Method, device and related equipment for resolving speed ambiguity and determining object moving speed

Abstract

This application discloses a method, apparatus, and related equipment for resolving velocity ambiguity and determining the moving speed of an object. The method includes: performing a Fast Fourier Transform (FFT) on the sampled signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampled signals; determining the phase difference between each phase of the phase sequence and a reference sampled signal based on multiple different directions of arrival and multiple different compensation frequencies to obtain multiple phase difference sequences; performing vector operations on these phase difference sequences with the phase sequence of the sampled signals to obtain the energy value corresponding to each phase difference sequence; and determining the moving speed of the object based on the compensation frequency corresponding to the phase difference sequence with the largest energy value. This increases the measurable range of Doppler frequencies in the MIMO radar system, thereby increasing the measurable range of object moving speeds that can be measured, and ultimately improving the accuracy of measuring object moving speed.

Description

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on February 28, 2020, with application number 202010134584.7, invention name “A method, device and equipment for determining the moving speed of an object”, and application number 202010131565.9, invention name “Method, device, equipment and storage medium for determining the azimuth of a target object”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of target detection technology, and in particular to a method for resolving speed ambiguity, a method and device for determining the moving speed of an object, an integrated circuit, a radio device, and equipment. Background Art

[0003] Currently, when using sensors for target detection, in order to achieve functions such as radiation directionality, target positioning, etc., it is generally necessary to set up two or more transmitting antennas (such as MIMO antennas).

[0004] However, compared with a sensor with a single transmitting antenna, adding a transmitting antenna will reduce the sampling frequency of the velocity dimension when the sensor performs signal processing, thereby reducing the maximum measurement speed range of the sensor. Summary of the invention

[0005] In order to solve the above technical problems, the embodiments of the present application provide a method for resolving speed ambiguity, a method and device for determining the moving speed of an object, an integrated circuit, a radio device, and equipment to expand the range of the moving speed of an object that can be measured by the target sensor and improve the accuracy of measuring the moving speed of the object.

[0006] In a first aspect, a method for resolving velocity ambiguity may be applied to a FMCW sensor having at least two transmitting antennas and at least one receiving antenna, the method comprising:

[0007] Based on the FFT result of the echo signal, a phase sequence corresponding to the transmitting and receiving channels is obtained;

[0008] Acquire a phase difference sequence between the transmitting and receiving channels based on the angle set to be searched and the fuzzy number set to be searched;

[0009] Performing beamforming based on the phase sequence and the phase difference sequence to obtain an energy spectrum corresponding to each phase difference sequence; and

[0010] The maximum energy spectrum among the extreme values ​​is taken as the target energy spectrum, and the speed fuzzification is solved according to the fuzzy number corresponding to the target energy spectrum.

[0011] In this embodiment, by using beamforming to resolve speed ambiguity, not only can the range and accuracy of target detection speed be improved, but also the amount of calculation can be effectively reduced, and the design difficulty of the transmitter can be reduced, which is suitable for different application scenarios.

[0012] In a possible implementation, the method further includes:

[0013] A direction of arrival angle is obtained based on the target energy spectrum.

[0014] In this embodiment, the direction of arrival angle can be obtained simultaneously while resolving the velocity ambiguity, which can effectively reuse traditional hardware resources and reduce the design difficulty and cost.

[0015] In a possible implementation manner, the angle set to be searched is defined as:

[0016] θ set ={arcsin(sinStart+sinStep·n)|n=0,1,2,...θ num-1}

[0017] Among them, θ set represents the angle set to be searched, θ num represents the number of angles to be searched, the sinStart represents the sine value of the starting angle to be searched, and the sinStep represents the search step of the angle to be searched in the sine domain.

[0018] In this embodiment, the amount of calculation can be further reduced and the efficiency of resolving speed ambiguity can be improved.

[0019] In a second aspect, an embodiment of the present application provides a method for determining a moving speed of an object, the method being applied to a multiple-input multiple-output MIMO radar system, the method comprising:

[0020] Performing fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals;

[0021] According to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal is determined to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs;

[0022] Performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence;

[0023] Determining the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, wherein the energy value corresponding to the target phase difference sequence is the largest;

[0024] The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0025] In this way, the measurable range of the Doppler frequency of the MIMO radar system can be increased, thereby increasing the measurable range of the object movement speed that can actually be measured by the system, and further improving the accuracy of measuring the object movement speed.

[0026] In a possible implementation, the method further includes:

[0027] The target arrival direction corresponding to the sampling signal is determined according to the target phase difference sequence.

[0028] In this implementation, not only can the actual moving speed of the object be measured, but the target arrival direction corresponding to the sampled signal obtained by sampling on the receiving antenna can also be further determined based on the target phase difference sequence, which can effectively reuse traditional hardware resources and reduce design difficulty and cost.

[0029] In a possible implementation manner, the first phase difference sequence is any one of the multiple phase difference sequences, and the method further includes:

[0030] Obtaining a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves;

[0031] Calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence to obtain the Doppler frequency corresponding to the first phase difference sequence;

[0032] The compensating phase difference corresponding to the first phase difference sequence is calculated according to the Doppler frequency corresponding to the first phase difference sequence.

[0033] In this embodiment, the compensated phase difference corresponding to each phase difference sequence can be calculated using the measured Doppler frequency, without requiring the MIMO radar system to use special hardware or test equipment to determine the compensated phase difference corresponding to each phase difference sequence. In this way, the hardware requirements for the MIMO radar system can be reduced.

[0034] In a possible implementation manner, performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence includes:

[0035] respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal;

[0036] The square of the modulus of the vector product corresponding to each phase difference sequence is calculated, and the square of the modulus is used as the energy value corresponding to the phase difference sequence.

[0037] In this embodiment, by calculating the energy value corresponding to the phase difference sequence, the difference between the guessed θ value and compensation frequency and the actual θ value and compensation frequency can be determined, so as to determine the θ value and compensation frequency that best fit the actual θ value and actual compensation frequency based on the energy value.

[0038] In a possible implementation, the MIMO radar system includes N transmitting antennas, where N is a positive integer greater than 1, and the compensation frequency has a value range of [0, (N-1)f D,max ] or [-(N-1)f D,max , 0], the f D , max is the Doppler frequency corresponding to the maximum unambiguous velocity measurable by the MIMO radar system.

[0039] In this embodiment, each set compensation frequency can make the maximum energy value finally determined to be one value, that is, the energy value corresponding to only one phase difference sequence is the maximum, thereby avoiding the situation where, when there are multiple phase difference sequences corresponding to the maximum energy values, it is impossible to determine which speed is the actual moving speed of the object from the multiple speed measurement results corresponding to the multiple phase difference sequences.

[0040] In a third aspect, an embodiment of the present application further provides a device for resolving velocity ambiguity, which is applied to a FMCW sensor having at least two transmitting antennas and at least one receiving antenna, and the device includes:

[0041] The first acquisition module includes acquiring a phase sequence corresponding to the transceiver channel one by one based on the fast Fourier transform (FFT) result of the echo signal;

[0042] A second acquisition module, used for acquiring a phase difference sequence between the transmitting and receiving channels based on the angle set to be searched and the fuzzy number set to be searched;

[0043] a beamforming module, configured to perform beamforming based on the phase sequence and the phase difference sequence to obtain an energy spectrum corresponding to each phase difference sequence; and

[0044] The speed defuzzification module is used to take the maximum energy spectrum among the extreme values ​​as the target energy spectrum, and perform the speed defuzzification according to the fuzzy number corresponding to the target energy spectrum.

[0045] In some possible implementations, the device further includes:

[0046] The third acquisition module is used to acquire a direction of arrival angle based on the target energy spectrum.

[0047] In some possible implementations, the set of angles to be searched is defined as:

[0048] θ set ={arcsin(sinStart+sinStep·n)|n=0,1,2,...θ num-1}

[0049] Among them, θ set represents the angle set to be searched, θ num represents the number of angles to be searched, the sinStart represents the sine value of the starting angle to be searched, and the sinStep represents the search step of the angle to be searched in the sine domain.

[0050] In a fourth aspect, an embodiment of the present application further provides a device for determining a moving speed of an object, the device being applied to a multiple-input multiple-output MIMO radar system, the device comprising:

[0051] A fast Fourier transform module is used to perform fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals;

[0052] A first determination module is used to determine the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal according to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, so as to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs;

[0053] A vector operation module, used to perform vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively, to obtain an energy value corresponding to each phase difference sequence;

[0054] A second determination module is used to determine the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, and the energy value corresponding to the target phase difference sequence is the largest;

[0055] The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0056] In a possible implementation, the device further includes:

[0057] The third determination module is used to determine the target arrival direction corresponding to the sampling signal according to the target phase difference sequence.

[0058] In a possible implementation manner, the first phase difference sequence is any one of the multiple phase difference sequences, and the device further includes:

[0059] an acquisition module, configured to acquire a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves;

[0060] A first calculation module, used for calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence, to obtain the Doppler frequency corresponding to the first phase difference sequence;

[0061] The second calculation module is used to calculate the compensation phase difference corresponding to the first phase difference sequence according to the Doppler frequency corresponding to the first phase difference sequence.

[0062] In a possible implementation, the vector operation module includes:

[0063] A first calculation unit, used for respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal;

[0064] The second calculation unit is used to calculate the modulus of the vector product corresponding to each phase difference sequence, and use the modulus as the energy value corresponding to the phase difference sequence.

[0065] In a possible implementation, the MIMO radar system includes N transmitting antennas, where N is a positive integer greater than 1, and the compensation frequency has a value range of [0, (N-1)f D,max ] or [-(N-1)f D,max , 0], the f D , max is the Doppler frequency corresponding to the maximum unambiguous velocity measurable by the MIMO radar system.

[0066] In a fifth aspect, an embodiment of the present application further provides an integrated circuit, which may include a processor and a memory:

[0067] The memory is used to store program code and transmit the program code to the processor;

[0068] The processor is used to execute the method for resolving velocity ambiguity described in any one of the first aspects or the method for determining the moving speed of an object described in any one of the second aspects according to the instructions in the program code.

[0069] In a possible implementation, the integrated circuit is a millimeter wave radar chip.

[0070] In a sixth aspect, an embodiment of the present application further provides a radio device, which may include: a carrier;

[0071] The integrated circuit as described in any of the above items is arranged on a carrier; the antenna is arranged on the carrier, or is integrated with the integrated circuit as a device arranged on the carrier; wherein the integrated circuit is connected to the antenna for sending and receiving radio signals. The carrier may be a printed circuit board PCB, and the first transmission line may be a PCB trace.

[0072] In a seventh aspect, an embodiment of the present application further provides a device, which may include: a device body; and

[0073] A radio device as described above is arranged on the device body; wherein the radio device is used for target detection and / or communication.

[0074] In the above implementation method of the embodiment of the present application, FFT processing can be performed on the sampling signals corresponding to each transmitting antenna in the MIMO radar system on each receiving antenna to obtain a phase sequence of the sampling signals, and each element in the phase sequence of the sampling signals corresponds to the phase information on the transmission link of a transmitting antenna and a receiving antenna; at the same time, the phase difference of the sampling signals corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal can be determined according to a preset plurality of different directions of arrival DOA and a plurality of different compensation frequencies to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the above-mentioned phases, and in each phase difference sequence, there exists a target phase difference of some sampling signals relative to the reference sampling signal, including a static phase difference and a compensation phase difference, and the static phase The difference is determined according to the wave arrival direction and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensated phase difference is determined according to the compensation frequency and the object moving speed measured by the MIMO radar system. The compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed that can be measured by the MIMO radar system. The compensation frequencies and / or DOAs corresponding to any two phase difference sequences in the multiple phase difference sequences are different; then, the multiple phase difference sequences can be respectively vectorized with the phase sequence of the sampling signal to obtain the energy value corresponding to each phase difference sequence, and the moving speed of the object is determined according to the compensation frequency corresponding to the target phase difference sequence, and the energy value corresponding to the target phase difference sequence is the largest, wherein the multiple different compensation frequencies are set so that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0075] It can be understood that the maximum unambiguous speed that the original MIMO radar system can measure is the object movement speed corresponding to the maximum Doppler frequency of the MIMO radar system. However, after using the compensation frequency to compensate for the measurement Doppler frequency generated when the MIMO radar system measures the movement of the object, the measurable range of the Doppler frequency generated when the MIMO radar system measures the movement of the object can be increased. The greater the Doppler frequency generated when the object moves, the greater the movement speed of the object. This increases the measurable range of the object movement speed that the MIMO radar system can actually measure, thereby improving the accuracy of the MIMO radar system in measuring the movement speed of the object. Moreover, the embodiment of the present application does not require the transmitter (including multiple transmitting antennas) of the MIMO radar system to generate a specific waveform, thereby reducing the design difficulty of the transmitter in the MIMO radar system. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0077] Figure 1 This is a flow chart of a method for determining the moving speed of an object in an embodiment of the present application;

[0078] Figure 2 Schematic diagram of the phase difference of the sampling signal in the 2T4R MIMO radar system;

[0079] Figure 3 Schematic diagram for finding the q value and θ value corresponding to the maximum energy value;

[0080] Figure 4 This is a schematic diagram of the structure of a device for determining the moving speed of an object in an embodiment of the present application;

[0081] Figure 5 This is a schematic diagram of the structure of a device for resolving velocity ambiguity in an embodiment of the present application;

[0082] Figure 6 This is a schematic diagram of the hardware structure of an integrated circuit in an embodiment of the present application. DETAILED DESCRIPTION

[0083] In a method for resolving velocity ambiguity provided in an embodiment of the present application, the detection of target velocity can be effectively achieved by utilizing beamforming, that is, the method is applied to a frequency modulated continuous wave (FMCW) sensor having at least two transmitting antennas and at least one receiving antenna, by first performing operations such as ADC and 2D-FFT processing on the echo signal to obtain a phase sequence corresponding to the transmitting and receiving channels one by one, and then obtaining a phase difference sequence between the transmitting and receiving channels based on a set of angles to be searched and a set of fuzzy numbers to be searched, and then performing beamforming operations based on the phase sequence and the phase difference sequence to obtain energy spectra corresponding to each phase difference sequence, and finally taking the largest energy spectrum among the extreme values ​​as the target energy spectrum, and performing the velocity ambiguity resolution according to the fuzzy numbers corresponding to the target energy spectrum, and further obtaining target parameters such as the direction of arrival angle based on the target energy spectrum.

[0084] In this embodiment, by using beamforming to resolve speed ambiguity, not only can the range and accuracy of target detection speed be improved, but also the amount of calculation can be effectively reduced, and the design difficulty of the transmitter can be reduced, which is suitable for different application scenarios; in addition, while resolving speed ambiguity, the arrival direction angle can be obtained at the same time, which can effectively reuse traditional hardware resources and reduce design difficulty and cost.

[0085] In a possible implementation, in order to further reduce the amount of computation and improve the efficiency of resolving speed ambiguity, the angles to be searched may be specially set based on the function used in the specific data processing process. For example, since a sine function is calculated for the angles to be searched in this application, the angles to be searched may be set based on the difference of equal sine functions, and the set of angles to be searched may be defined as:

[0086] θ set ={arcsin(sinStart+sinStep·n)|n=0,1,2,...θ num-1}

[0087] Among them, θ set represents the angle set to be searched, θ num represents the number of angles to be searched, the sinStart represents the sine value of the starting angle to be searched, and the sinStep represents the search step of the angle to be searched in the sine domain.

[0088] The solution of the present application is described in detail below using MIMO radar as an example, but it should be understood that those skilled in the art can apply the relevant technology to other radio devices capable of achieving target detection in combination with the contents recorded in the present application.

[0089] Multiple Input Multiple Output (MIMO) radar is an important technology to improve the angular resolution of millimeter wave radar, and is widely used in remote sensing, navigation, resource exploration and other fields. Among them, a MIMO radar system usually has N transmitting antennas (TX) and M receiving antennas (RX), where N and M are both positive integers greater than 1, and by properly arranging the positions of the antennas, an N TX ×M RX Virtual antenna array.

[0090] However, compared with a Single Input Multiple Output (SIMO) radar system (a SIMO radar system has only one transmitting antenna), the range of object movement speeds that a MIMO radar system can measure is 1 / N of the range of object movement speeds that a SIMO radar system with the same configuration can measure, where N is the number of transmitting antennas included in the MIMO radar system. This means that when the object's movement speed exceeds the maximum unambiguous speed of the MIMO radar system, the MIMO radar system cannot measure the object's actual movement speed.

[0091] Specifically, for SIMO radar system and MIMO radar system, the maximum unambiguous velocity v max It can be calculated by the following formula (1). The maximum unambiguous speed refers to the maximum moving speed of the object (person or object) that can be accurately measured by the radar system. When the moving speed of the object exceeds the maximum unambiguous speed of the radar system, the moving speed of the object measured by the radar system may not be accurate.

[0092]

[0093] Where c is the speed of light, f c is the initial frequency of the transmitter frequency sweep, f D,max It is the Doppler frequency corresponding to the maximum unambiguous velocity that can be measured by the radar system.

[0094] For a MIMO radar system with N transmitting antennas and M receiving antennas, no matter whether the N transmitting antennas send signals in a time division manner or a code division manner, the sampling period for measuring the moving speed of the object needs to be at least N*Tr, where Tr is a Chirp period. Specifically, when a time division method is used to send signals, at most only one transmitting antenna sends signals at the same time, that is, the first transmitting antenna sends signals in the first Tr. When the first Tr ends, the second transmitting antenna sends signals in the second Tr, and so on, until the Nth transmitting antenna completes signal transmission in the Nth Tr, so that each receiving antenna can receive N signals in sequence, which is equivalent to completing a Doppler domain (speed dimension) sampling on all N*M receiving antennas, and the duration is N*Tr; when a code division method is used to send signals, although N transmitting antennas can send signals at the same time at the same time, the signals received by the M receiving antennas are obtained by integrating the signals sent by the N transmitting antennas. Therefore, the N transmitting antennas need to send N signals in N Trs continuously to achieve decoding of the signals received by the receiving end, so as to achieve a Doppler domain (speed dimension) sampling on all N*M receiving antennas.

[0095] For a SIMO radar system with only one transmitting antenna and M receiving antennas, the transmitting antenna can complete the sampling of the M receiving antennas in the Doppler domain (velocity dimension) once only by sending a signal at 1 Tr, so the sampling period of the SIMO radar system to measure the moving speed of the object can be one Chirp period. The maximum Doppler frequency that can be measured by the radar system is determined according to the sampling period of the radar system in the Doppler domain (velocity dimension), so the maximum unambiguous velocity v of the MIMO radar system is max,MIMO is the maximum unambiguous velocity v of the SIMO radar system max,SIMO 1 / N of , as shown in the following formula:

[0096]

[0097]

[0098] Based on this, the embodiment of the present application provides a method for determining the moving speed of an object, aiming to expand the range of the moving speed of an object that can be measured by a MIMO radar system, thereby improving the accuracy of measuring the moving speed of an object. In specific implementation, the sampling signal corresponding to each transmitting antenna in the MIMO radar system on each receiving antenna can be processed by fast Fourier transform FFT to obtain a phase sequence of the sampling signal, and each element in the phase sequence of the sampling signal corresponds to the phase information on the transmission link of a transmitting antenna and a receiving antenna; at the same time, the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal can be determined according to a plurality of preset different directions of arrival (DOA) and a plurality of different compensation frequencies, to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the above-mentioned phases, and the target phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the MIMO radar system The compensation frequency is determined by the object moving speed measured by the system, the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and the compensation frequencies corresponding to any two phase difference sequences in the multiple phase difference sequences are different and / or the DOAs are different; then, the multiple phase difference sequences can be respectively vectorized with the phase sequence of the sampling signal to obtain the energy value corresponding to each phase difference sequence, and the moving speed of the object is determined according to the compensation frequency corresponding to the target phase difference sequence, and the energy value corresponding to the target phase difference sequence is the largest, wherein the multiple different compensation frequencies are set so that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0099] It can be understood that the maximum unambiguous speed that the original MIMO radar system can measure is the object movement speed corresponding to the maximum Doppler frequency of the MIMO radar system. However, after using the compensation frequency to compensate for the measurement Doppler frequency generated when the MIMO radar system measures the movement of the object, the measurable range of the Doppler frequency generated when the MIMO radar system measures the movement of the object can be increased. The greater the Doppler frequency generated when the object moves, the greater the movement speed of the object. This increases the measurable range of the object movement speed that the MIMO radar system can actually measure, thereby improving the accuracy of the MIMO radar system in measuring the movement speed of the object. Moreover, the embodiment of the present application does not require the transmitter (including multiple transmitting antennas) of the MIMO radar system to generate a specific waveform, thereby reducing the design difficulty of the transmitter in the MIMO radar system.

[0100] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, various non-limiting implementation methods in the embodiments of the present application are exemplarily described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0101] See also Figure 1 , Figure 1 A flow chart of a method for determining the moving speed of an object in an embodiment of the present application is shown, and the method can be applied to a MIMO radar system. For ease of description, the present embodiment takes the MIMO radar system transmitting signals in a time-division manner as an example to explain in detail the technical solution of the embodiment of the present application, and the method can specifically include:

[0102] S101: Perform FFT processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals.

[0103] When the MIMO radar system measures the moving speed of an object, the transmitting antenna of the MIMO radar system may transmit a signal, and the transmitted signal is reflected after contacting the object, and the reflected signal is received by the receiving antenna of the MIMO radar. The signals transmitted by each transmitting antenna in turn may be received by each receiving antenna in turn, so that the moving speed of the object is measured according to the signals received by the receiving antenna.

[0104] In specific implementation, multiple Chirp signals from different transmitting antennas received by all receiving antennas can be sampled in sequence to obtain multiple Chirp sampling signals (discrete signals), and the discrete signal in each chirp is processed by one-dimensional FFT (Fast Fourier Transform), and then the sampling signal Chirp of the same receiving antenna corresponding to the same transmitting antenna is processed by two-dimensional FFT, and then the obtained two-dimensional FFT result is processed by using a CFAR (constant false alarm detection probability) module, and the frequency position of the object is determined from the two-dimensional FFT results of all receiving antennas (that is, the difference frequency between the echo signal frequency received by the receiving antenna and the reference signal frequency, which can be used to determine the distance information and speed information of the target), so that the phase information of the signal transmitted by each transmitting antenna on each receiving antenna for the same target can be obtained; the phase information of all receiving antennas is represented by a vector to obtain a sequence containing multiple phase information, which is the phase sequence of the sampling signal described in step S101.

[0105] For ease of understanding, the sampling process is specifically described below using a 2T4R MIMO radar system (i.e., a MIMO radar system including two transmitting antennas and four receiving antennas). Assume that the transmitting antenna TX0 transmits a signal in the first Chirp period, and the signal can be received by the four receiving antennas RX0, RX1, RX2, and RX3, respectively. Then, the Chirp signals received by the four receiving antennas can be sampled to obtain the sampling signals corresponding to TX0 on the four receiving antennas, which are assumed to be sequence y0, sequence y1, sequence y2, and sequence y3, respectively (where each sampling signal corresponds to a sequence). Next, the transmitting antenna TX1 continues to transmit a signal in the second Chirp period, and the signal can also be received by the receiving antennas RX0, RX1, RX2, and RX3, respectively. After sampling the Chirp signals received by the four receiving antennas, the sampling signals corresponding to TX1 on the four receiving antennas can be obtained, which are assumed to be sequence y4, sequence y5, sequence y6, and sequence y7, respectively. The MIMO radar system can continuously send multiple Chirp signals to measure the moving speed of the object. Assuming that the number of sent Chirp signals is 128, the transmitting antenna TX0 will continue to transmit signals in the third Chirp cycle. Similarly, by sampling the Chirp signals received by the four receiving antennas, we can get the sequence y8, sequence y9, sequence y 10 , sequence y 11 . And so on.

[0106] In this way, 512 sequences can be obtained, among which:

[0107] Sequence y 8i(i=0,1,…,63) corresponds to the 64 sequences sent by TX0 and received by RX0;

[0108] Sequence y 8i+1 (i=0,1,…,63) corresponds to the 64 sequences sent by TX0 and received by RX1;

[0109] Sequence y 8i+2 (i=0,1,…,63) corresponds to the 64 sequences sent by TX0 and received by RX2;

[0110] Sequence y 8i+3 (i=0,1,…,63) corresponds to the 64 sequences sent by TX0 and received by RX3;

[0111] Sequence y 8i+4 (i=0,1,…,63) corresponds to the 64 sequences sent by TX1 and received by RX0;

[0112] Sequence y 8i+5 (i=0,1,…,63) corresponds to the 64 sequences sent by TX1 and received by RX1;

[0113] Sequence y 8i+6 (i=0,1,…,63) corresponds to the 64 sequences sent by TX1 and received by RX2;

[0114] Sequence y 8i+7 (i=0,1,…,63) corresponds to the 64 sequences sent by TX1 and received by RX3;

[0115] In practical applications, the receiving channel that receives the sequence sent by TX1 can be called a virtual receiving channel to facilitate comparison with a SIMO radar system with only one transmitting antenna. Therefore, a total of 8 (number of receiving channels) times 64 (number of Chirps) sampling signal sequences can be obtained, where the number of receiving channels 8 is equal to the number of transmitting antennas 2 times the number of receiving antennas 4.

[0116] Then, by performing one-dimensional FFT processing on each sequence, the frequency information caused by the distance of the object relative to the radar can be obtained; and by performing two-dimensional FFT processing on the 64 sequences of each receiving channel, the frequency (Doppler frequency) information caused by the movement of the object relative to the radar can be obtained.

[0117] After two-dimensional FFT processing, a total of 8 (the number of receiving channels) two-dimensional FFT results can be obtained, wherein each value in the two-dimensional FFT result represents the amplitude and phase information of a frequency.

[0118] The MIMO radar system can input all the two-dimensional FFT results to the CFAR module, which determines the frequency position of the object to be detected (i.e., the difference frequency between the echo signal frequency received by the receiving antenna and the reference signal frequency). Then, according to the frequency of the object to be detected given by the CFAR module, the amplitude and phase information of the frequency are output from the two-dimensional FFT results of each receiving channel. Thus, the phase sequence D = {d0, d1, d2, d3, d4, d5, d6, d7} of the sampling signals of the 8 receiving channels can be obtained.

[0119] S102: Determine the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to a reference sampling signal according to a preset plurality of different directions of arrival DOAs and a plurality of different compensation frequencies, and obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the above-mentioned phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and a measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences correspond to different compensation frequencies and / or different directions of arrival DOAs.

[0120] In this embodiment, after obtaining the phase sequence of the sampling signal, the phase difference between the sampling signals corresponding to each phase in the phase sequence of the sampling signal and the reference sampling signal can be further determined to obtain a phase difference sequence. The reference sampling signal can be any one of the sampling signals corresponding to the above-mentioned phases. It is worth noting that the phase difference of a part of the sampling signals in the phase difference sequence relative to the reference sampling signal is a static phase difference, which can be determined based on the wave direction and the distance between each receiving antenna and / or the distance between each transmitting antenna, while the phase difference of another part of the sampling signals relative to the reference signal can be the sum of the static phase difference and the compensation phase difference, wherein the compensation phase difference can be determined based on the compensation frequency and the measured value of the Doppler frequency measured by the MIMO radar system when the object moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed that can be measured by the MIMO radar system.

[0121] For ease of understanding, the process of obtaining the phase difference sequence is described in detail using the 2T4R MIMO radar system as an example. Figure 2As shown (assuming that the object is moving away from the MIMO radar system at a speed of V), the receiving antennas RX0, RX1, RX2, and RX3 can receive the signals transmitted by the transmitting antennas TX0 and TX1 respectively, and the distance between two adjacent transmitting antennas is 4d, and the distance between two adjacent receiving antennas is d. Among them, the sampling signal of TX0 on RX0 can be used as the reference sampling signal, then the phase difference of the sampling signal of TX0 on RX0 relative to the reference sampling signal is φ0=0, and the phase difference of the sampling signal of TX0 on RX1 relative to the reference sampling signal is Among them, d represents the distance between RX1 and RX0, θ is the direction of arrival (or called the angle of arrival), c represents the speed of light, and λ represents the wavelength of the signal. Similarly, the phase difference of the sampling signal of TX0 on RX2 relative to the reference sampling signal is φ2=2φ, and the phase difference of the sampling signal of TX0 on RX3 relative to the reference sampling signal is φ3=3φ. Since the distance between TX0 and TX1 is 4d, and the position change caused by the movement of the object, the sampling signal of TX1 on RX0 (i.e., the above-mentioned target sampling signal) relative to the reference sampling signal not only has a static phase difference of 4φ (determined based on the distance between TX0 and TX1 being 4d), but also has a compensating phase difference φ', and the compensating phase difference φ'=2πf d T r =2π(qf D，max +f 测 )T r , where f d Characterize the frequency of calculating the compensation phase difference φ', T r represents the Chirp period, q is the compensation coefficient, f D，max is the Doppler frequency corresponding to the maximum unambiguous velocity that can be measured by the MIMO radar system, which can be obtained by Calculated, qf D，max That is, it represents the compensation frequency, where f 测 The measured value that characterizes the Doppler frequency measured by the MIMO radar system when the object moves, therefore, the phase difference of the sampling signal of TX1 on RX0 relative to the reference sampling signal is φ4=4φ+φ'; similarly, the phase difference of the sampling signal of TX1 on RX1 relative to the reference sampling signal is φ5=5φ+φ', which phase difference includes the static phase difference 5φ determined according to the 4d distance between TX0 and TX1 and the d distance between RX0 and RX1 and the compensation phase difference φ'; the phase difference of the sampling signal of TX1 on RX2 relative to the reference sampling signal is φ6=6φ+φ', and the phase difference of the sampling signal of TX1 on RX3 relative to the reference sampling signal is φ7=7φ+φ', so that the phase difference sequence φ={φ0,φ1,φ2,φ3,φ4,φ5,φ6,φ7} composed of these phase differences can be obtained.

[0122] It is worth noting that due to φ'=2πf d T r =2π(qf D，max +f 测 )T r Therefore, when θ and q take different values, the values ​​of each phase difference in the obtained phase difference sequence are also different. Therefore, based on different θ values ​​and q values, multiple different phase difference sequences can be obtained. In practical applications, multiple different θ values ​​(i.e., the values ​​guessed at the possible DOA angles of the signals received by the receiving antenna) can be pre-set. For example, a certain number of θ values ​​can be set according to the measurement accuracy of the direction of arrival (such as 0.1°, etc.) and the measurement range (such as [-60°, 60°], etc.) in practical applications; at the same time, multiple different q values ​​(i.e., the values ​​guessed at the Doppler frequency values ​​generated by the actual movement of the object) can also be pre-set. The absolute value of the q value is usually less than the number of transmitting antennas in the MIMO radar system. Setting multiple different q values ​​is to set multiple different compensation frequencies. Assuming that the number of θ values ​​is n and the number of compensation frequencies (i.e., compensation coefficient q) values ​​is m, n*m different phase difference sequences can be obtained based on n different θ values ​​and m different compensation frequencies.

[0123] It can be understood that, since the MIMO radar cannot know the actual value of the arrival angle θ of the signal received on the receiving antenna during the measurement of the movement of the object, the possible values ​​of the arrival angle θ can be traversed to obtain n different values; similarly, the Doppler frequency measured by the MIMO radar system may not be the Doppler frequency actually generated when the object moves, but the actual Doppler frequency and the Doppler frequency measured by the MIMO radar system usually differ by an integer multiple of the maximum Doppler frequency. Therefore, the possible values ​​of the Doppler frequency actually generated when the object moves can also be traversed, that is, all possible values ​​of the compensation frequency (that is, the compensation coefficient q) can be traversed to obtain m different values, so that a combination of the θ value and the compensation frequency (that is, the compensation coefficient q) that can characterize the actual moving speed of the object can be determined from n*m different combinations, wherein the specific determination process can be the process of executing subsequent steps S103 to S104.

[0124] As an example, after determining the compensation frequency corresponding to each phase difference sequence, the compensation phase difference corresponding to each phase difference sequence can also be determined. Specifically, for each phase difference sequence (hereinafter referred to as the first phase difference sequence for ease of description), the measurement value of the Doppler frequency measured by the MIMO radar system when the object moves can be obtained, for example, it can be determined after two-dimensional FFT processing of multiple Chirp signals on the same receiving antenna, etc. Then, the sum of the measurement value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence can be calculated to obtain the Doppler frequency corresponding to the first phase difference sequence, so that the compensation phase difference corresponding to the first phase difference sequence can be calculated according to the Doppler frequency corresponding to the first phase difference sequence, for example, it can be through the formula φ'=2π(qf D，max +f 测 )T r Calculated etc.

[0125] S103: performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence.

[0126] In an exemplary specific implementation, after obtaining multiple different phase difference sequences based on different θ values ​​and different compensation frequencies, the vector product between each phase difference sequence and the phase sequence of the sampling signal obtained in step S101 can be calculated respectively, and the square of the modulus of the vector product corresponding to each phase difference sequence can be further calculated. The square of the modulus can be used as the energy value corresponding to the phase difference sequence, so that multiple energy values ​​can be obtained for multiple phase difference sequences.

[0127] In another possible implementation, when performing vector operations on multiple phase difference sequences and the phase sequence of the sampling signal respectively, the multiple phase difference sequences may be grouped based on the compensation frequency, that is, the phase difference sequences in the same group have different corresponding θ values, but the compensation frequency is the same, and the compensation frequencies corresponding to the phase difference sequences in different groups are different. In this way, for all phase difference sequences with different compensation frequencies, all energy values ​​can be obtained by using the existing hardware resources multiple times. The hardware resources can complete the vector operations of the phase difference sequences corresponding to all different θ values ​​of a certain fixed compensation frequency and the phase sequence of the sampling signal at one time, and obtain its energy spectrum (energy values ​​of all θ), and output its maximum energy value and the corresponding θ value.

[0128] S104: Determine the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, wherein the energy value corresponding to the target phase difference sequence is the largest, and the multiple different compensation frequencies result in only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0129] Generally, when the guessed θ value and compensation frequency are close to the actual θ value and compensation frequency, the energy value corresponding to the phase difference sequence determined according to the θ value and compensation frequency is usually the largest. Therefore, in one example, the phase difference sequence corresponding to the maximum energy value can be determined (hereinafter referred to as the target phase difference sequence for ease of description), and the compensation frequency used by the target phase difference sequence can be further determined, that is, the Doppler frequency actually generated by the object when it moves can be determined. In this way, the moving speed of the object can be determined based on the Doppler frequency, thereby completing the measurement of the moving speed of the object by the MIMO radar system.

[0130] In this embodiment, in order to facilitate the subsequent determination of the uniqueness of the θ value and the compensation frequency (or the compensation coefficient q), when setting the compensation frequency (i.e., the compensation coefficient q), it can be required that the set compensation frequency (i.e., the compensation coefficient q) can make the maximum energy value finally determined to be one value, that is, the energy value corresponding to only one phase difference sequence is the maximum. This can avoid the situation where, when there are multiple phase difference sequences corresponding to the maximum energy values, it is impossible to determine which speed is the actual moving speed of the object from the multiple speed measurement results corresponding to the multiple phase difference sequences.

[0131] As an example, the compensation frequency may range from [0, (N-1)f D,max ] or [-(N-1)f D,max ,0],f D，max is the Doppler frequency corresponding to the maximum unambiguous velocity measurable by the MIMO radar system, and N is the number of transmitting antennas included in the MIMO radar system, which is usually a positive integer greater than 1. Correspondingly, based on the value range of the compensation frequency, the value range of the compensation coefficient q can be adaptively adjusted according to the number of transmitting antennas. Optionally, the value range of the compensation coefficient q can be N consecutive integers including "0". For example, for a MIMO antenna with two transmitting antennas, q can be (0, 1) or (-1, 0); for a MIMO antenna with three transmitting antennas, q can be (0, 1, 2), (-2, -1, 0) or (-1, 0, 1); for a MIMO antenna with four transmitting antennas, q can be (0, 1, 2, 3), (-3, -2, -1, 0), (-1, 0, 1, 2) or (-2, -1, 0, 1), etc.

[0132] Optionally, in this embodiment, not only the actual moving speed of the object can be measured, but also, after determining the target phase difference sequence corresponding to the maximum energy value, the target direction of arrival corresponding to the sampled signal obtained by sampling on the receiving antenna can be further determined according to the target phase difference sequence. It can be understood that after determining the target phase difference sequence, the θ value based on which the target phase difference sequence is generated can be determined, and the θ value can be used as the direction of arrival DOA measured by the MIMO radar system.

[0133] As an example, after obtaining the energy values ​​corresponding to multiple phase difference sequences, multiple energy spectra can be generated based on different q values, such as Figure 3 As shown. The ordinate of each energy spectrum can represent the energy value, and the abscissa can represent the θ value, so that the maximum energy value can be located from the q energy spectra, and then the corresponding q value and θ value can be determined according to the maximum energy value. In this way, according to the determined q value, the compensation frequency can be obtained, and then the moving speed of the object can be calculated according to the compensation frequency; the determined θ value is used as the direction of arrival DOA measured by the MIMO radar system, so that the direction of arrival DOA can be determined while measuring the moving speed of the object.

[0134] It is worth noting that in this embodiment, the technical solution of the embodiment of the present application is introduced in the scenario that the MIMO radar system uses a time division method to send signals. In actual applications, the technical solution of the embodiment of the present application can also be applied to the scenario that the MIMO radar system uses a code division method to send signals. It can be understood that in the scenario where the signal is sent in a code division method, the signal received by the receiving antenna can be decoded, so that the decoding result is similar to the signal received on the receiving antenna when the signal is sent in a time division method, and the subsequent process is similar to the technical solution of this embodiment. Among them, there are detailed technical applications in the prior art for the decoding process of the received signal, which will not be repeated here.

[0135] In this embodiment, the maximum unambiguous speed that the original MIMO radar system can measure is the object movement speed corresponding to the maximum Doppler frequency of the MIMO radar system. However, after using the compensation frequency to compensate for the measurement Doppler frequency generated when the MIMO radar system measures the movement of the object, the measurable range of the Doppler frequency generated when the MIMO radar system measures the movement of the object can be increased. The greater the Doppler frequency generated when the object moves, the greater the movement speed of the object. This increases the measurable range of the object movement speed that the MIMO radar system can actually measure, thereby improving the accuracy of the MIMO radar system in measuring the movement speed of the object. Moreover, the embodiment of the present application can reuse existing hardware resources, and does not require the transmitter (including multiple transmitting antennas) of the MIMO radar system to generate a specific waveform, thereby reducing the design difficulty of the transmitter in the MIMO radar system.

[0136] In addition, the present application also provides a device for determining the moving speed of an object. Figure 4 , Figure 4 A schematic diagram of the structure of a device for determining the moving speed of an object in an embodiment of the present application is shown. The device 400 may specifically include:

[0137] The fast Fourier transform module 401 is used to perform fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals;

[0138] A first determination module 402 is used to determine the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal according to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, so as to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs;

[0139] A vector operation module 403 is used to perform vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence;

[0140] A second determination module 404 is used to determine the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, and the energy value corresponding to the target phase difference sequence is the largest;

[0141] The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0142] In a possible implementation manner, the device 400 further includes:

[0143] The third determination module is used to determine the target arrival direction corresponding to the sampling signal corresponding to each phase according to the target phase difference sequence.

[0144] In a possible implementation manner, the first phase difference sequence is any one of the multiple phase difference sequences, and the device further includes:

[0145] an acquisition module, configured to acquire a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves;

[0146] A first calculation module, used for calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence, to obtain the Doppler frequency corresponding to the first phase difference sequence;

[0147] The second calculation module is used to calculate the compensation phase difference corresponding to the first phase difference sequence according to the Doppler frequency corresponding to the first phase difference sequence.

[0148] In a possible implementation, the vector operation module 403 includes:

[0149] A first calculation unit, used for respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal;

[0150] The second calculation unit is used to calculate the square of the modulus of the vector product corresponding to each phase difference sequence, and use the square of the modulus as the energy value corresponding to the phase difference sequence.

[0151] In a possible implementation, the MIMO radar system includes N transmitting antennas, where N is a positive integer greater than 1. Then, the value range of the compensation frequency may be: when N is an odd number greater than 2, it may be [0, (N-1)f D,max ] or [-(N-1)f D,max ,0] or [-((N-1) / 2)f D,max ,((N-1) / 2)f D,max ] or [(-N / 2+1)f D,max ,(N / 2)fD,max ],[(-N / 2)f D,max ,(N / 2-1)f D,max ], depending on whether N is an odd or even number, it can be considered as N consecutive integers including "0", the f D , max is the Doppler frequency corresponding to the maximum unambiguous velocity measurable by the MIMO radar system.

[0152] It is worth noting that the device for determining the moving speed of an object described in this embodiment corresponds to the method for determining the moving speed of an object described in the above method embodiment. The specific implementation methods of each module and unit in this embodiment can be found in the relevant descriptions in the above method embodiment and will not be repeated here.

[0153] In addition, the present application also provides a device for resolving velocity ambiguity. Figure 5 , Figure 5 A schematic diagram of the structure of a device for resolving velocity ambiguity in an embodiment of the present application is shown. The device 500 can be applied to a FMCW sensor having at least two transmitting antennas and at least one receiving antenna. The device 500 can specifically include:

[0154] The first acquisition module 501 includes acquiring a phase sequence corresponding to a transceiver channel one by one based on a Fast Fourier Transform (FFT) result of an echo signal;

[0155] A second acquisition module 502 is used to acquire a phase difference sequence between the transmitting and receiving channels based on the angle set to be searched and the fuzzy number set to be searched;

[0156] A beamforming module 503, configured to perform beamforming based on the phase sequence and the phase difference sequence to obtain an energy spectrum corresponding to each phase difference sequence; and

[0157] The speed defuzzification module 504 is used to take the maximum energy spectrum among the extreme values ​​as the target energy spectrum, and perform the speed defuzzification according to the fuzzy number corresponding to the target energy spectrum.

[0158] In a possible implementation manner, the device 500 further includes:

[0159] The third acquisition module is used to acquire a direction of arrival angle based on the target energy spectrum.

[0160] In a possible implementation manner, the angle set to be searched is defined as:

[0161] θ set ={arcsin(sinStart+sinStep·n)|n=0,1,2,...θ num-1}

[0162] Among them, θ set represents the angle set to be searched, θ num represents the number of angles to be searched, the sinStart represents the sine value of the starting angle to be searched, and the sinStep represents the search step of the angle to be searched in the sine domain.

[0163] It is worth noting that the device for determining the moving speed of an object described in this embodiment corresponds to the method for determining the moving speed of an object described in the above method embodiment. The specific implementation methods of each module and unit in this embodiment can be found in the relevant descriptions in the above method embodiment and will not be repeated here.

[0164] In addition, the present application also provides an integrated circuit. Figure 6 , Figure 6 The hardware structure diagram of an integrated circuit in an embodiment of the present application is shown. The integrated circuit 600 includes a processor 601 and a memory 602:

[0165] The memory 602 is used to store program codes and transmit the program codes to the processor 601;

[0166] The processor 601 is configured to execute the following steps according to the instructions in the program code:

[0167] Performing fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals;

[0168] According to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal is determined to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs;

[0169] Performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence;

[0170] Determining the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, wherein the energy value corresponding to the target phase difference sequence is the largest;

[0171] The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

[0172] In a possible implementation, the processor 601 is further configured to perform the following steps according to the instructions in the program code:

[0173] The target arrival directions corresponding to the sampling signals corresponding to the respective phases are determined according to the target phase difference sequence.

[0174] In a possible implementation manner, the first phase difference sequence is any one of the multiple phase difference sequences, and the processor 601 is further configured to perform the following steps according to the instructions in the program code:

[0175] Obtaining a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves;

[0176] Calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence to obtain the Doppler frequency corresponding to the first phase difference sequence;

[0177] The compensating phase difference corresponding to the first phase difference sequence is calculated according to the Doppler frequency corresponding to the first phase difference sequence.

[0178] In a possible implementation, the processor 601 is specifically configured to perform the following steps according to the instructions in the program code:

[0179] respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal;

[0180] The square of the modulus of the vector product corresponding to each phase difference sequence is calculated, and the square of the modulus is used as the energy value corresponding to the phase difference sequence.

[0181] In a possible implementation, the MIMO radar system includes N transmitting antennas, where N is a positive integer greater than 1, and the compensation frequency may be in the range of [0, (N-1)f D,max ] or [-(N-1)f D,max ,0] or [-((N-1) / 2)f D,max ,((N-1) / 2)f D,max ] or [(-N / 2+1)f D,max ,(N / 2)f D,max],[(-N / 2)f D,max ,(N / 2-1)f D,max ], depending on whether N is an odd number or an even number, the f D，max is the Doppler frequency corresponding to the maximum unambiguous velocity measurable by the MIMO radar system.

[0182] or, Figure 6 In the integrated circuit shown, the processor 601 is used to perform the following steps according to the instructions in the program code stored in the memory 602:

[0183] The phase sequence corresponding to the transmitting and receiving channels is obtained based on the fast Fourier transform (FFT) result of the echo signal;

[0184] Acquire a phase difference sequence between the transmitting and receiving channels based on the angle set to be searched and the fuzzy number set to be searched;

[0185] Performing beamforming based on the phase sequence and the phase difference sequence to obtain an energy spectrum corresponding to each phase difference sequence; and

[0186] The maximum energy spectrum among the extreme values ​​is taken as the target energy spectrum, and the speed fuzzification is solved according to the fuzzy number corresponding to the target energy spectrum.

[0187] In a possible implementation, the processor 601 is further configured to execute the following steps according to instructions in the program code stored in the memory 602:

[0188] A direction of arrival angle is obtained based on the target energy spectrum.

[0189] In a possible implementation manner, the angle set to be searched is defined as:

[0190] θ set ={arcsin(sinStart+sinStep·n)|n=0,1,2,...θ num-1}

[0191] Among them, θ set represents the angle set to be searched, θ num represents the number of angles to be searched, the sinStart represents the sine value of the starting angle to be searched, and the sinStep represents the search step of the angle to be searched in the sine domain.

[0192] Optionally, in one embodiment, the above-mentioned integrated circuit may be a millimeter wave radar chip.

[0193] In one embodiment, the present application further provides a radio device, comprising: a carrier; an integrated circuit as in the above embodiment, arranged on the carrier; an antenna, arranged on the carrier; wherein the integrated circuit is connected to the antenna via a first transmission line for transmitting and receiving radio signals. The carrier may be a printed circuit board PCB, and the first transmission line may be a PCB trace.

[0194] In one embodiment, the present application further provides a device, comprising: a device body; and a radio device as described in the above embodiment disposed on the device body; wherein the radio device is used for target detection and / or communication.

[0195] Specifically, based on the above embodiments, in one embodiment of the present application, the radio device can be arranged outside the device body, in another embodiment of the present application, the radio device can also be arranged inside the device body, and in other embodiments of the present application, the radio device can also be arranged partially inside the device body and partially outside the device body. The present application does not limit this, and it depends on the specific situation.

[0196] It should be noted that radio devices can achieve functions such as target detection and communication by transmitting and receiving signals.

[0197] In an optional embodiment, the above-mentioned device body can be a component and product used in fields such as smart housing, transportation, smart home, consumer electronics, monitoring, industrial automation, cabin detection and health care; for example, the device body can be intelligent transportation equipment (such as cars, bicycles, motorcycles, ships, subways, trains, etc.), security equipment (such as cameras), smart wearable devices (such as bracelets, glasses, etc.), smart home equipment (such as TVs, air conditioners, smart lights, etc.), various communication devices (such as mobile phones, tablet computers, etc.), and gates, smart traffic lights, smart signs, traffic cameras and various industrial manipulators (or robots), etc., and can also be various instruments for detecting life characteristic parameters and various equipment equipped with the instruments. The radio device can be the radio device described in any embodiment of the present application. The structure and working principle of the radio device have been described in detail in the above embodiments, and will not be repeated here.

[0198] The "first" in the names of "first phase difference sequence", "first determination module", "first calculation module", "first calculation unit", etc. mentioned in the embodiments of the present application is only used as a name identifier and does not mean the first in order. The same rule applies to "second", etc.

[0199] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0200] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0201] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0202] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0203] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (full name in English: Read-Only Memory, English abbreviation: ROM), random access memory (full name in English: Random Access Memory, English abbreviation: RAM), disk or optical disk and other media that can store program codes.

[0204] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the moving speed of an object, characterized in that: The method is applied to a multiple-input multiple-output MIMO radar system, and the method comprises: Performing fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals; According to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal is determined to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs; Performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence; Determining the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, wherein the energy value corresponding to the target phase difference sequence is the largest; The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

2. The method according to claim 1, characterized in that The method further comprises: The target arrival direction corresponding to the sampling signal is determined according to the target phase difference sequence.

3. The method according to claim 1, characterized in that The first phase difference sequence is any one of the multiple phase difference sequences, and the method further includes: Obtaining a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves; Calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence to obtain the Doppler frequency corresponding to the first phase difference sequence; The compensating phase difference corresponding to the first phase difference sequence is calculated according to the Doppler frequency corresponding to the first phase difference sequence.

4. The method according to claim 1, characterized in that: The performing vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively to obtain an energy value corresponding to each phase difference sequence includes: respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal; The square of the modulus of the vector product corresponding to each phase difference sequence is calculated, and the square of the modulus is used as the energy value corresponding to the phase difference sequence.

5. The method according to any one of claims 1 to 4, characterized in that The MIMO radar system includes N transmitting antennas, where N is a positive integer greater than 1, and the value range of the compensation frequency is N consecutive integers including "0".

6. A device for determining the moving speed of an object, characterized in that The device is applied to a multiple-input multiple-output MIMO radar system, and the device comprises: A fast Fourier transform module is used to perform fast Fourier transform (FFT) processing on the sampling signals corresponding to each transmitting antenna on each receiving antenna to obtain a phase sequence of the sampling signals; A first determination module is used to determine the phase difference of the sampling signal corresponding to each phase in the phase sequence of the sampling signal relative to the reference sampling signal according to a plurality of preset different directions of arrival DOAs and a plurality of different compensation frequencies, so as to obtain a plurality of phase difference sequences, wherein the reference sampling signal is one of the sampling signals corresponding to the respective phases, and the phase difference of some sampling signals relative to the reference sampling signal in each phase difference sequence includes a static phase difference and a compensation phase difference, wherein the static phase difference is determined according to the direction of arrival DOA and the distance between each receiving antenna and / or the distance between each transmitting antenna, and the compensation phase difference is determined according to the compensation frequency and the measured Doppler frequency obtained when the object measured by the MIMO radar system moves, and the compensation frequency is an integer multiple of the Doppler frequency corresponding to the maximum unambiguous speed measurable by the MIMO radar system, and any two phase difference sequences in the plurality of phase difference sequences have different compensation frequencies and / or different directions of arrival DOAs; A vector operation module, used to perform vector operations on the multiple phase difference sequences and the phase sequence of the sampling signal respectively, to obtain an energy value corresponding to each phase difference sequence; A second determination module is used to determine the moving speed of the object according to the compensation frequency corresponding to the target phase difference sequence, and the energy value corresponding to the target phase difference sequence is the largest; The multiple different compensation frequencies ensure that there is only one maximum value among the energy values ​​corresponding to all phase difference sequences.

7. The device according to claim 6, characterized in that The device also includes: The third determination module is used to determine the target arrival direction corresponding to the sampling signal according to the target phase difference sequence.

8. The device according to claim 6, characterized in that The first phase difference sequence is any one of the multiple phase difference sequences, and the device further includes: an acquisition module, configured to acquire a measurement value of a Doppler frequency measured by the MIMO radar system when the object moves; A first calculation module, used for calculating the sum of the measured value of the Doppler frequency and the compensation frequency corresponding to the first phase difference sequence, to obtain the Doppler frequency corresponding to the first phase difference sequence; The second calculation module is used to calculate the compensation phase difference corresponding to the first phase difference sequence according to the Doppler frequency corresponding to the first phase difference sequence.

9. The device according to any one of claims 6 to 8, characterized in that The vector operation module comprises: A first calculation unit, used for respectively calculating the vector product between each phase difference sequence and the phase sequence of the sampling signal; The second calculation unit is used to calculate the square of the modulus of the vector product corresponding to each phase difference sequence, and use the square of the modulus as the energy value corresponding to the phase difference sequence.

10. An integrated circuit, characterized in that: Including processor and memory: The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method according to any one of claims 1 to 5 according to the instructions in the program code.

11. The integrated circuit according to claim 10, characterized in that The integrated circuit is a millimeter wave radar chip.

12. A radio device, characterized in that: include: Carrier; An integrated circuit as claimed in any one of claims 10 or 11, arranged on a carrier; An antenna, arranged on the carrier, or integrated with the integrated circuit as a device arranged on the carrier; Wherein, the integrated circuit is connected to the antenna for sending and receiving radio signals.

13. A device, characterized in that include: Equipment body; as well as The radio device as claimed in claim 12 is disposed on the device body; Wherein, the radio device is used for target detection and / or communication.

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