Multi-path passive reception system and signal reception method

Abstract

The application provides a multi-path passive receiving system and a signal receiving method, and relates to the technical field of passive receiving.The multi-path passive receiving system comprises a receiver, a switch matrix and an array surface, the switch matrix comprises a plurality of switches, and the plurality of switches form at least one level of switch matrix; the input end of the first level switch in the switch matrix is connected with the output end of the receiving channel of the array surface, the output end of the last level switch in the switch matrix is connected to the processing channel of the receiver, and part of the receiving channels of each array surface are selected to the processing channel of the receiver; and the sum of the number of the receiving channels of the array surface is greater than the number of the processing channels of the receiver.The application changes the output of the receiving channel to the receiving channel of the receiver by the on-off of the switch in the switch matrix, realizes that the number of the processing channels is less than the number of the receiving channels contained in all the array surfaces, and further reduces the number of the receiver and the cost.

Description

Technical Field

[0001] This invention relates to the field of passive receiver technology, and specifically to a multi-channel passive receiver system and receiving method. Background Technology

[0002] Acquiring and analyzing radio signals is a crucial method for gaining electromagnetic dominance. Currently, passive devices are commonly used to receive and analyze radio signals, thereby achieving passive target localization. Since passive devices receive non-cooperative signals, they need to possess wide spatial and frequency domain capabilities.

[0003] Due to the limitations of the array receiving antenna beam scanning range, the instantaneous coverage of a single array is limited. To achieve 360-degree omnidirectional high probability of intercept reception, existing passive receiving systems typically use multiple arrays to receive electromagnetic waves from different directions. Each array can achieve full-band reception of its operating frequency. To process these signals, one or more receivers are assigned to each array for signal processing. If the number of receiving channels in an array is too large, two or more receivers are required. Furthermore, to achieve 360-degree full coverage, multiple or more arrays are needed, thus requiring even more receivers. In other words, existing technologies generally employ significant redundancy, and the number of processing channels in the receivers must be at least greater than the total number of receiving channels in all arrays, necessitating the configuration of multiple receivers within the system.

[0004] As can be seen from the above description, existing passive receiving systems have low receiver utilization, resulting in high system costs. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a multi-channel passive receiving system and receiving method, which solves the technical problem of low receiver utilization in existing passive receiving systems.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a multi-channel passive receiving system, comprising an array, a switching matrix, and a receiver, wherein...

[0010] The array includes several sub-arrays located on the same plane. Each sub-array includes several receiving channels composed of receiving antennas. Each sub-array has the same receiving azimuth angle in the horizontal direction and different receiving frequency bands.

[0011] The switch matrix includes multiple switches, and the multiple switches form a switch matrix of at least one level;

[0012] The input terminal of the first-stage switch in the switch matrix is ​​connected to the output terminal of the receiving channel of the array, and the output terminal of the last-stage switch in the switch matrix is ​​connected to the processing channel of the receiver, which selects some receiving channels of each array to the processing channel of the receiver.

[0013] The sum of the number of receiving channels of the array is greater than the number of processing channels of the receiver.

[0014] Preferably, the receiving channel includes at least two receiving antennas, and the receiving antennas in the same receiving channel have different receiving elevation angles.

[0015] Preferably, the multi-channel passive receiver system includes at least two arrays, and the receiving directions of each array are different or the receiving directions overlap at the edges.

[0016] Preferably, the multi-channel passive receiving system includes four arrays. The receiving direction of the first array is 0 to 90 degrees in the horizontal direction, the receiving direction of the second array is 90 to 180 degrees in the horizontal direction, the receiving direction of the third array is 180 to 270 degrees in the horizontal direction, and the receiving direction of the fourth array is 270 to 360 degrees in the horizontal direction.

[0017] Preferably, the switch matrix is ​​a two-level switch matrix, wherein,

[0018] The first-stage switch of the two-stage switch matrix includes four switch groups. The input of each switch group is connected to the output of the receiving channel of each of the four arrays, thereby enabling the selection of the receiving channel signal on each array.

[0019] The input terminals of the second-stage switches in the two-stage switch matrix are connected to the outputs of the four switch groups, and the output terminals of the second-stage switches are connected to the processing channel of the receiver. The second-stage switches select the face by opening and closing the switches.

[0020] Secondly, the present invention provides a signal receiving method, the signal receiving method being applied to the multi-channel passive receiving system as described above, the signal receiving method comprising:

[0021] The array receives signals and outputs them to the switching matrix.

[0022] The switching matrix selects the signals received by the array to the processing channel of the receiver. The signals received by the array are distributed in at least two frequency bands and in at least two receiving directions.

[0023] Preferably, the signal receiving method further includes:

[0024] The signals received from each array are periodically selected and sent to the receiver's processing channel.

[0025] Preferably, the signal receiving method further includes:

[0026] Filter out frequency bands or directions where targets may exist;

[0027] The receiver selects the frequency band where the target may be located, or the direction in which the target may be located, to the receiver.

[0028] Preferably, the filtering of frequency bands or directions where targets may exist includes:

[0029] S301: Sort the receiving channels contained in each array to obtain the current receiving channel sequence corresponding to each array; extract a set number of receiving channels from each current receiving channel sequence, and then output the receiving channel signal corresponding to the extracted receiving channel as the current batch receiving channel signal to the current processing channel set of the receiver.

[0030] S302: The multi-channel passive receiver system identifies whether a target exists in the current batch of received channel signals. If not, for each current received channel, the other received channels in the current received channel sequence, excluding the already extracted received channels, are taken as the current received channels, and the system returns to execute step S301. This process is repeated to rotate the received channels. If a target exists, the receiver takes the received channel signal containing the target as the target received channel signal, then obtains the target received channel for receiving the target received channel signal. The receiver assigns a processing channel to each target received channel as the target processing channel. At the same time, the other received channels in the current received channel sequence, excluding the already extracted received channels, are taken as the current received channels. The receiver's other processing channels, excluding the target processing channels, are taken as the current processing channel set, and the system returns to execute step S301. This process is repeated to rotate the received channels.

[0031] or,

[0032] All receiving channels are randomly arranged into the current receiving channel sequence. A set number of receiving channels are extracted from the current receiving channel sequence and their corresponding signals are output to the receiver as the current batch signals.

[0033] Preferably, the signal receiving method further includes:

[0034] Based on the historical operating status data of the receiving channels, the receiving channels are dynamically sorted to obtain a sorted list. Channels ranked higher in the list are given more frequent selections. Specifically:

[0035] The signal strength index received by each receiving antenna is calculated using the following formula:

[0036]

[0037] In the formula, P i S represents the signal strength index corresponding to the i-th receiving antenna; i S represents the signal strength received by the i-th receiving antenna. max The maximum historical signal strength of the i-th receiving antenna;

[0038] The target distance index is calculated based on the signal strength index, using the following formula:

[0039]

[0040] In the formula, m = |0.28P i -0.5|;T i L represents the target range index corresponding to the i-th antenna; tar H is the target distance; A is the target elevation angle; L is the target azimuth angle; and L is the maximum reconnaissance range for this type of target.

[0041] The target motion index is calculated based on the signal strength index and the target distance index, using the following formula:

[0042]

[0043] In the formula, f i is the target motion index corresponding to the i-th antenna; v is the value of the radial velocity component of the target, which is equal to the value of the velocity component of the target motion velocity along the line connecting the target to the receiving antenna; V is the average velocity value of the target; k is the preset motion coefficient;

[0044] The importance index I of each receiving antenna is calculated based on the signal strength index, target distance index, and target motion index. i The calculation formula is:

[0045]

[0046] Calculate the ratio of the importance index to the sum of the importance indices of all receiving antennas to obtain a set of ratios; select the receiving antennas whose corresponding ratio is greater than a set threshold as the receiving antennas for the next receiving cycle, and execute the step of using a switching matrix to select the signal received by the receiving antenna array to the processing channel of the receiver.

[0047] (III) Beneficial Effects

[0048] This invention provides a multi-channel passive receiving system and method. Compared with the prior art, it has the following advantages:

[0049] The multi-channel passive receiving system of the present invention includes a receiver, a switch matrix, and an array. The switch matrix comprises multiple switches, forming at least one level of the switch matrix. The input terminals of the first-level switches in the switch matrix are connected to the output terminals of the receiving channels of the array, and the output terminals of the last-level switches in the switch matrix are connected to the processing channel of the receiver, selecting a portion of the receiving channels from all the receiving channels of each array to the processing channel of the receiver. The sum of the number of receiving channels of the array is greater than the number of processing channels of the receiver. The present invention uses the on / off state of the switches in the switch matrix to change the output of the receiving channels to the receiving channels of the receiver. Compared to the prior art where each receiving channel is assigned a processing channel, this achieves a processing channel count less than the total number of receiving channels in all arrays, thereby reducing the number of receivers and lowering the cost. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the array structure in a multi-channel passive receiver system provided in an embodiment of the present invention;

[0052] Figure 2 This is a schematic diagram of the distribution of receiving channels in an embodiment of the present invention. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] This application provides a multi-channel passive receiving system and receiving method, which solves the technical problem of low receiver utilization in existing passive receiving systems, thereby improving receiver utilization efficiency and reducing system costs.

[0055] The technical solution in this application is to solve the above-mentioned technical problems, and the general idea is as follows:

[0056] To address the issue that the number of processing channels in a receiver must be greater than the number of receiving channels across all arrays in existing technologies, this invention improves receiver utilization efficiency and maximizes system performance by changing the output of the receiving channels to the receiver's receiving channels through the switching of switches in a switch matrix.

[0057] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0058] Example 1:

[0059] Figure 1 This is a schematic diagram of the array structure in a multi-channel passive receiving system provided in an embodiment of the present invention. The receiving system includes four arrays, each with the same array layout structure, except for the receiving direction of each array. For example, the receiving direction of array 10 is 0-90 degrees horizontally, the receiving direction of array 20 is 90-180 degrees horizontally, the receiving direction of array 30 is 180-270 degrees horizontally, and the receiving direction of array 40 is 270-360 degrees horizontally. The receiving azimuth angles of the four arrays achieve a 360-degree panoramic effect in the horizontal direction. It should be noted that the embodiments of the present invention do not limit the range of the receiving elevation angle of the arrays in the vertical direction.

[0060] The following section uses array 10 as an example to introduce the signal selection process for a single array receiving channel.

[0061] like Figure 2 As shown, array 10 is a planar array containing four sub-arrays: sub-array 11, sub-array 13, sub-array 15, and sub-array 17. Each sub-array consists of several receiving antennas arranged in a matrix, and the receiving frequency bands of each sub-array differ: for example, the receiving frequency band of sub-array 11 is 0.1-0.2 GHz, the receiving frequency band of sub-array 13 is 0.2-0.3 GHz, the receiving frequency band of sub-array 15 is 0.3-0.4 GHz, and so on. Each sub-array can achieve a receiving azimuth angle of 90 degrees, and the receiving elevation angle range of each sub-array is the same. Furthermore, the receiving direction of each sub-array in array 10 is within the horizontal range of 0-90 degrees. In other words, the only difference between different sub-arrays within the same array is the receiving frequency band.

[0062] It should be emphasized that the receiving azimuth angle referred to in the embodiments of the present invention is also called the receiving direction.

[0063] In subarray 11, receiving antennas 1101a and 1101b have the same receiving azimuth angle but different receiving elevation angles, forming receiving channel 1101. The receiving frequency band of receiving channel 1101 is 0.1-0.2 GHz, and the receiving azimuth angle range is 0-18 degrees. In receiving channel 1101, receiving antenna 1101a receives at elevation angles of 0-45 degrees, and receiving antenna 1101b receives at elevation angles of 45-90 degrees. Similarly, each subarray contains one or more receiving channels. For ease of description, the signals output from each receiving channel of subarrays 11 to 17 are sequentially numbered: the signals output from subarray 11 are sequentially numbered receiving channel signal 1, receiving channel signal 2, receiving channel signal 3, receiving channel signal 4, and receiving channel signal 5; the signals output from subarray 13 are sequentially numbered receiving channel signal 6, receiving channel signal 7, receiving channel signal 8, receiving channel signal 9, and receiving channel signal 10, and so on.

[0064] During signal reception, for each subarray, the combiner combines the signals from the receiving antennas with the same receiving azimuth angle but different receiving elevation angles in the subarray to obtain a receiving channel signal, and then each subarray outputs multiple receiving channel signals. For subarray 11: Receive channel signal 1 corresponds to signals at all elevation angles within the 0-18 degree range, i.e., the signals received by receiving antennas 1101a and 1101b are combined into one channel to obtain the receiving channel signal corresponding to receiving channel 1101, with a receiving frequency band of 0.1-0.2 GHz. This signal originates from receiving antennas 1101a and 1101b. Similarly, receiving channel signal 2 corresponds to signals within the 18-36 degree range, with a receiving frequency band of 0.1-0.2 GHz. For subarray 13, receiving channel signal 6 corresponds to signals within the 0-18 degree range, with a receiving frequency band of 0.2-0.3 GHz; receiving channel signal 7 corresponds to signals within the 18-36 degree range, with a receiving frequency band of 0.2-0.3 GHz; and receiving channel signal 8 corresponds to signals within the 54-72 degree range, with a receiving frequency band of 0.2-0.3 GHz.

[0065] Array 10 has 4 sub-arrays, each with 5 receiving channels, resulting in 20 receiving channels distributed across 4 frequency bands. In practical applications, since a conventional receiver can process 23 signals simultaneously, each array comprising several sub-arrays can output a maximum of 23 receiving channel signals at any given time.

[0066] When the receiver has two processing channels, array 10 outputs the signal received by the receiving antenna array to the switch matrix. The input of the switch matrix receives the signal received by the receiving antenna array. After the switches in the switch matrix select and turn on / off, the receiving channel signal 1 in subarray 11 and the receiving channel signal 6 in subarray 13 are output to the receiver. Similarly, the receiving channel signal 1 and the receiving channel signal 7 in subarray 13 can also be output to the receiver. When the receiver has six processing channels, the receiving channel signals 1 and 4 in subarray 11, the receiving channel signals 6 and 9 in subarray 13, and the receiving channel signals 13 and 15 in subarray 15 can also be output to the receiver.

[0067] Of course, the receiver can also receive signals from more than two frequency bands, or receive signals from different receiving channels on the same frequency band.

[0068] Furthermore, the switching matrix can select the receiving channel signal between different arrays, and its principle and process are similar to those described above, so they will not be repeated here. In addition, the embodiments of the present invention do not limit the specific connection form or hierarchical structure of the switching matrix; any switching matrix that implements the above-described functions of the present invention can fall within the scope of switching matrices.

[0069] It is understandable that when the switching matrix selects the receiving channel signal, it can arbitrarily combine the receiving channel signals belonging to different subarrays on different arrays and output them to the receiver's processing channel.

[0070] As a further optimization of the array deployment method, the arrays can form a large ring array. The receiving direction of each array can be less than 90 degrees. In this case, more arrays are needed to achieve 360-degree panoramic view. That is, in this embodiment of the invention, the number of arrays includes, but is not limited to, 4; for example, it can be 2 or 3, or even 5 or 6 or more. The receiving direction of each array can be greater than 90 degrees. The receiving directions of adjacent arrays can overlap at the edges, thereby achieving 360-degree panoramic view without blind spots. For example, the receiving direction of array 10 is -10 to 100 degrees, the receiving direction of array 20 is 90 to 200 degrees, the receiving direction of array 30 can be 190 to 300 degrees, and the receiving direction of array 40 can be 290 to 0 degrees. The angle range for edge overlap of the receiving directions of the arrays in this embodiment of the invention includes, but is not limited to, 10 degrees; it can be 1 degree, 3 degrees, 4 degrees, 6 degrees, 12 degrees, 13 degrees, 15 degrees, etc.

[0071] Furthermore, since target signals do not exist simultaneously in all directions, in order to fully utilize the processing capabilities of the receiving processing channels, the number of receiving channels on the array can be increased to be greater than the number of processing channels of the receiver. For example, it can be 1.5 times, 2 times, 2.1 times, 2.7 times, 2.8 times, 4 times, etc., the number of receiving processing channels.

[0072] By applying the above embodiments of the present invention, the switch matrix sequentially distributes the received channel signals according to the frequency band distribution to fill the receiver's processing channels, enabling the receiver to operate at full capacity and thereby improving the signal interception probability and processing speed.

[0073] Example 2

[0074] An embodiment of the invention provides a multi-channel passive receiving system, the system comprising: a receiver, four arrays, and a switching matrix.

[0075] The structures of each array are identical; the only difference lies in the direction of reception. Figure 2 This is a schematic diagram of the distribution of receiving channels in an embodiment of the present invention, such as... Figure 2 As shown, each array consists of multiple receiving antennas arranged in an array. The distribution of the receiving antennas in the array is as shown in Embodiment 1. The embodiments of the present invention will not be described again here.

[0076] The first-level switch in the switch matrix includes four switch groups. The input of each switch group is connected to the output of the receiving channel of each array face. The sum of the number of receiving channels of the array face is greater than the number of processing channels of the receiver, so as to enable the selection of the receiving channel signal of each array face.

[0077] The input terminals of the second-stage switches in the switch matrix are connected to the outputs of the four switch groups, and the output terminals of the second-stage switches are connected to the processing channel of the receiver. The second-stage switches select the face by opening and closing the switches.

[0078] The two-stage switches work together to simultaneously select the receiving channel signals of different frequency bands on the array facet, and also to select the array facet: for example, they can process only the receiving channel signals output from array facet 10; they can process some of the receiving channel signals output from array facet 10 and some of the receiving channel signals output from array facet 30; they can process some of the receiving channels output from array facet 10, array facet 20, array facet 30, and array facet 40; similarly, they can simultaneously process the receiving channel signals of different frequency bands on array facet 10 and the receiving channel signals of different frequency bands on array facet 20.

[0079] Example 3:

[0080] This invention provides a signal receiving method applied to the multi-channel passive receiving system described in the above embodiments. The method includes:

[0081] The array receives signals and outputs them to the switching matrix.

[0082] The switching matrix selects the signals received by the array to the processing channel of the receiver. The signals received by the array are distributed in at least two frequency bands and in at least two receiving directions.

[0083] In one specific embodiment of the present invention, the method further includes:

[0084] The signals received from each array are periodically selected and sent to the receiver's processing channel.

[0085] In one specific embodiment of the present invention, the method further includes:

[0086] Filter out frequency bands or directions where targets may exist;

[0087] The receiver selects the frequency band where the target may be located, or the direction in which the target may be located, to the receiver.

[0088] Specifically, methods for filtering out frequency bands or directions where targets may exist include: pre-configuring the rotation order of each receiving channel in the system, for example,

[0089] S301: Sort the receiving channels contained in each array to obtain the current receiving channel sequence corresponding to each array; then extract a set number of receiving channels from each current receiving channel sequence, and output the receiving channel signal corresponding to the extracted receiving channel as the current batch receiving channel signal to the current processing channel set of the receiver.

[0090] S302: The system identifies whether a target exists in the current batch of received channel signals.

[0091] S303: If not, for each current receiving channel, take the other receiving channels in the current receiving channel sequence other than the already extracted receiving channels as the current receiving channels, and return to execute step S301. Repeat this process to achieve the rotation of receiving channels.

[0092] S304: If so, the receiver takes the target receiving channel signal as the target receiving channel signal, then acquires the target receiving channel that receives the target receiving channel signal, and assigns a processing channel as the target processing channel for each target receiving channel. Simultaneously, it takes all other receiving channels in the current receiving channel sequence (excluding the already extracted receiving channels) as the current receiving channels, and takes all other processing channels of the receiver (excluding the target processing channels) as the current processing channel set, then returns to execute step S301. This process is repeated to achieve the rotation of receiving channels.

[0093] Understandably, after all receiving channels have been rotated, step S301 can be repeated, or a different receiving channel extraction method can be used to rotate the receiving channels. For example, all receiving channels can be randomly arranged into a current receiving channel sequence, and then a set number of receiving channels can be extracted from the current receiving channel sequence, with their corresponding signals output to the receiver as the current batch signal. Alternatively, a preset receiving channel selection algorithm can be used to select receiving channels in batches (the preset receiving channel selection algorithm can be set according to actual conditions; the algorithm in Example 4 is an improved receiving channel selection algorithm), and then the corresponding signals are output to the receiver in batches. After the current batch of receiving channel signals is processed, the next batch of receiving channel signals is obtained according to the above method, and this process is repeated until all receiving channels have been rotated. Then, the next cycle begins.

[0094] In practical electronic warfare technology research, electronic signals are typically distributed across a limited number of frequency bands, rarely across all directions and frequency bands. This means that most frequency bands lack targets. While the corresponding receiving channels of the receiver process the signals, these channels are essentially processing noise. Therefore, only a few receiving channels are used for target detection, resulting in low efficiency and cost-effectiveness in current technology. In this invention, under the given conditions, a portion of the signals from all receiving channels are simultaneously selected for target filtering at the receiver. Then, the signals from the receiving channels containing the target are continuously tracked. This achieves target interception even with limited receiver processing resources.

[0095] Example 4

[0096] In order to increase the frequency of processing of the azimuth correspondence signal of key targets and ultimately achieve continuous tracking of targets, the following steps are added to Example 4 based on the method of Example 3.

[0097] Before providing a detailed description of Embodiment 4, the receiving process of the passive receiving system involved in this embodiment of the invention will first be introduced. In this embodiment of the invention, several receiving cycles are set in chronological order. During the time period corresponding to each receiving cycle, the signals received by each receiving channel during that time period are output to the processing channel.

[0098] Taking the current receiving loop number j as an example, the receiving channels are dynamically sorted according to the historical working status data of the receiving channels to obtain a sorted list. The channels that are ranked higher are selected more frequently. The specific process is as follows.

[0099] Step 1: Using the formula, Calculate the signal strength index received by each receiving antenna, where P i S represents the signal strength index corresponding to the i-th receiving antenna; i S represents the signal strength received by the i-th receiving antenna. max It represents the maximum historical signal strength of the i-th receiving antenna.

[0100] Step 2: Using the formula, m = |0.28P i -0.5|, calculate the value of m.

[0101] Step 3: Using the formula Calculate the target distance index, where T i L represents the target range index corresponding to the i-th antenna; tar H is the target distance; A is the target elevation angle; L is the target azimuth angle; and L is the maximum reconnaissance distance for this type of target.

[0102] The target distance L referred to in this embodiment of the invention tar It is obtained from multi-station passive positioning technology.

[0103] The fourth step is to use the formula. Calculate the target motion index, where f i is the target motion index corresponding to the i-th antenna; v is the value of the radial velocity component of the target, which is equal to the value of the velocity component of the target motion velocity along the line connecting the target to the receiving antenna; V is the average velocity value of the target; k is the preset motion coefficient, whose value range is (1, 1.735);

[0104] Fifth step, using the formula, Calculate the importance index of each receiving antenna.

[0105] The sixth step is to calculate the ratio of the importance index to the sum of the importance indices of all receiving antennas, and obtain a set of ratios; select the receiving antennas whose corresponding ratios are greater than a set threshold as the receiving antennas for the next receiving cycle, and execute the step of using a switching matrix to select the signals received by the receiving antenna array to the processing channel of the receiver.

[0106] In Application Example 4, during the first receiving loop, all receiving antennas participate in the construction of the processing channel. During the j-th receiving loop, some receiving antennas are selected to construct the receiving channel. When a target signal is present in the receiving channel, the importance index of the corresponding receiving antenna will be relatively high, and it will be ranked higher in each receiving loop. This can increase the frequency at which receiving channels with target signals are selected to the processing channel, thereby achieving continuous tracking of the target.

[0107] In addition, in embodiment 4, this can prevent signals from receiving channels without target signals from being selected to processing channels while ensuring detection performance, thereby reducing the operating frequency of the signal conversion lines connecting the receiving channel and the processing channel and improving the service life of the conversion lines.

[0108] In summary, compared with existing technologies, it has the following beneficial effects:

[0109] 1. In this embodiment of the invention, the on / off state of the switches in the switch matrix changes the output of the receiving channel to the receiving channel of the receiver. Compared with the prior art, which allocates a processing channel to each receiving channel, the number of processing channels is less than the number of receiving channels contained in all arrays, thereby reducing the number of receivers and lowering the cost.

[0110] 2. The embodiments of the present invention flexibly select the receiving channel signals of different frequency bands and different receiving directions to the processing channel of the receiver, so that a receiver can process the receiving channel signals of different frequency bands and different receiving directions at the same time.

[0111] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. 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. Such 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 multi-path passive reception system, characterized by, The system comprises an array, a switch matrix and a receiver, wherein, The array comprises a plurality of sub-arrays in the same plane, each of the sub-arrays comprises a plurality of receiving channels composed of receiving antennas, each of the sub-arrays has the same receiving azimuth angle in the horizontal direction, and each of the sub-arrays has a different receiving frequency band. The switch matrix comprises a plurality of switches, and the plurality of switches form at least one level of the switch matrix. The input end of the first level switch in the switch matrix is connected to the output end of the receiving channel of the array, and the output end of the last level switch in the switch matrix is connected to the processing channel of the receiver. The sum of the number of receiving channels of the array is greater than the number of processing channels of the receiver. The multi-path passive receiving system dynamically sorts the receiving channels according to historical working state data of the receiving channels to obtain a sorting list, and increases the number of being selected for the receiving channels with a higher sorting position, specifically as follows: The signal strength index received by each receiving antenna is calculated, and the calculation formula is as follows: In the formula, P i is the signal strength index corresponding to the ith receiving antenna; S i is the signal strength received by the ith receiving antenna; S max is the maximum historical signal strength of the ith receiving antenna; The target distance index is calculated based on the signal strength index, and the calculation formula is as follows: where m = |0.28P i -0.5|;T i is the target distance index corresponding to the ith antenna pair; L tar is the target distance; H is the target elevation angle; A is the target azimuth angle; L is the maximum detection range of the target; The target motion index is calculated based on the signal strength index and the target distance index, and the calculation formula is as follows: In the formula, f i is the target motion index corresponding to the i-th antenna; v is the value of the radial velocity component of the target, which is equal to the value of the velocity component of the target motion velocity on the line connecting the target to the receiving antenna; V is the average velocity value of the target; k is a preset motion coefficient; An importance index I of each receiving antenna is calculated based on a signal strength index, a target distance index, and a target motion index i The calculation formula is: The ratio of the importance index to the sum of the importance indexes of all receiving antennas is calculated to obtain a ratio set, and the receiving antennas with a ratio greater than a set threshold are used as the receiving antennas in the next receiving cycle, and the switch matrix is used to select the signals received by the receiving antenna array to the processing channel of the receiver.

2. The multi-path passive reception system of claim 1, wherein, The receiving channel comprises at least two receiving antennas, and the receiving antennas in the same receiving channel have different receiving elevation angles.

3. The multi-path passive reception system of claim 1, wherein, The multi-path passive receiving system comprises at least two arrays, and each of the arrays has a different receiving direction or an edge overlap of the receiving directions.

4. The multi-path passive reception system of claim 1, wherein, The multi-path passive receiving system comprises four arrays, the first array has a receiving direction of 0-90 degrees in the horizontal direction, the second array has a receiving direction of 90-180 degrees in the horizontal direction, the third array has a receiving direction of 180-270 degrees in the horizontal direction, and the fourth array has a receiving direction of 270-360 degrees in the horizontal direction.

5. The multi-path passive reception system of claim 4, wherein, The switch matrix is a two-level switch matrix, wherein, The first level switch of the two-level switch matrix comprises four switch groups, the input end of each switch group is connected to the output end of the receiving channel of the four arrays, and the selection of the receiving channel signals of each array is realized. The input end of the second level switch of the two-level switch matrix is connected to the output of the four switch groups, the output end of the second level switch is connected to the processing channel of the receiver, and the selection of the array is realized by the opening and closing of the switch.

6. A signal receiving method characterized by comprising: The signal receiving method is applied to the multi-path passive receiving system as claimed in any one of claims 1-5, and the signal receiving method comprises: The array receives signals and outputs the signals to the switch matrix. The switch matrix selects the signals received by the array to the processing channel of the receiver, and the signals received by the array are distributed in at least two frequency bands and at least two receiving directions. The signal receiving method further comprises: According to historical working state data of the receiving channels, the receiving channels are dynamically sorted to obtain a sorting list, and the number of selected channels is increased for the channels at the top of the sorting list, specifically as follows: The signal strength indexes of the signals received by the receiving antennas are calculated, and the calculation formula is as follows: In the formula, P i is the signal strength index corresponding to the ith receiving antenna; S i is the signal strength received by the ith receiving antenna; S max is the maximum historical signal strength of the ith receiving antenna; The target distance indexes are calculated based on the signal strength indexes, and the calculation formula is as follows: where m = |0.28P i -0.5|;T i is the target distance index corresponding to the ith antenna pair; L tar is the target distance; H is the target elevation angle; A is the target azimuth angle; L is the maximum detection distance of the target; The target motion indexes are calculated based on the signal strength indexes and the target distance indexes, and the calculation formula is as follows: In the formula, f i is the target motion index corresponding to the i-th antenna; v is the value of the radial velocity component of the target, which is equal to the value of the velocity component of the target motion velocity on the line connecting the target to the receiving antenna; V is the average velocity value of the target; k is a preset motion coefficient; An importance index I of each receiving antenna is calculated based on a signal strength index, a target distance index, and a target motion index i The calculation formula is: The ratio of the importance index to the sum of the importance indexes of all the receiving antennas is calculated to obtain a ratio set; the receiving antennas corresponding to the ratios greater than a set threshold are taken as the receiving antennas of the next receiving cycle, and the step of performing the switch matrix to select the signals received by the receiving antenna array to the processing channels of the receiver is performed.

7. The signal receiving method of claim 6, wherein, The signal receiving method further includes: The signals received by the array surfaces are periodically selected to the processing channels of the receiver.

8. The signal receiving method of claim 6, wherein, The signal receiving method further includes: The frequency bands or directions in which the target may exist are screened out; The receiving channel signals corresponding to the frequency bands in which the target may exist or the directions in which the target may exist are selected to the receiver.

9. The signal receiving method of claim 8, wherein, The screening of the frequency bands or directions in which the target may exist includes: S301: The receiving channels included in each array surface are sorted to obtain a current receiving channel sequence corresponding to each array surface; a set number of receiving channels are extracted from each current receiving channel sequence, and the receiving channel signals corresponding to the extracted receiving channels are output to a current processing channel set of the receiver as a current batch receiving channel signal; S302: The multi-path passive receiving system identifies whether the target exists in the current batch receiving channel signal; if not, for each current receiving channel, the other receiving channels in the current receiving channel sequence except the extracted receiving channels are taken as the current receiving channel, and the S301 step is returned to be executed, and the receiving channel is rotated in this way; if yes, the receiver takes the receiving channel signal in which the target exists as a target receiving channel signal, then obtains a target receiving channel receiving the target receiving channel signal, the receiver allocates a processing channel to each target receiving channel as a target processing channel, at the same time, the other receiving channels in the current receiving channel sequence except the extracted receiving channels are taken as the current receiving channel, and the other processing channels of the receiver except the target processing channels are taken as the current processing channel set, and the S301 step is returned to be executed, and the receiving channel is rotated in this way; Or, All the receiving channels are randomly arranged as a current receiving channel sequence, a set number of receiving channels are extracted from the current receiving channel sequence, and the signals corresponding to the extracted receiving channels are output to the receiver as a current batch signal.

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