Phase-coherent-non-coherent signal mixing synthesis method based on distributed radar network

Abstract

The application discloses a kind of signal mixed synthesis method and device based on distributed radar network's phase reference-non-phase reference, it is related to distributed radar technical field, the method includes: obtaining the echo signal of each receiving channel of distributed radar network, multiple echo signals are mixed, obtain multiple baseband signals, and pulse compression is carried out to baseband signal, obtain signal after pulse compression;Phase parameter estimation and time delay parameter estimation are carried out to it, and envelope phase alignment is carried out, obtain processed signal;Multiple processed signals are grouped multiple times, obtain multiple phase reference group sets;Respectively, in-group phase reference synthesis and inter-group non-phase reference synthesis are carried out, obtain multiple mixed signals;The phase reference group set corresponding to the mixed signal of maximum peak in multiple mixed signals is output;The problem that signal is not completely phase reference in the prior art is solved, and then in-group phase reference synthesis is realized, inter-group non-phase reference synthesis is carried out, synthesis gain is effectively improved, and target detection capability is improved.

Description

Technical Field

[0001] This invention relates to the field of distributed radar technology, and in particular to a method for coherent-noncoherent signal hybrid synthesis based on distributed radar networks. Background Technology

[0002] Distributed radar is an important application area of ​​radar development. Realizing moving target indication is crucial for radar, and target detection methods have become a hot topic in radar signal processing research. The synthesis of stealth and weak targets is a major research direction for improving echo signal-to-noise ratio and achieving target detection. However, limited by the anti-jamming and survivability capabilities of single-base radars, synthesis methods based on distributed radar networks have attracted attention. Distributed radar has strong anti-jamming and survivability capabilities, enabling better detection of weak and stealth targets. However, during synthesis in a distributed radar network, due to different viewing angles at each station and varying target radar scattering coefficients, incomplete signal coherence occurs, leading to incomplete correlation of echoes from different stations and low synthesis gain.

[0003] In existing technologies, the GRFT algorithm is used to achieve coherent multi-pulse synthesis of separate echoes in a slow time dimension. Then, a set of target parameter (position, velocity, and acceleration) estimation coupling equations are constructed, and the target parameters are estimated by solving these equations. Finally, envelope alignment and phase compensation functions for the inter-channel echoes are constructed based on the estimated parameters to achieve coherent synthesis of the multi-channel echoes. However, this method does not consider the problem of different radar cross-sections caused by different viewing angles of the distributed radar, resulting in incomplete signal coherence, and thus does not achieve optimal synthesis results. Summary of the Invention

[0004] This invention provides a coherent-noncoherent signal hybrid synthesis method and apparatus based on a distributed radar network, which solves the problem of incomplete signal coherence in the prior art. It enables coherent synthesis within a group and noncoherent synthesis between groups, effectively improving the synthesis gain and enhancing the target detection capability.

[0005] This invention provides a method for coherent-noncoherent signal hybrid synthesis based on a distributed radar network, the method comprising: The echo signals from each receiving channel of the distributed radar network are acquired, the multiple echo signals are mixed to obtain multiple baseband signals, and the baseband signals are pulse compressed to obtain pulse compressed signals. Phase parameter estimation and time delay parameter estimation are performed on the pulse compressed signal, and the signal envelope phase alignment is performed on the pulse compressed signal based on the phase parameter estimation and the time delay parameter estimation to obtain the processed signal; The processed signals are grouped multiple times to obtain multiple sets of coherent groups, wherein each set of coherent groups includes multiple coherent groups; The processed signals in multiple coherent groups in the coherent group set are coherently synthesized to obtain multiple signal groups, and the multiple signal groups are non-coherently synthesized between the groups to obtain multiple mixed signals. Output the set of phase coherent groups corresponding to the mixed signal with the largest peak value among the multiple mixed signals.

[0006] In one possible implementation, the echo signal is specifically represented as:

[0007] in, , This indicates the time delay from the transmitter to the target; Indicates the first The time delay from the channel to the target; Indicates the phase caused by the channel arrangement; This represents a random variable affected by the perspective of the distributed radar.

[0008] In one possible implementation, the baseband signal is specifically represented as:

[0009] in, Indicates the echo signal; Indicates the local oscillator signal; This represents a random variable, affected by the perspective of the distributed radar; Represents a linear frequency modulated signal; Indicates the current moment; Indicates the first The time delay from the channel to the target; Indicates the carrier frequency of the transmitted signal; This indicates the phase caused by the channel arrangement.

[0010] In one possible implementation, the pulse-compressed signal is specifically represented as follows:

[0011] in, Represents convolution; Indicates the transmission signal The conjugate; , This represents a random variable, affected by the perspective of the distributed radar; This indicates the amplitude information following the pulse pressure.

[0012] In one possible implementation, the phase parameter estimate is expressed as:

[0013] The time delay parameter estimate is expressed as follows:

[0014] in, This indicates the estimated value from the transmitted signal to the [missing information]. Signal delay in the receiving channel; This represents the estimated time delay from transmitter to target. The estimated first The delay from the receiving channel to the target; The estimated first Phase of the receiving channel; This represents the estimated phase caused by the channel arrangement.

[0015] In one possible implementation, the processed signal is specifically represented as follows:

[0016] in, This represents the signal after pulse compression. Indicates the first The time delay from the channel to the target; Indicates the current moment; , This represents a random variable, affected by the perspective of the distributed radar; This indicates the estimated value from the transmitted signal to the [missing information]. Signal delay in the receiving channel; Indicates the phase caused by the channel arrangement; Indicates the carrier frequency of the transmitted signal; The estimated first Phase of the receiving channel.

[0017] In one possible implementation, dividing the processed signals into multiple coherent groups specifically includes: Calculating the number of processed signals in each coherent group specifically includes: defining the number of processed signals as... The number of coherent sets is expressed as The number of processed signals in each coherent group is expressed as follows: ;in, This represents the floor function; judge If the value is 0, then the multiple processed signals are evenly divided. Group; If not, the coherent group is divided into an integer coherent group and a remainder coherent group. The signal after equal distribution processing and the signal after remainder processing are calculated. The signal after equal distribution processing is evenly divided into the integer coherent group, and the signal after remainder processing is placed into the remainder coherent group. The sum of the signal after equal distribution processing and the signal after remainder processing is the processed signal.

[0018] In one possible implementation, the integer parameter set is specifically represented as:

[0019] in, This indicates the number of signals after processing; Indicates the number of coherent groups.

[0020] In one possible implementation, the hybrid information is specifically represented as:

[0021] in, This represents the function that takes the absolute value. This indicates a coherent signal.

[0022] In a second aspect, the present invention provides a coherent-noncoherent signal mixing and synthesis device based on a distributed radar network, the device comprising: The pulse compression signal acquisition module is used to acquire echo signals from each receiving channel of the distributed radar network, mix multiple echo signals to obtain multiple baseband signals, and pulse compress the baseband signals to obtain a pulse-compressed signal. The signal processing module is used to estimate the phase parameter and the time delay parameter of the pulse compressed signal, and to perform signal envelope phase alignment on the pulse compressed signal based on the phase parameter estimation and the time delay parameter estimation to obtain the processed signal; The computation module is used to divide the multiple processed signals into multiple coherent groups, perform coherent synthesis on the processed signals in the same coherent group to obtain multiple groups of signals, and perform non-coherent synthesis between the multiple groups of signals to obtain a mixed signal. The judgment module is used to determine whether the peak value of the mixed signal is greater than or equal to the first threshold. If so, multiple phase parameter groups are input; if not, the phase parameter groups are re-divided until the peak value of the mixed signal is greater than or equal to the first threshold.

[0023] One or more technical solutions provided in this invention have at least the following technical effects or advantages: This invention employs a coherent-noncoherent signal hybrid synthesis method and apparatus based on a distributed radar network. The method includes: acquiring echo signals from each receiving channel of the distributed radar network; mixing multiple echo signals to obtain multiple baseband signals; pulse compressing the baseband signals to obtain a pulse-compressed signal; acquiring multi-view pulse-compressed signals, which, compared to single-base radar, can detect weak and stealthy targets with high accuracy; estimating phase parameters and time delay parameters on the pulse-compressed signal; and aligning the signal envelope phase of the pulse-compressed signal based on the phase and time delay parameter estimates to obtain a processed signal; the time delay and phase estimation enable echo alignment of each channel; and grouping the multiple processed signals multiple times to obtain multiple coherent sets, wherein each phase... The parameter set includes multiple coherent groups. Multiple signals are obtained by coherently synthesizing the processed signals from each coherent group within the set, and then non-coherently synthesizing these signals between groups to obtain multiple mixed signals. Coherent synthesis within a group and non-coherent synthesis between groups effectively improve the synthesis gain and enhance target detection capability. The set of coherent groups corresponding to the mixed signal with the largest peak value among the multiple mixed signals is output. Different coherent combinations are performed on the processed signals within each group, resulting in different coherent processed signals and thus changing the final mixed signal, effectively improving the signal-to-noise ratio and enhancing target detection capability. This effectively solves the problem of incomplete signal coherence in existing technologies, thereby achieving coherent synthesis within groups and non-coherent synthesis between groups, effectively improving the synthesis gain and enhancing target detection capability. Attached Figure Description

[0024] 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 of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a flowchart of the steps of the coherent-noncoherent signal mixing and synthesis method based on a distributed radar network provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of a single-cycle mixing synthesis process provided in an embodiment of the present invention; Figure 3A This is a detection probability map of fully coherent signals in the echo signal provided in an embodiment of the present invention; Figure 3B This is a detection probability diagram of completely non-coherent signals in the echo signal provided in an embodiment of the present invention; Figure 3CThis is a detection probability diagram of a portion of the phase coherent signals in the echo signal provided in an embodiment of the present invention; Figure 4A This is a time-domain result diagram of coherent synthesis in the echo signal provided in an embodiment of the present invention; Figure 4B This is a time-domain result diagram of non-coherent synthesis in the echo signal provided in an embodiment of the present invention; Figure 4C The diagram shows the time-domain results of coherent-noncoherent hybrid synthesis of echo signals provided in this embodiment of the invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present 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 the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0027] Target detection systems based on distributed radar networks typically deploy radar transmitters and receivers over a large area on the ground to monitor target areas from multiple angles, offering advantages such as high positioning accuracy, strong anti-interference capabilities, and high survivability. They are particularly effective at detecting stealth or weak targets. However, due to the varying viewing angles of each station in a distributed radar system, the radar cross-section (RCS) of a target is often not a constant but rather a fluctuating random variable. The echo signals from each station generate additional envelope and phase information due to the different RCSs, resulting in incomplete coherence of the target echoes. This leads to a significant decrease in coherent synthesis gain, while non-coherent synthesis has a theoretically low gain and suffers from signal-to-noise ratio (SNR) threshold issues. Therefore, using either coherent or non-coherent synthesis methods is highly likely to result in insufficient synthesis gain. This invention proposes a coherent-non-coherent hybrid synthesis method based on a distributed radar network. The echoes from each channel are divided into several coherent synthesis groups. Then, coherent synthesis is performed on the echo signals within each group, while non-coherent synthesis is performed on the signals between groups. This effectively solves the problem of incomplete coherence signals generated by distributed radar due to different viewing angles, and the low gain of coherent or non-coherent synthesis. The synthesis gain was increased, achieving the maximum signal-to-noise ratio improvement.

[0028] This invention provides a method for coherent-noncoherent signal hybrid synthesis based on distributed radar networks, such as... Figure 1 The method shown includes the following steps S101 to S105.

[0029] S101: Acquire echo signals from each receiving channel of the distributed radar network, mix multiple echo signals to obtain multiple baseband signals, and perform pulse compression on the baseband signals to obtain pulse-compressed signals.

[0030] In a specific embodiment provided by the present invention, the transmitted signal is specifically represented as follows:

[0031] in, Represents a linear frequency modulated signal. ; Indicates the carrier frequency of the transmitted signal; Indicates the current moment.

[0032] The echo signal is specifically represented as follows:

[0033] in, , This indicates the time delay from the transmitter to the target; Indicates the first The time delay from the channel to the target; Indicates the phase caused by the channel arrangement; This represents a random variable, affected by the viewing angle of the distributed radar. In the echo signal... Let represent a random variable, influenced by the perspective of the distributed radar, the th Receiving station and the The correlation coefficient of the receiving station is:

[0034] in At the speed of light, and These represent different perspectives from the two stations.

[0035] The baseband signal is specifically represented as:

[0036] in, Indicates the echo signal; Indicates the local oscillator signal; This represents a random variable, affected by the perspective of the distributed radar; Represents a linear frequency modulated signal; Indicates the current moment; Indicates the first The time delay from the channel to the target; Indicates the carrier frequency of the transmitted signal; This indicates the phase caused by the channel arrangement.

[0037] The pulse compression signal is specifically represented as follows:

[0038] in, Represents convolution; Indicates the transmission signal The conjugate; , This represents a random variable, affected by the perspective of the distributed radar; This indicates the amplitude information following the pulse pressure.

[0039] In target detection technology, the distributed network system proposed in this invention has superior anti-interference capability and stronger survivability. Due to its multi-view pulse synthesis, it has a greater advantage in detecting stealth targets or weak targets compared to single-base radar.

[0040] In a specific embodiment provided by the present invention, it is assumed that there are a total There are one receiving channel, that is, Each echo signal, respectively for Perform the S101 operation on each signal to obtain The pulse-compressed signal is then processed by S101. After this process, the pulse-compressed signal is sent back to the data fusion processing center.

[0041] The data processing center performs operations S102 to S104 on the pulse-compressed signal.

[0042] S102, perform phase parameter estimation and time delay parameter estimation on the pulse compressed signal, and perform signal envelope phase alignment on the pulse compressed signal based on the phase parameter estimation and time delay parameter estimation to obtain the processed signal.

[0043] The phase parameter estimate is expressed as:

[0044] The time delay parameter estimate is expressed as:

[0045] The processed signal is specifically represented as follows:

[0046] in, This represents the signal after pulse compression. Indicates the first The time delay from the channel to the target; This indicates the estimated value from the transmitted signal to the [missing information]. Signal delay in the receiving channel; Indicates the current moment; , This represents a random variable, affected by the perspective of the distributed radar; Indicates the phase caused by the channel arrangement; This represents the estimated phase due to the channel arrangement; Indicates the carrier frequency of the transmitted signal; The estimated first Phase of the receiving channel; This represents the estimated time delay from transmitter to target.

[0047] S103, group the multiple processed signals into multiple sets of coherent groups, wherein each set of coherent groups includes multiple coherent groups.

[0048] In step S103, the multiple processed signals are divided into multiple coherent groups, specifically including: (1) Calculate the number of processed signals in each coherent group, specifically including: setting the number of processed signals as... The number of coherent sets is expressed as The number of processed signals in each coherent group is represented as: ;in, This represents the function for rounding up.

[0049] (2)Judgment If the value is 0, then the multiple processed signals are evenly divided. If not, divide the coherent group into an integer coherent group and a remainder coherent group. Calculate the signal after equal distribution processing and the signal after remainder processing. Evenly distribute the evenly distributed signal into the integer coherent group, and place the remainder processed signal into the remainder coherent group. The sum of the evenly distributed signal and the remainder processed signal is the processed signal. The integer coherent group is specifically represented as follows: The remainder coherent set is specifically represented as: .

[0050] S104: Perform coherent synthesis on the processed signals in multiple coherent groups in the coherent group set to obtain multiple signal sets, and perform non-coherent synthesis between the multiple signal sets to obtain multiple mixed signals.

[0051] In step S104, the mixed signal is specifically represented as follows:

[0052] in, This represents the function that takes the absolute value. This indicates a coherent signal.

[0053] In distributed network radar signal synthesis technology, the hybrid synthesis method proposed in this invention can solve the problem of incomplete signal coherence caused by different perspectives of various stations, and can achieve higher synthesis gain. Furthermore, in the hybrid synthesis technology, the group search technique proposed in this invention can achieve optimal grouping of coherent signals, effectively improving the signal-to-noise ratio and enhancing target detection capabilities.

[0054] S105 outputs the set of coherent groups corresponding to the mixed signal with the largest peak value among multiple mixed signals.

[0055] In a specific embodiment of the present invention, combining steps S103 and S105, , ,like Figure 2 The diagram shows a single loop, which divides the 10 processed signals into 4 groups: the first coherent group contains the first to third processed signals, the second coherent group contains the fourth to sixth processed signals, the last coherent group contains the seventh to ninth processed signals, and the fourth coherent group contains the tenth processed signal.

[0056] The processed signals within the group are coherently synthesized to form a coherent signal. , coherent signal Represented as:

[0057] in Indicates the assumption that The signals from each channel are coherent signals, and the resulting signal is obtained after coherent synthesis. This refers to the number of channels within the coherent group, which is equivalent to the number of processed signals within the coherent group. Desirable , This refers to the total number of channels in a distributed radar network, i.e., the number of processed signals.

[0058] Next, noncoherent synthesis is performed between coherent groups according to the noncoherent formula to obtain a mixed signal.

[0059] Again , Therefore, the 10 processed signals are divided into 5 groups, that is, the 10 processed signals are evenly divided into 5 groups, with two processed signals in each group.

[0060] Next, noncoherent synthesis is performed between coherent groups according to the formula for noncoherent synthesis to obtain a mixed signal.

[0061] For the peak values ​​of multiple mixed signals, determine the number of processed signals in each coherent group corresponding to the maximum peak value.

[0062] In a specific embodiment provided by the present invention Figure 3A , Figure 3B , Figure 3CThe lines represent the detection probabilities under fully coherent, fully non-coherent, and partially coherent signal conditions, respectively. The lines with triangles represent the change in target detection probability with signal-to-noise ratio using coherent synthesis; the lines with model numbers represent non-coherent synthesis; and the lines with circles represent hybrid synthesis. It is evident that in the context of distributed radar network applications, where the echo signal is partially coherent, the proposed coherent-non-coherent hybrid synthesis method will achieve optimal synthesis and the highest detection probability.

[0063] A schematic diagram of the hybrid synthesis simulation echo experimental results proposed in this invention is shown below. Figure 4A , Figure 4B , Figure 4C As shown, the time-domain waveforms of incompletely coherent signals in coherent synthesis, non-coherent synthesis, and the coherent-non-coherent hybrid synthesis method proposed in this invention are respectively represented. It can be seen that the hybrid synthesis method proposed in this invention can achieve better synthesis effect for distributed radar network echoes.

[0064] This invention can be applied to target detection in distributed radar networks. As a new type of radar, distributed radar networks achieve high-power, high-precision detection through multi-station distributed deployment and electromagnetic wave spatial energy synthesis. It can detect stealth and weak targets, and is an effective means to resolve the contradiction between platform constraints and detection performance. It has technical advantages such as strong survivability, high cost-effectiveness, high angular resolution, strong scalability, and good implementation, making it an important direction for radar development. It is widely used in ballistic missile defense, space target surveillance, and deep space exploration. However, distributed radar network applications suffer from problems such as time delay, phase estimation, envelope and phase alignment, and signal synthesis, all of which affect its detection performance.

[0065] This invention proposes a distributed network-based coherent-noncoherent hybrid synthesis technique, primarily addressing the problem of low synthesis gain caused by incomplete signal coherence. Incomplete signal coherence arises because different viewing angles at each station result in varying target radar scattering interfaces, leading to different phase and envelope information added to each echo. This severely impacts the synthesis gain during coherent or noncoherent synthesis. The proposed distributed radar network-based coherent-noncoherent hybrid synthesis method transmits compressed pulse signals from each station back to the data center for time-delay phase estimation. Envelope phase alignment is performed on each echo, eliminating phase and envelope variations caused by station arrangement, retaining only the additional phase and envelope information resulting from different radar cross-sections due to varying viewing angles. The echo signals from each channel are coherently synthesized into groups, with coherent synthesis within each group and noncoherent synthesis between groups, effectively improving synthesis gain and target detection capabilities. This method has supplementary significance and practical value in applications involving the detection of stealth and weak targets. Next, the optimal coherent synthesis group is determined by searching. All channel echo signals are grouped, and coherent synthesis is performed within each group, while non-coherent synthesis is performed between groups to achieve the optimal synthesis.

[0066] This invention provides a coherent-noncoherent signal hybrid synthesis device based on a distributed radar network. The device includes: a pulse compression signal acquisition module, a signal processing module, a grouping module, a calculation module, and an output module.

[0067] The pulse compression signal acquisition module is used to acquire echo signals from each receiving channel of the distributed radar network, mix multiple echo signals to obtain multiple baseband signals, and then pulse compress the baseband signals to obtain the pulse-compressed signal.

[0068] The signal processing module is used to estimate the phase parameter and time delay parameter of the pulse compressed signal, and to perform signal envelope phase alignment on the pulse compressed signal based on the phase parameter estimation and time delay parameter estimation to obtain the processed signal.

[0069] The grouping module is used to group multiple processed signals into multiple sets of coherent groups, where each set of coherent groups includes multiple coherent groups.

[0070] The computation module is used to perform coherent synthesis on the processed signals in multiple coherent groups in the coherent group set to obtain multiple sets of signals, and to perform non-coherent synthesis between the multiple sets of signals to obtain multiple mixed signals.

[0071] The output module is used to output the set of phase coherent groups corresponding to the mixed signal with the largest peak value among multiple mixed signals.

[0072] The proposed coherent-noncoherent hybrid synthesis method based on a distributed radar network transmits compressed pulse signals from each station back to a data center for time delay and phase estimation. Envelope phase alignment is performed on each echo to eliminate phase and envelope variations caused by the station's arrangement, retaining only the additional phase and envelope resulting from differences in radar cross-section due to varying viewing angles at each station. Next, an optimal coherent synthesis group is determined through a search method. All channel echo signals are grouped, with coherent synthesis performed within each group and noncoherent synthesis performed between groups to achieve optimal synthesis.

[0073] Some modules in the apparatus described in this invention can be described in the general context of computer-executable instructions that are executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc., that perform a specific task or implement a specific abstract data type. This invention can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0074] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software and necessary hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, or it can be embodied in the process of data migration. The computer software product can be stored in a 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, mobile terminal, server, or network device, etc.) to execute the methods described in various embodiments or some parts of the embodiments of the present invention.

[0075] The various embodiments described in this specification are presented in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. All or part of this invention can be used in numerous general-purpose or special-purpose computer system environments or configurations. Examples include: personal computers, server computers, handheld or portable devices, tablet devices, mobile communication terminals, multiprocessor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, and distributed computing environments including any of the above systems or devices, etc.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the present invention. 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

Claims

1. A method for coherent-noncoherent signal hybrid synthesis based on a distributed radar network, characterized in that, include: The echo signals from each receiving channel of the distributed radar network are acquired, the multiple echo signals are mixed to obtain multiple baseband signals, and the baseband signals are pulse compressed to obtain pulse compressed signals. Phase parameter estimation and time delay parameter estimation are performed on the pulse compressed signal, and the signal envelope phase alignment is performed on the pulse compressed signal based on the phase parameter estimation and the time delay parameter estimation to obtain the processed signal; The processed signals are grouped multiple times to obtain multiple sets of coherent groups, wherein each set of coherent groups includes multiple coherent groups; The processed signals in multiple coherent groups in the coherent group set are coherently synthesized to obtain multiple signal groups, and the multiple signal groups are non-coherently synthesized between the groups to obtain multiple mixed signals. Output the set of phase coherent groups corresponding to the mixed signal with the largest peak value among the multiple mixed signals.

2. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The echo signal is specifically represented as follows: in, , This indicates the time delay from the transmitter to the target; Indicates the first The time delay from the channel to the target; Indicates the phase caused by the channel arrangement; This represents a random variable, affected by the perspective of the distributed radar; Indicates the current moment. Indicates the carrier frequency of the transmitted signal. Represents a linear frequency modulated signal; Indicates the distance from the transmitter to the target after reflection. Total latency of the receiving channel.

3. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The baseband signal is specifically represented as follows: in, Indicates the local oscillator signal; This represents a random variable, affected by the perspective of the distributed radar; Represents a linear frequency modulated signal; Indicates the current time; Indicates the distance from the transmitter to the target after reflection. Total latency of the receiving channel ,in This indicates the time delay from the transmitter to the target. Indicates the first The time delay from the channel to the target; Indicates the carrier frequency of the transmitted signal; Indicates the phase caused by the channel arrangement; Indicates the first The echo signal of the channel.

4. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The pulse-compressed signal is specifically represented as follows: in, Represents convolution; Indicates the transmission signal The conjugate; , This represents a random variable, affected by the perspective of the distributed radar; This indicates the amplitude information following the pulse pressure; Indicates the first The echo signal of the channel; Indicates the current time; Indicates the distance from the transmitter to the target after reflection. Total latency of the receiving channel ,in This indicates the time delay from the transmitter to the target. Indicates the first The time delay from the channel to the target; Indicates the carrier frequency of the transmitted signal; Represents a linear frequency modulated signal; This indicates the phase caused by the channel arrangement.

5. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The phase parameter estimate is expressed as: The time delay parameter estimate is expressed as follows: in, This indicates the estimated value from the transmitted signal to the [missing information]. Signal delay in the receiving channel; This represents the estimated time delay from transmitter to target. The estimated first The delay from the receiving channel to the target; The estimated first Phase of the receiving channel; This represents the estimated phase due to the channel arrangement; Indicates the carrier frequency of the transmitted signal.

6. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The processed signal is specifically represented as follows: in, This represents the signal after pulse compression. Indicates the first The time delay from the channel to the target; Indicates the current time; , This represents a random variable, affected by the perspective of the distributed radar; This indicates the estimated value from the transmitted signal to the [missing information]. Signal delay in the receiving channel; Indicates the phase caused by the channel arrangement; Indicates the carrier frequency of the transmitted signal; The estimated first Phase of the receiving channel; Indicates the current time; This indicates the amplitude information following the pulse pressure; This represents the estimated phase due to the channel arrangement.

7. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The step of dividing the processed signals into multiple coherent groups specifically includes: Calculating the number of processed signals in each coherent group specifically includes: defining the number of processed signals as... The number of coherent sets is expressed as The number of processed signals in each coherent group is expressed as follows: ;in, This represents the floor function; judge If the value is 0, then the multiple processed signals are evenly divided. Group; If not, the coherent group is divided into an integer coherent group and a remainder coherent group. The signal after equal distribution processing and the signal after remainder processing are calculated. The signal after equal distribution processing is evenly divided into the integer coherent group, and the signal after remainder processing is placed into the remainder coherent group. The sum of the signal after equal distribution processing and the signal after remainder processing is the processed signal.

8. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 7, characterized in that, The integer coherent set is specifically represented as follows: in, This indicates the number of signals after processing; Indicates the number of coherent groups.

9. The coherent-noncoherent signal hybrid synthesis method based on a distributed radar network according to claim 1, characterized in that, The mixed signal is specifically represented as follows: in, This represents the function that takes the absolute value. This indicates a coherent signal.

10. A coherent-noncoherent signal hybrid synthesis device based on a distributed radar network, characterized in that, include: The pulse compression signal acquisition module is used to acquire echo signals from each receiving channel of the distributed radar network, mix multiple echo signals to obtain multiple baseband signals, and pulse compress the baseband signals to obtain a pulse-compressed signal. The signal processing module is used to estimate the phase parameter and the time delay parameter of the pulse compressed signal, and to perform signal envelope phase alignment on the pulse compressed signal based on the phase parameter estimation and the time delay parameter estimation to obtain the processed signal; The grouping module is used to group the multiple processed signals multiple times to obtain multiple sets of coherent groups, wherein each set of coherent groups includes multiple coherent groups; The computation module is used to perform coherent synthesis on the processed signals in multiple coherent groups in the coherent group set to obtain multiple sets of signals, and to perform non-coherent synthesis between the multiple sets of signals to obtain multiple mixed signals. The output module is used to output the set of phase coherent groups corresponding to the mixed signal with the largest peak value among the multiple mixed signals.

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