CN111308435A - Frequency-variable multi-delay centralized MIMO radar signal processing method - Google Patents
Frequency-variable multi-delay centralized MIMO radar signal processing method Download PDFInfo
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- CN111308435A CN111308435A CN201911250734.4A CN201911250734A CN111308435A CN 111308435 A CN111308435 A CN 111308435A CN 201911250734 A CN201911250734 A CN 201911250734A CN 111308435 A CN111308435 A CN 111308435A
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Abstract
The invention relates to a centralized MIMO radar signal processing method with variable carrier frequency and multiple time delays, wherein an MIMO radar array is provided with LtA transmitting antenna and LrThe linear array is composed of receiving antennas, the signal of the 1 st transmitting antenna is used as a reference signal, and other transmitting signals have equal-interval time delay and frequency stepping. Mixing with reference signal at receiving end, down-converting by multiplying with corresponding frequency signal, and performing analog low-pass filtering to form Lt×LrA channel. Carrying out digital sampling and digital low-pass filtering on each channel signal, carrying out FFT processing, and extracting a target frequency fk,m,n. The invention creates frequency division multiplexing conditions by utilizing multipath time delay, saves detection time, and solves the problem of Doppler frequency ambiguity of a high-speed target through variable carrier frequency waveform design. The performance of the millimeter wave radar is improved by the centralized MIMO continuous wave radar.
Description
Technical Field
The invention belongs to the technical field of radars, and particularly relates to a frequency-variable multi-delay centralized MIMO radar signal processing method.
Background
The millimeter wave radar has many advantages such as all-weather working capability and good environmental adaptability, and is a mainstream technology for the commercial application of the automobile driving assistance. Particularly, in recent years, due to the development of the monolithic microwave integrated circuit technology, a solution is provided for realizing a high-integration millimeter wave radar transmitter/receiver on a chip, and the development of the vehicle-mounted millimeter wave radar technology is promoted. However, the current radar system with one or more receivers cannot meet the space detection requirement of automatic driving, and is only used as an auxiliary detection means outside a vision + laser sensor architecture.
The centralized MIMO continuous wave radar is a main technical means for improving the performance of the millimeter wave radar, and accords with the inevitable trend of the development of the radar technology. The cascade expansion of the radio frequency chip provides technical feasibility for the centralized MIMO continuous wave radar. The primary criteria to be met by the centralized MIMO continuous wave radar waveform design are as follows: ensuring the separation and reception of signals. Time division multiplexing and frequency division multiplexing are the most direct methods for solving the above problems. However, time division multiplexing increases the probe time, frequency division multiplexing wastes frequency resources or increases hardware cost, and no ideal scheme exists yet. Therefore, the invention provides a centralized MIMO radar signal processing method with variable carrier frequency and multiple time delays.
Disclosure of Invention
Aiming at the defects of the prior art, the invention relates to a centralized MIMO radar signal processing method with variable carrier frequency and multiple time delays.
The technical scheme adopted by the invention for realizing the purpose is as follows:
a centralized MIMO radar signal processing method with variable carrier frequency and multiple time delays comprises the following steps:
1) MIMO radar array having LtA transmitting antenna and LrA linear array of receiving antennas, wherein the transmitting signal of the 1 st transmitting antenna is used as a transmitting reference signal;
2) the transmitting signal is reflected by a target in the space to obtain a receiving signal of a receiving antenna;
3) mixing a receiving signal of a receiving antenna with a transmitting reference signal to obtain a beat signal after mixing;
4) processing the beat signals after frequency mixing, and realizing channel separation through low-pass filtering;
5) discrete sampling is carried out on the channels, FFT processing is carried out after digital low-pass filtering, and the frequency spectrum of each channel is extracted to obtain the frequency corresponding to the channel.
The transmission reference signal is:
where p (t) is a phase-encoded signal that varies with time t, f0For the carrier frequency of the signal, mu is the linear modulation frequency, and the modulation period is TsThe modulation bandwidth is B, mu is B/TsT represents time;
the transmission signal of the mth transmission antenna is:
wherein f ispFor stepped frequency of adjacent transmitting antennas, fp>μτmax,TrthSatisfying tau for transmission time delay of adjacent transmitting antennamax<Trth<T/LtOn request, τmaxSignal propagation time requirement expressed as the farthest sounding distance, T represents the MIMO signal period.
The transmitted signal is reflected by K targets in the space, and the received signal of the nth antenna is:
wherein,G(t,m,τm,k,n)=Akp(t-(m-1)Trth-τm,k,n) Expressed as the envelope of the received signal, with the parameters t, m, τm,k,nFunction of variation, t is time, μ is linear modulation frequency, fpFor stepped frequency of adjacent transmitting antennas, f0Is the carrier frequency of the signal, AkDenotes the reflection coefficient, τ, of k targetsm,k,nRepresenting the time, t, at which the signal is reflected by the mth transmitting antenna to the nth receiving antenna via the kth targetm,k,n=t-(m-1)Trth-τm,k,n,fD,k,mDoppler frequency, f, induced for the m-th transmitting antenna through the k-th targetD,k,m=2(f0+(m-1)fp)vk/c,vkIs the speed of the kth target relative to the radar, and c is the speed of light.
Receiving signal and transmitting reference signal S of nth receiving antenna1(t) complex mixing, the beat signal after mixing being:
the mixed signal is a combination of a plurality of single-frequency signals, and the frequency of the signal mixed by the kth target for the mth antenna is (m-1) fp-μ(m-1)Trth-μτm,k,nWherein (m-1) fpFrequency deviation caused by variable carrier frequency, -mu (m-1) TrthFor frequency deviation due to time delay, fB,k,m,nFor frequency deviation due to the object, fB,k,m,n=-μτm,k,n,GB(t,m,τm,k,n) Representing the envelope of the mixed signal, t being time, τm,k,nRepresenting the time of reflection of the signal from the mth transmitting antenna to the nth receiving antenna via the kth target, fpFor stepped frequency, T, of adjacent transmitting antennasrthFor transmission delays of adjacent transmitting antennas, fD,k,mFor the doppler frequency induced by the mth transmit antenna through the kth target,representing the induced phase change, expressed as:
the mth channel signal of the nth receiving antenna is:
wherein K is the number of targets, GB(t,m,τm,k,n) Representing the envelope of the mixed signal, (m-1) fpFrequency deviation due to frequency-varying carrier frequency, fB,k,m,nWhich is the frequency offset due to the target, t is the time,indicating the induced phase change.
The frequency corresponding to the kth target of the mth channel of the nth receiving antenna is as follows:
fk,m,n=fB,k,m,n+fD,k,m
wherein f can be extracted by multi-period signal FFT processingD,k,mAnd then according to fk,m,nCalculating fB,k,m,n。fB,k,m,nAnd fD,k,mDistance and speed information of the corresponding object, and fD,k,mCan be used for solving the Doppler frequency ambiguity problem of high-speed targets.
In the step 4), the processing process of the beat signal is to combine the beat signal with exp { j2 pi [ mu (m-1) Trtht]Multiplying, where μ is the linear modulation frequency, TrthT is the time for the transmission delay of the adjacent transmit antenna.
The invention has the following beneficial effects and advantages:
1. the invention uses multi-path time delay to create frequency division multiplexing condition, compared with time division multiplexing, the invention saves detection time;
2. the invention designs the waveform by variable carrier frequency fD,k,mThe method can be used for solving the Doppler frequency ambiguity problem of the high-speed target;
3. the invention carries out discrete sampling on each channel, and the sampling frequency is fs,fs=fpThe signal is reduced in frequency to baseband and no mixer is required.
Drawings
FIG. 1 is a diagram of a structure of a frequency-variable multi-path time-delay centralized MIMO radar according to the present invention;
FIG. 2 is a waveform diagram of a frequency-varying multi-path time-delay centralized MIMO radar according to the present invention;
FIG. 3a is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 1 st channel;
FIG. 3b is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 2 nd channel;
FIG. 3c is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 3 rd channel;
FIG. 3d is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 4 th channel;
FIG. 3e is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 5 th channel;
FIG. 3f is a diagram of the separation result of the 1 st receiving antenna channel of the present invention, i.e., the 6 th channel.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings and examples.
As shown in fig. 1, the present invention relates to a frequency-variable multipath time-delay centralized MIMO radar.
As shown in fig. 2, the parameters of a centralized MIMO radar waveform with variable carrier frequency and multiple delays are shown in the table.
A method for separating the waveform and the channel of a centralized MIMO radar with variable carrier frequency and multipath time delay comprises the following steps:
1) the MIMO radar array has a linear array of 6 transmit antennas and 8 receive antennas. The signal of the 1 st transmitting antenna is taken as a reference signal, and the signal form is expressed as
Where p (t) is the signal envelope, f0Is the carrier frequency of the signal, mu isAnd linearly adjusting the frequency.
The signal form of the m-th transmitting antenna is expressed as
Wherein f ispFor stepped frequency of adjacent transmitting antennas, fp>μτmax,TrthSatisfying tau for transmission time delay of adjacent transmitting antennamax<Trth<T/LtOn request, τmaxSignal propagation time requirement expressed as the farthest sounding distance, T represents the MIMO signal period.
2) The transmitted signal is reflected by K targets in the space, and the received signal of the nth antenna is
Wherein, G (t, m, τ)m,k,n)=Akp(t-(m-1)Trth-τm,k,n),AkDenotes the reflection coefficient, τ, of k targetsm,k,nRepresenting the time, t, at which the signal is reflected by the mth transmitting antenna to the nth receiving antenna via the kth targetm,k,n=t-(m-1)Trth-τm,k,n,fD,k,mDoppler frequency, f, induced for the m-th transmitting antenna through the k-th targetD,k,m=2(f0+(m-1)fp)vk/c,vkIs the speed of the kth target relative to the radar.
3) Receiving signal and transmitting reference signal S of nth receiving antenna1(t) complex mixing, the beat signal after mixing being in the form of
The mixed signal is a combination of a plurality of single-frequency signals, and the frequency of the signal mixed by the kth target for the mth antenna is (m-1) fp-μ(m-1)Trth-μτm,k,nWherein (m-1) fpCaused by varying carrier frequencyFrequency offset, -mu (m-1) TrthFor frequency deviation due to time delay, fB,k,m,nFor frequency deviation due to the object, fB,k,m,n=-μτm,k,n,GB(t,m,τm,k,n) Representing the envelope of the signal after the mixing,indicating the induced phase change.
4) The beat signals mixed by the nth receiving antenna are respectively mixed with exp { j2 pi [ mu (m-1) Trtht]Multiplying, low-pass filtering to separate channels, and obtaining the m channel signal of the n receiving antenna
5) Discrete sampling is carried out on each channel, and the sampling frequency is fs,fs=fpAfter digital low-pass filtering, FFT processing is carried out, the frequency spectrum of the channel is extracted, the frequency spectrum comprises k spectral lines corresponding to k targets, and the frequency corresponding to the kth target of the mth channel of the nth receiving antenna is
fk,m,n=fB,k,m,n+fD,k,m
The invention is further illustrated in the following specific examples, with the parameter values shown in the table.
TABLE 1 variable carrier frequency multipath time delay centralized MIMO radar waveform parameters
Parameter(s) | Numerical value |
Transmitting antenna Lt | 6 |
Receiving antenna Lr | 8 |
Signal carrier frequency f0 | 24GHz |
Modulation bandwidth B | 200MHz |
Modulation period Ts | 1ms |
Step frequency fp | 1.024MHz |
Sampling frequency fs | 1.024MHz |
Transmission delay T of adjacent antennarth | 0.1ms |
Assuming that there are 4 targets in the detection space, the range and velocity of the targets are shown in the following table.
TABLE 2 spatial object information
Fig. 3a to 3f show the separation result of the 1 st receiving antenna channel according to the present invention.
Claims (7)
1. A centralized MIMO radar signal processing method with variable carrier frequency and multiple time delays is characterized by comprising the following steps:
1) MIMO radar array having LtA transmitting antenna and LrA linear array of receiving antennas, wherein the transmitting signal of the 1 st transmitting antenna is used as a transmitting reference signal;
2) the transmitting signal is reflected by a target in the space to obtain a receiving signal of a receiving antenna;
3) mixing a receiving signal of a receiving antenna with a transmitting reference signal to obtain a beat signal after mixing;
4) processing the beat signals after frequency mixing, and realizing channel separation through low-pass filtering;
5) discrete sampling is carried out on the channels, FFT processing is carried out after digital low-pass filtering, and the frequency spectrum of each channel is extracted to obtain the frequency corresponding to the channel.
2. The method according to claim 1, wherein the transmitted reference signal is:
where p (t) is a phase-encoded signal that varies with time t, f0For the carrier frequency of the signal, mu is the linear modulation frequency, and the modulation period is TsThe modulation bandwidth is B, mu is B/TsT represents time;
the transmission signal of the mth transmission antenna is:
wherein f ispFor stepped frequency of adjacent transmitting antennas, fp>μτmax,TrthSatisfying tau for transmission time delay of adjacent transmitting antennamax<Trth<T/LtOn request, τmaxSignal propagation time requirement expressed as the farthest sounding distance, T represents the MIMO signal period.
3. The method as claimed in claim 1, wherein the transmit signal is reflected by K targets in space, and the receive signal of the nth antenna is:
wherein, G (t, m, τ)m,k,n)=Akp(t-(m-1)Trth-τm,k,n) Expressed as the envelope of the received signal, with the parameters t, m, τm,k,nFunction of variation, t is time, μ is linear modulation frequency, fpFor stepped frequency of adjacent transmitting antennas, f0Is the carrier frequency of the signal, AkDenotes the reflection coefficient, τ, of k targetsm,k,nRepresenting the time, t, at which the signal is reflected by the mth transmitting antenna to the nth receiving antenna via the kth targetm,k,n=t-(m-1)Trth-τm,k,n,fD,k,mFor the doppler frequency induced by the mth transmit antenna through the kth target,
fD,k,m=2(f0+(m-1)fp)vk/c,vkis the speed of the kth target relative to the radar, and c is the speed of light.
4. The method as claimed in claim 1, wherein the received signal of the nth receiving antenna and the transmitted reference signal S are transmitted1(t) complex mixing, the beat signal after mixing being:
the mixed signal is a combination of a plurality of single-frequency signals, and the frequency of the signal mixed by the kth target for the mth antenna is (m-1) fp-μ(m-1)Trth-μτm,k,nWherein (m-1) fpFrequency deviation caused by variable carrier frequency, -mu (m-1) TrthFor frequency deviation due to time delay, fB,k,m,nFor frequency deviation due to the object, fB,k,m,n=-μτm,k,n,GB(t,m,τm,k,n) Representing the envelope of the mixed signal, t being time, τm,k,nRepresenting the time of reflection of the signal from the mth transmitting antenna to the nth receiving antenna via the kth target, fpFor stepped frequency, T, of adjacent transmitting antennasrthFor transmission delays of adjacent transmitting antennas, fD,k,mFor the doppler frequency induced by the mth transmit antenna through the kth target,representing the induced phase change, expressed as:
5. the method according to claim 1, wherein the mth channel signal of the nth receiving antenna is:
6. The method according to claim 1, wherein the frequency corresponding to the kth target of the mth channel of the nth receiving antenna is:
fk,m,n=fB,k,m,n+fD,k,m
wherein f can be extracted by multi-period signal FFT processingD,k,mAnd then according to fk,m,nCalculating fB,k,m,n。fB,k,m,nAnd fD,k,mDistance and speed information of the corresponding object, and fD,k,mCan be used for solving the Doppler frequency ambiguity problem of high-speed targets.
7. The method as claimed in claim 1, wherein in step 4), the beating signal is processed by mixing the beating signal with exp { j2 pi [ μ (m-1) T ] Trtht]Multiplying, where μ is the linear modulation frequency, TrthT is the time for the transmission delay of the adjacent transmit antenna.
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CN113189592A (en) * | 2021-03-08 | 2021-07-30 | 苏州乐达纳米科技有限公司 | Vehicle-mounted millimeter wave MIMO radar angle measurement method considering amplitude mutual coupling error |
WO2021258292A1 (en) * | 2020-06-23 | 2021-12-30 | 华为技术有限公司 | Signal processing method and device, radar device and storage medium |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102565789A (en) * | 2010-11-12 | 2012-07-11 | 株式会社电装 | Radar apparatus |
CN104155637A (en) * | 2014-08-30 | 2014-11-19 | 电子科技大学 | Radar and communication integrated method based on stepping variable-frequency waves |
EP3339894A1 (en) * | 2016-12-22 | 2018-06-27 | Airbus Defence and Space GmbH | A multiple input multiple output, mimo, radar system |
CN109031275A (en) * | 2018-07-02 | 2018-12-18 | 北京理工大学 | A kind of insect horizontal flight VELOCITY EXTRACTION method based on high-resolution polarization radar |
CN110058219A (en) * | 2018-12-30 | 2019-07-26 | 上海微波技术研究所(中国电子科技集团公司第五十研究所) | MIMO harmonic radar |
-
2019
- 2019-12-09 CN CN201911250734.4A patent/CN111308435B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102565789A (en) * | 2010-11-12 | 2012-07-11 | 株式会社电装 | Radar apparatus |
CN104155637A (en) * | 2014-08-30 | 2014-11-19 | 电子科技大学 | Radar and communication integrated method based on stepping variable-frequency waves |
EP3339894A1 (en) * | 2016-12-22 | 2018-06-27 | Airbus Defence and Space GmbH | A multiple input multiple output, mimo, radar system |
CN109031275A (en) * | 2018-07-02 | 2018-12-18 | 北京理工大学 | A kind of insect horizontal flight VELOCITY EXTRACTION method based on high-resolution polarization radar |
CN110058219A (en) * | 2018-12-30 | 2019-07-26 | 上海微波技术研究所(中国电子科技集团公司第五十研究所) | MIMO harmonic radar |
Non-Patent Citations (2)
Title |
---|
孙瑞庚: "基于综合化架构的相位编码频率步进信号处理技术研究" * |
朱江: "双极化FMCW导航雷达系统分析与设计" * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021258292A1 (en) * | 2020-06-23 | 2021-12-30 | 华为技术有限公司 | Signal processing method and device, radar device and storage medium |
CN113189592A (en) * | 2021-03-08 | 2021-07-30 | 苏州乐达纳米科技有限公司 | Vehicle-mounted millimeter wave MIMO radar angle measurement method considering amplitude mutual coupling error |
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