Software defined automotive radar systems

Patent metadata

Field	Value
Publication number	US-9846228-B2
Application number	US-201715496313-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 7, 2016
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

A radar system processes signals in a flexible, adaptive manner to determine range, Doppler (velocity) and angle of objects in an environment. The radar system processes the received signal to achieve different objectives depending on the environment, the current information stored in the radar system, and/or external information provided to the radar system. The system allows improved resolution of range, Doppler and/or angle depending on the desired objective.

First claim

The invention claimed is:

1. A radar sensing system for a vehicle, the radar sensing system comprising:
a plurality of transmitters configured for installation and use on a vehicle, wherein the transmitters are configured to transmit modulated radio signals;
a plurality of receivers configured for installation and use on the vehicle, wherein the receivers are configured to receive radio signals, and wherein the received radio signals are transmitted radio signals reflected from an object in the environment;
wherein each transmitter of the plurality of transmitters comprises a digital processing unit, a digital-to-analog converter, an analog processing unit, and a transmit antenna;
wherein each receiver of the plurality of receivers comprises a receive antenna, an analog processing unit, an analog-to-digital converter, a digital front end processing unit, and a digital back end processing system;
a memory;
a control unit configured to select an operating mode for the radar sensing system and to modify the plurality of transmitters and the plurality of receivers based on a current environment condition and operation status, and based on one of a best range resolution and a best velocity resolution;
wherein range information data produced by the digital front end processing unit of at least one receiver of the plurality of receivers is stored in the memory and then processed by the corresponding digital back end processor of the at least one receiver of the plurality of receivers, as directed by the control unit; and
wherein the range information data includes range information of objects in the environment, and wherein the range information data is stored in the memory for different receivers and for different scans, and wherein the processing of the range information data is controlled by the control unit.

2. The radar sensing system of claim 1 , wherein the control unit is configured to modify at least one of an operation and a mode of at least one of (i) a digital processing unit of at least one transmitter of the plurality of transmitters, (ii) a digital-to-analog converter of at least one transmitter of the plurality of transmitters, (iii) an analog processing unit of at least one transmitter of the plurality of transmitters, and (iv) a transmit antenna of at least one transmitter of the plurality of transmitters, and wherein the control unit is configured to modify at least one of an operation and a mode of at least one of (i) a receive antenna of at least one receiver of the plurality of receivers, (ii) an analog processing unit of at least one receiver of the plurality of receivers, (iii) an analog-to-digital converter of at least one receiver of the plurality of receivers, (iv) a digital front end processing unit of at least one receiver of the plurality of receivers, and (v) a digital back end processing system of at least one receiver of the plurality of receivers.

3. The radar sensing system of claim 1 , wherein the data stored in the memory, before Doppler processing by the digital back end processor, is compressed, as controlled by the control unit.

4. The radar sensing system of claim 3 , wherein the compression used is MPEG4-audio lossless coding.

5. The radar sensing system of claim 3 , wherein before the Doppler processing, a window function, controlled by the control unit, is applied to a sequence of samples for a given range and receiver, and wherein the plurality of receivers includes virtual receivers.

6. The radar sensing system of claim 1 , wherein after the range information data is stored in the memory, a sequence of samples, as selected by the control unit, is padded with zero valued samples prior to Doppler processing as configured by the control unit.

7. The radar sensing system of claim 1 , wherein the control unit is operable to configure at least one receiver of the plurality of receivers to process the range information data stored in the memory, and wherein the at least one receiver is configured to:
identify a set of objects with a highest received signal strength;
estimate a Doppler velocity for the objects using one of a median, weighted arithmetic mean, and weighted geometric mean of corresponding samples for different range bins associated with the object;
calculate one of a first phase shift, from one complex correlator input sample to a next complex correlator input sample, that corresponds to the estimated Doppler velocity, and a second phase shift, from one complex correlator output sample to a next complex correlator output sample, that corresponds to the estimated Doppler velocity; and
derotate an Nth complex sample pre or post correlator by a multiple of one of the first phase shift and the second phase shift, depending on which phase shift was estimated.

8. The radar sensing system of claim 1 , wherein the control unit is operable to configure at least one receiver of the plurality of receivers to process the range information data stored in the memory, and wherein the at least one receiver is configured to:
select an object for which better Doppler estimation is desired;
store multiple time scans corresponding to a range of a desired object; and
perform Doppler processing on extended information from multiple scans to obtain more precise Doppler information.

9. The radar sensing system of claim 1 , wherein the control unit is operable to configure at least one transmitter of the plurality of transmitters, and at least one receiver of the plurality of receivers to process the range information data stored in the memory;
wherein the at least one transmitter is configured to transmit with a first periodic code with a given period N;
wherein the at least one receiver is configured to store first N time correlator output samples;
wherein the at least one transmitter is configured to transmit with a second periodic code with a same period as the first periodic code;
wherein the at least one receiver is configured to store the second N time samples;
wherein the at least one receiver is configured to perform Doppler processing on each of K sets of N time samples to compute K frequency spectrums;
wherein the at least one receiver is configured to compare a frequency spectrum and identify frequencies where a Doppler magnitude is large in one spectrum but varies across the K frequency spectrums;
wherein the at least one receiver is configured to identify frequencies where the Doppler magnitude is large and remains substantially constant across the K frequency spectrums;
wherein the at least one receiver is configured to modify all captured time samples to remove Doppler processed samples corresponding to frequencies that correspond to inconsistent signals; and
wherein the at least one receiver is configured to perform a single FFT over all K*N modified samples.

10. The radar sensing system of claim 1 , wherein the control unit is operable to configure at least one receiver of the plurality of receivers to process the range information data stored in the memory;
wherein the at least one receiver is configured to perform spatial windowing and beamforming on one or more input complex sample vectors from Doppler information stored in a radar data cube 2 (RDC2) for a given range and Doppler for various receivers and/or virtual receivers to produce output complex sample vectors stored in a radar data cube 3 (RDC3) for the corresponding range and Doppler and angle;
wherein the at least one receiver is configured to identify a region of samples in the RDC3 corresponding to a band of low absolute velocity that includes known ground clutter;
wherein the at least one receiver is configured to store samples of the RDC3 in the identified band in a separate memory buffer c

Assignees

• Uhnder Inc

Inventors

• Davis Curtis
• Maher Monier
• Bordes Jean P
• Hegde Manju
• Schmid Otto A
• Rao Raghunath K
• Goldenberg Marius
• Eshraghi Aria
• Giannini Vito
• Trager David S
• Bhagat Nikhilesh
• Gollapudi Srikanth
• Govindarajan Sundar
• Borho Steve
• Preussner Jonathan
• Dent Paul W
• Bassett Paul
• Alland Stephen W
• Harris Fred
• Stark Wayne E
• Ali Murtaza

Classifications

• G01S13/87

  Combinations of radar systems, e.g. primary radar and secondary radar · CPC title

• G01S2013/93271

  in the front of the vehicles · CPC title

• G01S13/878

  Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector (G01S13/874 takes precedence) · CPC title

• G01S2013/9316

  combined with communication equipment with other vehicles or with base stations · CPC title

• H04L27/2278

  using correlation techniques, e.g. for spread spectrum signals · CPC title