Vehicular radar system with self-interference cancellation

• US 10,551,482 B2
• Filed: 05/31/2018
• Issued: 02/04/2020
• Est. Priority Date: 04/25/2016
• Status: Active Grant

• Current Assignee: Uhnder, Inc.
• Original Assignee: Uhnder, Inc.
• Inventors: Eshraghi, Aria, Bordes, Jean P., Davis, Curtis, Rao, Raghunath K., Ali, Murtaza, Dent, Paul W.
• Primary Examiner(s): Bythrow, Peter M
• Application Number:
  US15/994,465
• Publication Number:
  US 20180329027A1
• Time in Patent Office: 614 Days
• CPC Class Codes: G01S 13/347 using more than one modulation frequency
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 7/0232 Avoidance by frequency multiplex
• CPC Class Codes: G01S 7/0234 Avoidance by code multiplex
• CPC Class Codes: G01S 7/038 Feedthrough nulling circuits
• CPC Class Codes: G01S 7/2813 Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00
• CPC Class Codes: G01S 7/292 Extracting wanted echo-signals
• CPC Class Codes: G01S 7/354 Extracting wanted echo-signals Doppler systems G01S13/50
• CPC Class Codes: G01S 7/358 using I/Q processing
• CPC Class Codes: G01S 7/4021 of receivers

Abstract

A radar system is described that comprises a transmitter and a receiver. The transmitter transmits radio signals. The receiver receives interfering signals due to local signal coupling of transmitted signals. The local signal coupling comprises at least one interfering path or mechanism. The receiver is configured to output a replica of each of the interfering signals. Each replica is configured to replicate a particular interfering signal received. The receiver is configured to combine into a signal path a replica of an interfering signal to subtract the interfering signal from the signal path. The receiver receives the transmitted radio signals transmitted by the transmitter and reflected from objects in an environment without saturating the signal path due to the subtraction of the interfering signal from the signal path.

Claims

1. A radar system for a vehicle, the radar system comprising:

a transmitter configured for installation and use on a vehicle, wherein the transmitter is configured to transmit radio signals;

a receiver configured for installation and use on the vehicle, wherein the receiver is configured to receive at least one interfering signal, each interfering signal due to local signal coupling of transmitted signals transmitted by the transmitter;

wherein the receiver is configured to generate a replica of each of the at least one interfering signal, wherein each replica is configured to replicate a particular interfering signal due to a particular local signal coupling of the transmitted signals;

wherein the receiver is configured to combine into a signal path each replica of the at least one interfering signal from which interference is to be suppressed to subtract the at least one interfering signal from the signal path; and

wherein the receiver is configured to receive the transmitted radio signals transmitted by the transmitter and reflected from objects in an environment without saturating the signal path due to the subtraction of the at least one interfering signal from the signal path.

2. The radar system of claim 1, wherein the local signal coupling comprises at least one interfering path or mechanism.

3. The radar system of claim 1, wherein the receiver comprises a spillover cancellation unit configured to generate the replica of each of the at least one interfering signal.

4. The radar system of claim 1, wherein the receiver comprises a combiner configured to combine into the signal path the replica of each of the at least one interfering signal.

5. The radar system of claim 1, wherein the transmitter is configured to transmit digitally modulated radio signals.

6. The radar system of claim 5, wherein the digitally modulated radio signal is frequency modulated with digital code sequences.

7. The radar system of claim 6, wherein the receiver comprises a digital modulator configured to output a delayed, amplitude weighted, and phase-changed replica of each of the at least one interfering signal, and wherein a particular delayed, amplitude weighted, and phase-changed signal replicates a particular interfering signal received through a particular interfering path or mechanism.

8. The radar system of claim 7, wherein the digital modulator is a replica of a digital modulator of the transmitter from which interference is to be suppressed.

9. The radar system of claim 7, wherein the digital modulator comprises a plurality of modulators, a modulator for each type of spillover interference.

10. The radar system of claim 1 further comprising a re-addition combiner configured to re-add into a later point of the signal path a signal constructed that at least in part adds back the interference which was subtracted earlier in the signal path.

11. The radar system of claim 1 further comprising one or more semiconductor chips attached to a printed circuit board comprising printed antennas and installed in the vehicle, the at least one interfering path comprising at least one of (i) an on-chip or chip-to-chip transmitter to receiver coupling path, (ii) a transmitter antenna to receiver antenna coupling path, and (iii) a reflective path that reflects a signal transmitted by a transmitter antenna from a nearby part of the receiver to the receiver antenna.

12. The radar system of claim 1, wherein the signal path is defined by a ball-grid array, wherein each signal ball of the ball-grid array is surrounded by ground balls, each interconnected with each other and with a ground connection.

13. The radar system of claim 1, wherein a replica of a first interfering signal is an equal and opposite replica of the first interfering signal.

14. The radar system of claim 1, wherein the receiver comprises an RF preamplifier, and wherein the receiver is configured to combine into the signal path the replica of each of the at least one interfering signal by injecting each replica of the at least one interfering signal into the RF preamplifier.

15. The radar system of claim 14, wherein the receiver is configured to inject the replica of each of the at least one interfering signal between stages of the RF preamplifier.

16. The radar system of claim 14, wherein each replica is defined as a current which is added to an output current of a first amplifier of the RF preamplifier.

17. A multiple-input, multiple-output (MIMO) radar system for use on a vehicle, the MIMO radar system comprising:

a plurality of transmitters configured for installation and use on a vehicle, and configured to transmit radio signals;

a plurality of receivers configured for installation and use on the vehicle, wherein a first receiver of the plurality of receivers is configured to receive interfering signals via local signal coupling of transmitted signals transmitted by the transmitters;

wherein the first receiver is configured to generate a replica of each of the interfering signals, wherein each replica is configured to replicate a particular interfering signal due to a particular local signal coupling of one of the transmitted signals transmitted by a particular transmitter of the plurality of transmitters;

wherein the first receiver is configured to combine into a signal path of the first receiver each replica of the interfering signals from which interference is to be suppressed to subtract the interfering signals from the signal path of the first receiver; and

wherein the first receiver is configured to receive transmitted radio signals transmitted by the transmitters and reflected from objects in an environment without saturating the signal path of the first receiver due to the subtraction of the interfering signals from the signal path of the first receiver.

18. The radar system of claim 17, wherein each transmitter of the plurality of transmitters is configured to transmit digitally modulated radio signals.

19. The radar system of claim 18, wherein the digitally modulated radio signal is frequency modulated with digital code sequences.

20. The radar system of claim 18, wherein the first receiver comprises a digital modulator configured to output a delayed, amplitude weighted, and phase-changed replica of each of the interfering signals, and wherein a particular delayed, amplitude weighted, and phase-changed signal replicates a particular interfering signal received through a particular interfering path or mechanism, and wherein the digital modulator comprises a plurality of modulators, a modulator for each type of spillover interference received from each transmitter of the plurality of transmitters.