WO2021031076A1 - 信号传输方法及装置、信号处理方法及装置以及雷达系统 - Google Patents

信号传输方法及装置、信号处理方法及装置以及雷达系统 Download PDF

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Publication number
WO2021031076A1
WO2021031076A1 PCT/CN2019/101408 CN2019101408W WO2021031076A1 WO 2021031076 A1 WO2021031076 A1 WO 2021031076A1 CN 2019101408 W CN2019101408 W CN 2019101408W WO 2021031076 A1 WO2021031076 A1 WO 2021031076A1
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Prior art keywords
burst
signal
targets
chirp
speed
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PCT/CN2019/101408
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English (en)
French (fr)
Inventor
刘劲楠
周沐
劳大鹏
杨晨
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华为技术有限公司
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Publication date
Priority to BR112022003018A priority Critical patent/BR112022003018A2/pt
Priority to PCT/CN2019/101408 priority patent/WO2021031076A1/zh
Priority to CA3148543A priority patent/CA3148543A1/en
Priority to KR1020227008705A priority patent/KR20220047622A/ko
Priority to CN201980059673.5A priority patent/CN112714877B/zh
Priority to EP19942160.3A priority patent/EP4016116A4/en
Application filed by 华为技术有限公司 filed Critical 华为技术有限公司
Priority to CN202211251489.0A priority patent/CN115792819A/zh
Priority to JP2022511089A priority patent/JP2022545002A/ja
Priority to CN202211257698.6A priority patent/CN115754926A/zh
Publication of WO2021031076A1 publication Critical patent/WO2021031076A1/zh
Priority to US17/675,743 priority patent/US20220171050A1/en
Priority to JP2023211171A priority patent/JP2024037897A/ja

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/46—Indirect determination of position data
    • G01S13/48—Indirect determination of position data using multiple beams at emission or reception
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/88—Radar or analogous systems specially adapted for specific applications
    • G01S13/93—Radar or analogous systems specially adapted for specific applications for anti-collision purposes
    • G01S13/931—Radar or analogous systems specially adapted for specific applications for anti-collision purposes of land vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/02—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to ambient conditions
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G01S13/32—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated
    • G01S13/34—Systems for measuring distance only using transmission of continuous waves, whether amplitude-, frequency-, or phase-modulated, or unmodulated using transmission of continuous, frequency-modulated waves while heterodyning the received signal, or a signal derived therefrom, with a locally-generated signal related to the contemporaneously transmitted signal
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G01S13/583—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets
    • G01S13/584—Velocity or trajectory determination systems; Sense-of-movement determination systems using transmission of continuous unmodulated waves, amplitude-, frequency-, or phase-modulated waves and based upon the Doppler effect resulting from movement of targets adapted for simultaneous range and velocity measurements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/74—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
    • G01S13/82—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted
    • G01S13/84—Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems wherein continuous-type signals are transmitted for distance determination by phase measurement
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/003—Transmission of data between radar, sonar or lidar systems and remote stations
    • G01S7/006—Transmission of data between radar, sonar or lidar systems and remote stations using shared front-end circuitry, e.g. antennas
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/35—Details of non-pulse systems
    • G01S7/352—Receivers
    • G01S7/354—Extracting wanted echo-signals
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W2050/0001—Details of the control system
    • B60W2050/0002—Automatic control, details of type of controller or control system architecture
    • B60W2050/0004—In digital systems, e.g. discrete-time systems involving sampling
    • B60W2050/0005—Processor details or data handling, e.g. memory registers or chip architecture
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W2050/0062—Adapting control system settings
    • B60W2050/0075—Automatic parameter input, automatic initialising or calibrating means
    • B60W2050/0083—Setting, resetting, calibration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2420/00—Indexing codes relating to the type of sensors based on the principle of their operation
    • B60W2420/40—Photo, light or radio wave sensitive means, e.g. infrared sensors
    • B60W2420/403—Image sensing, e.g. optical camera
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2420/00—Indexing codes relating to the type of sensors based on the principle of their operation
    • B60W2420/40—Photo, light or radio wave sensitive means, e.g. infrared sensors
    • B60W2420/408—Radar; Laser, e.g. lidar

Definitions

  • This application relates to the field of sensor technology, and in particular to a signal transmission method and device, a signal processing method and device, and a radar system.
  • Vehicle-mounted radar is an indispensable sensor in the automatic driving system.
  • the vehicle-mounted radar can provide obstacle (also known as target) detection for the vehicle. Specifically, the distance, speed, and azimuth of obstacles around the vehicle can be detected.
  • the frequency band has gradually evolved from 24GHz to 77GHz/79GHz, so as to obtain higher range resolution through larger scanning bandwidth; the number of channels is changed from single input multiple output (SIMO)
  • SIMO single input multiple output
  • MIMO multiple input multiple output
  • multiple antennas can use time division multiplexing (TDM) to transmit chirp signals.
  • TDM time division multiplexing
  • the maximum speed range of MIMO radar is reduced.
  • Tc_SIMO which can be called a time slot.
  • the relationship between the maximum speed measurement range Vmax_MIMO when using Nt antennas to transmit chirp and the maximum speed measurement range Vmax_SIMO (that is, the speed measurement range of SIMO radar) when using a single antenna to transmit chirp can be expressed as: Vmax_SIMO ⁇ Nt*Vmax_MIMO.
  • the embodiments of the present application provide a signal transmission method and device, a signal processing method and device, and a radar system, so that the MIMO radar can accurately restore the speed of the target to the speed measurement range of the SIMO radar.
  • embodiments of the present application provide a signal transmission method, which is applied to a multiple-input multiple-output MIMO radar.
  • the MIMO radar includes a transmitter, and the transmitter includes Nt transmitting antennas.
  • the method includes: the transmitter sends a measurement frame, The measurement frame is used to measure the speed of the target, and the measurement frame includes the first burst; where, in the first burst, each of the Nt transmitting antennas is used to transmit a chirp signal with a period of N1*T1, Where N1>Nt, T1 is the duration of each chirp signal in the first burst.
  • the measurement frame can be a frequency modulated continuous wave FMCW.
  • the high-density transmitting antenna (for example, the first transmitting antenna) transmits N1-Nt chirp signals continuously, the phase difference of the receiving antenna corresponding to the soft overlapping moment is only caused by the doppler of the target speed. The phase is determined. Therefore, the speed of the target calculated on the first transmitting antenna with a higher transmission density can be directly matched to the corresponding speed aliasing coefficient to determine the speed of the target.
  • the high-density transmitting antenna (for example, the first transmitting antenna) transmits N1-Nt chirp signals periodically, the maximum velocity range of the echo signal received by the high-density transmitting antenna is large, so the density is high.
  • the transmitting antenna can form a smaller transmission repetition period when transmitting.
  • the received echo signal corresponding to the high-density transmitting antenna has a small number of aliasing coefficients relative to the speed of SIMO, and the high-density transmitting antenna is used to correspond
  • the received echo signal assists the received echo signal corresponding to the low-density transmitting antenna to calculate the target speed, which can narrow the range of the aliasing coefficient in the angular spectrum peak search and reduce the calculation complexity.
  • the maximum speed range of the MIMO radar can be restored to the SIMO speed range without affecting subsequent angle measurement.
  • Using the method provided by the embodiment of the present application can ensure the accuracy of the azimuth angle calculation and improve the angular resolution.
  • the first transmitting antenna of the Nt transmitting antennas is also used to transmit a chirp signal at a period of M1*T1, where M1 ⁇ N1.
  • the chirp signal is transmitted in the above manner, and transmission of different density of the transmitting antenna can be realized, wherein the transmitting density of the first transmitting antenna is larger, and the transmitting density of the remaining transmitting antennas is smaller. Since the high-density transmitting antenna has a large maximum velocity measurement range corresponding to the echo signal received, the high-density transmitting antenna can form a smaller transmission repetition period when transmitting.
  • the received echo corresponding to the high-density transmitting antenna The number of speed aliasing coefficients of wave signal relative to SIMO is small, and the received echo signal corresponding to the high-density transmitting antenna is used to assist the received echo signal corresponding to the low-density transmitting antenna to calculate the target speed, which can narrow the angle spectrum peak search
  • the interval range of the middle aliasing coefficient reduces the complexity of calculation.
  • the first transmitting antenna in the first burst, is also used to transmit a chirp signal with a period of M2*T1, M2 ⁇ N1, and M1 and M2 are relatively prime.
  • the velocity resolution of the two sets of identifiers determined according to the echo signals of the two sets of chirp signals reflected by the first transmitting antenna at a high density is the same. Since M1 and M2 are relatively prime, and in the staggered algorithm, any integer equation that is mutually primed has a solution, so the above scheme can use the Chinese remainder method (staggered algorithm) to expand the speed measurement range of the MIMO radar.
  • the measurement frame may also include a second burst; in the second burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N2*T2, and Nt transmit antennas
  • the second transmitting antenna in is also used to send chirp signals with M3*T2, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst; M3*T2 and M1*T1 are relatively prime, or M3 and M1 Coprime and T1 and T2 are equal.
  • the velocity resolution of the two sets of identifiers respectively determined according to the echo signal after the chirp signal transmitted by the first transmitting antenna at high density and the echo signal after the chirp signal transmitted by the second transmitting antenna is the same . Because M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime, and in the staggered algorithm, any integer equation that is mutually primed has a solution, so the above scheme can be used to expand the Chinese remainder method (parametric algorithm) The speed range of MIMO radar.
  • the measurement frame may also include a third burst; in the third burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N3*T3, and T3 is the third burst.
  • At least one of the Nt transmitting antennas sends two chirp signals continuously in the first burst.
  • the phase difference of the receiving antennas corresponding to two or more adjacent time slots at the time of the soft overlap is only determined by the Doppler phase caused by the target velocity. Therefore, the corresponding velocity aliasing coefficient can be directly matched with the velocity identification of the target calculated on the first transmitting antenna with a higher emission density, thereby determining the aliasing velocity within the SIMO velocity measurement range of the target.
  • the MIMO radar further includes a processing unit
  • the method further includes: the processing unit determines the configuration of the measurement frame according to the configuration, and sends the configuration of the measurement frame to the monolithic microwave integrated circuit MMIC through the interface, and the MMIC is used for Enable the transmitter to send the measurement frame according to the configuration of the measurement frame.
  • the relevant parameters can be configured for the MMIC, thereby completing the transmission of the measurement frame.
  • inventions of the present application provide a signal processing method, which is applied to a MIMO radar.
  • the MIMO radar includes a transmitter, a receiver, and a processing unit.
  • the transmitter includes Nt transmit antennas.
  • the method includes the following steps: Receiver Receive the first echo signal and the second echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets.
  • the measurement frame includes the first burst.
  • the first echo signal is composed of Nt transmitting antennas.
  • the chirp signal sent by each transmitting antenna in the first burst with a period of N1*T1 is formed after being reflected by one or more targets, and the second echo signal is sent by the other chirps sent by the first transmitting antenna among the Nt transmitting antennas.
  • the signal is formed after being reflected by one or more targets, N1>Nt, T1 is the duration of each chirp signal in the first burst; the processing unit determines one or more targets according to the first echo signal and the second echo signal speed
  • the transmitting antennas are transmitted at different densities, so the maximum speed range of the first echo signal and the second echo signal obtained from the chirp signals sent by the transmitting antennas of different transmission densities are different.
  • the phase difference of the receiving antenna corresponding to the soft overlapping moment is only determined by the Doppler phase caused by the target velocity. Therefore, it is possible to directly match the corresponding velocity aliasing coefficient through the target's velocity identification calculated on the transmitting antenna with a higher transmission density, so as to restore the maximum velocity range of the MIMO radar to the SIMO velocity range to determine the target's velocity.
  • the high-density transmitting antenna can be smaller when transmitting. Transmission repetition period, then when the spectral peak search method is used, the number of aliasing coefficients of the received echo signal corresponding to the high-density transmitting antenna relative to the speed of SIMO is small, and the received echo signal corresponding to the high-density transmitting antenna is used to assist the low density
  • the target velocity is calculated for the received echo signal corresponding to the transmitting antenna, which can narrow the range of the aliasing coefficient in the angular spectrum peak search, and reduce the calculation complexity.
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, including: the processing unit determines the first identifier according to the first echo signal, and the first identifier is used to indicate a The distance measurement value and speed measurement value of one or more targets; the processing unit determines a second identifier according to the second echo signal, the second identifier is used to indicate the distance measurement value and speed measurement value of the one or more targets; the processing unit The speed of one or more targets is determined according to the first identification and the second identification.
  • the speed aliasing coefficient of the target can be determined according to the two sets of target identifiers (ie, the first identifier and the second identifier), and then the speed of the target can be determined.
  • the second echo signal is formed by the chirp signal sent by the first transmitting antenna with a period of M1*T1 after being reflected by one or more targets, M1 ⁇ N1.
  • the chirp signal can be periodically transmitted through the first transmitting antenna to achieve high-density transmission.
  • the processing unit determines the speed of one or more targets according to the first identifier and the second identifier, which can be specifically implemented in the following manner: the processing unit determines the first aliasing coefficient interval corresponding to the first identifier according to N1, and determines according to M1 The second aliasing coefficient interval corresponding to the second identifier; the processing unit determines the aliasing coefficient subset corresponding to the second aliasing coefficient interval in the first aliasing coefficient interval according to the first identifier and the second identifier; the processing unit The subset of overlap coefficients determines the velocity aliasing coefficient; the processing unit determines the velocity of one or more targets according to the velocity aliasing coefficient and the first identifier.
  • the method further includes: the receiver receives a third echo signal formed after the measurement frame is reflected by one or more targets, and the third echo signal is transmitted by the first transmitting antenna in the first burst with a period of M2*T1
  • the sent chirp signal is formed after being reflected by one or more targets, M2 ⁇ N1, M1 and M2 are relatively prime;
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, including: the processing unit according to the first The second echo signal and the third echo signal determine the velocity of one or more targets.
  • the method further includes: the receiver receives a fourth echo signal and a fifth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame further includes a second burst, and the fourth echo signal is composed of The second transmitting antenna of the Nt transmitting antennas is formed by reflecting the chirp signal sent by the second transmitting antenna with a period of M3*T2 in the second burst after one or more targets, and the fifth echo signal is formed by each of the Nt transmitting antennas
  • the chirp signal sent by the transmitting antenna in the second burst with a period of N2*T2 is formed after reflection from one or more targets, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst; M3*T2 M1*T1 is relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal;
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, including: the processing unit determines the speed of one or more targets
  • the echo signal transmitted according to the chirp signal transmitted at high density by the first transmitting antenna and after the chirp signal transmitted at high density by the second transmitting antenna is transmitted
  • the speed resolution of the two sets of identifications determined by the echo signals of the two groups is the same, and the Chinese remainder method (staggered algorithm) can be used to expand the speed measurement range of the MIMO radar.
  • the method further includes: the receiver receives a sixth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame further includes a third burst, and the sixth echo signal is composed of The chirp signal sent by each of the Nt transmitting antennas in the third burst with a period of N3*T3 is formed after being reflected by one or more targets.
  • T3 is the duration of each chirp signal in the third burst ; N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal; the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, including: the processing unit according to the second The echo signal and the sixth echo signal determine the velocity of one or more targets. Since N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime, the Chinese remainder method (staggered algorithm) can be used to expand the speed measurement range of the MIMO radar.
  • the method further includes: the receiver receives a seventh echo signal formed after the measurement frame is reflected by one or more targets, and the seventh echo signal is transmitted by the first transmitting antenna in the first burst
  • the multiple chirp signals sent continuously within the time N1*T1 are formed after reflection from one or more targets
  • the processing unit determines the speed of one or more targets according to the echo signals received by the receiver, including: the processing unit according to the second The echo signal and the seventh echo signal determine the velocity of one or more targets.
  • an embodiment of the present application provides a signal transmission device, including: a transmitter for sending a measurement frame, the transmitter includes Nt transmitting antennas, the measurement frame is used to measure the speed of the target, and the measurement frame includes a first burst ; Among them, in the first burst, each of the Nt transmit antennas is used to transmit a chirp signal with a period of N1*T1, where N1>Nt, T1 is each chirp signal in the first burst Duration.
  • the first transmitting antenna of the Nt transmitting antennas is also used to transmit a chirp signal at a period of M1*T1, where M1 ⁇ N1.
  • the first transmitting antenna is also used to transmit the chirp signal with a period of M2*T1, M2 ⁇ N1, and M1 and M2 are relatively prime.
  • the measurement frame also includes a second burst; in the second burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N2*T2, and Nt transmit
  • the second transmitting antenna in the antenna is also used to send chirp signals with M3*T2, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst; M3*T2 and M1*T1 are mutually primed, or M3 and M1 is relatively prime, and T1 and T2 are equal.
  • the measurement frame also includes a third burst; in the third burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N3*T3, and T3 is the first burst.
  • At least one of the Nt transmitting antennas sends two chirp signals continuously in the first burst.
  • the measurement frame is a frequency modulated continuous wave FMCW.
  • the device further includes: a processing unit for determining the configuration of the measurement frame, and sending the configuration of the measurement frame to the monolithic microwave integrated circuit MMIC through the interface, and the MMIC is used to make the configuration of the measurement frame
  • the transmitter can send measurement frames.
  • an embodiment of the present application provides a signal processing device, including a receiver, configured to receive a first echo signal and a second echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets
  • the measurement frame includes the first burst.
  • the first echo signal is transmitted by each of the Nt transmitting antennas included in the transmitter.
  • the chirp signal transmitted in the first burst with a period of N1*T1 passes through one or more It is formed after the target is reflected, and the second echo signal is formed by other chirp signals sent by the first transmitting antenna of the Nt transmitting antennas after being reflected by one or more targets, N1>Nt, T1 is each chirp in the first burst
  • the duration of the signal; the processing unit is used to determine the speed of one or more targets according to the first echo signal and the second echo signal.
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, it is specifically configured to: determine the first identifier according to the first echo signal, and the first identifier is used for Indicate the distance measurement value and speed measurement value of one or more targets; determine the second identifier according to the second echo signal, the second identifier is used to indicate the distance measurement value and speed measurement value of one or more targets; according to the first identifier And the second identification determines the speed of one or more targets.
  • the second echo signal is formed by the chirp signal sent by the first transmitting antenna with a period of M1*T1 after being reflected by one or more targets, M1 ⁇ N1.
  • the processing unit determines the speed of one or more targets according to the first identifier and the second identifier, it is specifically configured to: determine the first aliasing coefficient interval corresponding to the first identifier according to N1, and according to M1 determines the second aliasing coefficient interval corresponding to the second identifier; according to the first identifier and the second identifier, determines the aliasing coefficient subset corresponding to the second aliasing coefficient interval in the first aliasing coefficient interval; according to the aliasing coefficient The subset determines the velocity aliasing coefficient; the velocity of one or more targets is determined according to the velocity aliasing coefficient and the first identifier.
  • the receiver is also used to: receive a third echo signal formed after the measurement frame is reflected by one or more targets.
  • the third echo signal is transmitted by the first transmitting antenna in the first burst.
  • M2*T1 is formed after periodic transmission of chirp signals reflected by one or more targets, M2 ⁇ N1, M1 and M2 are relatively prime;
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver , Specifically used for: determining the speed of one or more targets according to the second echo signal and the third echo signal.
  • the receiver is also used to: receive the fourth echo signal and the fifth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame also includes the second burst, the fourth The echo signal is formed by the chirp signal sent by the second transmitting antenna in the second burst with a period of M3*T2 in the second burst after being reflected by one or more targets.
  • the fifth echo signal is formed by Nt transmitting antennas.
  • the chirp signal sent by each transmitting antenna in the second burst with a period of N2*T2 is formed after being reflected by one or more targets, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst ; M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal; when the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, it is specifically used to: The second echo signal and the fourth echo signal determine the velocity of one or more targets.
  • the receiver is also used to: receive the sixth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame also includes a third burst, the sixth echo signal consists of Nt
  • the chirp signal sent by each of the transmitting antennas in the third burst with a period of N3*T3 is formed after reflection by one or more targets.
  • T3 is the duration of each chirp signal in the third burst; N3 *T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal; when the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, it is specifically used to: The echo signal and the sixth echo signal determine the velocity of one or more targets.
  • the receiver is also used to: receive the seventh echo signal formed after the measurement frame is reflected by one or more targets.
  • the seventh echo signal is transmitted by the first transmitting antenna in the first burst.
  • Multiple chirp signals continuously sent within N1*T1 are formed after reflection from one or more targets; when the processing unit determines the speed of one or more targets according to the echo signals received by the receiver, it is specifically used to:
  • the second echo signal and the seventh echo signal determine the velocity of one or more targets.
  • an embodiment of the present application also provides a radar system, including: a transmitter, the transmitter includes Nt transmitting antennas, the transmitter is used to send a measurement frame, the measurement frame is used to measure the speed of the target, and the measurement frame includes a first projection.
  • each of the Nt transmit antennas is used to transmit chirp signals in a period of N1*T1, where N1>Nt, and T1 is the chirp signal of each chirp signal in the first burst Duration; receiver for receiving the first echo signal and the second echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame includes the first burst, and the first echo signal consists of each The chirp signal sent by the transmitting antenna in the first burst with a period of N1*T1 is formed after being reflected by one or more targets, and the second echo signal is reflected by other chirp signals sent by the first transmitting antenna by one or more targets After formation; processing unit, used to determine the speed of one or more targets according to the echo signal received by the receiver.
  • the transmitter in the radar system is also used to perform other operations performed by the transmitter in the method provided in the first aspect
  • the receiver in the radar system is also used to perform other operations performed by the receiver in the method provided in the second aspect
  • the processing unit in the radar system is also used to perform other operations performed by the processing unit in the method provided in the first aspect or the second aspect.
  • FIG. 1 is a schematic structural diagram of a MIMO radar provided by an embodiment of this application;
  • FIG. 2 is a schematic structural diagram of a vehicle provided by an embodiment of the application.
  • FIG. 3 is a schematic flowchart of a signal transmission method provided by an embodiment of this application.
  • FIG. 4 is a schematic diagram of a chirp signal sent by the first MIMO radar according to an embodiment of the application
  • FIG. 5 is a schematic diagram of a chirp signal sent by a second MIMO radar according to an embodiment of the application
  • FIG. 6 is a schematic diagram of a chirp signal sent by a third MIMO radar provided by an embodiment of the application.
  • FIG. 7 is a schematic diagram of a chirp signal sent by a fourth MIMO radar according to an embodiment of the application.
  • FIG. 8 is a schematic diagram of a chirp signal sent by a fifth MIMO radar according to an embodiment of the application.
  • FIG. 9 is a schematic diagram of a chirp signal sent by a sixth MIMO radar according to an embodiment of the application.
  • FIG. 10 is a schematic diagram of a chirp signal sent by a seventh MIMO radar according to an embodiment of the application.
  • FIG. 11 is a schematic diagram of a chirp signal sent by an eighth MIMO radar according to an embodiment of the application.
  • FIG. 12 is a schematic flowchart of a signal processing method provided by an embodiment of this application.
  • FIG. 13 is a schematic structural diagram of a signal transmission device provided by an embodiment of this application.
  • FIG. 14 is a schematic structural diagram of a signal processing device provided by an embodiment of this application.
  • FIG. 15 is a schematic structural diagram of a radar system provided by an embodiment of this application.
  • Tc_SIMO which can be called a time slot.
  • the relationship between the maximum velocity measurement range Vmax_MIMO when using Nt antennas to transmit chirp and the maximum velocity measurement range Vmax_SIMO when using a single antenna to transmit chirp can be expressed as: Vmax_SIMO ⁇ Nt*Vmax_MIMO.
  • Radar is a device that uses the Doppler effect to measure speed. Due to the movement of the target or radar, the frequency or phase of the received signal of the radar changes. In the FMCW system, the distance between the target and the radar is measured by measuring the frequency of the echo signal in a chirp, and the speed of the target is measured by the phase difference between the echo signals of the same antenna in different time slots. Therefore, the dimension corresponding to the velocity is also called the Doppler domain, that is, the dimension corresponding to the doppler on the RD map.
  • the radar signals on multiple antennas sent by time division cause the target's velocity to collide in the Doppler domain. That is, the reflected signal of multiple targets has the same observation value in the Doppler domain, which leads to the speed of each target.
  • the complexity and accuracy of the solution face challenges. For example, when the SIMO mode is used for transmission, the maximum speed range is -120km/h-120km/h; when the four antennas are used for TDM MIMO transmission, the maximum speed range is reduced to -30km/h-30km/h. Then, compared with sending in the SIMO mode, when sending in the TDM MIMO mode, the probability of the target's velocity colliding in the Doppler domain becomes greater.
  • embodiments of the present application provide a signal transmission method and device, a signal processing method and device, and a radar system, so that the MIMO radar can accurately restore the target speed to the speed measurement range of the SIMO radar.
  • the MIMO radar system may include an antenna array 101, a monolithic microwave integrated circuit (monolithic microwave integrated circuit, MMIC) 102, and a processing unit 103.
  • the antenna array 101 may include multiple transmitting antennas and multiple receiving antennas.
  • the monolithic microwave integrated circuit 102 is used to generate radar signals, and then the radar signals are sent out through the antenna array 101.
  • the radar signal consists of one or more bursts, and each burst includes multiple chirp signals. After the radar signal is sent out, it is reflected by one or more targets to form an echo signal, and the echo signal is received by the receiving antenna.
  • the monolithic microwave integrated circuit 102 is also used to perform processing such as transformation and sampling on the echo signal received by the antenna array 101, and transmit the processed echo signal to the processing unit 103.
  • the processing unit 103 is configured to perform Fast Fourier Transformation (FFT), signal processing and other operations on the echo signal, so as to determine the distance, speed, azimuth angle and other information of the target according to the received echo signal.
  • the processing unit 103 may be a microprocessor (microcontroller unit, MCU), a central processing unit (CPU), a digital signal processor (digital signal processor, DSP), or a field programmable gate array (field-programmable gate array). Programmable gate array, FPGA) and other devices with processing functions.
  • the radar system shown in FIG. 1 may also include an electronic control unit (ECU) 104, which is used to control the vehicle according to the target distance, speed, azimuth and other information processed by the processing unit 103, such as determining The route of the vehicle, etc.
  • ECU electronice control unit
  • one MMIC can be set for the transmitting antenna array and the receiving antenna array, or only one MMIC can be set for the transmitting antenna array and the receiving antenna array.
  • the former is illustrated in the example of FIG. 1 as an example.
  • the transmitter in the embodiment of the present application may be composed of a transmitting antenna and the transmitting channel in the monolithic microwave integrated circuit 102
  • the receiver may be composed of a receiving antenna and the receiving channel in the monolithic 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 in the chip, namely AOB (antenna on PCB); or, the transmitting antenna and the receiving antenna can be located in the chip package Inside, the transmitting channel and the receiving channel can be located in the chip, namely AIP (antenna in package).
  • the combination form is not specifically limited in the embodiments of the present application.
  • the radar system described in the embodiments of the present application can be applied to various fields.
  • the radar systems in the embodiments of the present application include, but are not limited to, vehicle-mounted radars, roadside traffic radars. Man-machine radar.
  • the entire radar system may include multiple radio frequency chip cascades, which connect the data output by the analog-digital converter (ADC) channel to the processing unit 103, such as MCU, DSP, FPGA, and general processing unit (General Process Unit, GPU) etc.
  • the entire vehicle may be equipped with one or more radar systems, which are connected to the central processing unit through the vehicle bus.
  • the central processing unit controls one or more vehicle sensors, including one or more millimeter wave radar sensors.
  • the MIMO radar system shown in Figure 1 can be applied to vehicles with autonomous driving functions.
  • FIG. 2 is a functional block diagram of a vehicle 200 with an automatic driving function provided by an embodiment of this application.
  • the vehicle 200 is configured in a fully or partially autonomous driving mode.
  • the vehicle 200 can control itself while in the automatic driving mode, and can determine the current state of the vehicle and its surrounding environment through human operations, determine the possible behavior of at least one other vehicle in the surrounding environment, and determine the other vehicle
  • the confidence level corresponding to the possibility of performing possible actions is controlled based on the determined information.
  • the vehicle 200 can be set to operate without human interaction.
  • the 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 and a power source 210, a computer system 212, and a user interface 216.
  • the vehicle 200 may include more or fewer subsystems, and each subsystem may include multiple elements.
  • each subsystem and element of the vehicle 200 may be interconnected by wires or wirelessly.
  • the travel system 202 may include components that provide power movement for the vehicle 200.
  • the travel system 202 may include an engine 218, an energy source 219, a transmission 220, and wheels/tires 221.
  • the engine 218 may be an internal combustion engine, an electric motor, an air compression engine, or other types of engine combinations, such as a hybrid engine composed of a gas oil engine and an electric motor, or a hybrid engine composed of an internal combustion engine and an air compression engine.
  • the engine 218 converts the energy source 219 into mechanical energy.
  • Examples of energy sources 219 include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, solar panels, batteries, and other sources of electricity.
  • the energy source 219 may also provide energy for other systems of the vehicle 100.
  • the transmission 220 can transmit the mechanical power from the engine 218 to the wheels 221.
  • the transmission 220 may include a gearbox, a differential, and a drive shaft.
  • the transmission device 220 may also include other components, such as a clutch.
  • the drive shaft may include one or more shafts that can be coupled to one or more wheels 221.
  • the sensor system 204 may include several sensors that sense information about the environment around the vehicle 200.
  • the sensor system 204 may include a positioning system 222 (the positioning system may be a global positioning system (GPS) system, a Beidou system or other positioning systems), an inertial measurement unit (IMU) 224, Radar 226, laser rangefinder 228, and camera 230.
  • the sensor system 204 may also include sensors of the internal system of the monitored vehicle 200 (for example, an in-vehicle air quality monitor, a fuel gauge, an oil temperature gauge, etc.). Sensor data from one or more of these sensors can be used to detect objects and their corresponding characteristics (position, shape, direction, speed, etc.). Such detection and identification are key functions for the safe operation of the autonomous vehicle 100.
  • the positioning system 222 can be used to estimate the geographic location of the vehicle 200.
  • the IMU 224 is used to sense the position and orientation changes of the vehicle 200 based on inertial acceleration.
  • the IMU 224 may be a combination of an accelerometer and a gyroscope.
  • the radar 226 may use radio signals to sense objects in the surrounding environment of the vehicle 200. In some embodiments, in addition to sensing the object, the radar 226 may also be used to sense the speed and/or direction of the object. In a specific example, the radar 226 can be implemented using the MIMO radar system shown in FIG. 1.
  • the laser rangefinder 228 can use laser light to sense objects in the environment where the vehicle 100 is located.
  • the laser rangefinder 228 may include one or more laser sources, laser scanners, and one or more detectors, as well as other system components.
  • 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.
  • the control system 206 controls the operation of the vehicle 200 and its components.
  • the control system 206 may include various components, including a steering system 232, a throttle 234, a braking unit 236, a sensor fusion algorithm 238, a computer vision system 240, a route control system 242, and an obstacle avoidance system 244.
  • the steering system 232 is operable to adjust the forward direction of the vehicle 200.
  • it may be a steering wheel system in one embodiment.
  • the throttle 234 is used to control the operating speed of the engine 218 and thereby control the speed of the vehicle 200.
  • the braking unit 236 is used to control the vehicle 200 to decelerate.
  • the braking unit 236 may use friction to slow the wheels 221.
  • the braking unit 236 may convert the kinetic energy of the wheels 221 into electric current.
  • the braking unit 236 may also take other forms to slow down the rotation speed of the wheels 221 to control the speed of the vehicle 200.
  • the computer vision system 240 may be operable to process and analyze the images captured by the camera 230 in order to identify objects and/or features in the surrounding environment of the vehicle 200.
  • the objects and/or features may include traffic signals, 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 technologies.
  • the computer vision system 240 may be used to map the environment, track objects, estimate the speed of objects, and so on.
  • the route control system 242 is used to determine the travel route of the vehicle 200.
  • the route control system 142 may combine data from the sensor 238, the GPS 222, and one or more predetermined maps to determine the driving route for the vehicle 200.
  • the obstacle avoidance system 244 is used to identify, evaluate, and avoid or otherwise cross over potential obstacles in the environment of the vehicle 200.
  • control system 206 may additionally or alternatively include components other than those shown and described. Alternatively, a part of the components shown above may be reduced.
  • the vehicle 200 interacts with external sensors, other vehicles, other computer systems, or users through peripheral devices 208.
  • the peripheral device 208 may include a wireless communication system 246, a car computer 248, a microphone 250, and/or a speaker 252.
  • the peripheral device 208 provides a means for the user of the vehicle 200 to interact with the user interface 216.
  • the onboard computer 248 can provide information to the user of the vehicle 200.
  • the user interface 216 can also operate the onboard computer 248 to receive user input.
  • the on-board computer 248 can be operated through a touch screen.
  • the peripheral device 208 may provide a means for the vehicle 200 to communicate with other devices located in the vehicle.
  • the microphone 250 may receive audio (eg, voice commands or other audio input) from a user of the vehicle 200.
  • the speaker 252 may output audio to the user of the vehicle 200.
  • the wireless communication system 246 may wirelessly communicate with one or more devices directly or via a communication network.
  • the wireless communication system 246 may use 3G cellular communication, such as code division multiple access (CDMA), EVD0, global system for mobile communications (GSM)/general packet radio service technology (general packet) radio service, GPRS), or 4G cellular communication, such as long term evolution (LTE), or 5G cellular communication.
  • the wireless communication system 246 may use WiFi to communicate with a wireless local area network (WLAN).
  • the wireless communication system 246 may directly communicate with the device using an infrared link, Bluetooth, or ZigBee.
  • Other wireless protocols such as various vehicle communication systems.
  • the wireless communication system 246 may include one or more dedicated short-range communication (DSRC) devices, which may include vehicles and/or roadside stations. Public and/or private data communications.
  • DSRC dedicated short-range communication
  • the power supply 210 may provide power to various components of the vehicle 200.
  • the power source 210 may be a rechargeable lithium ion or lead acid battery.
  • One or more battery packs of such batteries may be configured as a power source to provide power to various components of the vehicle 200.
  • the power source 210 and the energy source 219 may be implemented together, such as in some all-electric vehicles.
  • the computer system 212 may include at least one processor 223 that executes instructions 225 stored in a non-transitory computer readable medium such as the memory 224.
  • the computer system 212 may also be multiple computing devices that control individual components or subsystems of the vehicle 200 in a distributed manner.
  • 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.
  • FIG. 2 functionally illustrates the processor, memory, and other elements of the computer 210 in the same block, those of ordinary skill in the art should understand that the processor, computer, or memory may actually include Multiple processors, computers, or memories stored in the same physical enclosure.
  • the memory may be a hard disk drive or other storage medium located in a housing other than the computer 210. Therefore, a reference to a processor or computer will be understood to include a reference 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 here, some components such as steering components and deceleration components may each have its own processor that only performs calculations related to component-specific functions .
  • the processor may be located away from the vehicle and wirelessly communicate with the vehicle.
  • some of the processes described herein are executed on a processor disposed in the vehicle and others are executed by a remote processor, including taking the necessary steps to perform a single manipulation.
  • the memory 224 may contain instructions 225 (eg, program logic), which may be executed by the processor 223 to perform various functions of the vehicle 200, including those functions described above.
  • the memory 214 may also contain additional instructions, including those for sending data to, receiving data from, interacting with, and/or controlling one or more of the traveling system 202, the sensor system 204, the control system 206, and the peripheral device 208. instruction.
  • the memory 224 may also store data, such as road maps, route information, the location, direction, and speed of the vehicle, and other such vehicle data, as well as other information. Such information may be used by the vehicle 200 and the computer system 212 during operation of the vehicle 200 in autonomous, semi-autonomous, and/or manual modes.
  • the user interface 216 is used to provide information to or receive information from a user of the vehicle 200.
  • the user interface 216 may include one or more input/output devices in the set of peripheral devices 208, such as a wireless communication system 246, a car computer 248, a microphone 250, and a speaker 252.
  • the computer system 212 may control the functions of the vehicle 200 based on inputs received from various subsystems (eg, the travel system 202, the sensor system 204, and the control system 206) and from the user interface 216.
  • the computer system 212 may utilize input from the control system 206 to control the steering unit 232 to avoid obstacles detected by the sensor system 204 and the obstacle avoidance system 244.
  • the computer system 212 is operable to provide control of many aspects of the vehicle 200 and its subsystems.
  • one or more of these components described above may be installed or associated with the vehicle 200 separately.
  • the storage 224 may exist partially or completely separately from the vehicle 200.
  • the aforementioned components may be communicatively coupled together in a wired and/or wireless manner.
  • FIG. 2 should not be construed as a limitation to the embodiments of the present application.
  • An autonomous vehicle traveling on a road can recognize objects in its surrounding environment to determine the adjustment to the current speed.
  • the object may be other vehicles, traffic control equipment, or other types of objects.
  • each recognized object can be considered independently, and based on the respective characteristics of the object, such as its current speed, acceleration, distance from the vehicle, etc., can be used to determine the speed to be adjusted by the autonomous vehicle.
  • the self-driving car 200 or the computing device associated with the self-driving vehicle 200 may be based on the characteristics of the recognized object and the state of the surrounding environment (For example, traffic, rain, ice on the road, etc.) to predict the behavior of the identified object.
  • each recognized object depends on each other's behavior, so all recognized objects can also be considered together to predict the behavior of a single recognized object.
  • the vehicle 200 can adjust its speed based on the predicted behavior of the recognized object.
  • an autonomous vehicle can determine what stable state the vehicle will need to adjust to (for example, accelerate, decelerate, or stop) based on the predicted behavior of the object.
  • other factors may also be considered to determine the speed of the vehicle 200, such as the lateral position of the vehicle 200 on the road on which it is traveling, the curvature of the road, the proximity of static and dynamic objects, and so on.
  • the computing device can also provide instructions to modify the steering angle of the vehicle 200 so that the self-driving car follows a given trajectory and/or maintains an object near the self-driving car (such as , The safe horizontal and vertical distances of cars in adjacent lanes on the road.
  • the above-mentioned vehicle 200 may be a car, truck, motorcycle, bus, boat, airplane, helicopter, lawn mower, recreational vehicle, playground vehicle, construction equipment, tram, golf cart, train, and trolley, etc.
  • the application examples are not particularly limited.
  • the MIMO radar includes a transmitter, and the transmitter includes Nt transmitting antennas.
  • the method shown in FIG. 3 includes the following steps.
  • the transmitter sends a measurement frame.
  • the measurement frame includes the first burst (burst1), which is used to measure the velocity of the target.
  • the measurement frame can be frequency modulated continuous wave (FMCW), or other waveforms used by MIMO radars, such as multiple frequency-shift keying (MFSK), phase modulated continuous wave Any of the (phase modulated continuous wave, PMCW), this application does not limit this.
  • FMCW waveform is described as an example in the embodiment of the present application.
  • each of the Nt transmit antennas is used to transmit a chirp signal with a period of N1*T1, N1>Nt, and T1 is each chirp signal in the first burst Duration.
  • the duration of each chirp signal includes sweep time (ie, effective measurement time) and idle time (such as phase-locked loop stabilization time, analog-to-digital converter stabilization time, etc.).
  • N1>Nt the period for each transmitting antenna to transmit the chirp signal is N1*T1, assuming that the chirp signal transmitted in one period is called a round of chirp signal. Then, the number of chirp signals in one round (N1) is greater than the number of transmitting antennas (Nt). That is to say, in a round of chirp signals, in addition to Nt time slots that each transmit antenna sends one chirp signal (that is, one time slot), there are N1-Nt time slots. That is, at least one of the Nt transmitting antennas transmits chirp signals in N1-Nt time slots. In the embodiment of this application, both the first transmitting antenna and the second transmitting antenna can be regarded as transmitting chirp signals in N1-Nt time slots. Of the transmitting antenna.
  • the number of transmit antennas in a burst Nt and the specific value of the repetition period N1*T1 in TDM MIMO can be dynamically configured according to the vehicle environment.
  • ECUs use common vehicle-mounted buses, such as controller area network (CAN), controller area network with flexible data-rate (CAN-FD), and general ethernet (CAN-FD).
  • CAN controller area network
  • CAN-FD controller area network with flexible data-rate
  • CAN-FD general ethernet
  • GE vehicle interfaces configure parameters such as Nt and N1*T1 to the radar module.
  • the above-mentioned parameters can be configured to MIMC through a serial peripheral interface (SPI).
  • SPI serial peripheral interface
  • flexible configuration can be achieved by configuring the master and slave RF front-end chips.
  • the MMIC can be used to enable the transmitter to send the measurement frame according to the configuration of the measurement frame.
  • the configured parameters are not limited to the above examples, and the configuration parameters are used to instruct the transmitting antenna how to send the chirp signal.
  • the configuration parameters may be specific values of Nt, N1, and T1, and may also be equivalent parameters of specific values of Nt, N1, and T1.
  • burst is a concept of time period, and burst may also be referred to as a time slot, subframe, frame, etc.
  • a time slot is the smallest unit of time, one burst includes at least one time slot, one subframe includes at least one burst, and one frame includes at least one subframe.
  • the additional transmission overhead (ie, N1-Nt time slots) introduced in the embodiment of the present application may be one time slot or multiple time slots. If the additional transmission overhead is multiple time slots, the first transmitting antenna may send N1-Nt chirp signals periodically or non-periodically.
  • a round of chirp signals sent by Nt transmit antennas may be as shown in FIG. 4.
  • a long bar represents a chirp signal, and each chirp signal occupies a time slot.
  • the white filled part can be regarded as the chirp signal transmitted by each transmitting antenna with a period of N1*T1
  • the black filled part can be regarded as N1-Nt chirp signals transmitted by the first transmitting antenna.
  • the N1-Nt chirp signals transmitted by the first transmitting antenna and the chirp signals transmitted by the first transmitting antenna with a period of N1*T1 are two consecutive chirp signals in time (form a soft overlap A while ago).
  • the 12 transmitting antennas are numbered 1, 2, 3...12, and the first transmitting antenna is numbered 1, so the chirp signal sent by each transmitting antenna can be marked as shown in Figure 4. It can be seen from Figure 4 that in a round of chirp signals, the first transmitting antenna not only transmits the chirp signal on the third time slot with a period of N1*T1, but also transmits N1-Nt on the fourth time slot.
  • a chirp signal in a round of chirp signals, the first transmitting antenna not only transmits the chirp signal on the third time slot with a period of N1*T1, but also transmits N1-Nt on the fourth time slot.
  • the transmitting antenna can transmit Ndoppler round chirp signals to form the first burst.
  • Ndoppler 64,128.
  • a long bar represents a chirp signal.
  • the shape of the long bar is only for illustration and does not represent the waveform of the chirp signal in practical applications. .
  • the specific waveform of the chirp signal is not limited in the embodiment of the present application.
  • a round of chirp signal can be shown in Figure 5.
  • the white filled part can be regarded as the chirp signal transmitted by each transmitting antenna with a period of N1*T1
  • the black filled part can be regarded as N1-Nt chirp signals transmitted by the first transmitting antenna.
  • the chirp signal corresponding to each transmitting antenna can be marked as shown in Figure 5.
  • the first transmitting antenna not only transmits the chirp signal on the third time slot with a period of N1*T1, but also in the first time slot and the second time slot.
  • N1-Nt chirp signals are continuously sent on the slot (chirp signals sent on the first time slot, the second time slot, and the third time slot form a soft overlapping array).
  • the transmitting antenna can transmit the chirp signal shown in Figure 5 of the Ndoppler round to form the first burst.
  • Nt A round of chirp signals sent by the transmitting antenna can be shown in Figure 6.
  • Figure 6 for each transmitting antenna, there is a situation where multiple chirp signals are continuously transmitted in time.
  • N1>Nt but there are no antennas with high-density transmission in the strict sense among the Nt transmitting antennas, because the number of signals transmitted by each transmitting antenna in a round of chirp signals the same.
  • This can be regarded as a special example in this application. That is, in order to make N1>Nt, one or more high-density antennas are usually configured in the embodiment of the present application to transmit N1-Nt time slots. However, in some examples, the same number of chirp signals can also be sent in one cycle through each transmission signal, and the order of sending the chirp signals is disrupted. In this way, N1>Nt can also be achieved.
  • the transmitting antenna for high-density transmission in one round of chirp signals is not limited to the first transmitting antenna.
  • the transmitting antenna labeled 1 transmits chirp signals in the first time slot and the second time slot.
  • the transmitting antenna numbered 4 transmits chirp signals on the fifth and sixth time slots
  • the transmitting antenna numbered 7 transmits chirp signals on the ninth and tenth time slots.
  • the transmitting antenna numbered 10 transmits chirp signals on the thirteenth time slot and the fourteenth time slot. That is, there are four transmitting antennas for high-density transmission in the example of FIG. 7.
  • N1-Nt chirp signals can also be sent periodically.
  • the first transmitting antenna in the first burst, is also used to transmit the chirp signal with a period of M1*T1, M1 ⁇ N1. That is, in the first burst, each transmit antenna is used to transmit chirp signals with a period of N1*T1, and in addition, the first transmit antenna is also used to transmit chirp signals with a period of M1*T1.
  • the number of chirp signals sent by the first transmitting antenna with a period of M1*T1 is N1-Nt.
  • the black filled part can be regarded as the chirp signal sent by the first transmitting antenna with a period of M1*T1
  • the white filled part can be regarded as the chirp signal sent by each transmitting antenna with a period of N1*T1.
  • the black filled part can be regarded as the chirp signal sent by the first transmitting antenna with a period of M1*T1
  • the white filled part can be regarded as the chirp signal sent by each transmitting antenna with a period of N1*T1.
  • the combination shown in FIG. 9 can be sent Ndoppler times to form the first burst.
  • Nt transmitting antennas transmit one round of chirp signals
  • Nt transmitting antennas are divided into Nt/(M1-1) groups, and Nt transmitting antennas transmit Nt/(M1-1)+Nt chirp signals in one round.
  • 12 transmitting antennas are divided into 12/(4-1) groups, and each group includes a high-density chirp signal (black filled part) and three low-density chirp signals ( Fill the part with white).
  • the chirp signal is transmitted in the above manner, and transmission of different density of the transmitting antenna can be realized, wherein the transmitting density of the first transmitting antenna is larger, and the transmitting density of the remaining transmitting antennas is smaller. Since the high-density transmitting antenna has a large maximum velocity measurement range corresponding to the echo signal received, the high-density transmitting antenna can form a smaller transmission repetition period when transmitting.
  • the received echo corresponding to the high-density transmitting antenna The number of speed aliasing coefficients of wave signal relative to SIMO is small, and the received echo signal corresponding to the high-density transmitting antenna is used to assist the received echo signal corresponding to the low-density transmitting antenna to calculate the target speed, which can narrow the angle spectrum peak search
  • the interval range of the middle aliasing coefficient reduces the complexity of calculation.
  • the adjacent The transmitting antenna receives the phase difference of the echo signal to obtain the aliasing interval of the target velocity.
  • the first transmitting antenna is also used to transmit a chirp signal with a period of M2*T1, M2 ⁇ N1, and M1 and M2 are relatively prime.
  • the emission density of the first transmitting antenna is greater.
  • the identification of one or more targets ie a set of Identification
  • the identification of one or more targets can be obtained (That is a set of logos). Since M1 and M2 are relatively prime, the Chinese remainder method (staggered algorithm) can be used to expand the speed measurement range of the MIMO radar.
  • M1 time slots are occupied by a transmitting antenna with a transmission density of M2*T1
  • M2 time slots are occupied by a transmitting antenna with a transmission density of M1*T1.
  • one of the time slots (for example, the first time slot or the last time slot) can be shared.
  • M1*M0-M1-M0+1 G*Nt time slots that can be used for Nt transmitting antennas to transmit chirp signals with a period of N1*T1.
  • the 24 transmitting antennas can transmit a round of chirp signals as shown in the example of a in Fig. 10, or as As shown in the example of b in Figure 10.
  • the black filled part can be regarded as the chirp signal sent by the first transmitting antenna with a period of M1*N1
  • the stripe filled part can be regarded as the chirp signal sent by the first transmitting antenna with a period of M2*N1
  • the white The filling part can be regarded as the chirp signal sent by each transmitting antenna with a period of N1*T1.
  • the combination shown in example a or b in FIG. 10 can be sent Ndoppler times to form the first burst.
  • the difference between the b example and the a example is that in the b example, the chirp signal transmitted at a high density has a time offset compared with the a example.
  • the velocity resolution of the two sets of identifiers determined based on the echo signals of the two sets of chirp signals reflected by the first transmitting antenna at a high density is the same. Since M1 and M2 are relatively prime, and in the staggered algorithm, any integer equation that is mutually primed has a solution, so the above scheme can use the Chinese remainder method (staggered algorithm) to expand the speed measurement range of the MIMO radar.
  • the Chinese remainder method can be used to expand the MIMO radar Range of speed measurement.
  • the measurement frame may also include a second burst (burst2).
  • burst2 In the second burst, each of the Nt transmit antennas is used to transmit chirp signals in a period of N2*T2, and the second transmit antenna of the Nt transmit antennas is also used to transmit chirp signals in M3*T2.
  • M3 ⁇ N2 T2 is the duration of each chirp signal in the second burst; M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal.
  • first burst in the transmission process of the second burst, there are also transmitting antennas with higher transmission density (second transmitting antenna) and transmitting antennas with lower transmission density (except for the second transmitting antenna).
  • second transmitting antenna transmitting antenna
  • Other transmitting antennas may be the same transmitting antenna or different transmitting antennas.
  • the velocity resolution of the two sets of identifiers respectively determined according to the echo signal after the chirp signal transmitted by the first transmitting antenna at high density and the echo signal after the chirp signal transmitted by the second transmitting antenna is the same . Since M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime, and in the staggered algorithm, any integer equation that is mutually primed has a solution, so the above scheme can use the Chinese remainder method (staggered algorithm) to expand MIMO The speed range of the radar.
  • the measurement frame may also include a third burst; in the third burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N3*T3, T3 is the duration of each chirp signal in the third burst; N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T3 and T1 are equal.
  • N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal. Specifically, if T1 and T3 are not equal, N3*T3 and M1*T1 are mutually prime; if T1 and T3 are equal, N3 and M1 are relatively prime.
  • each of the Nt transmitting antennas is used to transmit chirp signals with a period of N1*T1, and the first transmitting antenna of the Nt transmitting antennas is also used to transmit the chirp signal with M1* T1 sends the chirp signal periodically.
  • the first transmitting antenna may be any one of the Nt transmitting antennas included in the transmitter.
  • the first transmitting antenna may be a transmitting antenna that transmits chirp signals adjacent to N1-Nt chirp signals. In this case, in the first burst, the first transmitting antenna transmits within N1*T1 There are two chirp signals continuously transmitted in time among the multiple chirp signals.
  • a possible implementation is that there is at least one transmitting antenna among the Nt transmitting antennas, and the at least one transmitting antenna transmits two consecutively within the time range of N1*T1 in the first burst. chirp signal.
  • the first transmitting antenna is a transmitting antenna that transmits chirp signals adjacent to N1-Nt chirp signals. In this case, the first transmitting antenna continuously transmits two chirp signals in the first burst. .
  • a chirp signal adjacent to it is the chirp signal sent by the first transmitting antenna with a period of N1*T1.
  • 12 transmitting antennas are marked with 1, 2, 3...12, and the first transmitting antenna is marked with 1.
  • the chirp signal sent by each transmitting antenna can be as shown in FIG. 11.
  • the chirp signal sent by the first transmitting antenna with a period of M1*T1 occupies three time slots, and the time slots adjacent to these three time slots have [2, 5 ,7,10,12], then the first transmitting antenna can transmit the chirp signal in any time slot in [2,5,7,10,12] with a period of N1*T1.
  • the first transmitting antenna continuously transmits two chirp signals as an example.
  • the number of chirp signals is also not limited to two.
  • the transmitting antenna labeled 1 continuously transmits three chirp signals; in the example in Figure 6, the transmitting antenna labeled 2 continuously transmits two chirp signals, and the transmitting antenna labeled 1 continuously transmits three chirp signals.
  • the transmitting antenna labeled 3 sends two chirp signals continuously.
  • the method of transmitting chirp signals on two adjacent time slots through two transmitting antennas with overlapping physical positions can be referred to as overlapping.
  • the above-mentioned method of transmitting chirp signals on two adjacent time slots through the same transmitting antenna may be referred to as a soft overlapping element in the embodiment of the present application, that is, through software Achieve overlap for a while.
  • the phase difference of the receiving antennas corresponding to two or more adjacent time slots at the time of the soft overlap is only determined by the Doppler phase caused by the target velocity.
  • the corresponding velocity aliasing coefficient can be directly matched with the velocity identification of the target calculated on the first transmitting antenna with a higher emission density, thereby determining the aliasing velocity within the SIMO velocity measurement range of the target.
  • specific calculation methods here can calculate the conjugate of the Doppler phase-compensated received echo data and the original overlapped array signal corresponding to the aliasing coefficient of the soft overlapping array pair (the adjacent two are a pair) Multiply, sum multiple received signals, and find the alias coefficient corresponding to the minimum value of multiple alias coefficients. Or directly average the phase difference of multiple soft overlapping array pairs to estimate the speed.
  • the first transmitting antenna in the embodiment of the present application is not necessarily a transmitting antenna with a physical serial number of one, and the first transmitting antenna may be any one of the Nt transmitting antennas.
  • the high-density transmitting antenna for example, the first transmitting antenna
  • N1-Nt chirp signals such as the examples in Figure 4-7, Figure 11
  • the phase of the receiving antenna corresponding to the soft overlapping moment The difference is only determined by the Doppler phase caused by the target velocity. Therefore, the speed of the target calculated on the first transmitting antenna with a higher transmission density can be directly matched to the corresponding speed aliasing coefficient to determine the speed of the target.
  • the high-density transmitting antenna (for example, the first transmitting antenna) transmits N1-Nt chirp signals periodically (such as the examples in Figure 8 to Figure 10), because the high-density transmitting antenna corresponds to the received echo
  • the maximum speed range of the signal is large, so the high-density transmitting antenna can form a smaller transmission repetition period when transmitting.
  • the spectral peak search method is used, the echo signal received corresponding to the high-density transmitting antenna is relative to the speed of SIMO.
  • the number is small, and the received echo signal corresponding to the high-density transmitting antenna is used to assist the received echo signal corresponding to the low-density transmitting antenna to calculate the target speed, which can narrow the range of the aliasing coefficient in the angular spectrum peak search and reduce the calculation the complexity.
  • the maximum speed range of the MIMO radar can be restored to the SIMO speed range without affecting the subsequent angle measurement.
  • Using the method provided by the embodiment of the present application can ensure the accuracy of the azimuth angle calculation and improve the angular resolution.
  • the embodiment of the present application also provides a signal processing method for processing the echo signal formed after the transmitted measurement frame is reflected by one or more targets, so as to obtain The speed of one or more targets, and then obtain the azimuth angle of one or more targets (for example, horizontal azimuth angle and vertical azimuth angle).
  • the method is applied to MIMO radar.
  • the MIMO radar includes a transmitter, a receiver, and a processing unit.
  • the transmitter includes Nt transmitting antennas, and the receiver includes Nr receiving antennas.
  • the method includes the following steps:
  • the receiver receives the first echo signal and the second echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets.
  • the measurement frame includes a first burst
  • the first echo signal is reflected by one or more targets by the chirp signal transmitted by each of the Nt transmitting antennas in the first burst with a period of N1*T1
  • the second echo signal is formed by other chirp signals sent by the first transmitting antenna among the Nt transmitting antennas after being reflected by one or more targets.
  • T1 is the duration of each chirp signal in the first burst.
  • the echo signal received by the receiver is the echo signal of the measurement frame sent by the transmitter in the method shown in FIG. 3 after being reflected by one or more targets.
  • the chirp signal sent by each transmitting antenna with a period of N1*T1 is reflected by one or more targets to form a first echo signal
  • other chirp signals sent by the first transmitting antenna are reflected by one or more targets to form The second echo signal.
  • the receiver includes Nr receiving antennas, and the Nr receiving antennas receive Nt echo signals according to the transmission sequence of the Nt transmitting antennas, and then according to the Nt transmitting antennas and Nr receiving antennas.
  • the positional relationship between the antennas and the transmission sequence of the transmitting antennas convert the received echo signal into a first echo signal and a second echo signal.
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver.
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, which can be implemented in the following manner: the processing unit determines the first identifier according to the first echo signal, and the first identifier is used for Indicate the distance measurement value and speed measurement value of one or more targets; the processing unit determines the second identifier according to the second echo signal, and the second identifier is used to indicate the distance measurement value and speed measurement value of one or more targets; the processing unit The speed of one or more targets is determined according to the first identification and the second identification.
  • the first identifier may include a first speed identifier and a first distance identifier
  • the second identifier may include a second speed identifier and a second distance identifier.
  • the range-Doppler map (RD) can be obtained through operations such as one-dimensional FFT (1D-FFT), two-dimensional FFT (2D-FFT), and coherent/incoherent combining.
  • the RD Map maps the first velocity identification (Vind_d) and the first distance identification (Rind_d) within the maximum velocity measurement range according to the RD Map detection; similarly, after obtaining the second echo signal, you can pass 1D-FFT, 2D- FFT, coherent combining/incoherent combining and other operations obtain another RD Map, and then detect according to the RD Map to obtain the second speed identifier (Vind_p) and the second distance identifier (Rind_p) within the maximum speed measurement range.
  • the maximum speed measurement range corresponding to the first identifier is smaller than the maximum speed measurement range corresponding to the second identifier.
  • RDMap when detecting according to RDMap, there can be multiple detection methods, including but not limited to ordered statistical-constant false alarm rate (OS-CFAR) detection or unit average-constant false alarm rate Common detection methods such as cell-averaging constant false alarm rate (CA-CFAR) are not particularly limited in the embodiments of this application.
  • OS-CFAR ordered statistical-constant false alarm rate
  • CA-CFAR cell-averaging constant false alarm rate
  • the received signals corresponding to the transmitting antennas in different time slots are supplemented with different aliasing coefficients, and the field of view (field of view, FFT) or digital beamforming (DBF) FOV) search for N fft_AOA angles. Then obtain the maximum value of the N fft_AOA angle spectrum (angle spectrum peak) of the different aliasing coefficients in the FOV, and take the element corresponding to the maximum value of the angle spectrum peak in the N1 aliasing coefficients as the velocity aliasing coefficient.
  • FFT field of view
  • DBF digital beamforming
  • the processing unit is based on the first identification and the second identification. There are also different ways of identifying the speed of one or more targets.
  • the second echo signal is formed by the chirp signal sent by the first transmitting antenna with a period of M1*T1 and reflected by one or more targets, M1 ⁇ N1.
  • each of the Nt transmitting antennas transmits a chirp signal with a period of N1*T1, and the first transmitting antenna also transmits a chirp signal with a period of M1*T1.
  • the Nr receiving antennas receive the measurement frame composed of multiple chirp signals, according to the positional relationship between the Nt transmitting antennas and the Nr receiving antennas and the transmission order of the transmitting antennas, the received echo signals are converted into the first The echo signal and the second echo signal.
  • the processing unit determines the speed of one or more targets according to the first identifier and the second identifier, which can be specifically implemented as follows: the processing unit determines the first aliasing coefficient interval corresponding to the first identifier according to N1, and determines the first aliasing coefficient interval according to M1
  • the second identifier corresponds to the second aliasing coefficient interval; the processing unit determines the aliasing coefficient subset corresponding to the second aliasing coefficient interval in the first aliasing coefficient interval according to the first identifier and the second identifier; the processing unit The coefficient subset determines the velocity aliasing coefficient; the processing unit determines the velocity of one or more targets according to the velocity aliasing coefficient and the first identifier.
  • the first aliasing coefficient interval is [-N1/2, N1/2-1]; if N1 is an odd number, then the first aliasing coefficient interval is [-(N1-1)/2 , (N1-1)/2]; if M1 is even, then the second aliasing coefficient interval is [-M1/2, M1/2-1]; if M1 is odd, then the second aliasing coefficient interval is [ -(M1-1)/2, (M1-1)/2]. It is not difficult to see that since M1 ⁇ N1, the range of the first aliasing coefficient interval is larger than the range of the second aliasing coefficient interval.
  • the interval of the first aliasing coefficient is [-8,-7,-6,-5,-4,-3,-2,-1,0,1,2 ,3,4,5,6,7]
  • the second aliasing coefficient interval is [-2,-1,0,1].
  • the first aliasing coefficient interval is [-7,-6,-5,-4,-3,-2,-1,0,1,2,3, 4,5,6,7]
  • the second aliasing coefficient interval is [-2,-1, 0,1,2].
  • the second identification is based on the first transmitting antenna with a higher transmission density
  • the transmitted chirp signal is determined, so in the second speed identification, the probability of multiple targets colliding is small; but because the range of the second aliasing coefficient interval is smaller than the range of the first aliasing coefficient interval, if you want to MIMO radar To restore the speed measurement range to the SIMO speed measurement range, the second aliasing coefficient interval needs to be converted to the first aliasing coefficient interval, and then the first identification and the converted aliasing coefficient are used to calculate the speed of one or more targets.
  • the second The overlap coefficient interval is [-2,-1,0,1,2] as an example. Converting the second alias coefficient interval to the first alias coefficient interval is in [-7,-6,-5,-4, -3,-2,-1,0,1,2,3,4,5,6,7] find the aliasing coefficient subset corresponding to [-2,-1,0,1,2].
  • the aliasing coefficient subset can have three combinations [-7,-4,-1,2,5], [-6,-3,0,3,6] and [-5,-2,1,4,7]. Which of the three sets is the aliasing coefficient subset S can be determined according to the first identifier and the second identifier. Among them, the aliasing coefficient subset S can be regarded as a subset of the first aliasing coefficient interval.
  • the distance identifiers in the first identifier and the second identifier will not be blurred, that is, for the same target, the first distance identifier and the second distance identifier should be approximately equal. Then, the first speed flag and the second speed flag corresponding to two approximately equal distance flags can be used to determine which value in the second aliasing coefficient interval corresponds to which value in the first aliasing coefficient interval. According to the correspondence relationship, it is determined which of the above three combinations is the aliasing coefficient subset.
  • the speed measurement range of the high-density antenna can correspond to the 4 sections of the speed measurement range of the low-density antenna.
  • the Doppler fft value range corresponding to the high-density antenna also corresponds to 4 times the fft value range of the low-density antenna. Therefore, when the aliasing coefficient in the high-density antenna is 0, the corresponding SS of the low-density antenna is a value in [0,1,2,3].
  • the speed measurement range of the high-density antenna can correspond to 3 intervals of the speed measurement range of the low-density antenna.
  • the echo signal received by the receiving antenna can also be compensated. If the processing gain of the chirp signal sent by the first transmitting antenna in the first burst is less than the processing gain of the chirp signal sent by each transmitting antenna in the first burst with a period of N1*T1, the first speed identification pair The echo signal is subjected to Doppler phase compensation; if the processing gain of the chirp signal transmitted by the first transmitting antenna in the first burst is greater than that of the chirp signal transmitted by each transmitting antenna in the first burst with a period of N1*T1 The processing gain can be used to perform Doppler phase compensation on the echo signal using the second velocity indicator.
  • a coef can only take the elements in the aliasing coefficient subset. Is the phase compensation value of the echo signal of the corresponding Nr receiving antennas of the transmitting antennas in the m time slots.
  • the aliasing coefficient subset After determining the aliasing coefficient subset, you can calculate the values of the sub-array received signals corresponding to different elements in the aliasing coefficient subset S at different angle spectra, and the elements in the aliasing coefficient subset S corresponding to the maximum value of the angle spectrum As the velocity aliasing coefficient. Then, the speed of one or more targets can be determined according to the speed aliasing coefficient, the maximum speed range and the first speed identifier. Among them, the specific manner of determining the velocity aliasing coefficient according to the aliasing coefficient subset can refer to the description in the prior art, which will not be repeated here.
  • the receiver also receives the third echo signal formed after the measurement frame is reflected by one or more targets.
  • the third echo signal is sent by the first transmitting antenna in the first burst with a period of M2*T1
  • the chirp signal is formed after being reflected by one or more targets, M2 ⁇ N1, M1 and M2 are relatively prime; then, the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, which can be specifically as follows Realization: The processing unit determines the speed of one or more targets according to the second echo signal and the third echo signal.
  • each of the Nt transmitting antennas transmits chirp signals with a period of N1*T1
  • the first transmitting antenna also transmits chirp signals with a period of M1*T1
  • a period of M2*T1 Send chirp signal See Figure 10 for a specific example.
  • the velocity resolutions of the velocity identifiers determined according to the second echo signal and the third echo signal are the same. Therefore, the two mixtures determined based on the second echo signal and the third echo signal can be directly used.
  • the overlap coefficient interval directly determines the velocity aliasing coefficient.
  • the receiver also receives the fourth echo signal and the fifth echo signal formed after the measurement frame is reflected by one or more targets.
  • the measurement frame also includes the second burst.
  • the fourth echo signal is composed of Nt
  • the second transmitting antenna of the two transmitting antennas is formed after the chirp signal sent by the period of M3*T2 in the second burst is reflected by one or more targets, and the fifth echo signal is transmitted by each of the Nt transmitting antennas
  • the chirp signal sent by the antenna in the second burst with a period of N2*T2 is formed after being reflected by one or more targets, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst; M3*T2 and M1*T1 is relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal; then, the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, which can be implemented in the following ways:
  • M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal.
  • the processing unit determines the speed of one or more targets based on the second echo signal and the fourth echo signal.
  • the manner is the same as the manner in which the processing unit determines the velocity of one or more targets according to the second echo signal and the third echo signal in the second manner, and will not be repeated here.
  • the receiver also receives a sixth echo signal formed after the measurement frame is reflected by one or more targets.
  • the measurement frame also includes a third burst.
  • the sixth echo signal is generated by each of the Nt transmitting antennas.
  • the chirp signals sent by two transmitting antennas in the third burst with a period of N3*T3 are formed after reflection by one or more targets.
  • T3 is the duration of each chirp signal in the third burst; N3*T3 and M1* T1 is relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal; then, the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, which can be specifically implemented as follows: The echo signal and the sixth echo signal determine the velocity of one or more targets.
  • N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal.
  • the processing unit determines the speed of one or more targets according to the second echo signal and the sixth echo signal.
  • the manner is the same as the manner in which the processing unit determines the velocity of one or more targets according to the second echo signal and the third echo signal in the second manner, and will not be repeated here.
  • the receiver also receives the seventh echo signal formed after the measurement frame is reflected by one or more targets.
  • the seventh echo signal is continuous by the first transmitting antenna within the N1*T1 time of the first burst.
  • the sent multiple chirp signals are formed after being reflected by one or more targets.
  • the processing unit determines the speed of one or more targets according to the echo signal received by the receiver, which can be specifically implemented as follows: the processing unit determines the speed of one or more targets according to the second echo signal and the seventh echo signal. speed.
  • the method of transmitting chirp signals on two adjacent time slots through two transmitting antennas that physically overlap each other can be called overlapping.
  • the foregoing manner of sending chirp signals on two adjacent time slots through the same transmitting antenna may be referred to as soft overlap in the embodiment of the present application, that is, the overlap is realized through software.
  • the phase difference of the receiving antenna corresponding to the soft overlapping moment is only determined by the Doppler phase caused by the target velocity. Therefore, the speed of the target calculated on the first transmitting antenna with a higher transmission density can be directly matched to the corresponding speed aliasing coefficient to determine the speed of the target.
  • the fifth method it is not necessary to calculate the aliasing coefficient subset to determine the velocity aliasing coefficient, but to directly match the velocity aliasing coefficient according to the echo signal after the reflection of multiple chirp signals continuously sent by the first transmitting antenna. .
  • the method of determining the target speed through overlapping is an existing technology, and will not be repeated here.
  • the transmitting antennas are transmitted at different densities, so the maximum speed range of the first echo signal and the second echo signal obtained from the chirp signal sent by the transmitting antennas of different transmission densities are different .
  • the phase difference of the receiving antenna corresponding to the soft overlapping moment is only caused by the target speed. Doppler phase determination. Therefore, it is possible to directly match the corresponding velocity aliasing coefficient through the target's velocity identification calculated on the transmitting antenna with a higher transmission density, so as to restore the maximum velocity range of the MIMO radar to the SIMO velocity range to determine the target's velocity.
  • the first transmitting antenna transmits N1-Nt chirp signals periodically (such as the examples in Figure 8 to Figure 10), since the maximum speed range of the echo signal received by the high-density transmitting antenna is large, the high The density transmitting antenna can form a smaller transmission repetition period when transmitting, so when the spectral peak search method is used, the number of aliasing coefficients of the received echo signal corresponding to the high-density transmitting antenna relative to SIMO is small, and the high-density transmitting antenna is used The corresponding received echo signal assists the received echo signal corresponding to the low-density transmitting antenna to calculate the target speed, which can narrow the range of the aliasing coefficient in the angular spectrum peak search and reduce the calculation complexity.
  • the embodiment of the present application also provides a signal transmission device, which can be used to execute the signal transmission method shown in FIG. 3.
  • the signal transmission device 1300 includes a transmitter 13011301 for sending a measurement frame, the transmitter 1301 includes Nt transmitting antennas, the measurement frame is used to measure the speed of the target, and the measurement frame includes the first burst; In the burst, each of the Nt transmit antennas is used to transmit the chirp signal in a period of N1*T1, where N1>Nt, and T1 is the duration of each chirp signal in the first burst.
  • the first transmitting antenna of the Nt transmitting antennas is also used to transmit a chirp signal at a period of M1*T1, where M1 ⁇ N1.
  • the first transmitting antenna is also used to transmit the chirp signal with a period of M2*T1, M2 ⁇ N1, and M1 and M2 are relatively prime.
  • the measurement frame also includes a second burst; in the second burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N2*T2, and Nt transmit
  • the second transmitting antenna in the antenna is also used to send chirp signals with M3*T2, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst; M3*T2 and M1*T1 are mutually primed, or M3 and M1 is relatively prime, and T1 and T2 are equal.
  • the measurement frame also includes a third burst; in the third burst, each of the Nt transmit antennas is used to transmit chirp signals at a period of N3*T3, and T3 is the first burst.
  • At least one of the Nt transmitting antennas sends two chirp signals continuously in the first burst.
  • the measurement frame is FMCW.
  • the device 1300 further includes: a processing unit 1302 for determining the configuration of the measurement frame, and sending the configuration of the measurement frame to the MMIC through the interface, and the MMIC is used for enabling the transmitter according to the configuration of the measurement frame Send measurement frame.
  • the signal transmission device 1300 shown in FIG. 13 can be used to implement the signal transmission method shown in FIG. 3, and the implementation of the signal transmission device 1300 that is not described in detail can be referred to the relevant information in the signal transmission method shown in FIG. description.
  • the embodiment of the present application also provides a signal processing device, which can be used to execute the signal processing method shown in FIG. 12.
  • the signal processing device 1400 includes a receiver 1401 for receiving a first echo signal and a second echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets.
  • the measurement frame includes the first echo signal.
  • Burst the first echo signal is formed by the chirp signal sent by each of the Nt transmitting antennas included in the transmitter with a period of N1*T1 in the first burst after being reflected by one or more targets.
  • the second echo signal is formed by other chirp signals sent by the first transmitting antenna of the Nt transmitting antennas after being reflected by one or more targets, N1>Nt, T1 is the duration of each chirp signal in the first burst; processing The unit 1402 is used to determine the speed of one or more targets according to the echo signal received by the receiver 1401.
  • the processing unit 1402 determines the speed of one or more targets according to the echo signal received by the receiver 1401, it is specifically configured to: determine the first identifier according to the first echo signal, and the first identifier It is used to indicate the distance measurement value and speed measurement value of one or more targets; the second identifier is determined according to the second echo signal, and the second identifier is used to indicate the distance measurement value and speed measurement value of one or more targets; An identification and a second identification determine the speed of one or more targets.
  • the second echo signal is formed by the chirp signal sent by the first transmitting antenna with a period of M1*T1 after being reflected by one or more targets, M1 ⁇ N1.
  • the processing unit 1402 determines the speed of one or more targets according to the first identifier and the second identifier, it is specifically configured to: determine the first aliasing coefficient interval corresponding to the first identifier according to N1, and Determine the second aliasing coefficient interval corresponding to the second identifier according to M1; determine the aliasing coefficient subset corresponding to the second aliasing coefficient interval in the first aliasing coefficient interval according to the first identifier and the second identifier; The coefficient subset determines the velocity aliasing coefficient; the velocity of one or more targets is determined according to the velocity aliasing coefficient and the first identifier.
  • the receiver 1401 is also used to: receive a third echo signal formed after the measurement frame is reflected by one or more targets.
  • the third echo signal is transmitted by the first transmitting antenna in the first burst.
  • the chirp signal sent in the period of M2*T1 is formed after reflection from one or more targets, M2 ⁇ N1, and M1 and M2 are relatively prime; the processing unit 1402 determines one or more targets according to the echo signal received by the receiver 1401
  • the speed is specifically used to determine the speed of one or more targets according to the second echo signal and the third echo signal.
  • the receiver 1401 is also used to: receive the fourth echo signal and the fifth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame also includes the second burst, the first The four-echo signal is formed by the chirp signal sent by the second transmitting antenna of the Nt transmitting antennas with a period of M3*T2 in the second burst after being reflected by one or more targets, and the fifth echo signal is transmitted by Nt
  • the chirp signal sent by each transmitting antenna in the second burst with a period of N2*T2 is formed after reflection by one or more targets, M3 ⁇ N2, T2 is the duration of each chirp signal in the second burst Time; M3*T2 and M1*T1 are relatively prime, or M3 and M1 are relatively prime and T1 and T2 are equal; when the processing unit 1402 determines the velocity of one or more targets according to the echo signal received by the receiver 1401, it specifically uses Yu: Determine the speed of one or more targets according to the second echo
  • the receiver 1401 is also used to: receive the sixth echo signal formed after the measurement frame is reflected by one or more targets, the measurement frame also includes a third burst, and the sixth echo signal is composed of Nt
  • the chirp signal sent by each of the two transmitting antennas in the third burst with a period of N3*T3 is formed after reflection by one or more targets, and T3 is the duration of each chirp signal in the third burst; N3*T3 and M1*T1 are relatively prime, or N3 and M1 are relatively prime and T1 and T3 are equal;
  • the processing unit 1402 determines the velocity of one or more targets according to the echo signal received by the receiver 1401, it is specifically used to: The velocity of one or more targets is determined according to the second echo signal and the sixth echo signal.
  • the receiver 1401 is also used to: receive the seventh echo signal formed after the measurement frame is reflected by one or more targets.
  • the seventh echo signal is transmitted by the first transmitting antenna in the first burst.
  • the multiple chirp signals continuously sent within the time N1*T1 are formed after reflection from one or more targets; when the processing unit 1402 determines the speed of one or more targets according to the echo signals received by the receiver 1401, it is specifically used for : Determine the speed of one or more targets according to the second echo signal and the seventh echo signal.
  • the signal processing device 1400 shown in FIG. 14 can be used to execute the signal processing method shown in FIG. 12, and the implementation manners that are not described in detail in the signal processing device 1400 can be referred to in the signal processing method shown in FIG. description.
  • the embodiments of the present application also provide a radar system.
  • the radar system 1500 includes a transmitter 1501, a receiver 1502 and a processing unit 1503.
  • the transmitter 1501 includes Nt transmitting antennas.
  • the transmitter 1501 is used to send a measurement frame for measuring the speed of the target.
  • the measurement frame includes a first burst; wherein, in the first burst, Nt transmitting antennas
  • Each transmit antenna in is used to transmit chirp signals in a period of N1*T1, where N1>Nt, and T1 is the duration of each chirp signal in the first burst.
  • the receiver 1502 is used to receive the first echo signal and the second echo signal formed after the measurement frame sent by the transmitter is reflected by one or more targets.
  • the first echo signal is transmitted by each transmitting antenna in the first burst.
  • the chirp signal sent with a period of N1*T1 is formed after reflection from one or more targets, and the second echo signal is formed after other chirp signals sent by the first transmitting antenna are reflected by one or more targets.
  • the processing unit 1503 is configured to determine the speed of one or more targets according to the echo signal received by the receiver 1502.
  • the transmitter 1501 can also be used to perform other operations performed by the transmitter in the method shown in Figure 3; the receiver 1502 can also be used to perform other operations performed by the receiver in the method shown in Figure 15; the processing unit 1503 can also be used to Other operations performed by the processing unit in the method shown in FIG. 15 are performed, which will not be repeated here.

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Abstract

一种信号传输方法及装置（1300）、信号处理方法及装置（1400）以及雷达系统（1500），使得MIMO雷达能够准确地将目标的速度恢复到SIMO雷达的测速范围。信号传输方法应用于多输入多输出MIMO雷达，其中MIMO雷达中的发射器（1301,1501）发送用于测量目标速度的测量帧（S301），测量帧包括第一突发。在第一突发中，每个低密度发射天线在每个时隙上分别发送一个chirp信号，并且还存在至少一个高密度发射天线在额外的时隙上发送更多的chirp信号。

Description

信号传输方法及装置、信号处理方法及装置以及雷达系统 技术领域
本申请涉及传感器技术领域，尤其涉及一种信号传输方法及装置、信号处理方法及装置以及雷达系统。
背景技术
车载雷达是自动驾驶系统中必不可少的传感器，通过车载雷达可以为车辆提供障碍物(也可以称为目标)检测。具体地，可以对车辆周围障碍物的距离、速度和方位角进行检测。
近年来，车载雷达技术不断演进，例如频段从24GHz逐渐演进到77GHz/79GHz，从而通过更大的扫描带宽获得更高的距离分辨率；通道数由单发射多接收(single input multiple output，SIMO)的模式，演进到多发射多接收(multiple input multiple output，MIMO)的模式，从而扩大虚拟天线口径，提高角度分辨率。
MIMO雷达中，多个天线可以采用时分复用(time division multiplexing，TDM)的方式发送啁啾(chirp)信号。虽然采用MIMO雷达可以提高角度分辨率，但是MIMO雷达存在最大测速范围下降的问题。通常，雷达的最大测速范围可以表示为Vmax＝λ/4*Tc，其中λ为调制频率的波长，Tc为同一根天线重复发送的周期。假设单个天线发送一个chirp的持续时间为Tc_SIMO(可以称为一个时隙)。那么，TDM MIMO雷达中，Nt个天线采用TDM方式发送Nt个chirp信号时，需要的时间Tc_MIMO满足：Tc_MIMO≥Nt*Tc_SIMO。因此，采用Nt个天线发送chirp时的最大测速范围Vmax_MIMO和采用单个天线发送chirp时的最大测速范围Vmax_SIMO(即SIMO雷达的测速范围)的关系可以表示为：Vmax_SIMO≥Nt*Vmax_MIMO。通过上述公式可以看出，MIMO雷达中，由于发射天线的数目增多，导致最大测速范围与SIMO雷达相比下降。而且发射天线的数量Nt越多，最大测速范围下降的问题越严重。在最大测速范围下降的情况下，在计算目标的速度时更易发生速度混叠的情况。此外，由于TDM MIMO雷达中速度和角度的测量耦合，使得速度的混叠影响角度的求解，达不到预期的提高角度分辨率的目的。
综上，亟需一种MIMO雷达的信号传输及处理的方案，使得MIMO雷达能够准确将目标的速度恢复到SIMO雷达的测速范围。
发明内容
本申请实施例提供了一种信号传输方法及装置、信号处理方法及装置以及雷达系统，使得MIMO雷达能够准确地将目标的速度恢复到SIMO雷达的测速范围。
第一方面，本申请实施例提供一种信号传输方法，该方法应用于多输入多输出MIMO雷达，MIMO雷达包括发射器，发射器包括Nt个发射天线，该方法包括：发射器发送测量帧，测量帧用于测量目标的速度，测量帧包括第一突发；其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾chirp信号，其中N1>Nt，T1为第一突发中每个chirp信号的持续时间。
其中，测量帧可以为调频连续波FMCW。
采用上述方案，可以实现发射天线的不同密度的发送。
若高密度发射天线(例如可以是第一发射天线)在发送N1-Nt个chirp信号时是连续发送的，软overlapping时刻对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的速度。
若高密度发射天线(例如可以是第一发射天线)在发送N1-Nt个chirp信号时是周期性发送的，由于高密度发射天线对应的接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算复杂度。
因此，采用第一方面提供的信号传输方法，可以将MIMO雷达的最大测速范围恢复到SIMO测速范围，不影响后续的角度测量。实际应用中，在计算出目标的速度之后，还需要根据补偿多普勒后的各接收通道上的数据进一步计算，以获取目标的方位角(例如包括水平方位角和垂直方位角)，从而对获得目标的距离、速度、角度信息。因此，速度计算的准确性对方位角计算的影响较大。采用本申请实施例提供的方法可以保证方位角计算的准确性，提高角度分辨率。
在一种可能的设计中，在第一突发中，Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号，其中M1＜N1。采用如上方式发送chirp信号，可以实现发射天线的不同密度的发送，其中第一发射天线的发送密度较大，其余发射天线的发送密度较小。由于高密度发射天线对应接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算的复杂度。
在一种可能的设计中，在第一突发中，第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。在上述方案中，根据第一发射天线高密度发送的两组chirp信号反射后的回波信号确定的两组标识的速度分辨率相同。由于M1和M2互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
此外，可选地，测量帧中还可以包括第二突发；在第二突发中，Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等。采用上述方案，根据第一发射天线高密度发送的chirp信号发射后的回波信号以及根据第二发射天线高密度发送的chirp信号发射后的回波信号分别确定的两组标识的速度分辨率相同，由于M3*T2和M1*T1互质，或者M3和M1互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
此外，可选地，测量帧中还可以包括第三突发；在第三突发中，Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为第三突发中每个chirp信号的持续 时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。由于N3*T3和M1*T1互质，或者N3和M1互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
在一种可能的设计中，Nt个发射天线中存在至少一个发射天线在第一突发中连续发送两个chirp信号。采用上述实现方式，软重叠阵子时刻两个或者多个相邻时隙对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的SIMO测速范围内的混叠速度。
在一种可能的设计中，该MIMO雷达还包括处理单元，该方法还包括：处理单元根据确定测量帧的配置，并通过接口将测量帧的配置发送至单片微波集成电路MMIC，MMIC用于根据测量帧的配置使能发射器发送测量帧。采用上述方案，可以为MMIC配置相关参数，从而完成测量帧的发送。
第二方面，本申请实施例提供一种信号处理方法，该方法应用于MIMO雷达，MIMO雷达包括发射器、接收器和处理单元，发射器包括Nt个发射天线，该方法包括如下步骤：接收器接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，该测量帧包括第一突发，第一回波信号由Nt个发射天线中的每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由Nt个发射天线中的第一发射天线发送的其他chirp信号经一个或多个目标反射后形成，N1>Nt，T1为第一突发中每个chirp信号的持续时间；处理单元根据第一回波信号和第二回波信号确定一个或多个目标的速度。
采用上述方案，发射天线采用不同密度发送，因而根据不同发送密度的发射天线发送的chirp信号得到的第一回波信号和第二回波信号的最大测速范围不同。
若第一发射天线在发送N1-Nt个chirp信号时是连续发送的，软overlapping时刻对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的发射天线上计算出的目标的速度标识，直接匹配出对应的速度混叠系数，从而将MIMO雷达的最大测速范围恢复到SIMO测速范围，确定目标的速度。
若第一发射天线在发送N1-Nt个chirp信号时是周期性发送的，由于高密度发射天线对应的接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算复杂度。
在一种可能的设计中，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，包括：处理单元根据第一回波信号确定第一标识，第一标识用于指示一个或多个目标的距离测量值和速度测量值；处理单元根据第二回波信号确定第二标识，第二标识用于指示所述一个或多个目标的距离测量值和速度测量值；处理单元根据第一标识和第二标识确定一个或多个目标的速度。采用上述方案，可以根据两组目标标识(即第一标识和第二标识)确定目标的速度混叠系数，进而确定目标的速度。
在一种可能的设计中，第二回波信号由第一发射天线以M1*T1为周期发送的chirp信号经一个或多个目标反射后形成，M1＜N1。采用上述方案，可以通过第一发射天线周期 性发送chirp信号实现高密度发送。
进一步地，处理单元根据第一标识和第二标识确定一个或多个目标的速度，具体可以通过如下方式实现：处理单元根据N1确定第一标识对应的第一混叠系数区间，并根据M1确定第二标识对应的第二混叠系数区间；处理单元根据第一标识和第二标识，确定第二混叠系数区间在第一混叠系数区间内对应的混叠系数子集；处理单元根据混叠系数子集确定速度混叠系数；处理单元根据速度混叠系数和第一标识确定一个或多个目标的速度。
此外，该方法还包括：接收器接收测量帧经一个或多个目标反射后形成的第三回波信号，第三回波信号由第一发射天线在第一突发中以M2*T1为周期发送的chirp信号经一个或多个目标反射后形成，M2＜N1，M1和M2互质；处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，包括：处理单元根据第二回波信号和第三回波信号确定一个或多个目标的速度。采用上述方案，由于M1和M2互质，因而根据第一发射天线高密度发送的两组chirp信号反射后的回波信号确定的两组标识的速度分辨率相同，可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
此外，该方法还包括：接收器接收测量帧经一个或多个目标反射后形成的第四回波信号和第五回波信号，该测量帧还包括第二突发，第四回波信号由Nt个发射天线中的第二发射天线在第二突发中以M3*T2为周期发送的chirp信号经一个或多个目标反射后形成，第五回波信号由Nt个发射天线中的每个发射天线在第二突发中以N2*T2为周期发送的chirp信号经一个或多个目标反射后形成，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等；处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，包括：处理单元根据第二回波信号和第四回波信号确定一个或多个目标的速度。由于M3*T2和M1*T1互质，或者M3和M1互质，因而根据第一发射天线高密度发送的chirp信号发射后的回波信号以及根据第二发射天线高密度发送的chirp信号发射后的回波信号分别确定的两组标识的速度分辨率相同，可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
在一种可能的设计中，该方法还包括：接收器接收测量帧经一个或多个目标反射后形成的第六回波信号，该测量帧还包括第三突发，第六回波信号由Nt个发射天线中的每个发射天线在第三突发中以N3*T3为周期发送的chirp信号经一个或多个目标反射后形成，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等；处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，包括：处理单元根据第二回波信号和第六回波信号确定一个或多个目标的速度。由于N3*T3和M1*T1互质，或者N3和M1互质，因而可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
在一种可能的设计中，该方法还包括：接收器接收测量帧经一个或多个目标反射后形成的第七回波信号，第七回波信号由第一发射天线在第一突发中的N1*T1时间内连续发送的多个chirp信号经过一个或多个目标反射后形成；处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，包括：处理单元根据第二回波信号和第七回波信号确定一个或多个目标的速度。采用上述实现方式，软重叠阵子时刻两个或者多个相邻时隙对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的SIMO测速范围内的混叠速度。
第三方面，本申请实施例提供一种信号传输装置，包括：发射器，用于发送测量帧，发射器包括Nt个发射天线，测量帧用于测量目标的速度，测量帧包括第一突发；其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾chirp信号，其中N1>Nt，T1为第一突发中每个chirp信号的持续时间。
在一种可能的设计中，在第一突发中，Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号，其中M1＜N1。
在一种可能的设计中，第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。
在一种可能的设计中，该测量帧还包括第二突发；在第二突发中，Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质，且T1和T2相等。
在一种可能的设计中，该测量帧还包括第三突发；在第三突发中，Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。
在一种可能的设计中，Nt个发射天线中存在至少一个发射天线在第一突发中连续发送两个chirp信号。
在一种可能的设计中，该测量帧为调频连续波FMCW。
在一种可能的设计中，该装置还包括：处理单元，用于确定测量帧的配置，并通过接口将测量帧的配置发送至单片微波集成电路MMIC，MMIC用于根据测量帧的配置使能发射器发送测量帧。
第四方面，本申请实施例提供一种信号处理装置，包括：接收器，用于接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，测量帧包括第一突发，第一回波信号由发射器包括的Nt个发射天线中的每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由Nt个发射天线中的第一发射天线发送的其他chirp信号经一个或多个目标反射后形成，N1>Nt，T1为第一突发中每个chirp信号的持续时间；处理单元，用于根据第一回波信号和第二回波信号确定一个或多个目标的速度。
在一种可能的设计中，处理单元在根据接收器接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第一回波信号确定第一标识，第一标识用于指示一个或多个目标的距离测量值和速度测量值；根据第二回波信号确定第二标识，第二标识用于指示一个或多个目标的距离测量值和速度测量值；根据第一标识和第二标识确定一个或多个目标的速度。
在一种可能的设计中，第二回波信号由第一发射天线以M1*T1为周期发送的chirp信号经一个或多个目标反射后形成，M1＜N1。
在一种可能的设计中，处理单元在根据第一标识和第二标识确定一个或多个目标的速度时，具体用于：根据N1确定第一标识对应的第一混叠系数区间，并根据M1确定第二标识对应的第二混叠系数区间；根据第一标识和第二标识，确定第二混叠系数区间在第一混叠系数区间内对应的混叠系数子集；根据混叠系数子集确定速度混叠系数；根据速度混叠系数和第一标识确定一个或多个目标的速度。
在一种可能的设计中，接收器还用于：接收测量帧经一个或多个目标反射后形成的第三回波信号，第三回波信号由第一发射天线在第一突发中以M2*T1为周期发送的chirp信号经一个或多个目标反射后形成，M2＜N1，M1和M2互质；处理单元在根据接收器接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第三回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器还用于：接收测量帧经一个或多个目标反射后形成的第四回波信号和第五回波信号，测量帧还包括第二突发，第四回波信号由Nt个发射天线中的第二发射天线在第二突发中以M3*T2为周期发送的chirp信号经一个或多个目标反射后形成，第五回波信号由Nt个发射天线中的每个发射天线在第二突发中以N2*T2为周期发送的chirp信号经一个或多个目标反射后形成，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等；处理单元在根据接收器接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第四回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器还用于：接收测量帧经一个或多个目标反射后形成的第六回波信号，测量帧还包括第三突发，第六回波信号由Nt个发射天线中的每个发射天线在第三突发中以N3*T3为周期发送的chirp信号经一个或多个目标反射后形成，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等；处理单元在根据接收器接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第六回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器还用于：接收测量帧经一个或多个目标反射后形成的第七回波信号，第七回波信号由第一发射天线在第一突发中的N1*T1时间内连续发送的多个chirp信号经过一个或多个目标反射后形成；处理单元在根据接收器接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第七回波信号确定一个或多个目标的速度。
第五方面，本申请实施例还提供一种雷达系统，包括：发射器，发射器包括Nt个发射天线，发射器用于发送测量帧，测量帧用于测量目标的速度，测量帧包括第一突发；其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送chirp信号，其中N1>Nt，T1为第一突发中每个chirp信号的持续时间；接收器，用于接收测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，该测量帧包括第一突发，第一回波信号由每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由第一发射天线发送的其他chirp信号经一个或多个目标反射后形成；处理单元，用于根据接收器接收到的回波信号确定一个或多个目标的速度。
此外，雷达系统中的发射器还用于执行第一方面提供的方法中发射器所执行的其他操作，雷达系统中的接收器还用于执行第二方面提供的方法中接收器所执行的其他操作，雷达系统中的处理单元还用于执行第一方面或第二方面提供的方法中处理单元所执行的其他操作。
附图说明
图1为本申请实施例提供的一种MIMO雷达的结构示意图；
图2为本申请实施例提供的一种车辆的结构示意图；
图3为本申请实施例提供的一种信号传输方法的流程示意图；
图4为本申请实施例提供的第一种MIMO雷达发送的啁啾信号的示意图；
图5为本申请实施例提供的第二种MIMO雷达发送的啁啾信号的示意图；
图6为本申请实施例提供的第三种MIMO雷达发送的啁啾信号的示意图；
图7为本申请实施例提供的第四种MIMO雷达发送的啁啾信号的示意图；
图8为本申请实施例提供的第五种MIMO雷达发送的啁啾信号的示意图；
图9为本申请实施例提供的第六种MIMO雷达发送的啁啾信号的示意图；
图10为本申请实施例提供的第七种MIMO雷达发送的啁啾信号的示意图；
图11为本申请实施例提供的第八种MIMO雷达发送的啁啾信号的示意图；
图12为本申请实施例提供的一种信号处理方法的流程示意图；
图13为本申请实施例提供的一种信号传输装置的结构示意图；
图14为本申请实施例提供的一种信号处理装置的结构示意图；
图15为本申请实施例提供的一种雷达系统的结构示意图。
具体实施方式
通常，雷达的最大测速范围可以表示为Vmax＝λ/4*Tc，其中λ为调制频率的波长，Tc为同一根天线重复发送的周期。假设单个天线发送一个chirp的持续时间为Tc_SIMO(可以称为一个时隙)。那么，TDM MIMO雷达中，Nt个天线采用TDM方式发送Nt个chirp信号时，需要的时间Tc_MIMO满足：Tc_MIMO≥Nt*Tc_SIMO。因此，采用Nt个天线发送chirp时的最大测速范围Vmax_MIMO和采用单个天线发送chirp时的最大测速范围Vmax_SIMO的关系可以表示为：Vmax_SIMO≥Nt*Vmax_MIMO。通过上述公式可以看出，MIMO雷达中，由于发射天线的数目增多，导致最大测速范围下降。而且发射天线的数量Nt越多，最大测速范围下降的问题越严重。
雷达是利用多普勒效应进行速度测量的装置。由于目标或雷达的运动，使得雷达的接收信号发射频率变化或者相位变化。在FMCW体制中，通过测量一个chirp内的回波信号频率来测量目标与雷达之间的距离，通过相同天线不同时隙的回波信号间的相位差来测量目标的速度。因此，也将对应速度的维度称为多普勒域，即RD map上doppler对应的维度。
时分发送的多个天线上的雷达信号导致目标的速度在多普勒域碰撞的概率变大，即发生多个目标的反射信号在多普勒域的观测值相同，从而导致每个目标的速度求解的复杂度和准确性面临考验。例如，采用SIMO方式发送时，最大测速范围为-120km/h-120km/h；通过4个天线采用TDM MIMO方式发送时，最大测速范围降低为-30km/h-30km/h。那么，与采用SIMO方式发送相比，采用TDM MIMO方式发送时，目标的速度在多普勒域碰撞的概率变大。
基于上述问题，本申请实施例提供一种信号传输方法及装置、信号处理方法及装置以及雷达系统，使得MIMO雷达能够准确地将目标的速度恢复到SIMO雷达的测速范围。
下面对本申请实施例的应用场景进行介绍。
具体地，本申请实施例中，如图1所示，MIMO雷达系统可以包括天线阵列101、单片微波集成电路(monolithic microwave integrated circuit，MMIC)102和处理单元103。天线阵列101可以包括多个发射天线和多个接收天线。
其中，单片微波集成电路102用于产生雷达信号，进而通过天线阵列101将雷达信号发出。雷达信号由一个或多个突发(burst)组成，每个突发包括多个啁啾信号。雷达信号发出后，经一个或多个目标反射后形成回波信号，回波信号被接收天线接收。单片微波集成电路102还用于对天线阵列101接收到的回波信号进行变换和采样等处理，并将处理后的回波信号传输至处理单元103。
其中，处理单元103用于对回波信号进行快速傅里叶变换(Fast Fourier Transformation，FFT)、信号处理等操作，从而根据接收到的回波信号确定目标的距离、速度、方位角等信息。具体地，该处理单元103可以是微处理器(microcontroller unit，MCU)、中央处理器(central process unit，CPU)、数字信号处理器(digital signal processor，DSP)、现场可编程门阵列(field－programmable gate array，FPGA)等具有处理功能的器件。
此外，图1所示的雷达系统还可以包括电子控制单元(electronic control unit，ECU)104，用于根据处理单元103处理后得到的目标距离、速度、方位角等信息对车辆进行控制，例如确定车辆的行使路线等。
需要说明的是，实际应用中，可以针对发射天线阵列和接收天线阵列分别设置一个MMIC，也可以针对发射天线阵列和接收天线阵列仅设置一个MMIC，图1的实例中以前者为例进行示意。
本申请实施例中的发射器可以由发射天线与单片微波集成电路102中的发射通道构成，接收器可以由接收天线与单片微波集成电路102中的接收通道构成。其中，发射天线和接收天线可以位于印刷电路板(print circuit board，PCB)上，发射通道和接收通道可以位于芯片内，即AOB(antenna on PCB)；或者，发射天线和接收天线可以位于芯片封装内，发射通道和接收通道可以位于芯片内，即AIP(antenna in package)。本申请实施例中对于组合形式不做具体限定。
应理解，本申请实施例中对发射通道和接收通道的具体结构不做限定，只要能实现相应发射和接收功能即可。
此外，同样需要说明的是，本申请实施例中所述的雷达系统可以应用于多种领域，示例性地，本申请实施例中的雷达系统包括但不限于车载雷达、路边交通雷达，无人机雷达。
另外由于单个射频芯片的通道规格数比较有限，系统需要的收发通道数大于单个射频芯片时，需要多个芯片级联。因此，整个雷达系统可能包括多个射频芯片级联，通过接口连接模拟数字转换器(analog digital converter，ADC)通道输出的数据到处理单元103，例如MCU，DSP，FPGA，通用处理单元(General Process Unit，GPU)等。另外整车可能安装一个或多个雷达系统，并且通过车载总线和中央处理器连接。中央处理器控制一个或多个车载传感器，包括一个或多个毫米波雷达传感器。
图1所示的MIMO雷达系统可以应用于具有自动驾驶功能的车辆。参见图2，为本申请实施例提供的具有自动驾驶功能的车辆200的功能框图。在一个实施例中，将车辆200配置为完全或部分地自动驾驶模式。例如，车辆200可以在处于自动驾驶模式中的同时控制自身，并且可通过人为操作来确定车辆及其周边环境的当前状态，确定周边环境中的至少一个其他车辆的可能行为，并确定该其他车辆执行可能行为的可能性相对应的置信水平，基于所确定的信息来控制车辆200。在车辆200处于自动驾驶模式中时，可以将车辆200置为在没有和人交互的情况下操作。
车辆200可包括各种子系统，例如行进系统202、传感器系统204、控制系统206、一个或多个外围设备208以及电源210、计算机系统212和用户接口216。可选地，车辆200可包括更多或更少的子系统，并且每个子系统可包括多个元件。另外，车辆200的每个子系统和元件可以通过有线或者无线互连。
行进系统202可包括为车辆200提供动力运动的组件。在一个实施例中，行进系统202可包括引擎218、能量源219、传动装置220和车轮/轮胎221。引擎218可以是内燃引擎、电动机、空气压缩引擎或其他类型的引擎组合，例如气油发动机和电动机组成的混动引擎，内燃引擎和空气压缩引擎组成的混动引擎。引擎218将能量源219转换成机械能量。
能量源219的示例包括汽油、柴油、其他基于石油的燃料、丙烷、其他基于压缩气体的燃料、乙醇、太阳能电池板、电池和其他电力来源。能量源219也可以为车辆100的其他系统提供能量。
传动装置220可以将来自引擎218的机械动力传送到车轮221。传动装置220可包括变速箱、差速器和驱动轴。在一个实施例中，传动装置220还可以包括其他器件，比如离合器。其中，驱动轴可包括可耦合到一个或多个车轮221的一个或多个轴。
传感器系统204可包括感测关于车辆200周边的环境的信息的若干个传感器。例如，传感器系统204可包括定位系统222(定位系统可以是全球定位系统(global positioning system，GPS)系统，也可以是北斗系统或者其他定位系统)、惯性测量单元(inertial measurement unit，IMU)224、雷达226、激光测距仪228以及相机230。传感器系统204还可包括被监视车辆200的内部系统的传感器(例如，车内空气质量监测器、燃油量表、机油温度表等)。来自这些传感器中的一个或多个的传感器数据可用于检测对象及其相应特性(位置、形状、方向、速度等)。这种检测和识别是自主车辆100的安全操作的关键功能。
定位系统222可用于估计车辆200的地理位置。IMU 224用于基于惯性加速度来感测车辆200的位置和朝向变化。在一个实施例中，IMU 224可以是加速度计和陀螺仪的组合。
雷达226可利用无线电信号来感测车辆200的周边环境内的物体。在一些实施例中，除了感测物体以外，雷达226还可用于感测物体的速度和/或前进方向。在一个具体示例中，雷达226可以采用图1所示的MIMO雷达系统实现。
激光测距仪228可利用激光来感测车辆100所位于的环境中的物体。在一些实施例中，激光测距仪228可包括一个或多个激光源、激光扫描器以及一个或多个检测器，以及其他系统组件。
相机230可用于捕捉车辆200的周边环境的多个图像。相机230可以是静态相机或视频相机。
控制系统206为控制车辆200及其组件的操作。控制系统206可包括各种元件，其中包括转向系统232、油门234、制动单元236、传感器融合算法238、计算机视觉系统240、路线控制系统242以及障碍物避免系统244。
转向系统232可操作来调整车辆200的前进方向。例如在一个实施例中可以为方向盘系统。
油门234用于控制引擎218的操作速度并进而控制车辆200的速度。
制动单元236用于控制车辆200减速。制动单元236可使用摩擦力来减慢车轮221。在其他实施例中，制动单元236可将车轮221的动能转换为电流。制动单元236也可采取其他形式来减慢车轮221转速从而控制车辆200的速度。
计算机视觉系统240可以操作来处理和分析由相机230捕捉的图像以便识别车辆200周边环境中的物体和/或特征。所述物体和/或特征可包括交通信号、道路边界和障碍物。计算机视觉系统240可使用物体识别算法、运动中恢复结构(structure from motion，SFM)算法、视频跟踪和其他计算机视觉技术。在一些实施例中，计算机视觉系统240可以用于为环境绘制地图、跟踪物体、估计物体的速度等等。
路线控制系统242用于确定车辆200的行驶路线。在一些实施例中，路线控制系统142可结合来自传感器238、GPS 222和一个或多个预定地图的数据以为车辆200确定行驶路线。
障碍物避免系统244用于识别、评估和避免或者以其他方式越过车辆200的环境中的潜在障碍物。
当然，在一个实例中，控制系统206可以增加或替换地包括除了所示出和描述的那些以外的组件。或者也可以减少一部分上述示出的组件。
车辆200通过外围设备208与外部传感器、其他车辆、其他计算机系统或用户之间进行交互。外围设备208可包括无线通信系统246、车载电脑248、麦克风250和/或扬声器252。
在一些实施例中，外围设备208提供车辆200的用户与用户接口216交互的手段。例如，车载电脑248可向车辆200的用户提供信息。用户接口216还可操作车载电脑248来接收用户的输入。车载电脑248可以通过触摸屏进行操作。在其他情况中，外围设备208可提供用于车辆200与位于车内的其它设备通信的手段。例如，麦克风250可从车辆200的用户接收音频(例如，语音命令或其他音频输入)。类似地，扬声器252可向车辆200的用户输出音频。
无线通信系统246可以直接地或者经由通信网络来与一个或多个设备无线通信。例如，无线通信系统246可使用3G蜂窝通信，例如码分多址(code division multiple access，CDMA)、EVD0、全球移动通信系统(global system for mobile communications，GSM)/通用分组无线服务技术(general packet radio service，GPRS)，或者4G蜂窝通信，例如长期演进(long term evolution，LTE)，或者5G蜂窝通信。无线通信系统246可利用WiFi与无线局域网(wireless local area network，WLAN)通信。在一些实施例中，无线通信系统246可利用红外链路、蓝牙或ZigBee与设备直接通信。其他无线协议，例如各种车辆通信系统，例如，无线通信系统246可包括一个或多个专用短程通信(dedicated short range communications，DSRC)设备，这些设备可包括车辆和/或路边台站之间的公共和/或私有数据通信。
电源210可向车辆200的各种组件提供电力。在一个实施例中，电源210可以为可再充电锂离子或铅酸电池。这种电池的一个或多个电池组可被配置为电源为车辆200的各种组件提供电力。在一些实施例中，电源210和能量源219可一起实现，例如一些全电动车中那样。
车辆200的部分或所有功能受计算机系统212控制。计算机系统212可包括至少一个处理器223，处理器223执行存储在例如存储器224这样的非暂态计算机可读介质中的指令225。计算机系统212还可以是采用分布式方式控制车辆200的个体组件或子系统的多个计算设备。
处理器223可以是任何常规的处理器，诸如商业可获得的中央处理器(central processing unit，CPU)。替选地，该处理器可以是诸如专用集成电路(application specific  integrated circuits,ASIC)或其它基于硬件的处理器的专用设备。尽管图2功能性地图示了处理器、存储器、和在相同块中的计算机210的其它元件，但是本领域的普通技术人员应该理解该处理器、计算机、或存储器实际上可以包括可以或者可以不存储在相同的物理外壳内的多个处理器、计算机、或存储器。例如，存储器可以是硬盘驱动器或位于不同于计算机210的外壳内的其它存储介质。因此，对处理器或计算机的引用将被理解为包括对可以或者可以不并行操作的处理器或计算机或存储器的集合的引用。不同于使用单一的处理器来执行此处所描述的步骤，诸如转向组件和减速组件的一些组件每个都可以具有其自己的处理器，所述处理器只执行与特定于组件的功能相关的计算。
在此处所描述的各个方面中，处理器可以位于远离该车辆并且与该车辆进行无线通信。在其它方面中，此处所描述的过程中的一些在布置于车辆内的处理器上执行而其它则由远程处理器执行，包括采取执行单一操纵的必要步骤。
在一些实施例中，存储器224可包含指令225(例如，程序逻辑)，指令225可被处理器223执行来执行车辆200的各种功能，包括以上描述的那些功能。存储器214也可包含额外的指令，包括向行进系统202、传感器系统204、控制系统206和外围设备208中的一个或多个发送数据、从其接收数据、与其交互和/或对其进行控制的指令。
除了指令225以外，存储器224还可存储数据，例如道路地图、路线信息，车辆的位置、方向、速度以及其它这样的车辆数据，以及其他信息。这种信息可在车辆200在自主、半自主和/或手动模式中操作期间被车辆200和计算机系统212使用。
用户接口216，用于向车辆200的用户提供信息或从其接收信息。可选地，用户接口216可包括在外围设备208的集合内的一个或多个输入/输出设备，例如无线通信系统246、车载电脑248、麦克风250和扬声器252。
计算机系统212可基于从各种子系统(例如，行进系统202、传感器系统204和控制系统206)以及从用户接口216接收的输入来控制车辆200的功能。例如，计算机系统212可利用来自控制系统206的输入以便控制转向单元232来避免由传感器系统204和障碍物避免系统244检测到的障碍物。在一些实施例中，计算机系统212可操作来对车辆200及其子系统的许多方面提供控制。
可选地，上述这些组件中的一个或多个可与车辆200分开安装或关联。例如，存储器224可以部分或完全地与车辆200分开存在。上述组件可以按有线和/或无线方式来通信地耦合在一起。
可选地，上述组件只是一个示例，实际应用中，上述各个模块中的组件有可能根据实际需要增添或者删除，图2不应理解为对本申请实施例的限制。
在道路行进的自动驾驶汽车，如上面的车辆200，可以识别其周围环境内的物体以确定对当前速度的调整。所述物体可以是其它车辆、交通控制设备、或者其它类型的物体。在一些示例中，可以独立地考虑每个识别的物体，并且基于物体的各自的特性，诸如它的当前速度、加速度、与车辆的间距等，可以用来确定自动驾驶汽车所要调整的速度。
可选地，自动驾驶汽车车辆200或者与自动驾驶车辆200相关联的计算设备(如图2的计算机系统212、计算机视觉系统240、存储器224)可以基于所识别的物体的特性和周围环境的状态(例如，交通、雨、道路上的冰、等等)来预测所述识别的物体的行为。可选地，每一个所识别的物体都依赖于彼此的行为，因此还可以将所识别的所有物体全部一起考虑来预测单个识别的物体的行为。车辆200能够基于预测的所述识别的物体的行为来调 整它的速度。换句话说，自动驾驶汽车能够基于所预测的物体的行为来确定车辆将需要调整到(例如，加速、减速、或者停止)什么稳定状态。在这个过程中，也可以考虑其它因素来确定车辆200的速度，诸如，车辆200在行驶的道路中的横向位置、道路的曲率、静态和动态物体的接近度等等。
除了提供调整自动驾驶汽车的速度的指令之外，计算设备还可以提供修改车辆200的转向角的指令，以使得自动驾驶汽车遵循给定的轨迹和/或维持与自动驾驶汽车附近的物体(例如，道路上的相邻车道中的轿车)的安全横向和纵向距离。
上述车辆200可以为轿车、卡车、摩托车、公共汽车、船、飞机、直升飞机、割草机、娱乐车、游乐场车辆、施工设备、电车、高尔夫球车、火车、和手推车等，本申请实施例不做特别的限定。
下面将结合附图对本申请实施例作进一步地详细描述。
需要说明的是，本申请实施例中，多个，是指两个或两个以上。另外，需要理解的是，在本申请的描述中，“第一”、“第二”等词汇，仅用于区分描述的目的，而不能理解为指示或暗示相对重要性，也不能理解为指示或暗示顺序。角度和速度耦合是指当仅存在一个目标时在角度和速度的模糊函数上，会出现多个虚假的峰值，影响目标的判断。下面，对本申请实施例的应用场景加以简单介绍。
参见图3，为本申请实施例提供的一种信号传输方法，该方法应用于MIMO雷达。其中，MIMO雷达包括发射器，发射器中包括Nt个发射天线。具体地，图3所示的方法包括如下步骤。
S301：发射器发送测量帧。该测量帧包括第一突发(burst1)，用于测量目标的速度。
其中，测量帧可以为调频连续波(frequency modulated continuous wave，FMCW)，也可以采用其他MIMO雷达所使用的波形，例如、多频移键控(multiple frequency-shift keying，MFSK)、调相连续波(phase modulated continuous wave，PMCW)中的任一种，本申请对此不做限定。为了方便描述，本申请实施例中以FMCW波形为例描述。
其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾(chirp)信号，N1＞Nt，T1为第一突发中每个chirp信号的持续时间。在实际信号中，每个chirp信号的持续时间包括扫频时间(即有效测量时间)和空闲时间(例如锁相环稳定时间、模数转换器稳定时间等)。
其中，N1＞Nt的含义是：每个发射天线发送chirp信号的周期是N1*T1，假设一个周期内发射的chirp信号称为一轮chirp信号。那么，一轮chirp信号的数量(N1)大于发射天线的数量(Nt)。也就是说，在一轮chirp信号中，除了每个发射天线发送一个chirp信号(即发送一个时隙)组成Nt个时隙之外，还存在N1-Nt个时隙。即Nt发射天线中至少一个天线在N1-Nt个时隙上发送chirp信号，本申请实施例中，第一发射天线和第二发射天线均可以视为在N1-Nt个时隙上发送chirp信号的发射天线。
由于N1-Nt>0，可以理解为本申请实施例与传统MIMO雷达(通常N1-Nt＝0)相比引入了传输开销，其中N1-Nt个时隙可以理解为本申请实施例中引入的额外传输开销。在工程上应该尽量避免开销过大，建议N1<2*G*Nt，其中G为Nt个发射天线分成整数个组的数目。当G＝1时，2*Nt>N1>Nt；当G≠1时，2*G*Nt>N1>Nt。在发射天线数比较少例如Nt＝2,3的时候，G＝1,2,3,4,5,6；当发射天线数比较多，例如Nt＝6～12时候，G＝1,2。
由于车载环境非常复杂，目标在空间维(距离，水平方位角和垂直方位角)和速度维的分辨率要求不一定相同。因此，可以根据车载环境动态配置一个突发中发射天线数Nt和TDM MIMO中重复周期N1*T1的具体数值。通常，ECU通过常用车载总线，如控制器局域网(controller area network，CAN)、具有可变速率的控制器局域网(controller area network with flexible data-rate，CAN-FD)、通用以太网(general ethernet，GE)等车载接口将Nt和N1*T1等参数配置给雷达模组。雷达模组中可以通过串行外设接口(serial peripheral interface，SPI)将上述参数配置给MIMC。在多片级联的情况下，可以通过配置主、从射频前端芯片实现灵活配置。MMIC可用于根据测量帧的配置使能发射器发送测量帧。
需要说明的是，车载接口将上述参数配置给雷达模组时，配置的参数不限于上述举例，配置参数用于指示发射天线如何发送chirp信号即可。示例性地，配置参数可以是Nt、N1、T1的具体数值，也可以是Nt、N1、T1的具体数值的等同参数。
本申请实施例中，突发是时间段上的概念，突发也可以称为时隙、子帧、帧等。此外，在本申请的描述中，时隙为最小的时间单元，一个突发包括至少一个时隙，一个子帧包括至少一个突发，一个帧包括至少一个子帧。
具体地，本申请实施例中引入的额外传输开销(即N1-Nt个时隙)可以为一个时隙，也可以为多个时隙。若额外传输开销为多个时隙，则第一发射天线在发送N1-Nt个chirp信号时，可以周期性发送，也可以非周期性发送。
示例性地，若额外传输开销为一个时隙，则以N1＝13、Nt＝12为例，Nt个发射天线发送的一轮chirp信号可以如图4所示。在图4的示例中，一个长条代表一个chirp信号，每个chirp信号占用一个时隙。其中，白色填充部分可以视为每个发射天线以N1*T1为周期发送的chirp信号，黑色填充部分可以视为第一发射天线发送的N1-Nt个chirp信号。特别地，在图4的示例中，第一发射天线发送的N1-Nt个chirp信号与第一发射天线以N1*T1为周期发送的chirp信号是时间上连续的两个chirp信号(形成软重叠阵子)。将12个发射天线以1、2、3……12编号，其中第一发射天线用1编号，那么每个发射天线对应发送的chirp信号可以如图4中的标示。从图4中可以看出，在一轮chirp信号中，第一发射天线除了在第3个时隙上以N1*T1为周期发送chirp信号外，还在第四个时隙上发送N1-Nt个chirp信号。
需要说明的是，在图4的示例中，仅示出了一轮chirp信号，实际应用中，发射天线可以发送Ndoppler轮chirp信号，以组成第一突发。示例性地，Ndoppler＝64，128。
同样需要说明的是，在本申请的示例中，均与图4的示例类似，用一个长条代表一个chirp信号，该长条的形状仅为示意，并不代表实际应用中的chirp信号的波形。本申请实施例中对chirp信号的具体波形不做限定。
示例性地，若额外传输开销为多个时隙，且在一轮chirp信号中，N1-Nt个chirp信号非周期性发送，则以N1＝14、Nt＝12为例，Nt个发射天线发送的一轮chirp信号可以如图5所示。其中，白色填充部分可以视为每个发射天线以N1*T1为周期发送的chirp信号，黑色填充部分可以视为第一发射天线发送的N1-Nt个chirp信号。其中，每个发射天线对应发送的chirp信号可以如图5中的标示。从图5中可以看出，在一轮chirp信号中，第一发射天线除了在第3个时隙上以N1*T1为周期发送chirp信号外，还在第一个时隙和第二个时隙上连续发送N1-Nt个chirp信号(第一个时隙、第二个时隙以及第三个时隙上发送的chirp信号形成软重叠阵子)。同样地，发射天线可以发送Ndoppler轮图5所示的chirp信 号，以组成第一突发。
在另一种示例中，若额外传输开销为多个时隙，且在一轮chirp信号中，N1-Nt个chirp信号非周期性发送，则以Nt＝3、N1＝12为例，Nt个发射天线发送的一轮chirp信号可以如图6所示。在图6中，对于每一个发射天线，均存在时间上连续发送多个chirp信号的情况。
应理解，在图6所示的示例中，N1＞Nt，但是在Nt个发射天线中并不存在严格意义上高密度发送的天线，因为每个发射天线在一轮chirp信号中发送的信号数量相同。这可以视为本申请中的一个特殊示例。也就是说，为了使得N1＞Nt，本申请实施例中通常配置一个或多个高密度天线，用以发送N1-Nt个时隙。但是在有些示例中，也可以通过每个发射信号在一个周期内分别发送相同数量的chirp信号、且发送chirp信号的顺序是打乱的，采用这种方式也可以实现N1＞Nt。
在另一种示例中，在一轮chirp信号中进行高密度发送的发射天线不限于第一发射天线。示例性地，如图7所示，以Nt＝12、N1＝16为例，在一轮chirp信号中，标号为1的发射天线在第一个时隙和第二个时隙上发送chirp信号，标号为4的发射天线在第五个时隙和第六个时隙上发送chirp信号，标号为7的发射天线在第九个时隙和第十个时隙上发送chirp信号。标号为10的发射天线在第十三个时隙和第十四个时隙上发送chirp信号。也就是说，在图7的示例中高密度发送的发射天线有四个。
当然，若N1-Nt的数量为多个，N1-Nt个chirp信号也可以周期性发送。在这种情况下，在第一突发中，第一发射天线还用于以M1*T1为周期发送chirp信号，M1＜N1。也就是说，在第一突发中，每个发射天线用于以N1*T1为周期发送chirp信号，此外，第一发射天线还用于以M1*T1为周期发送chirp信号。在一轮chirp信号中，第一发射天线以M1*T1为周期发送的chirp信号的数量为N1-Nt。
示例性地，若发射器中包括12个发射天线(Nt＝12)，N1＝16、M1＝4，则12个发射天线发射一轮chirp信号可以如图8所示。在图8中，黑色填充部分可以视为第一发射天线以M1*T1为周期发送的chirp信号，白色填充部分可以视为每个发射天线以N1*T1为周期发送的chirp信号。具体的，在图8所示的16个chirp信号中，第一发射天线发射的chirp信号的数量为4+1＝5，另外11个发射天线中的每个发射天线发送的chirp信号的数量为1。实际应用中，在第一突发中，图8所示的组合可以被发送Ndoppler次以组成第一突发。比如，Ndoppler＝128。
示例性，若发射器中包括12个发射天线(Nt＝12)，N1＝15、M1＝5，则12个发射天线发射一轮chirp信号可以如图9所示。在图9中，黑色填充部分可以视为第一发射天线以M1*T1为周期发送的chirp信号，白色填充部分可以视为每个发射天线以N1*T1为周期发送的chirp信号。具体的，在图9所示的15个chirp信号中，第一发射天线发射的chirp信号的数量为3+1＝4，另外11个发射天线中的每个发射天线发送的chirp信号的数量为1。同样地，在第一突发中，图9所示的组合可以被发送Ndoppler次以组成第一突发。
从图8和图9的两个示例可以看出，在第一突发中，除了每个发射天线周期性地发送chirp信号外，还存在一个发射密度较大的第一发射天线，该第一发射天线还额外地以较短的周期发送chirp信号。Nt个发射天线在发送一轮chirp信号时，Nt个发射天线被分成Nt/(M1-1)组，Nt个发射天线在一轮中发送Nt/(M1-1)+Nt个chirp信号。例如，在图8的示例中，12个发射天线被分成12/(4-1)组，每组中包括一个高密度发送的chirp信号 (黑色填充部分)和三个低密度发送的chirp信号(白色填充部分)。一轮chirp信号中包括12/(4-1)+12＝16个chirp信号。
此外，在实际应用中，考虑到处理时延和功耗等因素，一个测量帧中还存在占空比P％。例如在更新周期为20Hz的设计约束下，每个测量帧不能大于50ms，其中每个chirp信号的持续时间T1取20μs，Ndoppler＝128，Nt＝12，N1＝16，那么一个测量帧中可以用于有效测量的时间为20*128*16＝40.96ms，占空比为82％左右。
采用如上方式发送chirp信号，可以实现发射天线的不同密度的发送，其中第一发射天线的发送密度较大，其余发射天线的发送密度较小。由于高密度发射天线对应接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算的复杂度。此外，对于通过高密度发送chirp信号形成软重叠阵子的方式(图4～图7的示例)，由于时间上相邻发射的天线接收回波信号的相位仅有目标速度引入，可以通过计算相邻发射的天线接收回波信号的相位差，获得目标速度的混叠区间。
此外，在第一突发中，第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。
也就是说，与前述方案相比，在第一突发中，第一发射天线的发射密度更大。通过获取第一发射天线以M1*T1为周期发送chirp信号经一个或多个目标反射后的回波信号，并对该回波信号进行检测，可以获取一个或多个目标的标识(即一组标识)；通过获取第一发射天线以M2*T1为周期发送chirp信号经一个或多个目标反射后的回波信号，并对该回波信号进行检测，可以获取一个或多个目标的标识(即一组标识)。由于M1和M2互质，那么可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
在上述方案中，除了每个发射天线以N1*T1为周期发送chirp信号以外，第一发射天线还以M1*T1以及M2*T1为周期发送chirp信号。那么，在该方案中，发送一轮chirp信号则需要发送N1＝M1*M2个chirp信号。其中，M1个时隙被发送密度为M2*T1的发射天线占用，M2个时隙被发送密度为M1*T1的发射天线占用。其中，其中一个时隙(例如第一个时隙或最后一个时隙)可以共用。那么，还剩下M1*M0-M1-M0+1＝G*Nt个时隙可以用于Nt个发射天线以N1*T1为周期发送chirp信号。比如，M1＝3、M2＝7，那么有3*7-3-7+1＝12个时隙用于每个发射天线以N1*T1为周期发送chirp信号，那么高密度发送的占比约为(21-12)/21≈42.8％。再比如，M1＝5、M2＝7，那么有5*7-5-7+1＝24个时隙用于每个发射天线以N1*T1为周期发送chirp信号，那么高密度发送的占比约为(35-24)/35≈31.4％。
示例性地，若发射器中包括24个发射天线，M1＝5，M2＝7，N1＝35，则24个发射天线发射一轮chirp信号可以如图10中的a示例所示，也可以如图10的b示例所示。在图10的示例中，黑色填充部分可以视为第一发射天线以M1*N1为周期发送的chirp信号，条纹填充部分可以视为第一发射天线以M2*N1为周期发送的chirp信号，白色填充部分可以视为每个发射天线以N1*T1为周期发送的chirp信号。同样地，在第一突发中，图10中a示例或b示例所示的组合可以被发送Ndoppler次以组成第一突发。b示例与a示例不同的 是，b示例中，高密度发送的chirp信号与a示例相比有时间偏移。
采用上述方案，根据第一发射天线高密度发送的两组chirp信号反射后的回波信号确定的两组标识的速度分辨率相同。由于M1和M2互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
由于M1和M2互质，而根据第一发射天线高密度发送的两组chirp信号反射后的回波信号确定的两组标识的速度分辨率相同，可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
可选地，本申请实施例中，测量帧中还可以包括第二突发(burst2)。在第二突发中，Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等。
与第一突发相同的是，在第二突发的发送过程中，也存在发射密度较大的发射天线(第二发射天线)以及发射密度较小的发射天线(除第二发射天线之外的其他发射天线)。其中，第一发射天线和第二发射天线可以是同一个发射天线，也可以是不同发射天线。
在上述实现方式中，M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等。具体地，若T1和T2不相等，则M3*T2和M1*T1互质；若T1和T2相等，则M3和M1互质。比如，T1＝20μs，T2＝21μs，M1＝5，M3＝7，则M3*T2和M1*T1互质可以理解为20*5与21*7互质；再比如，T1＝T2＝10μs，M1＝3，M3＝8，则M1和M3互质。
采用上述方案，根据第一发射天线高密度发送的chirp信号发射后的回波信号以及根据第二发射天线高密度发送的chirp信号发射后的回波信号分别确定的两组标识的速度分辨率相同。由于M3*T2和M1*T1互质，或者M3和M1互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
可选地，本申请实施例中，测量帧中还可以包括第三突发；在第三突发中，Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T3和T1相等。
不难看出，在第三突发中，每个发射天线的发射密度相同。
此外，在上述实现方式中，N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。具体地，若T1和T3不相等，则N3*T3和M1*T1互质；若T1和T3相等，则N3和M1互质。
采用上述方案，由于N3*T3和M1*T1互质，或者N3和M1互质，而在参差算法中，两两互质的任意整数方程有解，因此采用上述方案可以利用中国余数法(参差算法)扩大MIMO雷达的测速范围。
如前所述，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送chirp信号，Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号。具体实现时，第一发射天线可以是发射器中包括的Nt个发射天线中的任一发射天线。那么，第一发射天线可以是发送与N1-Nt个chirp信号相邻的chirp信号的发射天线，在这种 情况下，在第一突发中，第一发射天线在N1*T1时间内发送的多个chirp信号中存在时间上连续发送的两个chirp信号。
本申请实施例中，一种可能的实现方式是，在Nt个发射天线中，存在至少一个发射天线，该至少一个发射天线在第一突发中的N1*T1时间范围内，连续发送两个chirp信号。比如在上述示例中，第一发射天线是发送与N1-Nt个chirp信号相邻的chirp信号的发射天线，在这种情况下，第一发射天线在第一突发中连续发送两个chirp信号。
也就是说，对于第一发射天线以M1*T1为周期发送的chirp信号，与其相邻的一个chirp信号是第一发射天线以N1*T1为周期发送的chirp信号。假设12个发射天线分别用1、2、3……12标示，第一发射天线用1标示。那么对于图8所示的示例，每个发射天线发送的chirp信号可以如图11所示。
换个角度来说，比如，在第一突发中，第一发射天线以M1*T1为周期发送的chirp信号占用三个时隙，与这三个时隙相邻的时隙有[2，5，7，10，12]，那么第一发射天线以N1*T1为周期发送chirp信号时可以在[2，5，7，10，12]中任一时隙上发送。
当然，上述几个示例中均以第一发射天线连续发送两个chirp信号为例进行描述，实际应用中，Nt个发射天线中可以存在一个多个连续发送chirp信号的发射天线，且连续发送的chirp信号的数量也不限定为两个。例如在图5示例中，标号为1的发射天线连续发送三个chirp信号；在图6的示例中，标号为2的发射天线连续发送两个chirp信号，标号为1的发射天线连续发送三个chirp信号，标号为3的发射天线连续发送两个chirp信号。
通过物理位置重叠的两个发射天线在相邻两个时隙上发送chirp信号的方式可以称为重叠阵子(overlapping)。而上述通过同一发射天线(例如可以是发射密度较大的第一发射天线)在相邻两个时隙上发送chirp信号的方式在本申请实施例中可以称为软重叠阵子，即通过软件方式实现重叠阵子。采用上述实现方式，软重叠阵子时刻两个或者多个相邻时隙对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的SIMO测速范围内的混叠速度。这里可以有多种具体计算方法，可以计算软重叠阵子对(相邻的两两为一对)的混叠系数对应的多普勒相位补偿后的接收回波数据和原始重叠阵子信号的共轭相乘，对多个接收信号求和，找多个混叠系数对应最小值对应的混叠系数。或者直接按照多个软重叠阵子对的相位差求平均，估计速度。
不难看出，对于图4～图7示出的发射天线在一轮chirp信号中连续发送的情况，也可以采用上述软overlapping方式计算目标的速度。需要说明的是，本申请实施例中的第一发射天线，不一定物理上序号为一的发射天线，第一发射天线可以是Nt个发射天线中的任一发射天线。
综上，采用图3所示的信号传输方法，可以实现发射天线的不同密度的发送。
若高密度发射天线(例如可以是第一发射天线)在发送N1-Nt个chirp信号时是连续发送的(比如图4～图7、图11的示例)，软overlapping时刻对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的速度。
若高密度发射天线(例如可以是第一发射天线)在发送N1-Nt个chirp信号时是周期性发送的(比如图8～图10的示例)，由于高密度发射天线对应的接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索 方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算复杂度。
因此，采用图3所示的信号传输方法，可以将MIMO雷达的最大测速范围恢复到SIMO测速范围，不影响后续的角度测量。实际应用中，在计算出目标的速度之后，还需要根据补偿多普勒后的各接收通道上的数据进一步计算，以获取目标的方位角(例如包括水平方位角和垂直方位角)，从而对获得目标的距离、速度、角度信息。因此，速度计算的准确性对方位角计算的影响较大。采用本申请实施例提供的方法可以保证方位角计算的准确性，提高角度分辨率。
与图3所示的信号传输方法相对应地，本申请实施例还提供一种信号处理方法，用于对发射的测量帧经一个或多个目标反射后形成的回波信号进行处理，从而获取一个或多个目标的速度，进而获取一个或多个目标的方位角(例如水平方位角和垂直方位角)。
该方法应用于MIMO雷达，MIMO雷达包括发射器、接收器和处理单元，发射器包括Nt个发射天线，接收器包括Nr个接收天线。参见图12，该方法包括如下步骤：
S1201：接收器接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号。
其中，该测量帧包括第一突发，第一回波信号由Nt个发射天线中的每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由Nt个发射天线中的第一发射天线发送的其他chirp信号经一个或多个目标反射后形成。
其中，N1>Nt，T1为第一突发中每个chirp信号的持续时间。
在S1201中，接收器接收的回波信号即图3所示方法中发射器发送的测量帧经一个或多个目标反射后的回波信号。具体地，每个发射天线以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成第一回波信号，第一发射天线发送的其他chirp信号经一个或多个目标反射后形成第二回波信号。
需要说明的是，本申请实施例中，接收器中包括Nr个接收天线，Nr个接收天线按照Nt个发射天线的发射顺序，接收Nt个回波信号，然后根据Nt个发射天线和Nr个接收天线之间的位置关系以及发射天线的发射顺序，将接收到的回波信号转换成第一回波信号和第二回波信号。
S1202：处理单元根据接收器接收到的回波信号确定一个或多个目标的速度。
具体地，S1202中，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，可以通过如下方式实现：处理单元根据第一回波信号确定第一标识，第一标识用于指示一个或多个目标的距离测量值和速度测量值；处理单元根据第二回波信号确定第二标识，第二标识用于指示一个或多个目标的距离测量值和速度测量值；处理单元根据第一标识和第二标识确定一个或多个目标的速度。
其中，第一标识中可以包括第一速度标识和第一距离标识，第二标识中可以包括第二速度标识和第二距离标识。在获取第一回波信号后，可以通过一维FFT(1D-FFT)、二维FFT(2D-FFT)以及相干合并/非相干合并等操作获取距离-多普勒图(range doppler map，RD Map)，然后根据RD Map检测获得最大测速范围内的第一速度标识(Vind_d)和第一距离标识(Rind_d)；同样地，在获取第二回波信号后，可以通过1D-FFT、2D-FFT以及 相干合并/非相干合并等操作获取另一RD Map，然后根据该RD Map检测获得最大测速范围内的第二速度标识(Vind_p)和第二距离标识(Rind_p)。其中，第一标识对应的最大测速范围比第二标识对应的最大测速范围小。
具体地，根据RD Map进行检测时，检测方法可以有多种，包括但不限于有序统计-恒虚警率(ordered statistic-constant false alarm rate，OS-CFAR)检测或单元平均-恒虚警率(cell-averaging constant false alarm rate，CA-CFAR)等常用检测方法，本申请实施例中不做特别限制。
在角度谱峰搜索方法中，把不同时隙下发射天线对应的接收信号，分别补充不同的混叠系数，并且通过FFT或数字波束成型(digitial beamforming，DBF)在视场角(field of view，FOV)范围内搜索得到N fft_AOA个角度。然后获得不同混叠系数在FOV内N fft_AOA角度谱的最大值(角度谱峰)，取N1个混叠系数中对应角度谱峰值最大值的元素作为速度混叠系数。
具体实现时，由于Nt个发射天线发射的测量帧中chirp信号的排列顺序有所不同，如图4～图9中所示出的不同示例，因而处理单元在根据第一标识和所述第二标识确定一个或多个目标的速度的方式也有所不同。
下面对确定一个或多个目标的速度的不同方式进行介绍。
方式一
在方式一中，第二回波信号由第一发射天线以M1*T1为周期发送的chirp信号经一个或多个目标反射后形成，M1＜N1。
也就是说，在方式一中，Nt个发射天线中每个发射天线以N1*T1为周期发送chirp信号，第一发射天线还以M1*T1为周期发送chirp信号。具体示例可以参见图8或图9。Nr个接收天线在接收到多个chirp信号组成的测量帧后，根据Nt个发射天线和Nr个接收天线之间的位置关系以及发射天线的发射顺序，将接收到的回波信号转换成第一回波信号和第二回波信号。
那么，处理单元根据第一标识和第二标识确定一个或多个目标的速度，具体可通过如下方式实现：处理单元根据N1确定第一标识对应的第一混叠系数区间，并根据M1确定第二标识对应的第二混叠系数区间；处理单元根据第一标识和第二标识，确定第二混叠系数区间在第一混叠系数区间内对应的混叠系数子集；处理单元根据混叠系数子集确定速度混叠系数；处理单元根据速度混叠系数和第一标识确定一个或多个目标的速度。
其中，若N1为偶数，那么第一混叠系数区间为[-N1/2，N1/2-1]；若N1为奇数，那么第一混叠系数区间为[-(N1-1)/2，(N1-1)/2]；若M1为偶数，那么第二混叠系数区间为[-M1/2，M1/2-1]；若M1为奇数，那么第二混叠系数区间为[-(M1-1)/2，(M1-1)/2]。不难看出，由于M1＜N1，因此第一混叠系数区间的范围比第二混叠系数区间的范围大。
以M1＝4，N1＝16为例，此时第一混叠系数区间为[-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]，第二混叠系数区间为[-2,-1,0,1]。
以M1＝5、N1＝15为例，此时第一混叠系数区间为[-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]，第二混叠系数区间为[-2,-1,0,1，2]。
在计算目标的速度时，我们可以将通过RD Map获取的第一标识或第二标识中的速度标识视为余数，将混叠系数区间中的数据视为商，将商与除数(最大测速范围)相乘，再 与速度标识相加，即可获取目标的速度。
在获取第一标识、第二标识、第一混叠系数区间和第二混叠系数区间之后，对于目标速度的求解还存在如下问题：由于第二标识是根据发送密度较大的第一发射天线发送的chirp信号确定，因而在第二速度标识中，多个目标碰撞的概率较小；但是由于第二混叠系数区间的范围比第一混叠系数区间的范围小，因而若要将MIMO雷达的测速范围恢复到SIMO测速范围，还需将第二混叠系数区间折算到第一混叠系数区间，然后再用第一标识和折算后的混叠系数计算出一个或多个目标的速度。
以第一混叠系数区间为[-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]、第二混叠系数区间为[-2,-1,0,1,2]为例，将第二混叠系数区间折算到第一混叠系数区间即在[-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]中找到与[-2,-1,0,1,2]对应的混叠系数子集。具体地，由于第一混叠系数区间的范围是第二混叠系数区间的范围的三倍，因而混叠系数子集可以有三种组合[-7,-4,-1,2,5]、[-6,-3,0,3,6]和[-5,-2,1,4,7]。这三个集合中哪个集合是混叠系数子集S，可以根据第一标识和第二标识确定。其中，混叠系数子集S可以视为第一混叠系数区间的子集。
具体地，第一标识和第二标识中的距离标识是不会出现模糊的情况的，即对于同一个目标，第一距离标识和第二距离标识应该是近似相等的。那么，可以通过两个近似相等的距离标识分别对应的第一速度标识和第二速度标识确定第二混叠系数区间中的某个数值与第一混叠系数区间中的哪个数值对应，即可根据该对应关系确定上述三种组合中的哪个组合是混叠系数子集。
以M1＝4、N1＝16为例，此时第一混叠系数区间为[-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]，第二混叠系数区间为[-2,-1,0,1]。那么高密度天线的测速范围可以对应低密度天线的测速范围的4个区间。高密度天线对应的多普勒的fft取值范围也对应低密度天线fft取值范围的4倍。因此，高密度天线中混叠系数为0时，对应的是低密度天线的SS＝[0,1,2,3]中某个值。把高密度天线测到的速度标识Vind_p除以低密度天线上测到的速度标识最大值并将二者的商向下取整，floor(Vind_p/Vind_d_max)，即可以获得0,1,2,3取值范围内与高密度天线混叠系数0相对应的值。假设floor(Vind_p/Vind_d_max)＝1,SS(1)＝1,即第一混叠系数区间中的1对应第二混叠系数区间中的0。在第一混叠系数区间内每隔4个取值为[-7,-3,1,5],[-7,-3,1,5]即为混叠系数子集S。值得注意的是，这里SS向量的下标是从0开始计数的。
具体M1＝5、N1＝15,此时第一混叠系数区间为[-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7]，第二混叠系数区间为[-1,0,1]，那么高密度天线的测速范围可以对应低密度天线的测速范围的3个区间。高密度天线对应的多普勒的fft取值范围也对应低密度天线fft取值范围的3倍。因此，高密度天线中混叠系数为0时，对应的是低密度天线的SS＝[-1,0,1]中某个值。把高密度天线测到的速度标识Vind_p除以低密度天线上测到的速度标识最大值并将二者的商向下取整，floor(Vind_p/Vind_d_max)，即可以获得-1,0,1取值范围内与高密度天线混叠系数0相对应的值。假设floor(Vind_p/Vind_d_max)＝1,SS(1)＝1,即第一混叠系数区间中的1对应第二混叠系数区间中的0。在第一混叠系数区间内每隔3个取值为[-6,-3,0,3,6]，[-6,-3,0,3,6]即为混叠系数子集S。
此外，在执行上述方案获取RD Map之后，还可以对接收天线接收到的回波信号进行补偿。若第一发射天线在第一突发中发送的chirp信号的处理增益小于每个发射天线在第 一突发中以N1*T1为周期发送的chirp信号的处理增益，可以利用第一速度标识对回波信号进行多普勒相位补偿；若第一发射天线在第一突发中发送的chirp信号的处理增益大于每个发射天线在第一突发中以N1*T1为周期发送的chirp信号的处理增益，可以利用第二速度标识对回波信号进行多普勒相位补偿。
示例性地，根据每个时隙中的发射天线对应的接收天线回波信号的相位，可以有如下公式。
Figure PCTCN2019101408-appb-000001
Figure PCTCN2019101408-appb-000002
其中，
Figure PCTCN2019101408-appb-000003
对应的是MIMO发送周期为N1*T1时第m个时隙内发射天线对应的Nr个接收天线回波信号相位；
Figure PCTCN2019101408-appb-000004
对应的是SIMO发送周期为T1时，当m个天线都在第1个时隙内发射时，对应的Nr接收回波信号相位；
Figure PCTCN2019101408-appb-000005
是在RD Map上观察到的TDM MIMO最大测速范围内目标速度对应的多普勒频率，
Figure PCTCN2019101408-appb-000006
是希望恢复的SIMO最大测速范围内目标速度对应的多普勒频率。此外，不难看出a coef的取值范围是第一混叠系数区间，但是在本申请实施例的实际应用中，a coef可以仅取到混叠系数子集中的元素即可。
Figure PCTCN2019101408-appb-000007
是m个时隙内发射天线的对应的Nr个接收天线的回波信号相位补偿值。
在确定混叠系数子集之后，可以计算混叠系数子集S中不同元素所对应的子阵接收信号在不同角度谱上的值，将混叠系数子集S中对应角度谱最大值的元素作为速度混叠系数。然后，根据速度混叠系数、最大测速范围和第一速度标识即可确定一个或多个目标的速度。其中，根据混叠系数子集确定速度混叠系数的具体方式可以参照现有技术中的描述，此处不再赘述。
方式二
在方式二中，接收器还接收测量帧经一个或多个目标反射后形成的第三回波信号，第三回波信号由第一发射天线在第一突发中以M2*T1为周期发送的chirp信号经一个或多个目标反射后形成，M2＜N1，M1和M2互质；那么，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，具体可通过如下方式实现：处理单元根据第二回波信号和第三回波信号确定一个或多个目标的速度。
也就是说，在方式一中，Nt个发射天线中每个发射天线以N1*T1为周期发送chirp信号，第一发射天线还以M1*T1为周期发送chirp信号，以及以M2*T1为周期发送chirp信号。具体示例可以参见图10。Nr个接收天线在接收到多个chirp信号组成的测量帧后，根据Nt个发射天线和Nr个接收天线之间的位置关系以及发射天线的发射顺序，将接收到的回波信号转换成第一回波信号、第二回波信号和第三回波信号。
由于M1和M2互质，因而根据第二回波信号和第三回波信号确定的速度标识的速度分辨率相同，因而可以直接根据第二回波信号和第三回波信号确定的两个混叠系数区间直接确定速度混叠系数。
方式二中的其他操作与方式一中类似，此处不再赘述。
方式三
在方式三中，接收器还接收测量帧经一个或多个目标反射后形成的第四回波信号和第五回波信号，该测量帧还包括第二突发，第四回波信号由Nt个发射天线中的第二发射天线在第二突发中以M3*T2为周期发送的chirp信号经一个或多个目标反射后形成，第五回波信号由Nt个发射天线中的每个发射天线在第二突发中以N2*T2为周期发送的chirp信号经一个或多个目标反射后形成，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等；那么，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，具体可通过如下方式实现：处理单元根据第二回波信号和第四回波信号确定一个或多个目标的速度。
在方式三中，M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等，处理单元根据第二回波信号和第四回波信号确定一个或多个目标的速度的方式，与方式二中处理单元根据第二回波信号和第三回波信号确定一个或多个目标的速度的方式相同，此处不再赘述。
方式四
在方式四中，接收器还接收测量帧经一个或多个目标反射后形成的第六回波信号，该测量帧还包括第三突发，第六回波信号由Nt个发射天线中的每个发射天线在第三突发中以N3*T3为周期发送的chirp信号经一个或多个目标反射后形成，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等；那么，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，具体可通过如下方式实现：处理单元根据第二回波信号和第六回波信号确定一个或多个目标的速度。
在方式四中，N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等，处理单元根据第二回波信号和第六回波信号确定一个或多个目标的速度的方式，与方式二中处理单元根据第二回波信号和第三回波信号确定一个或多个目标的速度的方式相同，此处不再赘述。
方式五
在方式五中，接收器还接收测量帧经一个或多个目标反射后形成的第七回波信号，第七回波信号由第一发射天线在第一突发中的N1*T1时间内连续发送的多个chirp信号经过一个或多个目标反射后形成。具体实现方式可以参见图4、图5或图9中的示例。那么，处理单元根据接收器接收到的回波信号确定一个或多个目标的速度，具体可通过如下方式实现：处理单元根据第二回波信号和第七回波信号确定一个或多个目标的速度。
如前所述，通过物理上位置重叠的两个发射天线在相邻两个时隙上发送chirp信号的方式可以称为overlapping。而上述通过同一发射天线在相邻的两个时隙上发送chirp信号的方式在本申请实施例中可以称为软overlapping，即通过软件方式实现overlapping。采用方式五，软overlapping时刻对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的第一发射天线上计算出的目标的速度标识直接匹配出对应的速度混叠系数，从而确定目标的速度。也就是说，采用方式五可以不必通过计算混叠系数子集进而确定速度混叠系数，而是直接根据第一发射天线连续发送的多个chirp信号反射后的回波信号匹配出速度混叠系数。通过overlapping确定目标速度的方式为现有技术，此处不再赘述。
综上，采用图12所示的信号处理方法，发射天线采用不同密度发送，因而根据不同发送密度的发射天线发送的chirp信号得到的第一回波信号和第二回波信号的最大测速范围不同。
若第一发射天线在发送N1-Nt个chirp信号时是连续发送的(比如图4～图7、图11的示例)，软overlapping时刻对应的接收天线的相位差别仅由目标速度引起的多普勒(doppler)相位确定。因此，可以通过发射密度较大的发射天线上计算出的目标的速度标识，直接匹配出对应的速度混叠系数，从而将MIMO雷达的最大测速范围恢复到SIMO测速范围，确定目标的速度。
若第一发射天线在发送N1-Nt个chirp信号时是周期性发送的(比如图8～图10的示例)，由于高密度发射天线对应的接收的回波信号的最大测速范围大，因而高密度发射天线发送时可以形成更小的发射重复周期，那么采用谱峰搜索方法时，高密度发射天线对应的接收的回波信号相对SIMO的速度混叠系数的数量少，利用高密度的发射天线对应的接收的回波信号辅助低密度发射天线对应的接收的回波信号进行目标速度的计算，可以缩小角度谱峰搜索中混叠系数的区间范围，降低计算复杂度。
本申请实施例还提供一种信号传输装置，该装置可以用于执行图3所示的信号传输方法。参见图13，信号传输装置1300包括发射器13011301，用于发送测量帧，发射器1301包括Nt个发射天线，测量帧用于测量目标的速度，测量帧包括第一突发；其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾chirp信号，其中N1>Nt，T1为第一突发中每个chirp信号的持续时间。
在一种可能的设计中，在第一突发中，Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号，其中M1＜N1。
在一种可能的设计中，第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。
在一种可能的设计中，该测量帧还包括第二突发；在第二突发中，Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质，且T1和T2相等。
在一种可能的设计中，该测量帧还包括第三突发；在第三突发中，Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。
在一种可能的设计中，Nt个发射天线中存在至少一个发射天线在第一突发中连续发送两个chirp信号。
在一种可能的设计中，该测量帧为FMCW。
在一种可能的设计中，该装置1300还包括：处理单元1302，用于确定测量帧的配置，并通过接口将测量帧的配置发送至MMIC，MMIC用于根据测量帧的配置使能发射器发送测量帧。
需要说明的是，图13所示的信号传输装置1300可用于执行图3所示的信号传输方法，信号传输装置1300中未详尽描述的实现方式可参见图3所示的信号传输方法中的相关描述。
本申请实施例还提供一种信号处理装置，该装置可以用于执行图12所示的信号处理方法。参见图14，信号处理装置1400包括：接收器1401，用于接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，测量帧包括第一突发，第一回波信号由发射器包括的Nt个发射天线中的每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由Nt个发射天线中的第一发射天线发送的其他chirp信号经一个或多个目标反射后形成，N1>Nt，T1为第一突发中每个chirp信号的持续时间；处理单元1402，用于根据接收器1401接收到的回波信号确定一个或多个目标的速度。
在一种可能的设计中，处理单元1402在根据接收器1401接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第一回波信号确定第一标识，第一标识用于指示一个或多个目标的距离测量值和速度测量值；根据第二回波信号确定第二标识，第二标识用于指示一个或多个目标的距离测量值和速度测量值；根据第一标识和第二标识确定一个或多个目标的速度。
在一种可能的设计中，第二回波信号由第一发射天线以M1*T1为周期发送的chirp信号经一个或多个目标反射后形成，M1＜N1。
在一种可能的设计中，处理单元1402在根据第一标识和第二标识确定一个或多个目标的速度时，具体用于：根据N1确定第一标识对应的第一混叠系数区间，并根据M1确定第二标识对应的第二混叠系数区间；根据第一标识和第二标识，确定第二混叠系数区间在第一混叠系数区间内对应的混叠系数子集；根据混叠系数子集确定速度混叠系数；根据速度混叠系数和第一标识确定一个或多个目标的速度。
在一种可能的设计中，接收器1401还用于：接收测量帧经一个或多个目标反射后形成的第三回波信号，第三回波信号由第一发射天线在第一突发中以M2*T1为周期发送的chirp信号经一个或多个目标反射后形成，M2＜N1，M1和M2互质；处理单元1402在根据接收器1401接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第三回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器1401还用于：接收测量帧经一个或多个目标反射后形成的第四回波信号和第五回波信号，测量帧还包括第二突发，第四回波信号由Nt个发射天线中的第二发射天线在第二突发中以M3*T2为周期发送的chirp信号经一个或多个目标反射后形成，第五回波信号由Nt个发射天线中的每个发射天线在第二突发中以N2*T2为周期发送的chirp信号经一个或多个目标反射后形成，M3＜N2，T2为第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质且T1和T2相等；处理单元1402在根据接收器1401接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第四回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器1401还用于：接收测量帧经一个或多个目标反射后形成的第六回波信号，测量帧还包括第三突发，第六回波信号由Nt个发射天线中的每个发射天线在第三突发中以N3*T3为周期发送的chirp信号经一个或多个目标反射后形成，T3为第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等；处理单元1402在根据接收器1401接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第六回波信号确定一个或多个目标的速度。
在一种可能的设计中，接收器1401还用于：接收测量帧经一个或多个目标反射后形 成的第七回波信号，第七回波信号由第一发射天线在第一突发中的N1*T1时间内连续发送的多个chirp信号经过一个或多个目标反射后形成；处理单元1402在根据接收器1401接收到的回波信号确定一个或多个目标的速度时，具体用于：根据第二回波信号和第七回波信号确定一个或多个目标的速度。
需要说明的是，图14所示的信号处理装置1400可用于执行图12所示的信号处理方法，信号处理装置1400中未详尽描述的实现方式可参见图12所示的信号处理方法中的相关描述。
基于同一发明构思，本申请实施例还提供一种雷达系统。参见图15，该雷达系统1500包括发射器1501、接收器1502和处理单元1503。
发射器1501包括Nt个发射天线，发射器1501用于发送测量帧，该测量帧用于测量目标的速度，该测量帧包括第一突发；其中，在第一突发中，Nt个发射天线中的每个发射天线用于以N1*T1为周期发送chirp信号，其中N1>Nt，T1为第一突发中每个chirp信号的持续时间。
接收器1502用于接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，第一回波信号由每个发射天线在第一突发中以N1*T1为周期发送的chirp信号经一个或多个目标反射后形成，第二回波信号由第一发射天线发送的其他chirp信号经一个或多个目标反射后形成。
处理单元1503用于根据接收器1502接收到的回波信号确定一个或多个目标的速度。
具体地，发射器1501还可用于执行图3所示方法中发射器执行的其他操作；接收器1502还可用于执行图15所示方法中接收器所执行的其他操作；处理单元1503还可用于执行图15所示方法中处理单元所执行的其他操作，此处不再赘述。
显然，本领域的技术人员可以对本申请实施例进行各种改动和变型而不脱离本申请实施例的范围。这样，倘若本申请实施例的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。

Claims (25)

  1. 一种信号传输方法，其特征在于，应用于多输入多输出MIMO雷达，所述MIMO雷达包括发射器，所述发射器包括Nt个发射天线，所述方法包括：
    所述发射器发送测量帧，所述测量帧用于测量目标的速度，所述测量帧包括第一突发；
    其中，在所述第一突发中，所述Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾chirp信号，其中N1>Nt，T1为所述第一突发中每个chirp信号的持续时间。
  2. 如权利要求1所述的方法，其特征在于，在所述第一突发中，所述Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号，其中M1＜N1。
  3. 如权利要求2所述的方法，其特征在于，在所述第一突发中，所述第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。
  4. 如权利要求1～3任一项所述的方法，其特征在于，所述测量帧还包括第二突发；
    在所述第二突发中，所述Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，所述Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为所述第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质，且T1和T2相等。
  5. 如权利要求1～3任一项所述的方法，其特征在于，所述测量帧还包括第三突发；
    在所述第三突发中，所述Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为所述第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。
  6. 如权利要求1～5任一项所述的方法，其特征在于，所述Nt个发射天线中存在至少一个发射天线在所述第一突发中连续发送两个chirp信号。
  7. 如权利要求1～6任一项所述的方法，其特征在于，所述测量帧为调频连续波FMCW。
  8. 如权利要求1～7任一项所述的方法，其特征在于，所述MIMO雷达还包括处理单元，所述方法还包括：
    所述处理单元确定所述测量帧的配置，并通过接口将所述测量帧的配置发送至单片微波集成电路MMIC，所述MMIC用于根据所述测量帧的配置使能所述发射器发送所述测量帧。
  9. 一种信号处理方法，其特征在于，应用于MIMO雷达，所述MIMO雷达包括发射器、接收器和处理单元，所述发射器包括Nt个发射天线，所述方法包括：
    所述接收器接收所述发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，所述测量帧包括第一突发，所述第一回波信号由所述Nt个发射天 线中的每个发射天线在所述第一突发中以N1*T1为周期发送的chirp信号经所述一个或多个目标反射后形成，所述第二回波信号由所述Nt个发射天线中的第一发射天线发送的其他chirp信号经所述一个或多个目标反射后形成，N1>Nt，T1为所述第一突发中每个chirp信号的持续时间；
    所述处理单元根据所述第一回波信号和所述第二回波信号确定所述一个或多个目标的速度。
  10. 如权利要求9所述的方法，其特征在于，所述第二回波信号由所述第一发射天线以M1*T1为周期发送的chirp信号经所述一个或多个目标反射后形成，M1＜N1。
  11. 如权利要求10所述的方法，其特征在于，所述处理单元根据所述第一回波信号和所述第二回波信号确定所述一个或多个目标的速度，包括：
    所述处理单元根据所述第一回波信号确定第一标识，所述第一标识用于指示所述一个或多个目标的距离测量值和速度测量值；
    所述处理单元根据所述第二回波信号确定第二标识，所述第二标识用于指示所述一个或多个目标的距离测量值和速度测量值；
    所述处理单元根据所述第一标识和所述第二标识确定所述一个或多个目标的速度。
  12. 如权利要求11所述的方法，其特征在于，所述处理单元根据所述第一标识和所述第二标识确定所述一个或多个目标的速度，包括：
    所述处理单元根据N1确定所述第一标识对应的第一混叠系数区间，并根据M1确定所述第二标识对应的第二混叠系数区间；
    所述处理单元根据所述第一标识和所述第二标识，确定所述第二混叠系数区间在所述第以混叠系数区间内对应的混叠系数子集；
    所述处理单元根据所述混叠系数子集确定速度混叠系数；
    所述处理单元根据所述速度混叠系数和所述第一标识确定所述一个或多个目标的速度。
  13. 一种信号传输装置，其特征在于，包括：
    发射器，用于发送测量帧，所述发射器包括Nt个发射天线，所述测量帧用于测量目标的速度，所述测量帧包括第一突发；
    其中，在所述第一突发中，所述Nt个发射天线中的每个发射天线用于以N1*T1为周期发送啁啾chirp信号，其中N1>Nt，T1为所述第一突发中每个chirp信号的持续时间。
  14. 如权利要求13所述的装置，其特征在于，在所述第一突发中，所述Nt个发射天线中的第一发射天线还用于以M1*T1为周期发送chirp信号，其中M1＜N1。
  15. 如权利要求14所述的装置，其特征在于，在所述第一突发中，所述第一发射天线还用于以M2*T1为周期发送chirp信号，M2＜N1，M1和M2互质。
  16. 如权利要求13～15任一项所述的装置，其特征在于，所述测量帧还包括第二突发；
    在所述第二突发中，所述Nt个发射天线中的每个发射天线用于以N2*T2为周期发送chirp信号，所述Nt个发射天线中的第二发射天线还用于以M3*T2发送chirp信号，M3＜N2，T2为所述第二突发中每个chirp信号的持续时间；M3*T2和M1*T1互质，或者M3和M1互质，且T1和T2相等。
  17. 如权利要求13～15任一项所述的装置，其特征在于，所述测量帧还包括第三突发；
    在所述第三突发中，所述Nt个发射天线中的每个发射天线用于以N3*T3为周期发送chirp信号，T3为所述第三突发中每个chirp信号的持续时间；N3*T3和M1*T1互质，或者N3和M1互质且T1和T3相等。
  18. 如权利要求13～17任一项所述的装置，其特征在于，所述Nt个发射天线中存在至少一个发射天线在所述第一突发中连续发送两个chirp信号。
  19. 如权利要求13～18任一项所述的装置，其特征在于，所述测量帧为调频连续波FMCW。
  20. 如权利要求13～19任一项所述的装置，其特征在于，所述装置还包括：
    处理单元，用于确定所述测量帧的配置，并通过接口将所述测量帧的配置发送至单片微波集成电路MMIC，所述MMIC用于根据所述测量帧的配置使能所述发射器发送所述测量帧。
  21. 一种信号处理装置，其特征在于，包括：
    接收器，用于接收发射器发送的测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，所述测量帧包括第一突发，所述第一回波信号由发射器包括的Nt个发射天线中的每个发射天线在所述第一突发中以N1*T1为周期发送的chirp信号经所述一个或多个目标反射后形成，所述第二回波信号由所述Nt个发射天线中的第一发射天线发送的其他chirp信号经所述一个或多个目标反射后形成，N1>Nt，T1为所述第一突发中每个chirp信号的持续时间；
    处理单元，用于根据所述第一回波信号和所述第二回波信号确定所述一个或多个目标的速度。
  22. 如权利要求21所述的装置，其特征在于，所述第二回波信号由所述第一发射天线以M1*T1为周期发送的chirp信号经所述一个或多个目标反射后形成，M1＜N1。
  23. 如权利要求22所述的装置，其特征在于，所述处理单元在根据所述第一回波信号和所述第二回波信号确定所述一个或多个目标的速度时，具体用于：
    根据所述第一回波信号确定第一标识，所述第一标识用于指示所述一个或多个目标的距离测量值和速度测量值；
    根据所述第二回波信号确定第二标识，所述第二标识用于指示所述一个或多个目标的 距离测量值和速度测量值；
    根据所述第一标识和所述第二标识确定所述一个或多个目标的速度。
  24. 如权利要求23所述的装置，其特征在于，所述处理单元在根据所述第一标识和所述第二标识确定所述一个或多个目标的速度时，具体用于：
    根据N1确定所述第一标识对应的第一混叠系数区间，并根据M1确定所述第二标识对应的第二混叠系数区间；
    根据所述第一标识和所述第二标识，确定所述第二混叠系数区间在所述第以混叠系数区间内对应的混叠系数子集；
    根据所述混叠系数子集确定速度混叠系数；
    根据所述速度混叠系数和所述第一标识确定所述一个或多个目标的速度。
  25. 一种雷达系统，其特征在于，包括：
    发射器，所述发射器包括Nt个发射天线，所述发射器用于发送测量帧，所述测量帧用于测量目标的速度，所述测量帧包括第一突发；其中，在所述第一突发中，所述Nt个发射天线中的每个发射天线用于以N1*T1为周期发送chirp信号，其中N1>Nt，T1为所述第一突发中每个chirp信号的持续时间；
    接收器，用于接收所述测量帧经一个或多个目标反射后形成的第一回波信号和第二回波信号，所述第一回波信号由所述每个发射天线在所述第一突发中以N1*T1为周期发送的chirp信号经所述一个或多个目标反射后形成，所述第二回波信号由所述第一发射天线发送的其他chirp信号经所述一个或多个目标反射后形成；
    处理单元，用于根据所述第一回波信号和所述第二回波信号确定所述一个或多个目标的速度。
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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230095228A1 (en) * 2021-09-24 2023-03-30 Nxp B.V. Radar communication with disparate pulse repetition frequency groups
EP4215941A1 (en) * 2022-01-19 2023-07-26 Samsung Electronics Co., Ltd. Device and method with radar signal processing

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11509436B2 (en) * 2020-11-30 2022-11-22 At&T Intellectual Property I, L.P. Facilitation of enhanced channel state information estimation for 5G or other next generation network

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104181517A (zh) * 2013-05-24 2014-12-03 罗伯特·博世有限公司 用于运行多输入多输出雷达的方法
JP2017112500A (ja) * 2015-12-16 2017-06-22 日本電信電話株式会社 Ｍｉｍｏ無線伝送システム、ｍｉｍｏ無線伝送方法、送信機および受信機
CN107132529A (zh) * 2016-02-29 2017-09-05 恩智浦有限公司 雷达系统
US20180172813A1 (en) * 2016-12-15 2018-06-21 Texas Instruments Incorporated Maximum Measurable Velocity in Frequency Modulated Continuous Wave (FMCW) Radar
CN109923433A (zh) * 2016-10-25 2019-06-21 索尼半导体解决方案公司 雷达装置、信号处理装置和信号处理方法
CN110058218A (zh) * 2019-04-25 2019-07-26 电子科技大学 一种基于四维天线阵的射频隐身发射波束形成方法及系统

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102970271B (zh) * 2012-12-10 2015-06-10 北京理工大学 一种联合估计载波频偏的频率同步方法
CN107923963B (zh) * 2015-05-29 2022-04-19 维里蒂工作室股份公司 用于调度定位信号传输和操作自定位装置的方法和系统
CN108141294B (zh) * 2015-07-12 2020-03-03 凝聚技术股份有限公司 与ofdm兼容的正交时间频率空间通信系统
JP2017173227A (ja) * 2016-03-25 2017-09-28 パナソニック株式会社 レーダ装置及びレーダ方法
US10591596B2 (en) * 2017-05-11 2020-03-17 GM Global Technology Operations LLC Doppler resolution improvement in low-duty cycle transmission
JP7057096B2 (ja) * 2017-10-16 2022-04-19 株式会社デンソーテン レーダ装置及びレーダ装置の送信処理方法
CN108387877B (zh) * 2018-05-25 2020-03-13 中国人民解放军国防科技大学 一种多输入多输出雷达的运动目标相位修正方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104181517A (zh) * 2013-05-24 2014-12-03 罗伯特·博世有限公司 用于运行多输入多输出雷达的方法
JP2017112500A (ja) * 2015-12-16 2017-06-22 日本電信電話株式会社 Ｍｉｍｏ無線伝送システム、ｍｉｍｏ無線伝送方法、送信機および受信機
CN107132529A (zh) * 2016-02-29 2017-09-05 恩智浦有限公司 雷达系统
CN109923433A (zh) * 2016-10-25 2019-06-21 索尼半导体解决方案公司 雷达装置、信号处理装置和信号处理方法
US20180172813A1 (en) * 2016-12-15 2018-06-21 Texas Instruments Incorporated Maximum Measurable Velocity in Frequency Modulated Continuous Wave (FMCW) Radar
CN110058218A (zh) * 2019-04-25 2019-07-26 电子科技大学 一种基于四维天线阵的射频隐身发射波束形成方法及系统

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4016116A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20230095228A1 (en) * 2021-09-24 2023-03-30 Nxp B.V. Radar communication with disparate pulse repetition frequency groups
EP4215941A1 (en) * 2022-01-19 2023-07-26 Samsung Electronics Co., Ltd. Device and method with radar signal processing

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