Successive signal interference mitigation

• US 9,806,914 B1
• Filed: 04/19/2017
• Issued: 10/31/2017
• Est. Priority Date: 04/25/2016
• Status: Active Grant

• Current Assignee: Uhnder, Inc.
• Original Assignee: Uhnder, Inc.
• Inventors: Bordes, Jean P., Eshraghi, Aria, Trager, David S., Ali, Murtaza, Rao, Raghunath K.
• Primary Examiner(s): Brainard, Timothy A
• Application Number:
  US15/491,193
• Publication Number:
  US 20170310507A1
• Time in Patent Office: 195 Days
• Field of Search: 342147
• CPC Class Codes: G01S 13/00 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
• CPC Class Codes: G01S 13/325 using transmission of coded signals, e.g. P.S.K. signals
• 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 7/023 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 Class Codes: G01S 7/0233 Avoidance by phase multiplex
• CPC Class Codes: G01S 7/0234 Avoidance by code multiplex
• CPC Class Codes: H04B 7/145 Passive relay systems
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04J 11/004 using regenerative subtractive interference cancellation
• CPC Class Codes: H04L 25/0204 of multiple channels
• CPC Class Codes: H04L 25/03006 Arrangements for removing intersymbol interference
• CPC Class Codes: H04L 49/3063 Pipelined operation

Abstract

A radar sensing system for a vehicle includes a transmitter, a receiver, and an interference mitigation processor. The transmitter transmits radio signals. The receiver receives radio signals. The received radio signals include reflected radio signals that are each transmitted radio signals reflected from objects in the environment. The receiver also down-converts and digitizes the received radio signals to produce a baseband sampled stream. The interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object. The interference mitigation processor uses the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream. The receiver uses the modified baseband sampled stream to detect a second object more distant than the first object.

Claims

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

at least one transmitter configured for installation and use on a vehicle, and configured to transmit radio signals;

at least one receiver configured for installation and use on the vehicle, and further configured to receive radio signals, wherein the received radio signals include transmitted radio signals that are reflected from objects in the environment;

an interference mitigation processor;

wherein the at least one receiver is further configured to down-convert and digitize the received radio signal to produce a baseband sampled stream;

wherein the baseband sampled stream is provided to the interference mitigation processor;

wherein the interference mitigation processor, via processing of the baseband sampled stream, determines estimates for reflected radio signals associated with selected objects at one or more ranges, determines estimates for parameters related to corresponding ones of the reflected radio signals, and generates attenuated baseband complex samples corresponding to those selected objects to form an attenuated baseband sampled stream; and

wherein the interference mitigation processor is further configured to modify the baseband sampled stream based on the attenuated baseband sampled stream corresponding to the selected objects to remove the effect of the selected objects from the modified baseband sampled stream, and wherein the receiver is configured to use the modified baseband sampled stream to detect at least one more additional object.

2. The radar sensing system of claim 1, wherein the estimate of the parameters includes filters that produce running weighted averages of a plurality of past samples of the generated attenuated baseband complex samples corresponding to a selected set of chips of the different transmitters for a given range or delay.

3. The radar sensing system of claim 1, wherein estimates of the parameters are updated using an error signal generated from previous estimates of the parameters and the baseband sampled stream.

4. The radar sensing system of claim 1, wherein the estimate of the parameters includes filters that produce exponentially weighted filtering of a plurality of past samples of the baseband samples corresponding to a selected set of chips of the different transmitters for a given range or delay.

5. The radar sensing system of claim 1, wherein the interference mitigation processor is further configured to modify the baseband sampled stream based on attenuated baseband complex samples corresponding to one or more additional objects.

6. The radar sensing system of claim 1, wherein the interference mitigation processor only modifies the baseband sampled stream for objects at ranges that are greater than a first threshold range value.

7. The radar sensing system of claim 6, wherein the interference mitigation processor is bypassed for radio signals reflected from objects that are at ranges below a second threshold range value.

8. A radar sensing system for a vehicle, the radar sensing system comprising:

a transmit pipeline comprising a transmitter configured for installation and use on a vehicle and configured to transmit radio signals;

a receive pipeline comprising a receiver configured for installation and use on the vehicle, and further configured to receive radio signals, wherein the received radio signals include reflected radio signals that are transmitted radio signals reflected from objects in the environment;

an interference mitigation processor;

wherein the receiver is further configured to down-convert and digitize the received radio signals to produce a baseband sampled stream;

wherein, responsive to processing by the interference mitigation processor of the baseband sampled stream, the interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object in the environment;

wherein the interference mitigation processor is further configured to use the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream where the effect of the first object has been removed; and

wherein the receiver is further configured to use the modified baseband sampled stream to detect a second object that is more distant than the first object.

9. The radar sensing system of claim 8, wherein the transmit pipeline further comprises a plurality of transmitters, and wherein the receive pipeline further comprises a plurality of receivers, and wherein the radar sensing system further comprises a plurality of interference mitigation processors, an interference mitigation processor for each transmitter/receiver pair.

10. The radar sensing system of claim 8, wherein the transmit pipeline further comprises a plurality of transmitters, wherein the receive pipeline further comprises a plurality of receivers, and wherein the interference mitigation processor is further configured to successively remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object that were transmitted by each respective transmitter.

11. The radar sensing system of claim 10, wherein the interference mitigation processor is further configured to determine estimates for reflected radio signals associated with at least the first object, to determine estimates for parameters of the corresponding reflected radio signals, and to generate attenuated baseband complex samples corresponding to at least the first object, such that the interference mitigation processor modifies the baseband sampled stream based on the attenuated baseband samples corresponding to the first object.

12. The radar sensing system of claim 11, wherein the estimate of the parameters includes filters that produce running weighted averages of a plurality of past samples of the baseband samples corresponding to a selected set of chips of the different transmitters for a range or delay associated with the first object.

13. The radar sensing system of claim 11, wherein the estimates of the parameters are updated using an error signal generated from previous estimates of the parameters and an actual baseband sample.

14. The radar sensing system of claim 11, wherein the estimate of the parameters includes filters that produce exponentially weighted filtering of a plurality of past samples of the baseband samples corresponding to a selected set of chips of the different transmitters for a range or delay associated with the first object.

15. The radar sensing system of claim 8, wherein the interference mitigation processor is further configured to only modify the baseband sampled stream for objects at ranges that are more distant than a first threshold value.

16. The radar sensing system of claim 15, wherein the receiver is further configured to bypass the interference mitigation processor and directly process the baseband sampled stream and detect the second object when the second object is at a distance less than a second threshold value.

17. A method for removing interference from a radio signal received by a vehicle radar sensing system, said method comprising:

providing a radar sensing system comprising a transmitter configured for installation and use on a vehicle and configured to transmit radio signals, and a receiver configured for installation and use on the vehicle and configured to receive radio signals, wherein the received radio signals include reflected radio signals that are the transmitted radio signals reflected from objects in the environment;

down-converting and digitizing the received radio signals to produce a baseband sampled stream;

determining estimates for reflected radio signals associated with one or more selected objects at one or more ranges, and determining estimates for parameters of the corresponding reflected radio signals, and generating attenuated baseband complex samples corresponding to those one or more selected objects;

modifying the baseband sampled stream based on the attenuated baseband samples corresponding to the one or more selected objects to remove the effect of those one or more selected objects from the modified baseband sampled stream; and

detecting, with the modified baseband sampled stream, at least one more additional object.

18. The method of claim 17, wherein determining estimates of the parameters includes producing running weighted averages of a plurality of past samples of the baseband samples corresponding to a selected set of chips of the different transmitters for a given range or delay.

19. The method of claim 17, wherein the estimates of the parameters are updated using an error signal generated from previous estimates of the parameters and an actual baseband sample.

20. The method of claim 17, wherein determining estimates of the parameters includes producing exponentially weighted filtering of a plurality of past samples of the baseband samples corresponding to a selected set of chips of the different transmitters for a given range or delay.