Radar signal transmitting and receiving method and radar

Abstract

A radar signal transmitting and receiving method and radar, wherein the receiving method comprises: receiving an echo signal (420) formed after a measurement frame sent by a transmitter is reflected by at least one target, wherein the measurement frame comprises U*N slow Chirp signals, where N Tx transmitting antennas and N Rx A virtual receiving array formed by receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2. A first aliasing coefficient and a second aliasing coefficient (430) are determined based on the echo signal. The first aliasing coefficient is the aliasing coefficient corresponding to the overlapping array with a transmission interval of N1 corresponding to the first target, and the second aliasing coefficient is the aliasing coefficient corresponding to the overlapping array with a transmission interval of N2 corresponding to the first target. The speed of the first target is determined based on the first aliasing coefficient and the second aliasing coefficient (440). The method can reduce the influence of noise on the overlapping arrays and improve the accuracy of the target speed solution.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a radar signal transmitting and receiving method and a radar. Background Art

[0002] On-board radar is an essential sensor in autonomous driving systems, enabling vehicle obstacle (or target) detection. Specifically, it transmits a frequency-modulated continuous wave (FMCW) signal and measures the obstacle's distance, velocity, and azimuth by detecting its reflected echo.

[0003] In recent years, automotive radar technology has continued to evolve, and its performance has continued to improve. This can be specifically reflected in the following aspects: the frequency band has gradually evolved from 24 GHz to 77 GHz / 79 GHz, thereby achieving higher range resolution through a larger scanning bandwidth; the waveform has been reduced from a chirp scanning period of several milliseconds to the μs level, decoupling the measured distance and speed, reducing the probability of false targets and effectively avoiding non-ideal characteristics near DC; the number of channels has evolved from a single-input multiple-output (SIMO) mode to a multiple-input multiple-output (MIMO) mode, and the continuous expansion of antenna size has increased the virtual antenna aperture, thereby improving angular resolution, which can meet the higher spatial resolution requirements of autonomous driving.

[0004] Currently, in MIMO radars, multiple antennas can use time division multiplexing (TDM) to send chirp signals to expand the virtual antenna aperture. However, TDM MIMO radars have the problem of a reduced maximum speed measurement range. Generally, the maximum speed measurement range of a radar can be expressed as ±V max =λ / (4*T), where λ is the wavelength of the modulation frequency and T is the period of repeated transmission by the same antenna. Assume that the duration of a chirp sent by a single antenna is T SIMO (It can be recorded as a time slot). Then, in TDM MIMO radar, N Tx Chirp signals require at least N Tx time slots, namely N Tx The antennas use time division multiplexing to transmit N Tx The duration of a chirp is T MIMO =N Tx *TSIMO Under the same single antenna transmission duration of a chirp, N Tx The maximum speed measurement range V transmitted by the antenna max_MIMO The speed measurement interval V transmitted by a single antenna max_SIMO The relationship is as follows: V max_SIMO =N Tx *V max_MIMO From the above formula, we can see that in TDM MIMO radar, due to the increase in the number of transmitting antennas, the maximum speed measurement range decreases compared with SIMO radar. Tx The greater the number of MIMO radars, the more severe the reduction in the maximum speed measurement range. This reduction in maximum speed measurement range increases the likelihood of velocity aliasing when calculating target speed. Furthermore, due to the coupled velocity and angle measurements in TDM MIMO radars, velocity aliasing affects angle calculations, defeating the intended goal of improving target spatial resolution.

[0005] To address this issue, the prior art paper "J. Bechter, F. Roos, C. Waldschmidt, "Compensation of Motion-Induced Phase Errors in TDM MIMO Radars," IEEE Microwave and Wireless Components Letters, vol. 27, no. 12, pp. 1164-1166, Dec. 2017" proposes a method for calculating velocity using the phase differences between identically positioned elements within a virtual receiving array formed by adjacent transmitting antennas. Identical elements within a virtual receiving array are also referred to as overlapping elements. However, this method suffers from the following issues: Because the number of overlapping elements is limited by the antenna array layout, the number of overlapping elements is typically small to minimize loss of virtual antenna aperture. Furthermore, the requirement to use overlapping elements formed by adjacent transmitting antennas further limits the number of available overlapping elements, making the phase differences between these elements susceptible to noise, thus affecting the accurate calculation of the target's velocity. Summary of the Invention

[0006] The embodiments of the present application provide a radar signal transmission and reception method and a radar, which are used to solve the problem that the phase difference of overlapping arrays is easily affected by noise, thereby affecting the correct solution of the target speed.

[0007] In a first aspect, the present application provides a radar signal transmission method, which is applied to a MIMO radar, wherein the MIMO radar includes a transmitter and a receiver, wherein the transmitter includes N Txtransmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, the method comprising: determining configuration information of a measurement frame, wherein the configuration information of the measurement frame indicates the N Tx The preset transmission order of the transmitting antennas and the transmission duration T of each chirp signal c and the N Tx The transmitting antennas repeat the transmission in the preset transmission order for a number of times N slow ; Send the measurement frame according to the configuration information of the measurement frame, the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx .

[0008] Adopt the design of the measurement frame provided in the embodiment of the present application, through N Tx The preset transmission sequence of the transmitting antennas can construct overlapping arrays with multiple transmission intervals and increase the number of overlapping arrays. Compared to the prior art with a smaller number of overlapping arrays and overlapping arrays with a single transmission interval, when the phase difference of the overlapping arrays is significantly affected by noise, it will directly affect the accurate solution of the target velocity. However, because the embodiments of the present application construct overlapping arrays with multiple transmission intervals and a large number of overlapping arrays, even if the phase difference of some overlapping arrays is significantly affected by noise, the phase differences of multiple overlapping arrays with multiple transmission intervals can be processed to effectively reduce the impact of the phase difference of the overlapping arrays that are significantly affected by noise on the velocity solution, thereby improving the accuracy of the target velocity solution.

[0009] In one possible design, for each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1, the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

[0010] In one possible design, the N Tx At least one transmitting antenna among the U transmitting antennas transmits chirp signals twice in the U time slots.

[0011] By adopting the above design, the number of overlapping arrays can be increased.

[0012] In one possible design, the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

[0013] Using the above design, by designing N Tx The preset transmission sequence of the transmitting antennas can realize the construction of overlapping arrays with multiple transmission intervals and increase the number of overlapping arrays.

[0014] In one possible design, the values ​​of N1 and N2 are determined by the antenna array and the preset transmission order.

[0015] It is understandable that, since the smaller the value of the transmission interval is, the larger the corresponding speed measurement range is, and fewer multiples of aliasing can be achieved, the values ​​of N1 and N2 are generally smaller.

[0016] In a second aspect, the present application provides a radar signal receiving method, which is applied to a MIMO radar, wherein the MIMO radar includes a transmitter and a receiver, wherein the transmitter includes N Txtransmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, the method comprising: receiving an echo signal formed after a measurement frame is reflected by at least one target, the measurement frame comprising U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx ; Determine a first aliasing coefficient and a second aliasing coefficient based on the echo signal; wherein the first aliasing coefficient is the aliasing coefficient corresponding to the overlapping array with a transmission interval of N1 corresponding to the first target, the second aliasing coefficient is the aliasing coefficient corresponding to the overlapping array with a transmission interval of N2 corresponding to the first target, and the first target is any one of the at least one target; determine the speed of the first target based on the first aliasing coefficient and the second aliasing coefficient.

[0017] Compared to the prior art with a smaller number of overlapping arrays and overlapping arrays with a single transmission interval, when the phase difference of the overlapping arrays is significantly affected by noise, it will directly affect the correct solution of the target's speed. Using the method provided in the embodiments of the present application, when solving for the speed of each target, the aliasing coefficients corresponding to the overlapping arrays of multiple transmission intervals and the larger number of overlapping arrays can be calculated. Even if the phase difference of some of the overlapping arrays in the above-mentioned overlapping arrays is significantly affected by noise, resulting in inaccurate solution of the corresponding aliasing coefficients, solving the target's speed based on the aliasing coefficients corresponding to the overlapping arrays of multiple transmission intervals can effectively reduce the impact of the aliasing coefficients corresponding to the overlapping arrays significantly affected by noise on the speed solution, thereby improving the accuracy of the target speed solution. In addition, using the above method, there will be no loss of virtual antenna aperture.

[0018] In one possible design, for each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is dm1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

[0019] In one possible design, the speed of the first target is determined based on the first aliasing coefficient and the second aliasing coefficient. The following design may be adopted: a first aliasing coefficient range is determined based on N1, and a second aliasing coefficient range is determined based on N2; a first aliasing coefficient set is determined based on the first aliasing coefficient range, the first aliasing coefficient, and N1, and a second aliasing coefficient set is determined based on the second aliasing coefficient range, the second aliasing coefficient, and N2; wherein the first aliasing coefficient set includes possible aliasing coefficients converted from the first aliasing coefficient to a third aliasing coefficient range, and the second aliasing coefficient set includes possible aliasing coefficients converted from the second aliasing coefficient to the third aliasing coefficient range, and the third aliasing coefficient range is an aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1; a third aliasing coefficient and a fourth aliasing coefficient are determined based on the first aliasing coefficient set and the second aliasing coefficient set, the third aliasing coefficient being an aliasing coefficient in the first aliasing coefficient set, and the fourth aliasing coefficient being an aliasing coefficient in the second aliasing coefficient set; and the speed of the first target is determined based on the third aliasing coefficient and the fourth aliasing coefficient.

[0020] The above design can convert the aliasing coefficients corresponding to overlapping arrays with different transmission intervals into the aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1, thereby restoring the maximum speed measurement range determined by Tc.

[0021] In one possible design, a difference between the third aliasing coefficient and the fourth aliasing coefficient is a minimum value of differences between any aliasing coefficient in the first aliasing coefficient set and any aliasing coefficient in the second aliasing coefficient set.

[0022] The above design can realize the correct selection of the third aliasing coefficient from the first aliasing coefficient set and the correct selection of the fourth aliasing coefficient from the second aliasing coefficient set.

[0023] In one possible design, determining the speed of the first target based on the third aliasing coefficient and the fourth aliasing coefficient can adopt the following design: determining the speed of the first target based on the average value of the third aliasing coefficient and the fourth aliasing coefficient; or determining the speed of the first target based on the weighted average value of the third aliasing coefficient and the fourth aliasing coefficient.

[0024] By adopting the above design, by averaging or weighted averaging multiple aliasing coefficients, the influence of noise on the phase difference of overlapping arrays can be effectively reduced, which helps to correctly solve the target speed.

[0025] In one possible design, N1 and N2 are relatively prime.

[0026] The mutual prime nature of N1 and N2 can ensure that the third aliasing coefficient and the fourth aliasing coefficient determined by the first aliasing coefficient set and the second aliasing coefficient set are unique.

[0027] In one possible design, the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

[0028] By adopting the above design, it is possible to construct overlapping arrays with various emission intervals and to increase the number of overlapping arrays.

[0029] In a third aspect, the embodiment of the present application further provides a radar device, the device comprising a transmitter, a receiver and a processing unit, the transmitter comprising N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, where:

[0030] The processing unit is configured to determine configuration information of a measurement frame, wherein the configuration information of the measurement frame indicates the N Tx The preset transmission order of the transmitting antennas, the transmission duration T of each chirp signal c and the NTx The transmitting antennas repeat the transmission in the preset transmission order for a number of times N slow ;

[0031] The transmitter is configured to send the measurement frame according to the configuration information of the measurement frame, wherein the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx .

[0032] In one possible design, for each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

[0033] In one possible design, the N TxAt least one transmitting antenna among the U transmitting antennas transmits chirp signals twice in the U time slots.

[0034] In one possible design, the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

[0035] For details, please refer to the technical effects described in the first aspect, and the repeated parts will not be repeated.

[0036] In a fourth aspect, an embodiment of the present application provides a radar device, wherein the device is a MIMO radar, and the MIMO radar includes a transmitter, a receiver, and a processing unit. The transmitter includes N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, where:

[0037] The receiver is used to receive an echo signal formed after the measurement frame is reflected by at least one target, and the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx ;

[0038] The processing unit is configured to determine a first aliasing coefficient and a second aliasing coefficient based on the echo signal; wherein the first aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N1 corresponding to a first target, the second aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N2 corresponding to the first target, and the first target is any one of the at least one target; and determine a speed of the first target based on the first aliasing coefficient and the second aliasing coefficient.

[0039] In one possible design, for each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

[0040] In one possible design, the processing unit is configured to: determine a first aliasing coefficient range based on N1, and determine a second aliasing coefficient range based on N2; determine a first aliasing coefficient set based on the first aliasing coefficient range, the first aliasing coefficient, and N1, and determine a second aliasing coefficient set based on the second aliasing coefficient range, the second aliasing coefficient, and N2; wherein the first aliasing coefficient set includes possible aliasing coefficients converted from the first aliasing coefficient to a third aliasing coefficient range, and the second aliasing coefficient set includes possible aliasing coefficients converted from the second aliasing coefficient to the third aliasing coefficient range, and the third aliasing coefficient range is an aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1; determine a third aliasing coefficient and a fourth aliasing coefficient based on the first aliasing coefficient set and the second aliasing coefficient set, the third aliasing coefficient being an aliasing coefficient in the first aliasing coefficient set, and the fourth aliasing coefficient being an aliasing coefficient in the second aliasing coefficient set; and determine a speed of the first target based on the third aliasing coefficient and the fourth aliasing coefficient.

[0041] In one possible design, a difference between the third aliasing coefficient and the fourth aliasing coefficient is a minimum value of differences between any aliasing coefficient in the first aliasing coefficient set and any aliasing coefficient in the second aliasing coefficient set.

[0042] In one possible design, the processing unit is used to: determine the speed of the first target based on an average value of the third aliasing coefficient and the fourth aliasing coefficient; or determine the speed of the first target based on a weighted average value of the third aliasing coefficient and the fourth aliasing coefficient.

[0043] In one possible design, the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

[0044] For details, please refer to the technical effects described in the second aspect, and the repeated parts will not be repeated. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is a schematic diagram of the structure of the MIMO radar system for this application;

[0046] Figure 2 This is a functional block diagram of a vehicle 200 with an autonomous driving function in this application;

[0047] Figure 3 This is one of the schematic diagrams of a horizontal array of three transmitting antennas and four receiving antennas forming two pairs of overlapping arrays in this application;

[0048] Figure 4 This is a flowchart summarizing a radar signal transmission method in this application;

[0049] Figure 5 This is the second schematic diagram of a horizontal array of three transmitting antennas and four receiving antennas forming two pairs of overlapping arrays in this application;

[0050] Figure 6(a) to Figure 6(c) A schematic diagram of a possible transmission sequence of a transmitting antenna in this application;

[0051] Figure 7 Schematic diagram of the aliasing coefficient ranges corresponding to overlapping arrays with different transmission intervals in this application;

[0052] Figure 8 This is a schematic diagram of the structure of a radar in this application. DETAILED DESCRIPTION

[0053] The embodiments of the present application are described below with reference to the accompanying drawings.

[0054] In the embodiment of this application, Figure 1As shown, the MIMO radar system may include an antenna array 101, a microwave integrated circuit (MMIC) 102, and a processing unit 103. The antenna array 101 may include multiple transmitting antennas and multiple receiving antennas.

[0055] Microwave integrated circuit 102 is used to generate radar signals, which are then transmitted through antenna array 101. Radar signals include multiple chirp signals. After being transmitted, the radar signals are reflected by one or more targets, forming echo signals, which are then received by the receiving antenna. Microwave integrated circuit 102 is also used to perform processing such as transformation and sampling on the echo signals received by antenna array 101, and transmit the processed echo signals to processing unit 103.

[0056] The processing unit 103 is used to perform operations such as Fast Fourier Transformation (FFT) and signal processing on the echo signal, thereby determining information such as the target's range, speed, and azimuth based on the received echo signal. Specifically, the processing unit 103 can be a device with processing capabilities, such as a microcontroller unit (MCU), a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), or a dedicated accelerator.

[0057] also, Figure 1 The radar system shown may also include an electronic control unit (ECU) 104 for controlling the vehicle based on target distance, speed, azimuth and other information obtained after processing by the processing unit 103, such as determining the vehicle's route and controlling the vehicle's speed.

[0058] The transmitter in the embodiments of the present application can be composed of a transmitting antenna and a transmitting channel in the microwave integrated circuit 102, and the receiver can be composed of a receiving antenna and a receiving channel in the microwave integrated circuit 102. The transmitting antenna and the receiving antenna can be located on a printed circuit board (PCB), and the transmitting channel and the receiving channel can be located within the chip, i.e., AOB (antenna on PCB); alternatively, the transmitting antenna and the receiving antenna can be located within the chip package, and the transmitting channel and the receiving channel can be located within the chip, i.e., AIP (antenna in package). The embodiments of the present application do not specifically limit the combination form. It should be understood that the embodiments of the present application do not limit the specific structure of the transmitting channel and the receiving channel, as long as the corresponding transmitting and receiving functions can be achieved.

[0059] In addition, since the number of channel specifications of a single microwave integrated circuit (RF chip) is relatively limited, when the number of transceiver channels required by the system is greater than that of a single RF chip, multiple RF chips need to be cascaded. Therefore, the entire radar system may include multiple RF chips cascaded. For example, the transmitting antenna array and the receiving antenna array are obtained by cascading multiple MIMO chips, and the data output by the analog digital converter (ADC) channel is connected through an interface to the processing unit 103, such as MCU, DSP, FPGA, general processing unit (GPU), etc. For another example, MMIC and DSP can be integrated into one chip, which is called a system on chip (SOC). For another example, MMIC and ADC, processing unit 103 can be integrated into one chip to form an SOC. In addition, the entire vehicle may be equipped with one or more radar systems, and connected to the central processing unit through the vehicle bus. The central processing unit controls one or more vehicle-mounted sensors, including one or more millimeter-wave radar sensors.

[0060] The following introduces the application scenarios of the embodiments of the present application.

[0061] Figure 1 The MIMO radar system shown can be applied to vehicles with autonomous driving functions. Figure 2, is a functional block diagram of a vehicle 200 with an autonomous driving function provided in an embodiment of the present application. In one embodiment, the vehicle 200 is configured to be in a fully or partially autonomous driving mode. For example, the vehicle 200 can simultaneously control itself in the autonomous driving mode, and can determine the current state of the vehicle and its surrounding environment through human operation, determine the possible behavior of at least one other vehicle in the surrounding environment, and determine the confidence level corresponding to the possibility of the other vehicle performing the possible behavior, and control the vehicle 200 based on the determined information. When the vehicle 200 is in the autonomous driving mode, the vehicle 200 can be set to operate without human interaction.

[0062] Vehicle 200 may include various subsystems, such as a travel system 202, a sensor system 204, a control system 206, one or more peripheral devices 208, a power source 210, a computer system 212, and a user interface 216. Alternatively, vehicle 200 may include more or fewer subsystems, and each subsystem may include multiple components. In addition, each subsystem and component of vehicle 200 may be interconnected via wired or wireless connections.

[0063] Propulsion system 202 may include components that provide powered motion for vehicle 200. In one embodiment, propulsion system 202 may include engine 218, energy source 219, transmission 220, and wheels / tires 221. Engine 218 may be an internal combustion engine, an electric motor, an air compression engine, or another combination of engines, such as a hybrid engine consisting of a gasoline engine and an electric motor, or a hybrid engine consisting of an internal combustion engine and an air compression engine. Engine 218 converts energy source 219 into mechanical energy.

[0064] Examples of energy source 219 include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, solar panels, batteries, and other sources of electricity. Energy source 219 can also provide energy to other systems of vehicle 200.

[0065] Transmission 220 can transmit mechanical power from engine 218 to wheels 221. Transmission 220 can include a gearbox, a differential, and a drive shaft. In one embodiment, transmission 220 can also include other components, such as a clutch. The drive shaft can include one or more shafts that can be coupled to one or more wheels 221.

[0066] The sensor system 204 may include several sensors that sense information about the environment surrounding the vehicle 200. For example, the sensor system 204 may include a positioning system 222 (the positioning system may be a global positioning system (GPS) system, or a BeiDou system or other positioning system), an inertial measurement unit (IMU) 224, a radar 226, a laser rangefinder 228, and a camera 230. The sensor system 204 may also include sensors of the internal systems of the monitored vehicle 200 (e.g., an in-vehicle air quality monitor, a fuel gauge, an oil temperature gauge, etc.). Sensor data from one or more of these sensors may be used to detect objects and their corresponding characteristics (position, shape, direction, speed, etc.). Such detection and recognition are key functions for the safe operation of the vehicle 200.

[0067] Positioning system 222 may be used to estimate the geographic location of vehicle 200. IMU 224 may be used to sense changes in position and orientation of vehicle 200 based on inertial acceleration. In one embodiment, IMU 224 may be a combination of an accelerometer and a gyroscope.

[0068] Radar 226 can use radio signals to sense objects in the surrounding environment of vehicle 200. In some embodiments, in addition to sensing objects, radar 226 can also be used to sense the speed and / or heading of the object. In a specific example, radar 226 can use Figure 1 The MIMO radar system implementation shown.

[0069] The laser rangefinder 228 may utilize laser light to sense objects in the environment in which the vehicle 100 is located. In some embodiments, the laser rangefinder 228 may include one or more laser sources, a laser scanner, and one or more detectors, among other system components.

[0070] The camera 230 may be used to capture multiple images of the surrounding environment of the vehicle 200. The camera 230 may be a still camera or a video camera.

[0071] Control system 206 controls the operation of vehicle 200 and its components. Control system 206 may include various components, including a steering system 232 , a throttle 234 , a brake unit 236 , a sensor fusion algorithm 238 , a computer vision system 240 , a path control system 242 , and an obstacle avoidance system 244 .

[0072] The steering system 232 is operable to adjust the forward direction of the vehicle 200. For example, in one embodiment, it may be a steering wheel system.

[0073] Throttle 234 is used to control the operating speed of engine 218 and, in turn, the speed of vehicle 200 .

[0074] Braking unit 236 is used to control the deceleration of vehicle 200. Braking unit 236 can use friction to slow down wheels 221. In other embodiments, braking unit 236 can convert the kinetic energy of wheels 221 into electric current. Braking unit 236 can also take other forms to slow the rotation speed of wheels 221 to control the speed of vehicle 200.

[0075] The computer vision system 240 can be operated to process and analyze images captured by the camera 230 to identify objects and / or features in the environment surrounding the vehicle 200. The objects and / or features may include traffic signs, road boundaries, and obstacles. The computer vision system 240 may use object recognition algorithms, structure from motion (SFM) algorithms, video tracking, and other computer vision techniques. In some embodiments, the computer vision system 240 can be used to map the environment, track objects, estimate the velocity of objects, and so on.

[0076] Route control system 242 is used to determine a driving route for vehicle 200. In some embodiments, route control system 142 may combine data from sensors 238, GPS 222, and one or more predetermined maps to determine a driving route for vehicle 200.

[0077] Obstacle avoidance system 244 is used to identify, assess, and avoid or otherwise negotiate potential obstacles in the environment of vehicle 200 .

[0078] Of course, in one example, the control system 206 may include additional or alternative components other than those shown and described, or may include fewer than some of the components shown.

[0079] Vehicle 200 interacts with external sensors, other vehicles, other computer systems, or users via peripherals 208. Peripherals 208 may include a wireless communication system 246, an onboard computer 248, a microphone 250, and / or a speaker 252.

[0080] In some embodiments, peripheral devices 208 provide a means for a user of vehicle 200 to interact with user interface 216. For example, onboard computer 248 can provide information to the user of vehicle 200. User interface 216 can also operate onboard computer 248 to receive user input. Onboard computer 248 can be operated via a touch screen. In other cases, peripheral devices 208 can provide a means for vehicle 200 to communicate with other devices located within the vehicle. For example, microphone 250 can receive audio (e.g., voice commands or other audio input) from the user of vehicle 200. Similarly, speaker 252 can output audio to the user of vehicle 200.

[0081] The wireless communication system 246 can communicate wirelessly with one or more devices directly or via a communication network. For example, the wireless communication system 246 can use 3G cellular communication, such as code division multiple access (CDMA), EVDO, global system for mobile communications (GSM) / general packet radio service (GPRS), or 4G cellular communication, such as long term evolution (LTE), or 5G cellular communication. The wireless communication system 246 can use WiFi to communicate with a wireless local area network (WLAN). In some embodiments, the wireless communication system 246 can use an infrared link, Bluetooth, or ZigBee to communicate directly with the device. Other wireless protocols, such as various vehicle communication systems, for example, the wireless communication system 246 may include one or more dedicated short-range communications (DSRC) devices, which may include public and / or private data communications between vehicles and / or roadside stations.

[0082] Power source 210 can provide power to various components of vehicle 200. In one embodiment, power source 210 can be a rechargeable lithium-ion or lead-acid battery. One or more battery packs of such batteries can be configured as a power source to provide power to various components of vehicle 200. In some embodiments, power source 210 and energy source 219 can be implemented together, such as in some all-electric vehicles.

[0083] Some or all functions of vehicle 200 are controlled by computer system 212. Computer system 212 may include at least one processor 223 that executes instructions 225 stored in a non-transitory computer-readable medium, such as memory 224. Computer system 212 may also be a plurality of computing devices that control individual components or subsystems of vehicle 200 in a distributed manner.

[0084] The processor 223 may be any conventional processor, such as a commercially available central processing unit (CPU). Alternatively, the processor may be a dedicated device such as an application specific integrated circuit (ASIC) or other hardware based processor. Figure 2 The processor, memory, and other elements of the computer 210 are functionally illustrated as being in the same block, but one of ordinary skill in the art will appreciate that the processor, computer, or memory may actually include multiple processors, computers, or memories that may or may not be stored in the same physical housing. For example, the memory may be a hard drive or other storage medium that is located in a housing different from the computer 210. Therefore, references to a processor or computer will be understood to include references to a collection of processors or computers or memories that may or may not operate in parallel. Rather than using a single processor to perform the steps described herein, some components, such as the steering assembly and the deceleration assembly, may each have their own processor that performs only calculations related to the functionality of the component.

[0085] In various aspects described herein, the processor can be located remotely from the vehicle and in wireless communication with the vehicle. In other aspects, some of the processes described herein are performed on a processor disposed within the vehicle while others are performed by a remote processor, including taking the necessary steps to perform a single maneuver.

[0086] In some embodiments, memory 224 may contain instructions 225 (e.g., program logic) that are executable by processor 223 to perform various functions of vehicle 200, including those described above. Memory 214 may also contain additional instructions, including instructions for sending data to, receiving data from, interacting with, and / or controlling one or more of travel system 202, sensor system 204, control system 206, and peripherals 208.

[0087] In addition to instructions 225, memory 224 may also store data such as road maps, route information, the vehicle's location, direction, speed, and other such vehicle data, as well as other information. This information may be used by vehicle 200 and computer system 212 during operation of vehicle 200 in autonomous, semi-autonomous, and / or manual modes.

[0088] User interface 216 is used to provide information to or receive information from a user of vehicle 200. Optionally, user interface 216 may include one or more input / output devices within the set of peripherals 208, such as wireless communication system 246, onboard computer 248, microphone 250, and speaker 252.

[0089] Computer system 212 may control functions of vehicle 200 based on input received from various subsystems (e.g., travel system 202, sensor system 204, and control system 206) and from user interface 216. For example, computer system 212 may utilize input from control system 206 to control steering unit 232 to avoid obstacles detected by sensor system 204 and obstacle avoidance system 244. In some embodiments, computer system 212 may be operable to provide control over many aspects of vehicle 200 and its subsystems.

[0090] Alternatively, one or more of the above components may be installed or associated separately from the vehicle 200. For example, the memory 224 may be partially or completely separate from the vehicle 200. The above components may be communicatively coupled together in a wired and / or wireless manner.

[0091] Optionally, the above components are just an example. In actual applications, the components in the above modules may be added or deleted according to actual needs. Figure 2 It should not be understood as limiting the embodiments of the present application.

[0092] An autonomous vehicle traveling on a road, such as vehicle 200 above, can identify objects in its surroundings to determine adjustments to its current speed. The objects can be other vehicles, traffic control devices, or other types of objects. In some examples, each identified object can be considered independently, and the speed adjustment to be made to the autonomous vehicle can be determined based on its respective characteristics, such as its current speed, acceleration, and distance from the vehicle.

[0093] Optionally, the autonomous vehicle 200 or a computing device associated with the autonomous vehicle 200 (e.g. Figure 2The computer system 212, the computer vision system 240, the memory 224) can predict the behavior of the identified target based on the characteristics of the identified target and the state of the surrounding environment (e.g., traffic, rain, ice on the road, etc.). Optionally, each identified target is dependent on the behavior of each other, so all identified targets can also be considered together to predict the behavior of a single identified target. The vehicle 200 can adjust its speed based on the predicted behavior of the identified target. In other words, the autonomous vehicle can determine what stable state the vehicle will need to adjust to (e.g., accelerate, decelerate, or stop) based on the predicted behavior of the target. In this process, other factors can also be considered to determine the speed of the vehicle 200, such as the lateral position of the vehicle 200 in the road it is traveling on, the curvature of the road, the proximity of static and dynamic targets, etc.

[0094] In addition to providing instructions to adjust the speed of the autonomous vehicle, the computing device may also provide instructions to modify the steering angle of vehicle 200 so that the autonomous vehicle follows a given trajectory and / or maintains a safe lateral and longitudinal distance from targets near the autonomous vehicle (e.g., cars in adjacent lanes on the road).

[0095] The vehicle 200 may be a car, truck, motorcycle, bus, ship, airplane, helicopter, lawn mower, recreational vehicle, amusement park vehicle, construction equipment, tram, golf cart, train, and cart, etc., and the embodiments of the present application do not impose any particular limitation.

[0096] In addition, it should also be noted that the radar system described in the embodiments of the present application can be applied to a variety of fields. For example, the radar system in the embodiments of the present application includes but is not limited to vehicle-mounted radar, roadside traffic radar, and drone radar.

[0097] It should be noted that, in the embodiments of the present application, "a plurality" refers to two or more. In addition, it should be understood that, in the description of the present application, words such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be understood as indicating or implying relative importance or order.

[0098] Based on this, the present application provides a radar signal transmission and reception method, which is applied to MIMO radar. The MIMO radar includes a transmitter, a receiver and a processing unit. The transmitter includes N Tx The receiver includes N transmitting antennas Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2. It should be understood that the specific structure of the MIMO radar can be as follows Figure 1 As shown, it can also be limited to Figure 1The specific structure is not limited in this application.

[0099] The method includes:

[0100] Step 400: The processing unit determines the configuration information of the measurement frame, wherein the configuration information of the measurement frame indicates N Tx The preset transmission order of the transmitting antennas and the transmission duration T of each chirp signal c and N Tx The transmitting antennas repeat the transmission in the preset transmission order for the number of times N slow .

[0101] Exemplarily, the configuration information of the measurement frame includes N Tx The preset transmission order of the transmitting antennas, T c and N slow , or, N Tx The preset transmission order of the transmitting antennas, U*T c and N slow It should be understood that the present application does not limit the specific form of the configuration information of the measurement frame.

[0102] After determining the configuration information of the measurement frame, the processing unit sends the configuration information of the measurement frame to the single-chip or multi-chip MMIC through the interface. The single-chip or multi-chip MMIC is used to enable the transmitter to send the measurement frame according to the configuration information of the measurement frame.

[0103] Step 410: The transmitter sends a measurement frame according to the configuration information of the measurement frame. The measurement frame includes U*N slow chirp signals, where U*N slow The chirp signal includes N slow Group chirp signals, each group of chirp signals includes U chirp signals, U chirp signals are N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; N Tx transmitting antennas and N Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx .

[0104] Among them, for each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in time slot u1 among U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1, the transmitting antenna m1' transmits a chirp signal in time slot u1' among U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in time slot u2 among U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in time slot u2' among U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

[0105] The measurement frame may be FMCW, or may adopt waveforms used by other MIMO radars. For example, the measurement frame may also be a pulse waveform or an Orthogonal Frequency Division Multiplex (OFDM) waveform.

[0106] This application does not limit this. The following description only takes FMCW as an example.

[0107] In one possible design, N1 and N2 are relatively prime. For example, N1=1, N2=2.

[0108] In one possible design, the values ​​of N1 and N2 are determined by the antenna array and the preset order. As can be understood, since a smaller transmission interval corresponds to a larger speed measurement range and can achieve less aliasing, the values ​​of N1 and N2 are generally smaller.

[0109] Furthermore, in one possible design, N Tx transmitting antennas and N Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N1≠N2≠N3, and N3 is a positive integer. For example, N1=1, N2=2, and N3=3.

[0110] The following is a brief introduction to the method of determining overlapping arrays based on the preset transmission sequence and antenna array:

[0111] 1) According to the preset transmission sequence and antenna array, determine the virtual receiving antenna position formed by the transmitting antenna and the receiving antenna.

[0112] Traditional virtual receiving antenna (Virtual Receiver antenna): The antenna obtained by combining the transmitting antenna and the receiving antenna is a virtual receiving antenna, which can also be described as a virtual receiving array obtained by combining the transmitting antenna and the receiving antenna. Among them, the number of transmitting antennas is N Tx , the number of receiving antennas is N Rx . Transmitting antenna Tx i The coordinate position of the two-dimensional plane is expressed as (x i ,y i ), where 1≤i≤N Tx ;Receiving antenna Rx i The coordinate position of the two-dimensional plane is expressed as (x i ,y i ), where 1≤j≤N Rx , then we can get a total of N Tx *N Rx To facilitate the description of the transmission interval introduced by the antenna transmission sequence and the virtual array with the same position formed by repeated transmission of the same transmitting antenna, in this application, U chirp signals are transmitted according to the preset transmission sequence, and the transmitting antenna m transmits the chirp signal in time slot u. The position of the virtual array formed by the transmitting antenna m and the receiving antenna n in time slot u is:

[0113] d k =d mn =(x m ,y m ) u +(x n ,y n ) u =(x m +x n ,y m +y n ) u (Formula 1)

[0114] Among them, d k Indicates that N is arranged in the preset transmission order and sequence Rx The virtual antenna position formed by the received signal.

[0115] k=(u-1)*N Rx +n Rx , 1≤k≤U*N Rx， 1≤u≤U,1≤n Rx ≤N Rx

[0116] The coordinate position of the transmitting antenna m in the two-dimensional plane is expressed as (x m ,y m ) u , where 1≤m≤N Tx , the coordinate position of the receiving antenna n is expressed in the two-dimensional plane as (x n ,y n ) u , where 1≤n≤N Rx .

[0117] 2) Mark the virtual receiving array pairs in which the positions are repeated (ie, overlapping arrays) and the intervals of the transmitting time slots forming the overlapping arrays (ie, the transmitting intervals).

[0118] 3) Group overlapping arrays with the same transmission interval. In this application, there are at least two groups of overlapping arrays with different transmission intervals, and each group includes at least one pair of overlapping arrays.

[0119] It is worth noting that the prior art only includes overlapping arrays with a transmission interval of 1, and only includes overlapping arrays formed by hardware, excluding those due to U>N Tx When multiple transmissions are made from the same transmitting antenna, overlapping arrays are formed.

[0120] Here, the method of forming the overlapping array may include but is not limited to the following two methods:

[0121] Method 1: Overlapping arrays are formed by deploying different antennas.

[0122] The overlapping array formed by method 1 can also be called a hardware overlapping array.

[0123] Virtual arrays are generally categorized as one-dimensional and two-dimensional. A one-dimensional array is one in which each element in the transmitting antenna array has the same vertical Y-axis coordinate position, and each element in the receiving antenna array also has the same vertical Y-axis coordinate position. A one-dimensional array can only detect the horizontal angle of the target, i.e., a horizontal array. A two-dimensional array is one in which each element in the transmitting antenna array has at least one element position on the Y-axis that differs from the other elements, and each element in the receiving antenna array has at least one element position on the Y-axis that differs from the other elements. A two-dimensional array consists of one or more one-dimensional sub-arrays.

[0124] Here is an example of hardware overlap, such as Figure 3 As shown in the figure, a schematic diagram of a one-dimensional horizontal array of three transmitting antennas and four receiving antennas (abbreviated as 3 transmit 4 receive (3T4R)) forming two pairs of overlapping arrays. The transmitting antennas are spaced 3λ / 2 apart in a horizontal array, and the receiving antennas are spaced λ / 2 apart in a horizontal array, where λ is half a wavelength. Since the transmitting and receiving antenna arrays are both one-dimensional, the position of the transmitting antenna array can be written as X Tx=[0, 3λ / 2, 3λ], the position of the receiving antenna array is written as X Rx =[0,λ / 2,λ,3λ / 2].

[0125] When the transmission order of the transmitting antenna is 1, 2, 3, U = 3, it can be obtained that N Rx The virtual receiving array position matrix D corresponding to the receiving antennas is D=[d k ],1≤k≤U*N Rx， , D=[0,λ / 2,λ,3λ / 2,3λ / 2,2λ,5λ / 2,3λ,3λ,7λ / 2,4λ,9λ / 2]. In the virtual receiving array formed by 3 transmitting antennas and 4 receiving antennas, there are overlapping arrays with a transmission interval of 1 at the position of 3λ / 2 and overlapping arrays with a transmission interval of 1 at the position of 3λ, that is, two pairs of overlapping arrays are formed on the receiving side, and the transmission intervals of these two pairs of overlapping arrays are the same, both of which are 1. Figure 5 As shown in the figure, when the transmission order of the transmitting antennas is 1, 3, 2, D = [0, λ / 2, λ, 3λ / 2, 3λ, 7λ / 2, 4λ, 9λ / 2, 3λ / 2, 2λ, 5λ / 2, 3λ]. In the virtual receiving array, there are overlapping arrays with a transmission interval of 2 at the position of 3λ / 2 and overlapping arrays with a transmission interval of 1 at the position of 3λ. Therefore, when the transmission order changes from 1, 2, 3 to 1, 3, 2, this change in transmission order does not cause a change in the position of the overlapping arrays, but only affects the transmission interval.

[0126] Method 2: Overlapping arrays are formed by the same antenna occupying different transmission times.

[0127] In one possible design, N Tx There is at least one transmitting antenna among the U transmitting antennas that transmits the chirp signal twice in U transmitting time slots.

[0128] The overlapping array formed by the method 1 can also be called a software overlapping array or a soft overlapping array.

[0129] For example, Figures 6(a) to 6(c) As shown, taking the 3T4R horizontal array as an example, when N Tx =3, U=4*3, then each antenna transmits 4 times. The transmission order is 2-2-1-1-1-2-3-3-2-3-3-1. It should be understood that this transmission order is only an example and is not a limitation of this application. The following is based on Figures 6(a) to 6(c) Describe the soft overlapping array and the corresponding transmission interval.

[0130] As shown in Figure 6(a), when transmitting antenna 2 transmits twice in succession, four pairs of overlapping arrays are formed on the receiving side, and the transmission intervals of these four pairs are the same, namely 1. Similarly, as shown by the dotted line in Figure 6(a), 20 pairs of overlapping arrays are formed on the receiving side, that is, 5*4=20.

[0131] As shown in Figure 6(b), the bold lines 1 and 1 form four pairs of overlapping arrays on the receiving side, and the transmission intervals of these four pairs of overlapping arrays are the same, which is 2. Similarly, the bold lines 3 and 3 form four pairs of overlapping arrays on the receiving side, and the transmission intervals of these four pairs of overlapping arrays are the same, which is 2.

[0132] As shown in Figure 6(c), the connecting line connects pairs 2 and 2, forming four pairs of overlapping arrays on the receiving side. The transmission intervals of these four pairs of overlapping arrays are the same, which is 3. Similarly, the connecting line connects two pairs of pairs 3 and 3, forming 2*4 pairs of overlapping arrays on the receiving side. The transmission intervals of these eight pairs of overlapping arrays are the same, which is 3.

[0133] Note that the soft overlap array does not lose aperture, although due to U>N Tx , which will reduce the maximum speed measurement range corresponding to maximum MIMO, but this method does not affect the transmission duration Tc of each chirp. Therefore, the system can eventually recover to the maximum test range determined by Tc. It can be understood that if the two methods are combined, the number of overlapping arrays can be further increased. Among them, the overlapping arrays formed by method 1 include: the overlapping arrays with a transmission interval of 1 are: transmitting antenna 2 and transmitting antenna 1 (represented by 2-1) forming a pair of overlapping arrays on the receiving side, transmitting antenna 1 and transmitting antenna 2 (represented by 1-2) forming a pair of overlapping arrays on the receiving side, transmitting antenna 3 and transmitting antenna 2 (represented by 3-2) forming a pair of overlapping arrays on the receiving side, and transmitting antenna 2 and transmitting antenna 3 (represented by 2-3) forming a pair of overlapping arrays on the receiving side. The overlapping arrays with a transmission interval of 2 are as follows: transmitting antenna 2 and transmitting antenna 1 with an interval of 1 (represented by 2-1-1) form a pair of overlapping arrays on the receiving side, transmitting antenna 1 and transmitting antenna 2 with an interval of 1 (represented by 1-1-2) form a pair of overlapping arrays on the receiving side, transmitting antenna 3 and transmitting antenna 2 with an interval of 1 (represented by 3-3-2) form a pair of overlapping arrays on the receiving side, and transmitting antenna 2 and transmitting antenna 3 with an interval of 1 (represented by 2-3-3) form a pair of overlapping arrays on the receiving side.

[0134] In summary, using the above two methods, we conclude that overlapping arrays with a transmission interval of 1 include 4 + 20 = 24 pairs, and overlapping arrays with a transmission interval of 2 include 8 + 4 = 12 pairs. Note that in actual projects, if hardware overlapping arrays cause losses in software overlapping arrays, it is necessary to further exclude the duplicated calculations, but this application does not impose any restrictions.

[0135] In addition, according to actual needs, the number of overlapping arrays with a transmission interval of 3 under the two modes and the number of overlapping arrays with other transmission intervals can be further counted, which is not limited in this application.

[0136] Therefore, the design of the measurement frame provided in the embodiment of the present application is adopted, through N Tx The preset transmission sequence of the transmitting antennas can construct overlapping arrays with multiple transmission intervals and increase the number of overlapping arrays. Compared to the prior art with a smaller number of overlapping arrays and overlapping arrays with a single transmission interval, when the phase difference of the overlapping arrays is significantly affected by noise, it will directly affect the accurate solution of the target velocity. However, because the embodiments of the present application construct overlapping arrays with multiple transmission intervals and a large number of overlapping arrays, even if the phase difference of some overlapping arrays is significantly affected by noise, the phase differences of multiple overlapping arrays with multiple transmission intervals can be processed to effectively reduce the impact of the phase difference of the overlapping arrays that are significantly affected by noise on the velocity solution, thereby improving the accuracy of the target velocity solution.

[0137] Step 420: The receiver receives an echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets.

[0138] It should be noted that, in the embodiment of the present application, the receiver includes N Rx receiving antennas, N Rx There are N receiving antennas Tx The transmission order of the transmitting antennas is used to receive U receiving signals, and then according to N Tx transmit antennas and N Rx The positional relationship between the receiving antennas and the transmission order of the transmitting antennas convert the received U receiving signals into echo signals.

[0139] Since N slow is the number of times the transmission is repeated in the preset order, then N slow an echo signal.

[0140] Among them, U represents the number of time slots in which different antennas transmit signals in a repetition period according to the TDM method, and the transmission period is U*T c , wherein the same antenna can transmit multiple times in U time slots. Furthermore, one of the U received signals is a chirp signal formed after a transmitted chirp signal is reflected by one or more targets.

[0141] Step 430: The processing unit determines a first aliasing coefficient and a second aliasing coefficient.

[0142] The first aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N1 corresponding to the first target, the second aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N2 corresponding to the first target, and the first target is any one of the at least one target.

[0143] Typically, a single chirp signal is called a fast chirp, which can be used to obtain the distance information of the target, and multiple chirp signals are called slow chirps, which can be used to obtain the speed information of the target.

[0144] The processing unit calculates the distance dimension fast Fourier transform corresponding to each fast chirp. Further, based on the fast chirp FFT, the speed dimension fast Fourier transform of different slow chirps on the same range bin is calculated to obtain U*N Rx The two-dimensional Fourier transform result of a virtual receiving array. For example, the two-dimensional Fourier transform result of a virtual receiving array refers to the range-Doppler map corresponding to the virtual receiving array. For the embodiment of the present application, it can be understood that N s sampling points, do N range Fast Fourier transform of point distance dimension; N is obtained on slow chirp slow sampling points, do N doppler The point velocity dimension fast Fourier transform obtains U*N Rx RD diagram corresponding to each virtual receiving array.

[0145] The processing unit will U*N Rx The two-dimensional Fourier transform results of the virtual receiving arrays are accumulated to obtain the total RD map. Rx The accumulation of the two-dimensional Fourier transform results of the virtual receiving array is to add U*N Rx The RD graphs corresponding to the virtual receiving arrays are accumulated to obtain a total RD graph. Rx The accumulation of the two-dimensional Fourier transform results of the virtual receiving array can be done by incoherent superposition, that is, U*N Rx The amplitude superposition of the two-dimensional Fourier of the virtual receiving array, or the incoherent superposition, that is, U*N Rx The present application does not impose any special restrictions on the complex superposition of the peak values ​​synthesized on the fixed beam by the two-dimensional Fourier transform of the virtual receiving array, or other superposition methods.

[0146] The RD graph is a radar output graph with one dimension representing range information and one dimension representing Doppler information. Extraction from the range dimension is called a range bin, extraction from the Doppler dimension is called a Doppler bin, and extraction from both the range and Doppler dimensions is called a range-Doppler cell.

[0147] Specifically, the processing unit detects the target on the total RD map. For example, the processing unit can use various existing detection methods for detection, such as ordered statistics-constant false alarm rate (detection) (Ordered Statistic-Constant False Alarm Rate, OS-CFAR) or cell-averaging-constant false alarm rate (detection) (Cell-Averaging Constant False Alarm Rate, CA-CFAR) and other commonly used detection methods, which are not limited in this application.

[0148] After the processing unit detects a target on the overall RD map, it extracts the signals from the overlapping arrays corresponding to the target. The signals from the overlapping arrays corresponding to each target on the overall RD map include the signals from the overlapping arrays with a transmission interval of N1 and the signals from the overlapping arrays with a transmission interval of N2.

[0149] Illustratively, the processing unit may determine the first aliasing coefficient in the following manner but is not limited thereto. The processing unit may determine the second aliasing coefficient in the same manner, and repeated details will be omitted.

[0150] Among them, any overlapping matrix can be represented by (m, n) and (m, n'), d mn =d m′n′ , where transmitting antenna m transmits a chirp signal in time slot u among U time slots, and the position of the virtual receiving antenna array formed by transmitting antenna m and receiving antenna n is d mn , the transmitting antenna m' transmits a chirp signal in time slot u' among U time slots, and the position d of the virtual receiving antenna array formed by the transmitting antenna m' and the receiving antenna n' is m’n’ , |u-u'|=N ii , the emission interval corresponding to the overlapping array is N ii .

[0151] The transmitting antenna m transmits a chirp signal in time slot u among U time slots. If the waveform of the signal is represented by S(t), it passes through a distance R i , radial velocity is V i , the horizontal angle is θ iAfter the target is reflected (taking the horizontal angle as an example), the virtual receiving array formed by the transmitting antenna m and the receiving antenna n can represent the target detection distance and the aliased speed obtained from the total RD diagram (R ind ,V ind ), where the measured target distance can be expressed as

[0152] where R Res Is the distance resolution. On the RD diagram corresponding to the virtual receiving array, take (R ind ,V ind ) in the corresponding RD unit

[0153] The phase of the complex value

[0154] It can be expressed as:

[0155]

[0156] Therefore, for any overlapping arrays (m, n) and (m', n'), d mn =d m′n′ , when the target's velocity is zero, then

[0157] When the transmission interval corresponding to the overlapping array is N ii , that is |u-u'|=N ii , when the target speed is not zero, the phase difference

[0158] The relationship between the target radial velocity and the target radial velocity is obtained by transforming Formula 2:

[0159] Without loss of generality, we take u>u'.

[0160] Understandably,

[0161]

[0162] Among them, V i_amb is the aliased velocity obtained by the total RD map, that is

[0163] is the velocity resolution. Further, we can

[0164]

[0165] Traverse k Nii The values ​​within the range of that make the expression closest to 0

[0166] is the aliasing coefficient.

[0167] The corresponding d on the RD diagram for the virtual receiving array mn signal,

[0168] The corresponding d on the RD diagram for the virtual receiving array m′n′ signal,

[0169] The value range is determined by the transmission interval N ii Sure.

[0170] Furthermore, according to the fact that all transmission intervals are N ii The overlapping arrays are obtained respectively

[0171] Find the average value, and the corresponding launch interval as the target is N ii The aliasing coefficient corresponding to the overlapping array.

[0172] It should be understood that other schemes may be used to determine the first aliasing coefficient and the second aliasing coefficient, and this application does not limit this.

[0173] Step 440: The processing unit determines the speed of the first target according to the first aliasing coefficient and the second aliasing coefficient.

[0174] In one possible design, the processing unit may determine the speed of the first target using, but not limited to, the following method:

[0175] First, the processing unit determines a first aliasing coefficient range according to N1 and determines a second aliasing coefficient range according to N2.

[0176] The speed measurement ranges corresponding to overlapping arrays with different transmission intervals are different, that is, when they are transmitted adjacently in time (and the transmission interval is 1), |u-u'|=N ii = 1, the velocity measurement range of the overlapping array is ±V max =λ / (4*T C ), the transmission interval is N ii The speed measurement range of the overlapping array is ±V max =λ / (4*N ii *T C ). The speed measurement range of the MIMO radar with a transmission period of U is ±V max =λ / (4*U*T C ), U≥N Tx .

[0177] It can be understood that the overlapping array with a transmission interval of 1 can obtain a U-fold expansion of the target speed relative to the MIMO radar with a transmission period of U, and the aliasing coefficient has U values. The transmission interval is N ii The overlapping array can obtain the target speed U / N relative to the MIMO radar with a transmission period of U ii times expansion, the transmission interval is N ii The value of the aliasing coefficient corresponding to the overlapping array is U / N ii The aliasing coefficient can be 1, 2, ..., U / N ii Specifically indicates the aliasing multiple 0, 1, ..., U / N ii -1, where 0 means no aliasing. The positive and negative relationship of the speed of the vehicle environment can be ii The conversion is done later and here as well. ii The following is an example of post-conversion.

[0178] Then it can be understood that the overlapping arrays with a transmission interval of N1 can use the aliasing coefficient of 1, 2, ..., U / N1 to alias the range of 0, 1, ..., U / (N1-1), and the overlapping arrays with a transmission interval of N2 correspond to the aliasing coefficient range of 0, 1, ..., U / (N2-1).

[0179] Then, the processing unit determines a first aliasing coefficient set according to the first aliasing coefficient range, the first aliasing coefficient, and N1, and determines a second aliasing coefficient set according to the second aliasing coefficient range, the second aliasing coefficient, and N2.

[0180] The first aliasing coefficient set includes possible aliasing coefficients obtained by converting the first aliasing coefficient into a third aliasing coefficient range, and the second aliasing coefficient set includes possible aliasing coefficients obtained by converting the second aliasing coefficient into a third aliasing coefficient range. The third aliasing coefficient range is an aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1.

[0181] From the above, we can see that

[0182]

[0183] Due to the overlapping arrays with different emission intervals

[0184] Different ranges of values ​​and overlapping arrays with different emission intervals correspond to V i_amb The same, therefore, the aliasing coefficients corresponding to overlapping arrays with different transmission intervals are

[0185] There is a certain conversion relationship. In order to reduce the impact of noise on overlapping arrays, the aliasing coefficients corresponding to overlapping arrays with different transmission intervals cannot be directly added together to obtain the average or weighted average.

[0186] For example, when N ii >1, the transmission interval is N ii The method for converting the aliasing coefficient corresponding to the overlapping array to the aliasing coefficient range corresponding to the overlapping array with a transmission interval of 1 is as follows:

[0187]

[0188] Among them, N ii Indicates the transmission interval,

[0189] The transmission interval is N ii The aliasing coefficient corresponding to the overlapping array. k is the transmission interval N ii The aliasing coefficient corresponding to the overlapping array is converted into the aliasing coefficient. When N ii When >1, j has multiple values, so the multiple values ​​of k are also called aliasing coefficient sets, that is, ii The aliasing coefficients corresponding to the overlapping arrays are converted to the set of aliasing coefficients corresponding to the overlapping arrays with a transmission interval of 1.

[0190] Next, the processing unit determines a third aliasing coefficient and a fourth aliasing coefficient according to the first aliasing coefficient set and the second aliasing coefficient set, where the third aliasing coefficient is an aliasing coefficient in the first aliasing coefficient set and the fourth aliasing coefficient is an aliasing coefficient in the second aliasing coefficient set.

[0191] The difference between the third aliasing coefficient and the fourth aliasing coefficient is a minimum value of the differences between any one aliasing coefficient in the first aliasing coefficient set and any one aliasing coefficient in the second aliasing coefficient set.

[0192] Furthermore, the processing unit processes the third aliasing coefficient and the fourth aliasing coefficient:

[0193] In an example, the processing unit calculates an average of the third aliasing coefficient and the fourth aliasing coefficient.

[0194] In another example, the processing unit calculates a weighted average of the third aliasing coefficient and the fourth aliasing coefficient. For example, the weights corresponding to the third aliasing coefficient and the fourth aliasing coefficient may be determined based on the number of overlapping arrays at different transmission intervals or the signal-to-noise ratio on the channel.

[0195] Example 1: Figure 7As shown, when N1 = 1, N2 = 2, N3 = 3, and U = 24, the aliasing coefficients for overlapping arrays with a transmit interval of 1 range from 1, 2, 3, ... 24; the aliasing coefficients for overlapping arrays with a transmit interval of 2 range from 1, 2, 3, ... 12; and the aliasing coefficients for overlapping arrays with a transmit interval of 3 range from 1, 2, 3, ... 8. The following describes the conversion process for aliasing coefficients corresponding to overlapping arrays with different transmit intervals corresponding to target 1, using target 1 as an example.

[0196] k1=13, N1=1, then k=k1. This aliasing coefficient is the aliasing coefficient corresponding to the overlapping array with a transmission interval of 1, so no conversion is required.

[0197] k2=5, N2=2, which are even numbers. Since k2 is less than 6, k=11 or 23.

[0198] Specifically, there are two cases: no aliasing and double aliasing. If there is no aliasing, k=5+12 / 2=11; if there is double aliasing, k=5+3*12 / 2=23.

[0199] k3=4, N3=3, which is an odd number, then k=4, 12 or 20.

[0200] Specifically, there are three cases: no aliasing, double aliasing, and double aliasing. If there is no aliasing, k=4+0*24 / 3=4; if there is double aliasing, k=4+1*24 / 3=12; if there is double aliasing, k=4+2*24 / 3=20.

[0201] Furthermore, after converting the aliasing coefficients corresponding to the overlapping arrays of the three different transmission intervals, the difference between the three is the smallest when k=13, k=11, and k=12. At this time, the average of the three values ​​is (13+12+11) / 3)=12.

[0202] It is understandable that if there are no overlapping arrays formed by adjacent interval transmissions in the antenna array and the transmission sequence, the conversion can be performed using a similar method.

[0203] Example 2: When N1 = 2, N2 = 3, and U = 24, the aliasing coefficients for overlapping arrays with a transmit interval of 2 range from 1, 2, 3, ..., 12, and the aliasing coefficients for overlapping arrays with a transmit interval of 3 range from 1, 2, 3, ..., 8. The following uses target 1 as an example to describe the conversion process for aliasing coefficients for overlapping arrays with different transmit intervals corresponding to target 1.

[0204] k2=5, N1=2, which are even numbers. Since k2 is less than 6, k=11 or 23.

[0205] Specifically, there are two cases: no aliasing and double aliasing. If there is no aliasing, k=5+12 / 2=11; if there is double aliasing, k=5+3*12 / 2=23.

[0206] k3=4, N2=3, which is an odd number, then k=4, 12 or 20.

[0207] Specifically, there are three cases: no aliasing, double aliasing, and double aliasing. If there is no aliasing, k=4+0*24 / 3=4; if there is double aliasing, k=4+1*24 / 3=12; if there is double aliasing, k=4+2*24 / 3=20.

[0208] Furthermore, after converting the aliasing coefficients corresponding to the overlapping arrays with the two different transmission intervals, the difference between the two is the smallest when k=11 and k=12. At this time, the average of the two values ​​is rounded off to (round(12+11) / 2)=12.

[0209] Therefore, by converting the aliasing coefficients corresponding to overlapping arrays with multiple transmission intervals and processing the converted aliasing coefficients, the aliasing coefficients within the aliasing coefficient range corresponding to the overlapping array with a transmission interval of 1 are obtained, and the speed of the first target after aliasing is restored to the maximum speed measurement range determined by Tc.

[0210] Furthermore, it should be understood that since velocity can be defined as positive or negative, when U is an odd number, the aliasing coefficient range is [-U / 2, U / 2], and when U is an even number, the aliasing coefficient range is [-U / 2, U / 2).

[0211] Further solve the following parameters:

[0212] k∈1, 2, U is an odd number

[0213]

[0214] k∈1,2,U,U is an even number,

[0215]

[0216]

[0217] k∈1,2,U,U is an even number,

[0218]

[0219] where dopplerInd amb The aliased Doppler signature V of the first target detected on the total RD map ind , N dopplerRepresents the Doppler dimension of the RD graph. This allows the aliased velocity to be extended to the entire U*N doppler The value of the range is i, which represents the aliasing coefficient of the first target obtained by overlapping arrays of multiple transmission intervals. For example, i is the average value obtained based on the k corresponding to the three different transmission intervals in Example 1. The processing unit obtains dopplerInd umamb And the velocity resolution obtains the velocity of the first target. It can be understood that N doppler Greater than or equal to N slow , greater than N slow The chirp values ​​are usually padded with zeros.

[0220] like Figure 8 As shown, the embodiment of the present application further provides a radar device 800, which is a MIMO radar. The MIMO radar includes a transmitter 801, a receiver 802 and a processing unit 803. The transmitter includes N Tx The receiver includes N transmitting antennas Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, and the radar device 800 is used to perform the above Figure 4 The method shown.

[0221] In summary, the method provided in the embodiment of the present application is adopted, through N Tx The preset transmission sequence of the transmitting antennas can construct overlapping arrays with multiple transmission intervals and increase the number of overlapping arrays. When solving for each target's velocity, the aliasing coefficients corresponding to the overlapping arrays with multiple transmission intervals and the large number of overlapping arrays can be calculated. Even if the phase difference of some of the overlapping arrays is significantly affected by noise, resulting in inaccurate solution of the corresponding aliasing coefficients, solving for the target's velocity based on the aliasing coefficients corresponding to the overlapping arrays with multiple transmission intervals can effectively mitigate the impact of the aliasing coefficients corresponding to the overlapping arrays significantly affected by noise on the velocity solution, thereby improving the accuracy of the target velocity solution. Furthermore, the above method does not cause loss of virtual antenna aperture.

[0222] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the embodiments of the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the embodiments of the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0223] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0224] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0225] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0226] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the embodiments of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations.

Claims

1. A radar signal transmitting method, characterized in that: Applied to multiple-input multiple-output MIMO radar, the MIMO radar includes a transmitter and a receiver, the transmitter includes N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, and the method includes: Determine the configuration information of the measurement frame, wherein the configuration information of the measurement frame indicates the N Tx The preset transmission order of the transmitting antennas, the transmission duration T of each chirp signal c and the N Tx The transmitting antennas repeat the transmission in the preset transmission order for a number of times N slow ; The measurement frame is sent according to the configuration information of the measurement frame, and the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx .

2. The method according to claim 1, wherein For each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

3. The method according to claim 1 or 2, wherein: The N Tx At least one transmitting antenna among the U transmitting antennas transmits chirp signals twice in the U time slots.

4. The method according to claim 1 or 2, wherein: The N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

5. A radar signal receiving method, characterized in that: Applied to MIMO radar, the MIMO radar includes a transmitter and a receiver, the transmitter includes N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, and the method includes: Receive the echo signal formed by the reflection of at least one target after the measurement frame is reflected, and the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx ; determining a first aliasing coefficient and a second aliasing coefficient based on the echo signal; wherein the first aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N1 corresponding to a first target, the second aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N2 corresponding to the first target, the first target being any one of the at least one target, and the aliasing coefficient is used to correct a velocity aliasing error for the first target; The speed of the first object is determined based on the first aliasing coefficient and the second aliasing coefficient.

6. The method according to claim 5, wherein For each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

7. The method according to claim 5 or 6, wherein: Determining the speed of the first target according to the first aliasing coefficient and the second aliasing coefficient includes: Determine a first aliasing coefficient range according to N1, and determine a second aliasing coefficient range according to N2; Determining a first aliasing coefficient set based on the first aliasing coefficient range, the first aliasing coefficient, and N1, and determining a second aliasing coefficient set based on the second aliasing coefficient range, the second aliasing coefficient, and N2; wherein the first aliasing coefficient set includes possible aliasing coefficients obtained by converting the first aliasing coefficient into a third aliasing coefficient range, and the second aliasing coefficient set includes possible aliasing coefficients obtained by converting the second aliasing coefficient into the third aliasing coefficient range, and the third aliasing coefficient range is an aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1; determining a third aliasing coefficient and a fourth aliasing coefficient according to the first aliasing coefficient set and the second aliasing coefficient set, the third aliasing coefficient being an aliasing coefficient in the first aliasing coefficient set, and the fourth aliasing coefficient being an aliasing coefficient in the second aliasing coefficient set; The speed of the first object is determined according to the third aliasing coefficient and the fourth aliasing coefficient.

8. The method according to claim 7, wherein A difference between the third aliasing coefficient and the fourth aliasing coefficient is a minimum value of differences between any one aliasing coefficient in the first aliasing coefficient set and any one aliasing coefficient in the second aliasing coefficient set.

9. The method according to claim 7, wherein Determining the speed of the first target according to the third aliasing coefficient and the fourth aliasing coefficient includes: determining a speed of the first target according to an average of the third aliasing coefficient and the fourth aliasing coefficient; Alternatively, the speed of the first object is determined according to a weighted average of the third aliasing coefficient and the fourth aliasing coefficient.

10. The method according to claim 5 or 6, characterized in that The N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

11. A radar device, characterized in that: The device is a MIMO radar, which includes a transmitter, a receiver and a processing unit. The transmitter includes N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, where: The processing unit is configured to determine configuration information of a measurement frame, wherein the configuration information of the measurement frame indicates the N Tx The preset transmission order of the transmitting antennas, the transmission duration T of each chirp signal c and the N Tx The transmitting antennas repeat the transmission in the preset transmission order for a number of times N slow ; The transmitter is configured to send the measurement frame according to the configuration information of the measurement frame, wherein the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx .

12. The device according to claim 11, wherein For each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

13. The device according to claim 11 or 12, characterized in that The N Tx At least one transmitting antenna among the U transmitting antennas transmits chirp signals twice in the U time slots.

14. The device according to claim 11 or 12, characterized in that The N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

15. A radar device, characterized in that: The device is a MIMO radar, which includes a transmitter, a receiver and a processing unit. The transmitter includes N Tx transmitting antennas, the receiver includes N Rx receive antennas, where N Tx and N Rx are all positive integers greater than or equal to 2, where: The receiver is used to receive an echo signal formed after the measurement frame is reflected by at least one target, and the measurement frame includes U*N slow chirp signal, wherein the U*N slow The chirp signal includes N slow A group of chirp signals, each group of chirp signals includes U chirp signals, and the U chirp signals are the N Tx The transmitting antennas transmit in U time slots according to the preset transmission order, and the transmission duration of each chirp signal is T c Recorded as a time slot; the N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N1 and overlapping arrays with a transmission interval of N2, N1≠N2, N1 is a positive integer, N2 is a positive integer, U≥N Tx ; The processing unit is configured to determine a first aliasing coefficient and a second aliasing coefficient based on the echo signal; wherein the first aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N1 corresponding to a first target, the second aliasing coefficient is an aliasing coefficient corresponding to an overlapping array with a transmission interval of N2 corresponding to the first target, the first target is any one of the at least one target, and the aliasing coefficient is used to correct a velocity aliasing error for the first target; and the velocity of the first target is determined based on the first aliasing coefficient and the second aliasing coefficient.

16. The device according to claim 15, characterized in that For each group of chirp signals, the transmitting antenna m1 transmits the chirp signal in the time slot u1 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1 and the receiving antenna n1 is d m1n1 , the transmitting antenna m1' transmits a chirp signal in the time slot u1' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m1' and the receiving antenna n1' is d m1’n1’ , the transmitting antenna m2 transmits a chirp signal in the time slot u2 of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2 and the receiving antenna n2 is d m2n2 , the transmitting antenna m2' transmits a chirp signal in the time slot u2' of the U time slots, and the position of the virtual receiving antenna array formed by the transmitting antenna m2' and the receiving antenna n2' is d m2’n2’ , the overlapping arrays with a transmission interval of N1 satisfy d m1n1 =d m1’n1’ , the overlapping arrays with a transmission interval of N2 satisfy d m2n2 =d m2’n2’ ; Among them, |u1-u1'|=N1, |u2-u2'|=N2; m1, n1, m1', n1', m2, n2, m2', n2' are all integers greater than or equal to 0, and u1, u1', u2, u2' are all integers greater than or equal to 0.

17. The device according to claim 15 or 16, characterized in that The processing unit is configured to: Determine a first aliasing coefficient range according to N1, and determine a second aliasing coefficient range according to N2; Determining a first aliasing coefficient set based on the first aliasing coefficient range, the first aliasing coefficient, and N1, and determining a second aliasing coefficient set based on the second aliasing coefficient range, the second aliasing coefficient, and N2; wherein the first aliasing coefficient set includes possible aliasing coefficients obtained by converting the first aliasing coefficient into a third aliasing coefficient range, and the second aliasing coefficient set includes possible aliasing coefficients obtained by converting the second aliasing coefficient into the third aliasing coefficient range, and the third aliasing coefficient range is an aliasing coefficient range corresponding to overlapping arrays with a transmission interval of 1; determining a third aliasing coefficient and a fourth aliasing coefficient according to the first aliasing coefficient set and the second aliasing coefficient set, the third aliasing coefficient being an aliasing coefficient in the first aliasing coefficient set, and the fourth aliasing coefficient being an aliasing coefficient in the second aliasing coefficient set; The speed of the first object is determined according to the third aliasing coefficient and the fourth aliasing coefficient.

18. The device according to claim 17, wherein A difference between the third aliasing coefficient and the fourth aliasing coefficient is a minimum value of differences between any one aliasing coefficient in the first aliasing coefficient set and any one aliasing coefficient in the second aliasing coefficient set.

19. The device according to claim 17, wherein The processing unit is configured to: determining a speed of the first target according to an average of the third aliasing coefficient and the fourth aliasing coefficient; Alternatively, the speed of the first object is determined according to a weighted average of the third aliasing coefficient and the fourth aliasing coefficient.

20. The device according to claim 15 or 16, characterized in that The N Tx The N transmitting antennas Rx The virtual receiving array formed by the receiving antennas includes overlapping arrays with a transmission interval of N3, N2≠N2≠N3, and N3 is a positive integer.

Images