PMCW-PMCW interference mitigation

Patent metadata

Field	Value
Publication number	US-11175377-B2
Application number	US-201916443205-A
Country	US
Kind code	B2
Filing date	Jun 17, 2019
Priority date	Apr 25, 2016
Publication date	Nov 16, 2021
Grant date	Nov 16, 2021

Abstract

A radar system includes a transmitter, a receiver, and a processor. The transmitter is configured to transmit a radio signal. The receiver is configured to receive a radio signal which includes the transmitted radio signal reflected from an object in the environment. The processor is configured to control the transmitter and the receiver to at least one of mitigate interference in the received radio signals, and avoid interfering radio signals transmitted by another radio transmitter.

First claim

The invention claimed is:

1. A radar sensing system comprising:
one or more transmitters configured for installation and use with the radar sensing system, and configured to transmit phase modulated radio signals;
one or more receivers configured for installation and use with the radar sensing system, and configured to receive radio signals that include transmitted radio signals transmitted by the one or more transmitters and reflected from objects in the environment; and
a processor configured to control an operation of the one or more transmitters and the one or more receivers to mitigate interference present in the received radio signals and to avoid interfering radio signals transmitted by another radio transmitter;
wherein the processor is operable to control the one or more transmitters and the one or more receivers to both actively and passively avoid and mitigate the interfering radio signals, and wherein the one or more transmitters are passively modified to avoid interference when no interference is detected.

2. The radar sensing system of claim 1 , wherein the mitigating interference comprises at least one of:
controlling the operation of at least one of the one or more transmitters and the one or more receivers to mitigate interference in the received radio signals when interference has been detected in the received radio signals; and
controlling the operation of at least one of the one or more transmitters and the one or more receivers to mitigate interference in the received radio signals whether or not interference has been detected in the received radio signals.

3. The radar sensing system of claim 2 , wherein the one or more receivers are configured to monitor a noise floor of the received radio signals, and wherein the processor is configured to determine that interference is present in the received radio signals when the noise floor rises above a threshold.

4. The radar sensing system of claim 2 , wherein the processor is configured to selectively stop the one or more transmitters from transmitting, wherein the one or more receivers are configured to correlate the received radio signals during a period of time when the one or more transmitters have stopped transmitting, and wherein the processor is configured to determine that interference is present in the received radio signals when correlation output values comprise consistent correlation peak values during the period of time when the one or more transmitters have stopped transmitting.

5. The radar sensing system of claim 2 , wherein the processor is configured to control the one or more receivers to correlate received radio signals with modulation codes not used by any of the one or more transmitters, and wherein the processor is configured to determine that interference is present in the received radio signals when the resultant correlation values are above a threshold.

6. The radar sensing system of claim 2 , wherein the processor is configured to control the one or more transmitters to select carrier frequencies from among a plurality of frequencies, wherein the one or more receivers are configured to correlate the received radio signals, and wherein the processor is configured to determine that interference is present in the received radio signals at particular carrier frequencies when corresponding correlation output values are above a threshold.

7. The radar sensing system of claim 1 , wherein the processor is configured to control the operation of at least one of the one or more transmitters and the one or more receivers to avoid interfering radio signals transmitted by another radio transmitter, such that at least one of the one or more transmitters and the one or more receivers operate in selected operational periods to avoid operational periods of an interfering radio transmitter.

8. The radar sensing system of claim 1 , wherein the processor is configured to control the operation of the one or more transmitters to avoid interfering radio signals transmitted by another radio transmitter, such that the one or more transmitters periodically change a carrier signal according to a selected pattern, wherein the selected pattern is one of a periodic pattern and an aperiodic pattern, and wherein the processor is configured to control the operation of the one or more transmitters such that the one or more transmitters select carrier frequencies with minimal radio signal interference compared to the radio signal interference present in other carrier frequencies.

9. The radar sensing system of claim 1 , wherein the processor is configured to control the operation of the one or more transmitters and the one or more receivers to avoid interfering radio signals transmitted by another radio transmitter, such that the one or more transmitters are synchronized with the interfering radio transmitter, and wherein the one or more transmitters and the interfering radio transmitter each modulate with orthogonal sets of Hadamard codes such that the one or more transmitters use a subset of available codes that is different from any of the codes used by the interfering radio transmitter.

10. The radar sensing system of claim 1 , wherein the processor is configured to identify that a particular object detected by the one or more receivers is a ghost target caused by an interfering radio signal transmitted by another radio transmitter, and wherein the processor is configured to ignore any identified ghost targets such that any related interference in the received radio signals is ignored.

11. A method for operating a radar sensing system comprising a transmitter and a receiver, the method comprising:
transmitting, with the transmitter, a phase modulated radio signal;
receiving, with the receiver, a radio signal, wherein the received radio signal includes the transmitted radio signal transmitted by the transmitter and reflected from objects in the environment; and
controlling the transmitter and the receiver to mitigate interference present in the received radio signals and to avoid interfering radio signals transmitted by another radio transmitter, wherein controlling the transmitter and the receiver actively and passively avoids and mitigates the interfering radio signals, and wherein the one or more transmitters are passively modified to avoid interference when no interference is detected.

12. The method of claim 11 , wherein mitigating interference present in the received radio signals comprises at least one of:
controlling the operation of at least one of the transmitter and the receiver to mitigate interference in the received radio signals when interference has been detected in the received radio signals; and
controlling the operation of at least one of the transmitter and the receiver to mitigate interference in the received radio signals whether or not interference has been detected in the received radio signals.

13. The method of claim 12 further comprising monitoring, with the receiver, a noise floor of the received radio signals, and determining there is interference in the received radio signals when the noise floor rises above a threshold.

14. The method of claim 12 further comprising:
selectively stopping the transmitter from transmitting;
correlating, with the receiver, the received radio signals during a period of time when the transmitter has stopped transmitting; and
determining there is interference in the received radio signals when correlation output values comprise consistent correlation peak values during the period of time when the transmitter has stopped transmitting.

15. The method of claim 12 further comprising correlating, with

Assignees

• Uhnder Inc

Inventors

• Bordes Jean P
• Davis Curtis
• Stark Wayne E
• Schmid Otto A
• Rao Raghunath K

Classifications

• G01S7/0233

  Avoidance by phase multiplex · CPC title

• G01S7/023 Primary

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title

• G01S7/0232

  Avoidance by frequency multiplex · CPC title

• G01S13/325

  using transmission of coded signals, e.g. P.S.K. signals · CPC title

• G01S2013/93271

  in the front of the vehicles · CPC title