A wideband signal direction of arrival detection method suitable for missing circular array

Abstract

The application provides a wideband signal direction of arrival detection method suitable for a circular array, which comprises sampling analog data of each array element received by the array to obtain digital signals, buffering the data in batches, and segmenting each batch of data; performing DFT processing on each segment of the segmented data to obtain frequency domain narrowband data; designing a narrowband beamformer for each frequency domain narrowband signal; and synthesizing the outputs of the narrowband beams to obtain a wideband beam output. The method can realize the detection of the direction of arrival of a wideband signal source signal of an antenna circular array.

Description

Technical Field

[0001] This invention belongs to the field of wireless array signal technology, and in particular relates to a method for detecting the direction of arrival of broadband signals suitable for missing circular arrays. Background Technology

[0002] Due to limitations in the usage environment and conditions, circular array antennas may experience obstruction, damage, or other issues during use, resulting in missing array elements. To address this issue, this patent introduces a calculation method that flexibly responds to missing elements and allows for adjustments to the formula as needed, whether missing or restored. This method is simple and convenient to use.

[0003] Traditional methods for detecting incoming signals based on antenna arrays are mostly designed for narrowband source signals, and there are currently no methods for detecting incoming signals from circular antenna arrays that can detect broadband source signals. Summary of the Invention

[0004] In view of this, the present invention proposes a method for detecting the direction of arrival of broadband signals in the absence of a circular array, so as to realize the detection of the incoming signal of a circular array of antennas for broadband source signals.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] A method for detecting the direction of arrival of broadband signals suitable for missing circular arrays includes the following steps:

[0007] Step 1: Sample the analog data received by each array element of the array to obtain digital signals, buffer them in batches, and then segment each batch of data separately;

[0008] Step 2: Perform DFT processing on each segment of the data to obtain narrowband frequency domain data;

[0009] Step 3: Form a matrix from the frequency domain data of each array element in each sub-band;

[0010] Step 4: Design a narrowband beamformer for each narrowband signal in the frequency domain;

[0011] Step 5: Extract the sub-frequency band where the broadband source signal is located according to the pre-designed receiving frequency band;

[0012] Step 6: Perform a weighted summation on the extracted sub-band data to obtain the beamforming output data for each frequency domain sub-band;

[0013] Step 7: Perform IDFT transform on the frequency domain output data of each sub-band to obtain the time domain output sequence;

[0014] Step 8: Connect the output sequences in chronological order to form the overall time output sequence of the broadband signal;

[0015] Step 9: Compare the output power and select the direction of the maximum power as the direction of incoming wave.

[0016] Furthermore, step 4 specifically includes:

[0017] Given the input parameters: a sampled discrete signal x(n), where x(n) has dimensions M×K, K is the number of samples, M is the number of array elements, R is the radius of the circular array, f is the baseband signal frequency, and c = 3*10. 8 m / s;

[0018] Azimuth φ = [φ1,…φ i ,…φ 360 ] = [-180:1:180),

[0019] Pitch angle θ = [θ1,…θ j ,…θ 91 ] = [0:1:90],

[0020] The noise field distribution information n(t) is known;

[0021] Step 401: Calculate the signal wavelength λ = c / f, take the elevation angle θ = 90°, and let i = [1:1:360];

[0022] Step 402: Determine if all array elements are functioning correctly. If so, calculate the incoming wave direction vector a:

[0023]

[0024] Where γ m =2π(m-1) / M, m=1,2,…,M;

[0025] If K antennas are working normally, and hollow dots represent L antennas not working, then calculate...

[0026]

[0027] Where M k Let the locations of the K normally functioning antennas be numbered, k = [1, 2, ... K];

[0028] Step 403: Obtain the beam weighting vector w(φ) i )=a(φ i ), its dimension is M×1;

[0029] Step 404: Calculation Where x(n) has a dimension of M×K, and K is the number of samples;

[0030] Step 405: Calculate power

[0031] Step 406: Comparison Find the largest value. The value of i at this time is denoted as i max , That is, the azimuth angle we are looking for;

[0032] Step 407: Azimuth at this time Given that j = [1:1:91], calculate the incoming wave direction vector a:

[0033]

[0034] There may be cases where the antenna is not working:

[0035]

[0036] Step 408: Obtain the beam weighting vector w(θ) j )=a(θ j );

[0037] Step 409: Calculation

[0038] Step 410: Calculate the power

[0039] Step 411: Comparison Find the largest value. The value of j at this time is denoted as j. max θ jmaI That is, the pitch angle we are looking for;

[0040] Step 412: Determine the direction of arrival of the signal source as follows:

[0041] Furthermore, the sampling frequency during sampling must be greater than twice the baseband signal frequency f and be an integer power of 2.

[0042] Compared with existing technologies, the broadband signal arrival direction detection method for missing circular arrays described in this invention has the following advantages:

[0043] Due to limitations in the usage environment and conditions, circular array antennas may experience obstruction, damage, or other issues during use, resulting in missing array elements. To address the problem of missing antenna array elements, this invention introduces a calculation method that can flexibly respond to missing array elements and change the formula at any time as array elements are missing or restored. It is simple and convenient to use.

[0044] Traditional antenna array-based arrival signal detection methods are mostly designed for narrowband source signals. This invention introduces an arrival signal detection method using a circular antenna array designed for broadband source signals. Attached Figure Description

[0045] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0046] Figure 1 This is a schematic diagram of the method flow of the present invention. Detailed Implementation

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0048] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] Traditional methods for detecting incoming signals based on antenna arrays are mostly designed for narrowband signal sources. This invention provides a method for detecting incoming signals using a circular antenna array, specifically for wideband signal sources. For example... Figure 1 As shown, specifically including

[0052] Step 1: Sample the analog data received by each array element from the array to obtain x m(i), m=1,2,…M, i=1,2,…, are cached in batches. Each batch of data is further divided into segments of length L. Taking the nth segment (batch) as an example, we get…

[0053]

[0054] Step 2: Perform DFT processing on each data segment. Taking the nth segment as an example, process the data of each matrix... Perform a DFT of length L on l = 0, ..., L-1 to obtain frequency domain data. Where k is the sub-band number in the frequency domain, i.e.

[0055]

[0056] Step 3: Form a matrix from the frequency domain data of each array element in a certain sub-band.

[0057]

[0058] Step 4: For each narrowband sub-band, design the beam weighting vector w(f) using methods from narrowband beamforming. k );

[0059] Step 5: According to the pre-designed receiving frequency band, extract the sub-frequency band where the broadband source signal is located from k (k=0,...L-1) frequency domain sub-bands. The sub-frequency band number is k', k'∈(0,...L-1);

[0060] Step 6: For each sub-band data extracted, perform a weighted summation using the beam weighting vector obtained in Step 4 to obtain the beamforming output data Y for each frequency domain sub-band. (n) (k′);

[0061] Step 7: Output frequency domain data Y for each sub-band (n) (k′) is transformed using the IDFT method to obtain the time-domain output sequence y. (n) (l);

[0062] Step 8: Output sequence y in chronological order (n) (l) Connect them together to form the total time output sequence y(i) of the broadband signal;

[0063] Step 9: Compare the power of the output y(i) and select the direction of the maximum power as the direction of the incoming wave.

[0064] Specifically, step 4 includes the following steps:

[0065] Given the input parameters: a sampled discrete signal x(n), where x(n) has dimensions M×K, K is the number of samples, M is the number of array elements, R is the radius of the circular array, and the baseband signal frequency f, c = 3*10.8 m / s. The sampling frequency should be greater than twice the baseband signal frequency f and is generally taken as an integer power of 2. The azimuth angle φ = [φ1,…φ i ,…φ 360 ]=[-180:1:180), pitch angle θ=[θ1,…θ j ,…θ 91 ] = [0:1:90], the noise field distribution information is assumed to be known, that is, n(t) is known.

[0066] Step 401: Calculate the signal wavelength λ = c / f, take the elevation angle θ = 90°, and let i = [1:1:360];

[0067] Step 402: Determine if all array elements are functioning correctly. If so, calculate:

[0068]

[0069] Where γ m =2π(m-1) / M, m=1,2,…,M;

[0070] If K antennas are working normally, and hollow dots represent L antennas not working, then calculate...

[0071] Where M k Let the locations of the K normally functioning antennas be numbered, k = [1, 2, ... K];

[0072] Step 403: Take w(φ) i )=a(φ i ), its dimension is M×1;

[0073] Step 404: Calculation Where x(n) has a dimension of M×K, and K is the number of samples;

[0074] Step 405: Calculate power

[0075] Step 406: Comparison Find the largest value. The value of i at this time is denoted as i max , That is, the azimuth angle we are looking for;

[0076] Step 407: Azimuth at this time Given that j = [1:1:91], calculate:

[0077]

[0078] There may be cases where the antenna is not working:

[0079]

[0080] Step 408: Take w(θ) j )=a(θ j );

[0081] Step 409: Calculation

[0082] Step 410: Calculate the power

[0083] Step 411: Comparison Find the largest value. The value of j at this time is denoted as j. max θ jmax That is, the pitch angle we are looking for;

[0084] Step 412: Determine the direction of arrival of the signal source as follows:

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting the direction of arrival of broadband signals applicable to missing circular arrays, characterized in that: Includes the following steps: Step 1: Sample the analog data received by each array element of the array to obtain digital signals, buffer them in batches, and then segment each batch of data separately; Step 2: Perform DFT processing on each segment of data to obtain narrowband frequency domain data; Step 3: Form a matrix from the frequency domain narrowband data of each array element in each sub-band; Step 4: For each narrowband sub-band, design the beam weighting vector using methods from narrowband beamforming; Step 4 specifically includes: Given input parameters: the sampled discrete signal ,in Dimensions The number of samples, the number of array elements M, and the radius of the circular array are given. Baseband signal frequency , ; Azimuth , Pitch angle Noise field distribution information Known; Step 401: Calculate the signal wavelength Pitch angle ,make ; Step 402: Determine if all array elements are functioning correctly. If so, calculate the incoming wave direction vector. : in ， ; If there is The antenna is working normally, and the hollow dot indicates that... If the antenna is not working, then calculate... in for The location number of the normally functioning antenna. ; Step 403: Obtain the beam weighting vector Its dimensions are ; Step 404: Calculation ,in Dimensions The number of samples; Step 405: Calculation ,in, In azimuth angle The signal power estimate obtained from the upper scan; Step 406: Comparison Find the largest value. ,at this time That is, the azimuth angle we are looking for; Step 407: Azimuth at this time It has been confirmed that... Calculate the incoming wave direction vector : There may be cases where the antenna is not working: Step 408: Obtain the beam weighting vector ; Step 409: Calculation ; Step 410: Calculation ,in, Indicated at pitch angle The signal power estimate obtained from the upper scan; Step 411: Comparison Find the largest value. ,at this time That is, the pitch angle we are looking for; Step 412: Determine the direction of arrival of the signal source as follows: ; The sampling frequency during sampling must be greater than the baseband signal frequency. Twice the power of 2; Step 5: Extract the sub-band containing the broadband source signal according to the pre-designed receiving frequency band; Step 6: For each sub-band data extracted, use the beam weighting vector obtained in Step 4 to perform weighted summation to obtain the beamforming output data of each frequency domain sub-band; Step 7: Perform IDFT transform on the beamforming output data of each frequency domain sub-band to obtain the time domain output sequence. ; Step 8: Output the time-domain sequence in chronological order. Connect them to form the overall time output sequence of the broadband signal. ; Step 9: Compare the time output sequences The direction of the incoming wave is selected based on the power magnitude and the direction of maximum power.

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