CN112740068A

CN112740068A - Signal processing method and device

Info

Publication number: CN112740068A
Application number: CN202080005168.5A
Authority: CN
Inventors: 朱金台; 劳大鹏; 李德建; 杨晨
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-04-14
Filing date: 2020-04-14
Publication date: 2021-04-30
Anticipated expiration: 2040-04-14
Also published as: CN112740068B; WO2021207929A1; WO2021207929A9

Abstract

The application provides a method and a device for processing signals, which can improve the efficiency of processing signals. The method comprises the following steps: acquiring M multiplied by N groups of signals, wherein the M multiplied by N groups of signals correspond to M multiplied by N channel combinations one by one, and the M multiplied by N channel combinations are channel combinations respectively formed by M transmitting channels and N receiving channels; performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms; performing phase compensation on complex signals of a plurality of first spectrograms to obtain a plurality of second spectrograms, wherein the plurality of first spectrograms correspond to the plurality of second spectrograms in a one-to-one manner, and the phase compensation comprises at least one of the following steps: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels; and carrying out complex addition on the complex signals based on the plurality of second frequency spectrograms to obtain the accumulated frequency spectrograms.

Description

Signal processing method and device

Technical Field

The present application relates to the field of communications, and in particular, to a signal processing method and apparatus.

Background

In some communication systems, there are multiple transmit channels or multiple receive channels between the transmit end and the receive end to form multiple signal transmission paths. For example, the communication system may include: a Multiple Input Multiple Output (MIMO) system, a Single Input Multiple Output (SIMO) system, a Multiple Input Single Output (MISO) system, and the like.

In a scenario of signal transmission based on these communication systems, after a receiving end receives signals through multiple paths, it is necessary to perform spectrum analysis on signals acquired through different paths respectively to obtain multiple frequency spectrograms. The spectral analysis includes, for example, a Fast Fourier Transform (FFT), a doppler dimension FFT, an angle dimension FFT, and the like. The receiving end can accumulate the spectrograms corresponding to different approaches to obtain the accumulated spectrograms, and continue to perform subsequent signal processing. Such as Constant False Alarm Rate (CFAR), direction of arrival (DOA), and tracking.

When a plurality of frequency spectrogram are accumulated, a plurality of accumulation modes exist. For example, coherent accumulation, non-coherent accumulation, or partially coherent accumulation may be used. The coherent accumulation or partial coherent accumulation can improve the accumulation gain of the signal, but the spectrum analysis is needed for performing the correlation accumulation, so that the calculation complexity is high, and the consumption of calculation resources is large.

Disclosure of Invention

The application provides a method and a device for processing signals, which can improve the efficiency of processing signals.

In a first aspect, a method of signal processing is provided, including: acquiring M × N groups of signals, wherein the M × N groups of signals correspond to M × N channel combinations one by one, the M × N channel combinations are channel combinations respectively formed by M transmitting channels and N receiving channels, and M, N is a positive integer; performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms; performing phase compensation on complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, wherein the plurality of first spectrograms correspond to the plurality of second spectrograms in a one-to-one manner, and the phase compensation comprises at least one of the following steps: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels; and carrying out complex addition on the basis of the complex signals of the plurality of second frequency spectrograms to obtain the accumulated frequency spectrograms.

In this embodiment, after the receiving end acquires the plurality of first spectrograms, the receiving end may perform phase compensation of the receiving channel or the transmitting channel on the plurality of first spectrograms, and obtain a plurality of second spectrograms. The second spectrogram after phase compensation can eliminate the phase difference of complex signals caused by different receiving channels or different transmitting channels, so that the accumulation gain of the spectrogram obtained by accumulating the complex signals in a plurality of second spectrograms is larger, and the efficiency of processing signals can be improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, before performing phase compensation on the complex signals of the plurality of first spectrograms, the method further includes: performing amplitude normalization on the complex signals in the plurality of first spectrograms.

In the embodiment of the present application, amplitude normalization is performed before phase compensation is performed on the complex signals of the plurality of first spectrograms, so as to improve the accuracy of the phase compensation, thereby improving the signal processing efficiency.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing phase compensation on complex signals of the plurality of first spectrograms includes: performing phase compensation of a receiving channel on at least a portion of the first spectrograms so that the phases of complex signals of at least two of the second spectrograms at the same position are the same; or, performing phase compensation of a transmission channel on at least a part of the plurality of first spectrograms so that the phases of the complex signals of at least two of the plurality of second spectrograms at the same position are the same.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing phase compensation on complex signals of the plurality of first spectrograms includes: dividing the plurality of first spectrogram groups into at least one first spectrogram group, wherein the first spectrogram included in each first spectrogram group corresponds to the same transmission channel; performing phase compensation of a receiving channel on the first spectrograms in each first spectrogram group, so that the phases of complex signals of the first spectrograms and the first target spectrograms in the same position in each first spectrogram group are the same, wherein at least one spectrogram group corresponds to at least one first target spectrogram one by one, and the at least one first target spectrogram corresponds to the same receiving channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the receiving channel.

In the embodiment of the present application, through phase compensation of a receiving channel, phases of complex signals of a first spectrogram of each first spectrogram group and a first target spectrogram are the same, at least one first spectrogram group corresponds to at least one first target spectrogram one to one, and at least one first target spectrogram corresponds to the same receiving channel, so that a phase difference between the first spectrograms in the at least one first spectrogram group due to different receiving channels can be eliminated, and an accumulation gain during signal accumulation is improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, the determining the plurality of second spectrograms according to a plurality of first spectrograms after performing phase compensation on the receiving channel includes: determining a plurality of first spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the receiving channel as a plurality of third spectrograms; performing phase compensation of a transmission channel on the plurality of third spectrograms so that the phase of the complex signal of the plurality of third spectrograms is the same as the phase of the complex signal of a second target spectrogram, wherein the second target spectrogram is any one of the plurality of third spectrograms; determining a plurality of third spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms.

In the embodiment of the application, the phase compensation of the transmitting channel enables the phases of the complex signals of the plurality of third frequency spectrograms and the second target spectrogram to be the same, so that the phase difference caused by the fact that the receiving channels are different and the transmitting channels are different of the plurality of third frequency spectrograms can be eliminated, and the accumulation gain during signal accumulation is improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing phase compensation on complex signals of the plurality of first spectrograms includes: dividing the plurality of first spectrogram groups into at least one second spectrogram group, wherein the first spectrogram included in each second spectrogram group corresponds to the same receiving channel; performing phase compensation of a transmission channel on the first spectrogram in each second spectrogram group, so that the phase of the complex signal of the first spectrogram in each second spectrogram group and a phase of a complex signal of a third target spectrogram in the same position are the same, wherein the at least one second spectrogram group corresponds to at least one third target spectrogram in a one-to-one manner, and the at least one third target spectrogram corresponds to the same transmission channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the transmission channel.

In the embodiment of the present application, through phase compensation of a transmission channel, phases of complex signals of a first spectrogram and a third spectrogram of each second spectrogram group are the same, at least one second spectrogram group corresponds to at least one third target spectrogram one to one, and at least one third target spectrogram corresponds to the same transmission channel, so that a phase difference between the first spectrograms of the at least one second spectrogram group due to different transmission channels can be eliminated, and an accumulation gain during signal accumulation is improved.

With reference to the first aspect, in a possible implementation manner of the first aspect, the determining the plurality of second spectrograms according to a plurality of first spectrograms after performing phase compensation on the transmission channel includes: determining a plurality of first spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the transmission channel as a plurality of fourth spectrograms; performing phase compensation of a receiving channel on the plurality of fourth spectrograms so that a phase of a complex signal of the plurality of fourth spectrograms is the same as a phase of a complex signal of a fourth target spectrogram, wherein the fourth target spectrogram is any one of the plurality of fourth spectrograms; determining a plurality of fourth spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing spectrum analysis on the mxn groups of signals to obtain a plurality of first spectrograms includes: performing at least one type of spectral analysis on the M x N sets of signals to obtain the plurality of first spectrograms: distance dimension FFT, doppler dimension FFT, angle dimension FFT.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing spectrum analysis on the mxn groups of signals to obtain a plurality of first spectrograms includes: performing distance dimension FFT on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing Doppler dimension FFT on the range spectrograms to obtain M multiplied by N range-Doppler FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N range-Doppler FFT spectrograms.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing spectrum analysis on the mxn groups of signals to obtain a plurality of first spectrograms includes: performing distance dimension FFT transformation on the M multiplied by N groups of signals to acquire M multiplied by N distance FFT spectrograms, wherein the first spectrogram is the M multiplied by N distance FFT spectrograms.

With reference to the first aspect, in a possible implementation manner of the first aspect, the performing complex addition on the complex signals based on the plurality of second spectrograms to obtain an accumulated spectrogram includes: performing a doppler dimension FFT on the second plurality of spectrograms to obtain a plurality of range-doppler FFT spectrograms; and performing complex addition on the plurality of range-Doppler FFT spectrograms to obtain the accumulated spectrogram.

With reference to the first aspect, in a possible implementation manner of the first aspect, after the complex signals based on the plurality of second spectrograms are subjected to complex addition to obtain an accumulated spectrogram, the method further includes: and performing Doppler dimension FFT on the accumulated spectrogram to obtain a range-Doppler FFT spectrogram.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing spectrum analysis on the mxn groups of signals to obtain a plurality of first spectrograms includes: performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms; dividing the MxN fifth spectrograms into M spectrogram groups, wherein N fifth spectrograms included in each spectrogram group correspond to the same transmitting channel; performing coherent accumulation on each spectrogram group in the M spectrogram groups by using spectrum analysis to obtain M spectrograms, wherein the M spectrograms are the plurality of first spectrograms.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing phase compensation on the plurality of first spectrograms to obtain a plurality of second spectrograms includes: and performing phase compensation of a transmission channel on the plurality of first spectrograms so as to enable phases of complex signals of the plurality of second spectrograms at the same position after phase compensation to be the same.

With reference to the first aspect, in a possible implementation manner of the first aspect, performing spectrum analysis on the mxn groups of signals to obtain mxn fifth spectrograms includes: performing distance dimension FFT transformation on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing doppler dimension FFT on the M × N range FFT spectrograms to obtain M × N range-doppler FFT spectrograms, where the M × N fifth spectrograms are the M × N range-doppler FFT spectrograms.

In a second aspect, there is provided an apparatus for signal processing, comprising: an obtaining unit, configured to obtain M × N groups of signals, where the M × N groups of signals correspond to M × N channel combinations in a one-to-one manner, the M × N channel combinations are channel combinations respectively formed by M transmitting channels and N receiving channels, and M, N is a positive integer; a processing unit for performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms; the processing unit is further configured to perform phase compensation on the complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, where the plurality of first spectrograms correspond to the plurality of second spectrograms one to one, and the phase compensation includes at least one of: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels; the processing unit is further configured to perform complex addition based on the complex signals of the plurality of second spectrograms to obtain an accumulated spectrogram.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is further configured to perform amplitude normalization on the complex signals in the plurality of first spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to perform phase compensation of a receiving channel on at least part of the first spectrograms, so that phases of complex signals of at least two of the second spectrograms at the same position are the same; or, performing phase compensation of a transmission channel on at least a part of the plurality of first spectrograms so that the phases of the complex signals of at least two of the plurality of second spectrograms at the same position are the same.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: dividing the plurality of first spectrogram groups into at least one first spectrogram group, wherein the first spectrogram included in each first spectrogram group corresponds to the same transmission channel; performing phase compensation of a receiving channel on the first spectrograms in each first spectrogram group, so that the phases of complex signals of the first spectrograms and the first target spectrograms in the same position in each first spectrogram group are the same, wherein at least one spectrogram group corresponds to at least one first target spectrogram one by one, and the at least one first target spectrogram corresponds to the same receiving channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the receiving channel.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: determining a plurality of first spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the receiving channel as a plurality of third spectrograms; performing phase compensation of a transmission channel on the plurality of third spectrograms so that the phase of the complex signal of the plurality of third spectrograms is the same as the phase of the complex signal of a second target spectrogram, wherein the second target spectrogram is any one of the plurality of third spectrograms; determining a plurality of third spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: dividing the plurality of first spectrogram groups into at least one second spectrogram group, wherein the first spectrogram included in each second spectrogram group corresponds to the same receiving channel; performing phase compensation of a transmission channel on the first spectrogram in each second spectrogram group, so that the phase of the complex signal of the first spectrogram in each second spectrogram group and a phase of a complex signal of a third target spectrogram in the same position are the same, wherein the at least one second spectrogram group corresponds to at least one third target spectrogram in a one-to-one manner, and the at least one third target spectrogram corresponds to the same transmission channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the transmission channel.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: determining a plurality of first spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the transmission channel as a plurality of fourth spectrograms; performing phase compensation of a receiving channel on the plurality of fourth spectrograms so that a phase of a complex signal of the plurality of fourth spectrograms is the same as a phase of a complex signal of a fourth target spectrogram, wherein the fourth target spectrogram is any one of the plurality of fourth spectrograms; determining a plurality of fourth spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing at least one type of spectral analysis on the M x N sets of signals to obtain the plurality of first spectrograms: distance dimension FFT, doppler dimension FFT, angle dimension FFT.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing distance dimension FFT on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing Doppler dimension FFT on the range spectrograms to obtain M multiplied by N range-Doppler FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N range-Doppler FFT spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing distance dimension FFT transformation on the M multiplied by N groups of signals to acquire M multiplied by N distance FFT spectrograms, wherein the first spectrogram is the M multiplied by N distance FFT spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing a doppler dimension FFT on the second plurality of spectrograms to obtain a plurality of range-doppler FFT spectrograms; and performing complex addition on the plurality of range-Doppler FFT spectrograms to obtain the accumulated spectrogram.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: and performing Doppler dimension FFT on the accumulated spectrogram to obtain a range-Doppler FFT spectrogram.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms; dividing the MxN fifth spectrograms into M spectrogram groups, wherein N fifth spectrograms included in each spectrogram group correspond to the same transmitting channel; performing coherent accumulation on each spectrogram group in the M spectrogram groups by using spectrum analysis to obtain M spectrograms, wherein the M spectrograms are the plurality of first spectrograms.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: and performing phase compensation of a transmission channel on the plurality of first spectrograms so as to enable phases of complex signals of the plurality of second spectrograms at the same position after phase compensation to be the same.

With reference to the second aspect, in a possible implementation manner of the second aspect, the processing unit is specifically configured to: performing distance dimension FFT transformation on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing doppler dimension FFT on the M × N range FFT spectrograms to obtain M × N range-doppler FFT spectrograms, where the M × N fifth spectrograms are the M × N range-doppler FFT spectrograms.

In a third aspect, there is provided an apparatus having functionality to implement the method of the first aspect. These functions may be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units corresponding to the above functions.

In a fourth aspect, there is provided an apparatus comprising a memory for storing a computer program or instructions, a communication interface, and a processor coupled to the memory and the communication interface, which when executed by the processor, causes the apparatus to perform the method of the first aspect.

In a fifth aspect, there is provided a computer program product comprising: computer program code which, when run on a computer, causes the computer to perform the method of the first aspect described above.

In a sixth aspect, the present application provides a computer readable storage medium storing a computer program which, when executed, implements the method of the first aspect described above.

Drawings

Fig. 1 is a schematic diagram of a communication system in an embodiment of the present application.

Fig. 2 is a flow chart of signal processing.

Fig. 3 is a flowchart illustrating a signal processing method according to an embodiment of the present application.

Fig. 4 is a schematic diagram of signal accumulation in a receiving end including multiple receiving channels according to an embodiment of the present application.

Fig. 5 is a schematic diagram of different receiving channels receiving the same transmitted signal according to an embodiment of the present application.

Fig. 6 is a spectrum diagram corresponding to signals acquired through different channel combinations in a MIMO system.

Fig. 7 is a schematic diagram of a signal processing method according to an embodiment of the present application.

Fig. 8 is a schematic diagram of a signal processing method according to an embodiment of the present application.

Fig. 9 is a schematic diagram of a signal processing method according to an embodiment of the present application.

Fig. 10 is a schematic structural diagram of an apparatus for signal processing according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of an apparatus for signal processing according to an embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a future fifth generation (5th generation, 5G) system, a New Radio (NR), or the like.

Optionally, the technical solution of the embodiment of the present application may be applied to a MIMO system, a Single Input Multiple Output (SIMO) system, a Multiple Input Single Output (MISO) system, and the like. The following describes a technical solution of an embodiment of the present application by taking a MIMO system as an example.

Optionally, the technical scheme of the embodiment of the application can be applied to radar measurement scenarios and can also be applied to other communication scenarios.

Fig. 1 is a schematic diagram of a communication system in an embodiment of the present application. As shown in fig. 1, the communication system includes a receiving end 100 and a transmitting end 200. The receiving end 100 may include N receiving antennas, and each receiving antenna corresponds to one receiving channel. The transmitting end 200 includes M transmitting antennas, and each transmitting antenna corresponds to one transmitting channel. M and N are integers which are respectively greater than or equal to 1. The M transmit channels and the N receive channels form a combination of M × N transmit channels and receive channels. When the transmitting end 200 transmits a set of signals through M transmitting channels, respectively, for the receiving end 100, it can receive M × N sets of signals through N receiving channels.

The receiving end 100 further includes a processor 110, and after receiving the M × N groups of signals, the processor 110 may perform signal processing on the M × N groups of signals, for example, may sample the M × N groups of signals and perform processing such as spectrum analysis and accumulation on sampled data.

The processor 110 may include a Central Processing Unit (CPU), a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), or other types of processing chips.

It should be understood that in the embodiment of the present application, the receiving end 100 and the transmitting end 200 may be located in different devices, or may be located in the same device. For example, in some radar ranging scenarios, the receiving end 100 and the transmitting end 200 may be located in the same device, and a signal transmitted by the receiving end 100 is reflected after encountering a target object, and then the reflected signal is received by the transmitting end 200.

Fig. 2 is a flow chart of signal processing, which illustrates a signal processing flow at a receiving end, taking a radar measurement scenario as an example. The steps in fig. 2 may be performed by processor 110 in fig. 1. As shown in fig. 2, after the receiving end acquires multiple sets of signals through multiple channel combinations, the receiving end may perform spectrum analysis on the multiple sets of signals respectively to obtain a spectrogram corresponding to the multiple sets of signals. The above-mentioned spectral analysis may include, for example and without limitation, at least one of the following types: discrete Fourier Transform (DFT), FFT, multiple signal classification (MUSIC), Digital Beam Forming (DBF) as examples, FFT may include distance dimension FFT, doppler dimension FFT, or angle dimension FFT.

After the spectrum analysis, the processor 110 may perform an accumulation process on the complex signals in the plurality of spectrograms to obtain an accumulated spectrogram. By performing accumulation processing on a plurality of frequency spectrogram, the accumulation gain of the signal can be improved, and the signal-to-noise ratio of the signal can be improved.

After acquiring the accumulated spectrogram, the processor 110 may continue with subsequent signal processing, such as CFAR processing, DOA estimation, tracking, and so on.

The spectrogram is used for representing the representation form of a signal in a time domain in a frequency domain, and can be obtained by performing spectrum analysis on the signal. Spectrograms may be used to represent the varying relationship between the amplitude or phase of a signal and the spectrum. In some cases, the spectrogram can also represent the relationship between the amplitude or phase of a signal and the distance, velocity or angle of an observation target, with an appropriate transformation, since there is a correspondence between the signal spectrum and the distance, velocity or angle of the observation target. For example, if the spectrogram is obtained by FFT, the spectrogram may be referred to as a range FFT spectrogram, a doppler FFT spectrogram, an angle FFT spectrogram, a range-doppler FFT spectrogram, or the like, a range-angle FFT spectrogram, or the like, according to different information represented by the spectrogram.

Wherein the spectrogram can be represented by a plurality of complex signals, each complex signal comprising phase information, amplitude information and frequency information of the signal.

In the accumulation of complex signals in multiple spectrograms, coherent accumulation or partially coherent accumulation may be adopted. However, coherent accumulation or partially coherent accumulation generally requires correlation accumulation by using a spectrum analysis method, and has high computational complexity and large consumption of computational resources.

In order to solve the above problem, an embodiment of the present application provides a signal processing method, which can further reduce the computational complexity of signal processing and save computational resources while using a coherent accumulation method for signals, so that the signal processing method is suitable for a system with high real-time requirement and limited power consumption and computational power.

Fig. 3 is a flowchart illustrating a signal processing method according to an embodiment of the present application. The method of fig. 3 may be performed by the receiving end 100 in fig. 1, for example, may be performed by the processor 110 in the receiving end 100. As shown in fig. 3, the method includes:

s301, obtaining M × N groups of signals, wherein the M × N groups of signals correspond to M × N channel combinations one by one, the M × N channel combinations are channel combinations formed by M transmitting channels and N receiving channels, and M, N is a positive integer.

Alternatively, each of the M × N sets of signals may include K signals, where K is an integer greater than or equal to 1. Alternatively, the signals in each of the mxn sets of signals may be a chamois (chirp) signal. Alternatively, the signals in each of the M × N sets of signals may be signals using other unit metrics.

Alternatively, N receive channels may correspond to N receive antennas and M transmit channels may correspond to M transmit antennas.

S302, performing spectrum analysis on the mxn groups of signals to obtain a plurality of first spectrograms.

Spectral analysis refers to estimating the characteristics of an object or a signal by measuring the frequency spectrum of the signal. For example, in radar measurements, spectral analysis may be used to estimate the range, velocity, or angle of a signal or target.

Optionally, the performing the spectral analysis may include, but is not limited to, at least one of: DFT, FFT, DFT, MUSIC, DBF. The above FFT may include, but is not limited to, at least one of: distance dimension FFT, doppler dimension FFT, angle dimension FFT.

In some examples, the performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms as described above includes: performing distance dimension FFT on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing Doppler dimension FFT on the M multiplied by N range FFT spectrograms to obtain M multiplied by N range-Doppler FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N range-Doppler FFT spectrograms.

In some examples, the performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms as described above includes: and performing distance dimension FFT (fast Fourier transform) on the M multiplied by N groups of signals to acquire M multiplied by N distance FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N distance FFT spectrograms.

Optionally, the performing the spectral analysis further comprises: and obtaining a plurality of spectrograms by utilizing spectrum analysis, grouping the plurality of spectrograms, and performing coherent accumulation on the complex signals in each group of spectrograms to obtain a plurality of accumulated spectrograms. For example, each set of spectrograms may be coherently accumulated for the receive channel using spectral analysis, where coherent accumulation for the receive channel refers to coherent accumulation of complex signals in the spectrograms corresponding to the same transmit channel and different receive channels.

In some examples, performing spectral analysis on the M × N sets of signals to obtain a plurality of first spectrograms includes: performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms; dividing the M multiplied by N fifth spectrograms into M spectrogram groups, wherein N fifth spectrograms included in each spectrogram group correspond to the same transmitting channel; and performing coherent accumulation on each spectrogram group in the M spectrogram groups by utilizing spectrum analysis to obtain M spectrograms, wherein the M spectrograms are a plurality of first spectrograms.

S303, performing phase compensation on the complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, where the plurality of first spectrograms correspond to the plurality of second spectrograms one to one.

The phase compensation is to estimate and compensate the phase difference between signals caused by different receiving channels, different transmitting channels or different signal transmitting times, so as to achieve the purpose that the phases of the signals acquired through different paths are approximately consistent.

In some examples, the phase compensation includes at least one of: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels.

In the embodiment of the present application, a phase difference caused by different receiving channels, different transmitting channels, or signal transmitting time may be calculated by using a formula, and the phase of the complex signal may be compensated. Hereinafter, the manner of phase compensation of the receiving channel or the transmitting channel according to the embodiment of the present application will be described in conjunction with fig. 4 to 6 and equations (1) to (9).

In some examples, the performing phase compensation on the plurality of first spectrograms as described above includes: performing phase compensation of the receiving channel on at least a portion of the first spectrograms of the plurality of first spectrograms so that the phases of the complex signals at the same position of at least two of the second spectrograms of the plurality of second spectrograms are the same.

In some examples, the performing phase compensation on the plurality of first spectrograms as described above includes: phase compensation of the transmission channel is performed on at least a portion of the first spectrograms of the plurality of first spectrograms such that the phases of the complex signals at the same location of at least two of the second spectrograms of the plurality of second spectrograms are the same.

It should be understood that the at least two second spectrograms are of the same phase, which means that ideally, after phase compensation, the phase of the complex signal at the same position in the different second spectrograms is the same. Those skilled in the art will appreciate that in practice, after performing phase compensation, there may be some deviation between the phases of the complex signals at the same location in the spectrogram.

In S303, the performing phase compensation on the plurality of first spectrograms may include performing phase compensation on all of the plurality of first spectrograms, or may include performing phase compensation on a part of the plurality of first spectrograms. The performing phase compensation on the plurality of first spectrograms may include: performing phase compensation of only the reception channel; performing phase compensation of only the transmit channel; or performs phase compensation of the receive channel and phase compensation of the transmit channel.

In some examples, if phase compensation of the receive channel is performed, the plurality of first spectrogram can be divided into at least one first spectrogram group. At least one first spectrogram group corresponds to at least one transmission channel one by one, and the first spectrograms in each first spectrogram group correspond to the same transmission channel. The performing phase compensation on the plurality of first spectrograms includes: and performing phase compensation of the receiving channel on the first spectrograms in each first spectrogram group, so that the phases of the complex signals of the first spectrograms and the first target spectrograms in the same position in each first spectrogram group are the same, wherein at least one spectrogram group corresponds to at least one first target spectrogram in a one-to-one correspondence manner, and at least one first target spectrogram corresponds to the same receiving channel. In other words, the phase compensation of the receiving channel may be performed on a set of first spectrograms corresponding to the same transmitting channel, such that the phases of the complex signals at the same position in the set of phase-compensated first spectrograms are the same. The first target spectrogram may be any one of the first spectrograms in each of the first spectrogram groups.

Further, if only the phase compensation of the receiving channel is performed, the plurality of first spectrograms after performing the phase compensation of the receiving channel may be determined as the plurality of second spectrograms.

Or if the phase compensation of the transmitting channel is continuously executed. The plurality of first spectrograms after performing the phase compensation of the receiving channel may be determined as a plurality of third spectrograms; performing phase compensation of a transmitting channel on the plurality of third spectrograms so that the phase of the complex signal of the plurality of third spectrograms is the same as the phase of the complex signal of a second target spectrogram, wherein the second target spectrogram is any one of the plurality of third spectrograms; determining a plurality of third spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms.

Similarly, in some examples, if phase compensation of the transmission channel is performed, the plurality of second spectrogram groups may be divided into at least one second spectrogram group, and the first spectrogram included in each second spectrogram group corresponds to the same reception channel; and performing phase compensation of a transmission channel on the first spectrogram in each second spectrogram group, so that the phase of the complex signal of the first spectrogram in each second spectrogram group and the phase of the complex signal of a third target spectrogram in the same position are the same, wherein the at least one second spectrogram group corresponds to at least one third target spectrogram in a one-to-one manner, and the at least one third target spectrogram corresponds to the same transmission channel.

Further, if only the phase compensation of the transmission channel is performed, the plurality of first spectrograms after performing the phase compensation of the transmission channel may be determined as the plurality of second spectrograms.

Or, if the phase compensation of the receiving channel is continuously performed, the plurality of first spectrograms after the phase compensation of the transmitting channel is performed may be determined as a plurality of fourth spectrograms; performing phase compensation of the receiving channel on the plurality of fourth spectrograms so that the phase of the complex signal of the plurality of fourth spectrograms is the same as the phase of the complex signal of a fourth target spectrogram, wherein the fourth target spectrogram is any one of the plurality of fourth spectrograms; determining a plurality of fourth spectrograms after performing phase compensation of the receiving channel as a plurality of second spectrograms.

And S304, performing complex addition on the complex signals based on the plurality of second spectrogram to obtain the accumulated spectrogram.

Optionally, the complex addition of the complex signals based on the plurality of second spectrograms may refer to adding the complex signals at the same positions of the plurality of second spectrograms to obtain an accumulated spectrogram. In the embodiments of the present application, accumulation may also be referred to as accumulation or superposition.

Next, a calculation method of a phase difference of signals obtained by combining different receiving channels and transmitting channels is described with reference to fig. 4, and a method of performing phase compensation on a complex signal according to an embodiment of the present application is described with reference to fig. 6.

Fig. 4 is a schematic diagram of signal accumulation in a receiving end including multiple receiving channels according to an embodiment of the present application. As shown in fig. 4, it is assumed that the receiving end includes N receiving channels, which are respectively denoted as RX₁、RX₂，...，RX_NEach receiving channel receives a set of signals, each set of signals comprising K signals. As an example, each signal may be a chirp signal. The influence factors of the phase difference between different signals received in the same receiving channel include: the doppler frequency due to relative motion and the time difference between the transmission of different signals. Wherein the relative movement may include: motion of the receiving end, motion of the transmitting end, and motion of the target. In a radar measurement system, a target may refer to an object to be measured.

As an example, the phase difference between any two signals from the same transmit channel received by the same receive channel can be expressed as formula (1):

wherein the content of the first and second substances,

representing the phase difference between the signals, f_DRepresenting the Doppler frequency, tau, due to movement_nRepresenting the time difference between the transmission of two signals on the same transmit channel.

Fig. 5 is a schematic diagram of different receiving channels receiving the same transmitted signal according to an embodiment of the present application. Wherein RX1, RX2 represent different receive channels. As an example, for the same transmission signal, the influence factors of the phase difference of the signals obtained by different receiving channels include: the position of the receiving channel and the phase of the observation target, for example, the phase difference of the same signal received by any two receiving channels can be expressed as:

wherein the content of the first and second substances,

representing the phase difference between the transmitted signals, lambda representing the wavelength of the transmitted signals, d_nRepresenting the distance of the two receive channels. The distance between the receiving channels may refer to a distance between antenna phase centers corresponding to the receiving channels. Theta represents the angle of the line between the receiving end and the transmitting end relative to the normal of the transmitting end. Where an observation target is present, θ may also refer to the arrival angle of the target.

As an example, in a MIMO system, the influencing factors of the phase difference of signals from different transmission channels received through the same reception channel include: the position of the transmit channel and the time difference between the transmit signals. For example, for signals transmitted by any two different transmission channels, the phase difference between signals received by the same receiving channel can be expressed as formula (3)

Wherein the content of the first and second substances,

representing the phase difference between the signals. d_nRepresenting the distance between the two transmit channels. The distance between the transmission channels may refer to the distance between the antenna phase centers corresponding to the transmission channels. λ represents the wavelength of the signal. Theta represents the angle of the line between the receiving end and the transmitting end relative to the normal of the receiving end. Where an observation target is present, θ may also refer to the arrival angle of the target. f. of_DRepresenting the Doppler frequency, τ, due to motion_nRepresenting the time difference between the transmission of the two signals.

Fig. 6 is a spectrum diagram corresponding to signals acquired through different channel combinations in a MIMO system. It is assumed that the MIMO system includes M transmission channels and N reception channels, each reception channel receives a set of signals, where a set of signals includes K signals, and K is an integer greater than or equal to 1. For convenience of description, the M transmit channels may be referred to as first transmit channels (TX), respectively₁) A second transmission channel (TX)₂) … …, Mth transmit channel (TX)_M). The N receive paths may be referred to as first receive paths (RX) respectively₁) A second receiving channel (RX)₂) … …, Nth receiving channel (RX)_N). It should be understood that the above ordering of the receive channels and transmit channels is merely to distinguish between different transmit channels or receive channels.

The mxn spectrograms of fig. 6 are one-to-one associated with the mxn groups of signals, each spectrogram corresponding to a combination of a transmit channel and a receive channel. In particular, each spectrogram represents a spectrogram obtained after spectral analysis of a set of signals. The spectral analysis may include, for example, DFT, doppler dimension FFT, distance dimension FFT, angle dimension FFT, and the like.

The spectrogram in fig. 6 includes a plurality of complex signals, and a small square can represent a complex signal. Alternatively, a small square may also be referred to as a dot. The complex signal obtained after the signal received by the mth transmitting channel and the nth receiving channel is subjected to spectrum analysis is denoted as z_m,n(x, y), M is more than or equal to 1 and less than or equal to M, and N is more than or equal to 1 and less than or equal to N. Wherein z is_m,n(x, y) is a complex signal, and (x, y) represents the coordinates of an arbitrary point in the spectrogram. z is a radical of_m,nThe normalized form of the amplitude of (x, y) is expressed as Norm (z)_m,n(x,y))。z_m,nThe complex conjugate of (x, y) is represented by z_m,n(x,y)^*。

It should be understood that the plurality of first spectrograms in fig. 3 may include, but are not limited to, the spectrograms shown in fig. 6.

In the embodiment of the application, before coherent accumulation is performed on first spectrograms corresponding to signals acquired through different transmitting channels and receiving channels, phase compensation can be performed on a plurality of first spectrograms, so that phase differences caused by different receiving channels or different transmitting channels of a plurality of second spectrograms obtained after compensation are eliminated, and therefore greater accumulation gain can be obtained by performing coherent accumulation on the plurality of second spectrograms.

Next, the phase compensation of the receiving channel and the phase compensation of the transmitting channel according to the embodiment of the present application will be described. It should be understood that, in the embodiment of the present application, the phase compensation of the receiving channel and the phase compensation of the transmitting channel may be performed successively on the plurality of first spectrogram, and the order of performing the two is not limited. Alternatively, only one of the first spectrograms may be executed.

(1) And (4) phase compensation of a receiving channel.

In some examples, if the phase compensation of the receiving channel is performed before the phase compensation of the transmitting channel, the plurality of first spectrograms may be divided into at least one first spectrogram group, the first spectrograms in each first spectrogram group corresponding to the same transmitting channel. Phase compensation of the receiving channels is performed separately for each first spectral group. It is to be understood that the first spectrogram in each first spectrogram group corresponds to the same transmit channel and to different receive channels. For example, the plurality of first spectrograms may include M × N first spectrograms, and the plurality of first spectrograms may be divided into M first spectrogram groups, where the M first spectrogram groups correspond to the M transmission channels one to one. Each first spectrogram group may include N first spectrograms, which correspond to N receive channels one-to-one.

It should be understood that the above-mentioned manner of dividing the first spectrogram groups is only an example, and in some cases, the number of the first spectrogram groups may be less than M × N, and the above-mentioned manner of dividing the first spectrogram groups may be different as long as it meets the condition that the first spectrogram in each first spectrogram group corresponds to the same transmission channel.

In some examples, the phase compensation of the receive channel may also be performed on only a portion of the plurality of first spectrograms.

In some examples, if the phase compensation of the receiving channel is performed after the phase compensation of the transmitting channel, the plurality of first spectrograms after the phase compensation of the transmitting channel is performed may be determined as the plurality of fourth spectrograms. Since, after performing phase compensation of the transmission channels, it can be considered that phase differences of the complex signals of the plurality of fourth spectrograms due to different transmission channels have been eliminated, and then the transmission channels corresponding to the plurality of fourth spectrograms are considered to be the same, it is not necessary to group the plurality of fourth spectrograms according to different transmission channels.

In some examples, the phase compensation of the receive channels may also be performed on only a portion of the fourth spectrogram in the plurality of fourth spectrograms.

Hereinafter, the phase compensation of the receiving channel is performed before the phase compensation of the transmitting channel for example, and those skilled in the art can understand that by appropriately modifying the correlation formula and the description, a scheme in which the phase compensation of the receiving channel is performed after the phase compensation of the transmitting channel can be obtained, and for brevity, the details are not described here again.

For each first spectrogram group, since the corresponding transmission channels are the same, it can be considered that the complex signals of the plurality of first spectrograms included in the first spectrogram group do not have a phase difference due to the difference of the transmission channels, but have a phase difference due to the difference of the reception channels. Therefore, the phase compensation of the receiving channel may be performed on the first spectrograms in each first spectrogram group to compensate for the phase difference of the complex signals of the first spectrograms in each first spectrogram group caused by different receiving channels, so that the phases of the complex signals at the same position in the first spectrograms in each first spectrogram group are the same.

In the embodiment of the present application, the same phase may be referred to as a first reference phase. For example, the first reference phase may be a phase of a complex signal of the first target spectrogram. The at least one first spectrogram group corresponds to the at least one first target spectrogram one by one, and the at least one target spectrogram corresponds to the same receiving channel. The same receive channel may be referred to as a target receive channel, which may be any one of the N receive channels. The first target spectrogram is any one of the first spectrogram groups. Next, an example in which the target receiving channel is the first receiving channel will be described.

In the embodiment of the present application, through phase compensation of a receiving channel, phases of complex signals of a first spectrogram of each first spectrogram group and a first target spectrogram are the same, at least one first spectrogram group corresponds to at least one first target spectrogram one to one, and at least one first target spectrogram corresponds to the same receiving channel, so that a phase difference between the first spectrograms in at least one spectrogram group due to different receiving channels can be eliminated, and an accumulation gain during signal accumulation is improved.

(i) Assume that the first spectrogram to be phase compensated for the receive channel corresponds to the mth transmit channel and the nth receive channel. Wherein, the mth transmitting channel may be any transmitting channel of the M transmitting channels. The nth receive channel may be any receive channel of the N receive channels other than the first receive channel.

The phase difference between the nth receive channel and the (n-1) th receive channel for the mth transmit channel can be expressed as the following equation (4):

wherein, Δ z_m,(n,n-1)Representing a phase difference between an nth receiving channel and an n-1 th receiving channel; z is a radical of_m,n(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the nth receiving channel; z is a radical of_m,n-1(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the (n-1) th receiving channel; z is a radical of_m,n-1(x,y)^*Denotes z_m,n-1Complex conjugation of (x, y).

Norm(z_m,n(x, y)) represents a complex signal z_m,nAn amplitude normalized form of (x, y); norm (z)_m,n-1(x, y) denotes the complex signal z_m,n-1(x,y)^*Normalized form of (a).

(ii) For the mth transmit channel, the phase difference between the first receive channel and the second receive channel can be expressed as the following equation (5):

wherein the content of the first and second substances,

representing a phase difference between the first receive channel and the second receive channel; z is a radical of_m,1(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the 1 st receiving channel;

z_m,2(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the 1 st receiving channel; z is a radical of_m,2(x,y)^*Denotes z_m,2(x, y) complex conjugation;

Norm(z_m,1(x, y)) represents a complex signal z_m,1Normalized form of (x, y); norm (z)_m,2(x, y) denotes the complex signal z_m,2Normalized form of (x, y).

(iii) For complex signal z_m,n(x, y) phase-compensated complex signal of reception channel

Can be expressed as the following formula (6):

wherein z is_m,n(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the nth receiving channel; z is a radical of_m,n-1(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the (n-1) th receiving channel; z is a radical of_m,1(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the 1 st receiving channel;

representing a complex signal z_m,n(x, y) performing phase compensation on the complex signal after the phase compensation of the receiving channel; norm (z)_m,n-1(x, y)) represents a complex signal z_m,n-1Normalized form of (x, y);

Norm(z_m,1(x, y)) represents a complex signal z_m,1Normalized form of (x, y);

representing the phase difference between the first receive channel and the second receive channel. Δ z_m,(n,n-1)Represents the phase difference between the nth receiving channel and the (N-1) th receiving channel, wherein M is more than or equal to 1 and less than or equal to M, and N is more than or equal to 2 and less than or equal to N.

In some examples, equation (6) needs to satisfy the following condition: to achieve phase compensation of the receive path, ω is the frequency of the complex signal in the case of noise₁And ω₂Is a random term. In the case where the complex signal is a signal, ω₁And ω₂Are equal. Thus, in the formula (6), ω is the signal in the case where the complex signal is a signal₁And ω₂Are approximately equal in size to each other,so that

Can be approximated to 1, so that ω need not be obtained₁And ω₂Specific values of (a). To satisfy this condition, the distance between the nth receiving channel and the (n-1) th receiving channel may be made approximately equal to the distance between the first receiving channel and the second receiving channel, which makes ω equal₁And ω₂May be approximately equal.

(2) Phase compensation of the transmit channel.

In some examples, if the phase compensation of the transmit channel is performed before the phase compensation of the receive channel, the plurality of first spectrograms may be divided into a plurality of second spectrogram groups, the first spectrogram in each second spectrogram group corresponding to the same receive channel. It is to be understood that the second spectrogram in each second spectrogram group corresponds to different transmission channels and the same reception channel. For example, the plurality of first spectrograms may include M × N first spectrograms, the M × N first spectrograms are divided into N second spectrogram groups, the N second spectrogram groups correspond to the N receiving channels one to one, each second spectrogram group may include M first spectrograms, and the M first spectrograms correspond to the M transmitting channels one to one. It should be understood that the above-mentioned manner of dividing the second spectrogram groups is only an example, and in some cases, the number of the plurality of first spectrogram patterns may be less than M × N, and the above-mentioned manner of dividing the second spectrogram groups may be different as long as it meets the condition that the first spectrogram patterns in each second spectrogram group correspond to the same receiving channel.

In some examples, to reduce the computational burden, phase compensation of the transmit channels may also be performed on only a portion of the first spectrogram.

In some examples, if the phase compensation of the transmit channel is performed after the phase compensation of the receive channel, the plurality of first spectral plots after the phase compensation of the receive channel is performed may be determined as the plurality of third spectral plots. After the phase compensation of the receiving channels is performed, it can be considered that the phase differences of the complex signals of the plurality of third spectrograms due to the difference of the receiving channels are eliminated, and then the receiving channels corresponding to the plurality of third spectrograms are considered to be the same, so that the plurality of third spectrograms do not need to be grouped according to different receiving channels.

In some examples, phase compensation of the transmit channels may also be performed only on a portion of the third spectrogram.

In the following, the phase compensation of the transmitting channel is performed before the phase compensation of the receiving channel, and those skilled in the art can understand that by appropriately modifying the related formula and description, a scheme in which the phase compensation of the transmitting channel is performed before the phase compensation of the receiving channel can be obtained, and details are not described here for brevity.

After the phase compensation of the receiving channels, it can be considered that the complex signals of the plurality of third frequency spectrums have no phase difference due to the difference of the receiving channels, but have phase difference due to the difference of the transmitting channels. Therefore, the phase compensation of the emission channels can be performed on the plurality of third frequency spectrums, so as to compensate the phase difference of the plurality of third frequency spectrums caused by different emission channels, and the phases of the plurality of third frequency spectrums are the same.

In the embodiment of the present application, this same phase may be referred to as a second reference phase. For example, the second reference phase may be a phase of a complex signal of the second target spectrogram. The second target spectrogram may be any spectrogram of a plurality of third spectrograms. The second target spectrogram corresponds to a target transmit channel, which may be any one of the M transmit channels. Next, a description will be given taking the target transmission channel as the first transmission channel as an example.

It should be noted that, assuming that a plurality of third spectral patterns are grouped along the phase compensation process used in the receiving channel, the phase of the third spectral pattern in each first spectral pattern group is considered to be the same. Therefore, the phases of all the third spectrograms in the first spectrogram group to which the second target spectrogram belongs are the same, so that the phase compensation of the transmitting channel is not required for the third spectrograms in the first spectrogram group.

(i) Assume that the third spectrogram to be phase-compensated for the transmit channel corresponds to the mth transmit channel and the nth receive channel. Wherein, the mth transmit channel may be any transmit channel other than the first transmit channel. The nth receiving channel is any receiving channel.

For the nth receive channel, the phase difference between the mth transmit channel and the (m-1) th transmit channel can be expressed as the following equation (7):

wherein the content of the first and second substances,

representing a phase difference between the mth transmit channel and the m-1 th transmit channel;

the complex signal which represents that the signal acquired by the mth transmitting channel and the nth receiving channel corresponds to the third spectrogram;

the complex signal which represents that the signal acquired by the m-1 th transmitting channel and the nth receiving channel corresponds to the third spectrogram;

representing complex signals

Complex conjugation of (a).

Representing complex signals

The amplitude normalization form of (1);

representing complex signals

Normalized form of (a).

(ii) For the nth receive channel, the phase difference between the first transmit channel and the second transmit channel is expressed as equation (8):

wherein the content of the first and second substances,

representing a phase difference between the first transmit channel and the second transmit channel;

a complex signal representing a signal acquired through a first transmitting channel and an nth receiving channel corresponding to a first spectrogram;

indicating that the signals acquired through the second transmit channel and the nth receive channel correspond to complex signals in the first spectrogram.

To represent

Complex conjugation of (a).

Representing complex signals

Normalized form of (a);

representing complex signals

Normalized form of (a).

(iii) To complex signal

Complex signal after phase compensation of transmission channel

Can be expressed as the following formula (9):

wherein z is_m,n(x, y) represents a complex signal in the first spectrogram corresponding to a signal acquired through the mth transmitting channel and the nth receiving channel;

representing a complex signal z_m,n(x, y) performing a complex signal obtained after the phase compensation of the reception channel;

representing complex signals

Performing a complex signal obtained after phase compensation of the transmit channel;

representing a complex signal z_m-1,n(x, y) performing a complex signal obtained after the phase compensation of the reception channel;

representing a complex signal z_1,n(x, y) a complex signal obtained after performing phase compensation of the reception channel.

Representing complex signals

Normalized form of (a);

representing complex signals

Normalized form of (a);

representing complex signals

Normalized form of (a);

indicating the phase difference between the 1 st transmit channel and the 2 nd transmit channel.

The phase difference between the M-th transmitting channel and the M-1 th transmitting channel is expressed, M is more than or equal to 2 and less than or equal to M, and N is more than or equal to 1 and less than or equal to N.

In some examples, equation (9) needs to satisfy the following condition: in order to achieve phase compensation of the transmit path, in the case where the complex signal is noise,

and

is a random term. In the case where the complex signal is a signal,

and

are equal. Thus, in the formula (9), in the case where the complex signal is a signal,

and

are approximately equal in size, so that

Can be approximately 1 and thus need not be acquired. To satisfy this condition, the distance between the m-th receiving channel and the m-1-th receiving channel may be made approximately equal, which makes it possible to make the m-th receiving channel and the m-1-th receiving channel equal

And

may be approximately equal.

(3) Coherent accumulation

After the phase compensation is performed, the complex signals at the same position in the plurality of second spectrograms are superposed, so that the accumulated spectrograms can be obtained. By way of example, the complex signal to be superimposed is taken as

For example, the complex signal z (x, y) in the superimposed spectrogram can be expressed as formula (10):

wherein M represents the number of transmit channels and N represents the number of receive channels; z (x, y) represents the superimposed complex signal,

representing the complex signal to be superimposed.

Since the square rate detection is performed by the detector on the receiving side in the equation (10), the complex signal is superimposed in a square form. It should be understood that equation (10) is merely exemplary and not limiting, and in the embodiments of the present application, coherent accumulation of signals may be implemented in other manners. For example, the complex signal superposition may be in the form of an absolute value or a logarithmic value.

In the embodiment of the application, the phase compensation of the transmitting channel and the receiving channel is performed by adopting the formula, so that the calculation complexity of the phase compensation can be simplified, and the calculation resources can be saved. Moreover, by adopting the formula, the noise is not iterated and accumulated while phase differences caused by different transmitting channels or different receiving channels are eliminated, so that the signal processing quality is improved.

Fig. 7 is a schematic diagram of a signal processing method according to an embodiment of the present application. As shown in fig. 7, the method may be performed by the receiving end and includes the following steps.

S601, obtaining M × N groups of signals, and performing distance dimension FFT to obtain M × N distance FFT spectrograms (denoted as RMap 0).

Optionally, before performing the distance dimensional FFT, the M × N sets of signals may be analog to digital converted (ADC).

S602, perform a doppler dimension FFT on the M × N RMap 0 to obtain M × N range-doppler FFT spectrograms (denoted as RDMap 1).

Wherein, the M × N range-doppler FFT spectrograms can be used as the plurality of first spectrograms. Alternatively, other types of spectral analysis may be continued based on the M × N range-doppler FFT spectrograms, and then a plurality of first spectrograms may be obtained. For example, an angular dimension FFT may also be performed.

And S603, performing phase compensation on the M × N RDMap1 channels to obtain M × N third frequency spectrograms (denoted as RDMap 2).

For example, M × N rdmaps 1 may perform amplitude normalization and phase compensation on the reception data of a certain reception channel. For a specific implementation of the phase compensation of the receiving channel, reference may be made to the foregoing (for example, fig. 4 to fig. 6 and the related description), and details thereof are not repeated here.

S604, performing phase compensation on the M × N rdmaps 2 to obtain M × N second spectrograms (denoted as rdmaps 3).

For example, M × N rdmaps 2 may perform amplitude normalization and phase compensation for the received data of a certain transmission channel. For a specific implementation of the phase compensation of the transmission channel, reference may be made to the contents in the foregoing (for example, fig. 4 and fig. 6 and the related description), and details are not repeated here.

S605, perform coherent superposition on the M × N rdmaps 3 to obtain a superposed spectrogram (denoted as RDMap).

And S606, based on the RDMap, continuing to execute the subsequent signal processing flow (for example, CFAR and the like).

Fig. 8 is a schematic diagram of a signal processing method according to an embodiment of the present application. As shown in fig. 8, the method may be performed by the receiving end and includes the following steps.

S701, obtaining M × N groups of signals, and performing distance dimension FFT to obtain M × N distance FFT spectrograms (denoted as RMap 0).

The M × N range FFT spectrograms may serve as the plurality of first spectrograms.

S702, performing phase compensation on the M × N RMap 0 channels to obtain M × N third frequency spectrums (denoted as RMap 1).

For example, M × N RMap 0 may perform amplitude normalization and phase compensation for the reception data of a certain reception channel. For a specific implementation of the phase compensation of the receiving channel, reference may be made to the foregoing (for example, fig. 4 and fig. 6 and the related description), and details are not repeated here.

S703, performing phase compensation on the M × N RMap 1 channels to obtain M × N second spectrogram (referred to as RMap 2).

For example, M × N RMap 1 may perform phase-amplitude normalization and phase compensation on the received data of a certain transmission channel. For a specific implementation of the phase compensation of the transmission channel, reference may be made to the contents in the foregoing (for example, fig. 4 to fig. 6 and the related description), and details are not repeated here.

S704, performing coherent superposition on the M × N rmaps 2 to obtain a superposed spectrogram (denoted as RMap).

S705, performing Doppler dimension FFT on the RMap to obtain a range-Doppler FFT spectrogram (denoted as RDmap).

Alternatively, in S704 and S705 sections, doppler dimension FFT may also be performed on M × N RMap 2 to obtain M × N range-doppler FFT spectrograms (denoted as RDMap 3), respectively. The M × N rdmaps 3 are then complex-added to obtain a superimposed spectrogram (denoted as RDMap).

And S706, based on the RDMap, continuing to execute the subsequent signal processing flow (for example, CFAR and the like).

Fig. 9 is a schematic diagram of a signal processing method according to an embodiment of the present application. As shown in fig. 9, the method may be performed by the receiving end and includes the following steps.

S801, obtaining M × N groups of signals, and performing distance dimension FFT to obtain M × N distance FFT spectrograms (denoted as RMap 0).

S802, perform a doppler dimension FFT on the M × N RMap 0 to obtain M × N range-doppler FFT spectrograms (denoted as RDMap 1).

S803, performing coherent superposition on the receiving channels in the M × N rdmaps 1, where coherent superposition of the receiving channels refers to performing coherent superposition on rdmaps 1 corresponding to the same transmitting channel to obtain M spectrograms (denoted as RDMap 2).

The M spectrograms may be used as a plurality of first spectrograms.

In some examples, M × N rdmaps 1 may be divided into M spectral map groups, each including N rdmaps 1 corresponding to the same transmit channel. For each spectrogram group, complex signals at the same position in N rdmaps 1 can be superimposed based on spectral analysis (e.g., FFT or DBF), to obtain M × NFFT spectrograms, where NFFT represents the number of points of spectral analysis when RDMap1 is coherently superimposed. For each transmission channel, in NFFT spectrograms, determining a complex value corresponding to a maximum amplitude value in complex signals at the same position as a complex value in RDMap2, and finally obtaining M rdmaps 2.

And S804, performing phase compensation on the M RDMap2 to obtain M third frequency spectrograms (denoted as RDMap 3).

For example, M rdmaps 2 may perform amplitude normalization and phase compensation for the received data of a certain transmit channel. For a specific implementation of the phase compensation of the receiving channel, reference may be made to the foregoing (for example, fig. 4 to fig. 6 and the related description), and details thereof are not repeated here.

In this embodiment of the present application, in S803, the rdmaps 1 corresponding to the same transmit channel and different receive channels are coherently superimposed to obtain M rdmaps 2, where the M rdmaps 2 respectively correspond to different transmit channels. It is considered that the phase difference effect on the complex signals of the M rdmaps 2 due to the difference of the receiving channels has been eliminated, and therefore, only the phase compensation of the transmitting channel needs to be performed on the M rdmaps 2.

S805, performing complex addition on the M × N rdmaps 3 to obtain a superimposed spectrogram (denoted as RDMap).

And S806, based on the RDMap, continuing to execute the subsequent signal processing flow (for example, CFAR and the like).

The communication method according to the embodiment of the present application is described above with reference to fig. 1 to 9, and the apparatus according to the embodiment of the present application is described below with reference to fig. 10 and 11.

Fig. 10 is a schematic block diagram of an apparatus 900 for signal processing according to an embodiment of the present application. The apparatus 1000 is capable of performing the steps performed by the receiving end in the method embodiment of the present application, and therefore, in order to avoid repetition, detailed description thereof is omitted here. The apparatus 1000 comprises:

an obtaining unit 1010, configured to obtain M × N groups of signals, where the M × N groups of signals correspond to M × N channel combinations in a one-to-one manner, the M × N channel combinations are channel combinations formed by M transmitting channels and N receiving channels, and M, N is a positive integer.

A processing unit 1020 for performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms.

The processing unit 1020 is further configured to perform phase compensation on the complex signals of the first spectrograms to obtain second spectrograms, where the first spectrograms correspond to the second spectrograms in a one-to-one manner.

The processing unit 1020 is further configured to perform complex addition based on the complex signals of the plurality of second spectrograms to obtain an accumulated spectrogram.

Fig. 11 is a schematic block diagram of an apparatus 1100 for signal processing according to an embodiment of the present application. The apparatus 1100 is capable of performing the steps performed by the receiving end in the embodiments of the method of the present application, and therefore, in order to avoid repetition, detailed descriptions thereof are omitted here. The apparatus 1100 comprises:

memory 1110 (which may be one or more) for storing programs.

A communication interface 1120.

A processor 1130 (which may be one or more) for executing the programs in the memory 1110, wherein when the programs are executed, the processor 1130 is configured to obtain M × N groups of signals through the communication interface 1120, the M × N groups of signals correspond to M × N channel combinations in a one-to-one manner, the M × N channel combinations are channel combinations formed by M transmitting channels and N receiving channels respectively, and M, N is a positive integer. Processor 1130 is also configured to perform spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms; the processor 1130 is further configured to perform phase compensation on the complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, where the plurality of first spectrograms correspond to the plurality of second spectrograms one to one, and the phase compensation includes at least one of: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels; processor 1130 is further configured to perform a complex addition based on the plurality of complex signals of the second spectrogram to obtain an accumulated spectrogram.

It is understood that the above-described apparatus or device may perform some or all of the steps in the above-described embodiments, and these steps or operations are merely examples, and other operations or variations of various operations may be performed by the embodiments of the present application. Further, the various steps may be performed in a different order presented in the above-described embodiments, and it is possible that not all of the operations in the above-described embodiments are performed.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a read-only memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A signal processing method, comprising:

acquiring M × N groups of signals, wherein the M × N groups of signals correspond to M × N channel combinations one by one, the M × N channel combinations are channel combinations respectively formed by M transmitting channels and N receiving channels, and M, N is a positive integer;

performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms;

performing phase compensation on complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, wherein the plurality of first spectrograms correspond to the plurality of second spectrograms in a one-to-one manner, and the phase compensation comprises at least one of the following steps: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels;

and carrying out complex addition on the basis of the complex signals of the plurality of second frequency spectrograms to obtain the accumulated frequency spectrograms.

2. The method of claim 1, wherein prior to performing phase compensation on the complex signals of the plurality of first spectrograms, the method further comprises:

performing amplitude normalization on the complex signals in the plurality of first spectrograms.

3. The method of claim 1 or 2, wherein performing phase compensation on the complex signals of the plurality of first spectrograms comprises:

performing phase compensation of a receiving channel on at least a portion of the first spectrograms so that the phases of complex signals of at least two of the second spectrograms at the same position are the same; or the like, or, alternatively,

performing phase compensation of a transmission channel on at least a portion of the first spectrograms so that phases of complex signals of at least two of the second spectrograms at the same position are the same.

4. The method of any one of claims 1 to 3, wherein performing phase compensation on the complex signals of the plurality of first spectrograms comprises:

dividing the plurality of first spectrogram groups into at least one first spectrogram group, wherein the first spectrogram included in each first spectrogram group corresponds to the same transmission channel;

performing phase compensation of a receiving channel on the first spectrograms in each first spectrogram group, so that the phases of complex signals of the first spectrograms and the first target spectrograms in the same position in each first spectrogram group are the same, wherein at least one spectrogram group corresponds to at least one first target spectrogram one by one, and the at least one first target spectrogram corresponds to the same receiving channel;

determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the receiving channel.

5. The method of claim 4, wherein determining the plurality of second spectrograms from the plurality of first spectrograms after performing phase compensation of the receive channel comprises:

determining a plurality of first spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms; or the like, or, alternatively,

determining a plurality of first spectrograms after performing phase compensation of the receiving channel as a plurality of third spectrograms;

performing phase compensation of a transmission channel on the plurality of third spectrograms so that the phase of the complex signal of the plurality of third spectrograms is the same as the phase of the complex signal of a second target spectrogram, wherein the second target spectrogram is any one of the plurality of third spectrograms;

determining a plurality of third spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms.

6. The method of any one of claims 1 to 3, wherein performing phase compensation on the complex signals of the plurality of first spectrograms comprises:

dividing the plurality of first spectrogram groups into at least one second spectrogram group, wherein the first spectrogram included in each second spectrogram group corresponds to the same receiving channel;

performing phase compensation of a transmission channel on the first spectrogram in each second spectrogram group, so that the phase of the complex signal of the first spectrogram in each second spectrogram group and a phase of a complex signal of a third target spectrogram in the same position are the same, wherein the at least one second spectrogram group corresponds to at least one third target spectrogram in a one-to-one manner, and the at least one third target spectrogram corresponds to the same transmission channel;

determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the transmission channel.

7. The method of claim 6, wherein determining the plurality of second spectrograms from the plurality of first spectrograms after performing the phase compensation of the transmission channel comprises:

determining a plurality of first spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms; or the like, or, alternatively,

determining a plurality of first spectrograms after performing phase compensation of the transmission channel as a plurality of fourth spectrograms;

performing phase compensation of a receiving channel on the plurality of fourth spectrograms so that a phase of a complex signal of the plurality of fourth spectrograms is the same as a phase of a complex signal of a fourth target spectrogram, wherein the fourth target spectrogram is any one of the plurality of fourth spectrograms;

determining a plurality of fourth spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms.

8. The method of any one of claims 1 to 7, wherein performing spectral analysis on the M x N sets of signals to obtain a plurality of first spectrograms comprises:

performing at least one type of spectral analysis on the M x N sets of signals to obtain the plurality of first spectrograms: distance dimension fast fourier transform FFT, doppler dimension FFT, angle dimension FFT.

9. The method of any one of claims 1 to 8, wherein performing spectral analysis on the M x N sets of signals to obtain a plurality of first spectrograms comprises:

performing distance dimension FFT on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms;

performing Doppler dimension FFT on the range spectrograms to obtain M multiplied by N range-Doppler FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N range-Doppler FFT spectrograms.

10. The method of any one of claims 1 to 8, wherein performing spectral analysis on the M x N sets of signals to obtain a plurality of first spectrograms comprises:

performing distance dimension FFT transformation on the M multiplied by N groups of signals to acquire M multiplied by N distance FFT spectrograms, wherein the first spectrogram is the M multiplied by N distance FFT spectrograms.

11. The method of claim 10, wherein the complex adding based on the plurality of second spectrograms to obtain the accumulated spectrogram comprises:

performing a doppler dimension FFT on the second plurality of spectrograms to obtain a plurality of range-doppler FFT spectrograms;

and performing complex addition on the plurality of range-Doppler FFT spectrograms to obtain the accumulated spectrogram.

12. The method of claim 10, wherein after said complex signal based on said second plurality of spectrograms is complex added to obtain an accumulated spectrogram, the method further comprises:

and performing Doppler dimension FFT on the accumulated spectrogram to obtain a range-Doppler FFT spectrogram.

13. The method of any one of claims 1 to 8, wherein performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms comprises:

performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms;

dividing the MxN fifth spectrograms into M spectrogram groups, wherein N fifth spectrograms included in each spectrogram group correspond to the same transmitting channel;

performing coherent accumulation on each spectrogram group in the M spectrogram groups by using spectrum analysis to obtain M spectrograms, wherein the M spectrograms are the plurality of first spectrograms.

14. The method of claim 13, wherein performing phase compensation on the plurality of first spectrograms to obtain a plurality of second spectrograms comprises:

and performing phase compensation of a transmission channel on the plurality of first spectrograms so as to enable phases of complex signals of the plurality of second spectrograms at the same position after phase compensation to be the same.

15. The method of claim 13 or 14, wherein performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms comprises:

performing distance dimension FFT transformation on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms;

performing doppler dimension FFT on the M × N range FFT spectrograms to obtain M × N range-doppler FFT spectrograms, where the M × N fifth spectrograms are the M × N range-doppler FFT spectrograms.

16. An apparatus for signal processing, comprising:

an obtaining unit, configured to obtain M × N groups of signals, where the M × N groups of signals correspond to M × N channel combinations in a one-to-one manner, the M × N channel combinations are channel combinations respectively formed by M transmitting channels and N receiving channels, and M, N is a positive integer;

a processing unit for performing spectral analysis on the mxn groups of signals to obtain a plurality of first spectrograms;

the processing unit is further configured to perform phase compensation on the complex signals of the plurality of first spectrograms to obtain a plurality of second spectrograms, where the plurality of first spectrograms correspond to the plurality of second spectrograms one to one, and the phase compensation includes at least one of: the phase compensation of the receiving channel is used for compensating the phase difference of the complex signals caused by different receiving channels, and the phase compensation of the transmitting channel is used for compensating the phase difference of the complex signals caused by different transmitting channels;

the processing unit is further configured to perform complex addition based on the complex signals of the plurality of second spectrograms to obtain an accumulated spectrogram.

17. The apparatus of claim 16, wherein the processing unit is further operative to perform amplitude normalization on the complex signals in the plurality of first spectrograms.

18. The apparatus according to claim 16 or 17, wherein the processing unit is specifically configured to perform phase compensation of the receive channel on at least a portion of the first spectrograms of the plurality of first spectrograms, so that phases of complex signals of at least two of the second spectrograms at a same position are the same; or, performing phase compensation of a transmission channel on at least a part of the plurality of first spectrograms so that the phases of the complex signals of at least two of the plurality of second spectrograms at the same position are the same.

19. The device according to any one of claims 16 to 18, wherein the processing unit is specifically configured to: dividing the plurality of first spectrogram groups into at least one first spectrogram group, wherein the first spectrogram included in each first spectrogram group corresponds to the same transmission channel; performing phase compensation of a receiving channel on the first spectrograms in each first spectrogram group, so that the phases of complex signals of the first spectrograms and the first target spectrograms in the same position in each first spectrogram group are the same, wherein at least one spectrogram group corresponds to at least one first target spectrogram one by one, and the at least one first target spectrogram corresponds to the same receiving channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the receiving channel.

20. The device of claim 19, wherein the processing unit is specifically configured to: determining a plurality of first spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the receiving channel as a plurality of third spectrograms; performing phase compensation of a transmission channel on the plurality of third spectrograms so that the phase of the complex signal of the plurality of third spectrograms is the same as the phase of the complex signal of a second target spectrogram, wherein the second target spectrogram is any one of the plurality of third spectrograms;

21. The device according to any one of claims 16 to 18, wherein the processing unit is specifically configured to: dividing the plurality of first spectrogram groups into at least one second spectrogram group, wherein the first spectrogram included in each second spectrogram group corresponds to the same receiving channel; performing phase compensation of a transmission channel on the first spectrogram in each second spectrogram group, so that the phase of the complex signal of the first spectrogram in each second spectrogram group and a phase of a complex signal of a third target spectrogram in the same position are the same, wherein the at least one second spectrogram group corresponds to at least one third target spectrogram in a one-to-one manner, and the at least one third target spectrogram corresponds to the same transmission channel; determining the plurality of second spectrograms according to the plurality of first spectrograms after performing the phase compensation of the transmission channel.

22. The device of claim 21, wherein the processing unit is specifically configured to: determining a plurality of first spectrograms after performing phase compensation of the transmission channel as the plurality of second spectrograms; or, determining a plurality of first spectrograms after performing phase compensation of the transmission channel as a plurality of fourth spectrograms; performing phase compensation of a receiving channel on the plurality of fourth spectrograms so that a phase of a complex signal of the plurality of fourth spectrograms is the same as a phase of a complex signal of a fourth target spectrogram, wherein the fourth target spectrogram is any one of the plurality of fourth spectrograms; determining a plurality of fourth spectrograms after performing phase compensation of the receiving channel as the plurality of second spectrograms.

23. The device according to any one of claims 16 to 22, wherein the processing unit is specifically configured to: performing at least one type of spectral analysis on the M x N sets of signals to obtain the plurality of first spectrograms: distance dimension FFT, doppler dimension FFT, angle dimension FFT.

24. The device according to any one of claims 16 to 23, wherein the processing unit is specifically configured to: performing distance dimension FFT on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing Doppler dimension FFT on the range spectrograms to obtain M multiplied by N range-Doppler FFT spectrograms, wherein the plurality of first spectrograms are the M multiplied by N range-Doppler FFT spectrograms.

25. The device according to any one of claims 16 to 23, wherein the processing unit is specifically configured to: performing distance dimension FFT transformation on the M multiplied by N groups of signals to acquire M multiplied by N distance FFT spectrograms, wherein the first spectrogram is the M multiplied by N distance FFT spectrograms.

26. The device of claim 25, wherein the processing unit is specifically configured to: performing a doppler dimension FFT on the second plurality of spectrograms to obtain a plurality of range-doppler FFT spectrograms; and performing complex addition on the plurality of range-Doppler FFT spectrograms to obtain the accumulated spectrogram.

27. The device of claim 25, wherein the processing unit is specifically configured to: and performing Doppler dimension FFT on the accumulated spectrogram to obtain a range-Doppler FFT spectrogram.

28. The device according to any one of claims 16 to 23, wherein the processing unit is specifically configured to: performing spectral analysis on the mxn groups of signals to obtain mxn fifth spectrograms; dividing the MxN fifth spectrograms into M spectrogram groups, wherein N fifth spectrograms included in each spectrogram group correspond to the same transmitting channel; performing coherent accumulation on each spectrogram group in the M spectrogram groups by using spectrum analysis to obtain M spectrograms, wherein the M spectrograms are the plurality of first spectrograms.

29. The device of claim 28, wherein the processing unit is specifically configured to: and performing phase compensation of a transmission channel on the plurality of first spectrograms so as to enable phases of complex signals of the plurality of second spectrograms at the same position after phase compensation to be the same.

30. The device according to claim 28 or 29, wherein the processing unit is specifically configured to: performing distance dimension FFT transformation on the M multiplied by N groups of signals to obtain M multiplied by N distance FFT spectrograms; performing doppler dimension FFT on the M × N range FFT spectrograms to obtain M × N range-doppler FFT spectrograms, where the M × N fifth spectrograms are the M × N range-doppler FFT spectrograms.