , Construct phase-frequency characteristic steering vector : 。 6. The broadband signal direction of arrival estimation method based on frequency domain interferometry within bandwidth according to claim 1, characterized in that, Based on the phase-frequency characteristic matrix and phase-frequency characteristic steering vector, spatial spectrum estimation of the direction of arrival is performed to determine the spectral peak position as the direction of arrival of the broadband signal, including: Determine the phase-frequency characteristic matrix covariance matrix : in, Represents the conjugate transpose of a matrix; Combined with phase-frequency characteristic steering vector The spatial spectrum of the incoming wave direction is obtained. : Since the direction of the wave spatial spectrum The spectral peak position is the direction of arrival of the broadband signal.

7. A broadband signal direction-of-arrival estimation system based on frequency domain interferometry within bandwidth, characterized in that, include: The calculation module is used to calculate the unambiguous spacing of the bandwidth direction-finding array elements based on the phase difference of the signals of each array element in the frequency domain and the correspondence with the direction of arrival, and to obtain the calculation result of the unambiguous spacing of the bandwidth direction-finding array elements. The determination module is used to determine the element spacing of the antenna array based on the unambiguous spacing calculation results of the bandwidth direction-finding array elements; The transformation module is used to receive incoming wave signals from an antenna array with a predetermined element spacing, and transform the incoming wave signals received by each element to the frequency domain to obtain the element frequency domain signal. The first construction module is used to construct a phase-frequency feature sequence using the frequency domain signal of the array element, and to construct a phase-frequency feature matrix from the phase-frequency feature sequence. The second construction module is used to construct the phase-frequency characteristic steering vector based on the phase-frequency characteristic matrix; The estimation module is used to estimate the spatial spectrum of the incoming wave direction based on the phase-frequency characteristic matrix and the phase-frequency characteristic steering vector, and to determine the position of the spectral peak as the incoming wave direction of the broadband signal.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry as described in any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the broadband signal direction of arrival estimation method based on intra-bandwidth frequency domain interferometry as described in any one of claims 1 to 6.

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