Radar jamming mitigation using signal pattern matching

Abstract

This document describes techniques, apparatus, and systems for radar interference mitigation using signal pattern matching. Radar signals received by a radar system (e.g., chirp) can include interference from other nearby radar systems. Interference can reduce the sensitivity of a radar system. The techniques, apparatus, and systems described herein mitigate interference by selecting undamaged segments of radar signals adjacent to damaged segments, analyzing the radar signals to identify matching segments with signal characteristics similar to the adjacent segments, and replacing the damaged segments with segments adjacent to the matching segments. In this way, the noise floor of the radar system can be reduced, resulting in increased sensitivity.

Description

Background Technology

[0001] Radar systems can provide distance, speed, and azimuth information about objects in the environment surrounding vehicles equipped with perception systems, including autonomous or semi-autonomous driving systems. This object information is used to provide features such as adaptive cruise control, lane centering, lane change assist, and emergency braking. As radar-equipped vehicles become increasingly common, the presence of radar interference can impair radar performance. During signal processing, such interference can increase the noise floor, potentially leading to unreliable object detection and tracking. Summary of the Invention

[0002] This document describes techniques, apparatus, and systems for radar interference mitigation using signal pattern matching. Radar signals received by a radar system (e.g., chirp) can include interference from other nearby radar systems. Interference can reduce the sensitivity of a radar system. The techniques, apparatus, and systems described herein mitigate interference by selecting undamaged segments of radar signals adjacent to damaged segments, analyzing the radar signals to identify matching segments with signal characteristics similar to the adjacent segments, and replacing the damaged segments with segments adjacent to the matching segments. In this way, the noise floor of the radar system can be reduced, resulting in increased sensitivity.

[0003] In one example, a method includes determining, by a processor of a radar system, the presence of interference in a radar signal. Before generating radar data based on the radar signal, the method includes mitigating the interference by performing a series of operations. The operations include identifying damaged segments of the radar signal corresponding to the interference. The operations further include: determining adjacent segments of the radar signal adjacent to the damaged segments, and determining matching segments of the radar signal having similar signal characteristics to the adjacent segments. The operations further include: determining replacement segments of the radar signal adjacent to the matching segments, and adjusting the signal characteristics of the damaged segments of the radar signal based on the signal characteristics of the replacement segments to generate a mitigated radar signal free of interference. The method further includes generating radar data based on the mitigated radar signal. The method further includes: outputting the radar data for at least detecting or tracking objects in the environment of the radar system.

[0004] In another example, a system includes a processor configured to perform this method and other methods. In addition to describing systems configured to perform the methods outlined above and other methods set forth herein, this document also describes a computer-readable storage medium including instructions that, when executed, configure at least one processor to perform the methods outlined above and other methods set forth herein.

[0005] This invention provides a simplified concept related to radar interference mitigation using signal pattern matching, which is further described in the detailed description and accompanying drawings. This invention is not intended to identify essential features of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter. That is, one problem addressed by the technology is mitigating radar interference between vehicles that can lead to false detections or low sensitivity. Other interference mitigation techniques may overload processing resources or otherwise become too complex for driving applications. Therefore, although described primarily in the context of improving radar signal processing for motor vehicles, radar interference mitigation using signal pattern matching can also be applied to other real-time applications that desire robustness against interference and increased sensitivity of the radar system. Brief description of the attached figures

[0006] This document describes in detail one or more aspects of radar jamming mitigation using signal pattern matching, with reference to the following figures: Figure 1 An example environment is shown that demonstrates the technology according to this disclosure, in which radar jamming mitigation using signal pattern matching can be applied; Figure 2 An example of an automotive system configured to perform radar interference mitigation using signal pattern matching, based on the technology of this disclosure, is shown. Figure 3 An example diagram of interference according to the technology of this disclosure is shown, in which radar interference mitigation using signal pattern matching can be applied; Figure 4 An example is shown where a radar signal with interference, according to the technology of this disclosure, is mitigated by using radar interference mitigation with signal pattern matching; Figure 5 Examples of the spectra of a beat signal without mitigation, a beat signal mitigated using zero-forcing, and a beat signal mitigated using signal pattern matching according to the techniques of this disclosure are shown; and Figure 6 An example method for radar interference mitigation using signal pattern matching based on the techniques described herein is shown. Detailed Implementation Overview

[0007] Vehicles equipped with autonomous, semi-autonomous, or other driving systems address radar interference in various ways. Several interference mitigation techniques exist, including zero-forcing, pruning, temporal parameter interpolation, and iterative application of adaptive thresholding; however, these techniques have limited success. These techniques typically have drawbacks, including false detections, reduced sensitivity of the radar system, or increased processing burden on the radar system.

[0008] For radar signals damaged by interference, null forcing sets the amplitude of samples within a signal segment to zero to eliminate the interference. However, applying zero amplitude to segments of the samples introduces gaps in the signal. During further radar processing, these gaps can introduce spectral spread around strong targets and lead to false detections by the radar system, potentially increasing the processing burden on the radar system.

[0009] Pruning radar signals involves setting the amplitude of corrupted segments of the radar signal above or below a predetermined threshold. While this suppresses interference, the interference still exists in the signal. Insufficient removal of radar interference can lead to false detections and potentially worse sensitivity than zero-forcing.

[0010] In time-domain parameter interpolation, a parameter prediction model is performed to reconstruct damaged segments into usable radar samples. However, selecting model parameters is difficult, and inaccurate model parameter selection can also lead to worse performance than zero-forcing.

[0011] Iteratively applying adaptive thresholding resolves interference by replacing corrupted segments with iterative Fast Fourier Transform. This effectively mitigates interference, but the technique may be too complex to support real-time applications when computational resources are not overloaded.

[0012] Compared to the techniques described above, radar interference mitigation using signal pattern matching, as described in this paper, is a more effective and efficient technique for mitigating interference present in radar signals. The technique described in this paper overcomes the shortcomings of other techniques by reconstructing damaged segments using pattern matching, which preserves the accuracy of information in the radar signal and does so without overloading or requiring additional computational resources.

[0013] In frequency-modulated continuous wave (FMCW) radar systems, the time difference between the transmitted chirp and the reflected chirp is called the beat signal (or beat frequency). The beat signal may not be strictly periodic within a single chirp duration, but it can be assumed to be a quasi-periodic signal with a fundamental frequency and a dominant frequency that can be estimated by an autocorrelation function. If the fundamental frequency is not less than twice the frequency resolution, the quasi-periodic signal can pass through at least two approximately equal periods within one chirp duration. This means that the chirp can contain candidate replacement segments that can effectively replace damaged segments.

[0014] The techniques described herein identify candidate replacement segments by analyzing segments of the radar signal adjacent to the damaged segment (e.g., neighboring segments). Candidate replacement segments are selected by locating matching segments that have similar signal characteristics to those of neighboring segments adjacent to the damaged segment. The damaged segment can then be replaced with a candidate replacement segment. In some aspects, if the signal characteristics of the neighboring and matching segments have a correlation higher than a threshold, the damaged segment is replaced with a candidate replacement segment. These techniques are advantageous compared to other techniques by maintaining a low noise floor for the radar signal, which results in increased radar system sensitivity without increasing computational complexity. Example Environment

[0015] Figure 1 An example environment 100 according to the technology of this disclosure is shown, in which radar jamming mitigation using signal pattern matching can be applied. Vehicle 102 is equipped with a radar system 104 configured for radar jamming mitigation using signal pattern matching. Although depicted as a car, vehicle 102 may represent other types of vehicles and machinery (e.g., motorcycles, buses, tractors, semi-trailer trucks, watercraft, aircraft, other heavy equipment), including manned or unmanned systems that can be used for various purposes.

[0016] Radar system 104 may include one or more radar sensors 106 and radar tracking module 108. Through the radar sensors 106 specifically located on vehicle 102, radar system 104 provides an instrumented field of view (FOV) that can cover one or more vehicles 110 (including vehicles 110-1 and 110-2). For example, positioning several radar sensors 106 together can ensure that the FOV includes the area above road 112, the area adjacent to road 112, or the area on road 112 on which vehicle 102 can travel. Radar sensors 106 can capture signals from any location on vehicle 102 (including behind side mirrors, bumpers, roofs, or any other part of vehicle 102, or integrated into side mirrors, bumpers, roofs, or any other part of vehicle 102) to obtain the desired FOV.

[0017] Through radar tracking module 108, radar system 104 is configured to detect other vehicles, pedestrians, or other objects traveling on or near road 112. Radar tracking module 108 associates transmitted radar signal 114-1 with received radar signal 114-2 (e.g., chirp), which is reflected from the surface of an object (such as vehicle 110-1). Within environment 100, other objects (including vehicles 110-1 and 110-2) may be using radar, and vehicles 110-1 and 110-2 may be emitting radar signals 116 and 118, respectively. Radar system 104 can detect interference to radar signal 114-2 caused by radar signals 116 and 118. If tracking relies on interference, this interference may cause radar tracking module 108 to have difficulty tracking and may report inaccurate results.

[0018] Radar tracking module 108 is configured to enable radar system 104 to use signal mode matching to mitigate radar interference. Radar tracking module 108 generates a beat frequency signal by mixing transmitted radar signal 114-1 and received radar signal 114-2. Radar tracking module 108 can select undamaged segments of the beat frequency signal adjacent to damaged segments. By analyzing the beat frequency signal, radar tracking module 108 can search for and identify matching segments in the beat frequency signal that have similar signal characteristics to the undamaged segments, and replace damaged segments with candidate replacement segments adjacent to the matching segments. In this way, the beat frequency signal is more accurately approximated despite interference, and the noise floor of radar system 104 can be reduced, which can lead to increased sensitivity and an increased ability to perform more accurate radar tracking based on information in the beat frequency signal. Example System

[0019] Figure 2 An example of an automotive system 200 configured to perform radar interference mitigation using signal pattern matching, according to the technology of this disclosure, is shown. The automotive system 200 can be integrated into... Figure 1 The vehicle 102 shown and described in this context. For example, vehicle system 200 may include controller 202 and radar system 104. Radar system 104 and controller 202 communicate via link 204. Link 204 may be a wired or wireless link and in some cases includes a communication bus. Controller 202 performs operations based on information received via link 204, such as indications from radar system 104 of one or more objects traveling on road 112 when objects in the FOV are identified according to processed radar signal 114-2.

[0020] The controller 202 includes a processor 206 and a computer-readable storage medium (CRM) 208 (e.g., memory, long-term storage, short-term storage) that stores instructions for the vehicle module 210. The radar system 104 includes one or more radar sensors 106. The radar system 104 may include processing hardware including one or more processors 212 (e.g., hardware processors, processing units) and a CRM 214. The CRM 214 stores instructions associated with the radar tracking module 108, which may include instructions associated with the preprocessing submodule 216 and the object tracking submodule 218.

[0021] Processors 206 and 212 may be two separate processing units or a single processing unit (e.g., a microprocessor, multiple processors within a processing unit) or a pair of on-chip systems or a single on-chip system of a computing device, controller, or control unit. Processors 206 and 212 execute computer-executable instructions stored within CRMs 208 and 214. As an example, processor 206 may execute vehicle module 210 to perform driving functions of vehicle system 200 (e.g., autonomous lane change maneuvers, semi-autonomous lane keeping features) or other operations. Similarly, processor 212 may execute radar tracking module 108, including executing instructions for implementing preprocessing submodule 216.

[0022] The preprocessing submodule 216 configures the radar tracking module 108 to mitigate interference present in the radar signal 114-2 obtained from the radar sensor 106 of the vehicle 102. The preprocessing submodule 216 can modify the radar signal 114-2 before the radar tracking module 108 can use the radar signal 114-2 to detect objects or perform tracking.

[0023] The object tracking submodule 218 receives the output from the preprocessing submodule 218 and enables the radar tracking module 108 to infer objects in the field of view (FOV) based on the preprocessed version of radar signal 114-2 provided by the preprocessing submodule 216. In response to the object tracking submodule 218 detecting and tracking objects determined from these preprocessed versions of radar signal 114-2, the radar tracking module 108 outputs indications of one or more objects detected by the object tracking submodule 218.

[0024] Typically, vehicle system 200 executes vehicle module 210 to perform vehicle functions, which may include using output from radar system 104. When vehicle module 210 is executed at processor 206, vehicle module 210 may receive indications of objects detected by object tracking submodule 218 to enable one or more of these vehicle functions.

[0025] For example, vehicle module 210 can provide adaptive cruise control and monitor radar system 104 to obtain output indicating the presence of an object in or near the field of view (FOV), for example, to reduce speed and prevent a collision with the rear of vehicle 110-1. In such an example, object tracking submodule 218 provides radar-based data as output to vehicle module 210. The radar data indicates objects detected or tracked from preprocessed radar signals 114-2, rather than objects detected or tracked based on radar signals 114-2 initially received at the antenna of radar system 104.

[0026] When interference-mitigated radar data obtained from the object tracking submodule 218 indicates one or more objects in the collision zone around vehicle 102, vehicle module 210 can provide an alert or perform specific maneuvers. By using preprocessed radar signals 114-2 obtained from preprocessing submodule 216, object tracking submodule 218 can more accurately detect objects within the collision zone and FOV, which can reduce false detections caused by radar interference in noisy environments (such as driving scenarios where other vehicles operate their own onboard radar systems). Example Implementation

[0027] Figure 3 An example diagram 300 illustrating interference according to the technology of this disclosure is shown, in which radar interference mitigation using signal pattern matching can be applied. Figure 300-1 has a frequency dimension that varies over time and illustrates transmit chirp 302, receive chirp 304, jamming chirp 306, and jamming band limitation 308.

[0028] In this example, transmit chirp 302 is transmit signal 114-1, and receive chirp 304 is receive signal 114-2. Transmit chirp 302 is transmitted by radar system 104, and the receive chirp 304 is reflected from the object and received by radar system 104. When this process occurs, chirps from other radar systems in the same environment as radar system 104 (e.g., other radar systems associated with vehicles 110-1 and 110-2 in environment 110) may respectively interfere with transmit chirp 302 and receive chirp 304. Due to radar signals 116 or 118, this interference can manifest as interfering chirp 306, which is shown within the interference band limit 308. As shown in Figure 300-2 in the amplitude dimension as it changes over time, once the transmit chirp 302 and the receive chirp 304 are down-converted, the interference chirp 306 can appear as interference 310 on the beat signal 312.

[0029] If left unmitigated, this interference 310 will increase the noise floor and reduce the sensitivity of the radar system 104. For example, when in Figure 1 and Figure 2 When considered in the context of the environment 100, if the chirp 304 initially captured by radar system 104 and the received signal 114-2 are used for object detection and tracking, radar system 104 may report objects in environment 100 (including some false detections) or fail to report some detections that are hidden by the enhanced noise floor.

[0030] Figure 4 Example 400 illustrates how radar signals with interference, according to the technology of this disclosure, are mitigated by using radar interference mitigation with signal pattern matching. From Figure 3 Instead of ignoring the interference chirp 306 as described above, the radar tracking module 108 enables the radar system 104 to mitigate this type of interference and avoid increasing the noise floor, thereby reporting accurate radar data as a result.

[0031] In Example 400, the radar signal 114-2 (e.g., a single chirp) has been down-converted and sampled, resulting in a beat signal 402 comprising three interference bursts 404, 406, and 408. Typically, all three interference bursts 404 to 408 can be mitigated, but for simplicity, only interference burst 408 is discussed. During preprocessing by the preprocessing submodule 216, corrupted segments 410 of the beat signal 402 are identified as interference bursts 408. In some aspects, the preprocessing submodule 216 applies adaptive thresholding to the amplitude or squared amplitude of the beat signal 402 to determine a threshold for identifying corrupted segments 410. Segments with amplitudes greater than the threshold can be identified as interference.

[0032] Preprocessing submodule 216 can identify adjacent segments 412 that are adjacent to or immediately adjacent to the damaged segment 410. Adjacent segments 412 are adjacent to the damaged segment 410 in the time domain; for example, the adjacent segments may precede or follow the damaged segment 410. In example 400, adjacent segment 412 precedes the damaged segment 410. The length of adjacent segments 412 can be obtained by training a data model within preprocessing module 216. The data training model can be programmed to analyze the portion of radar signal 114-2 immediately preceding or following the damaged segment 410. Once adjacent segments 412 are identified, beat signals 402 are analyzed to match patterns in another segment of beat signals 402 associated with adjacent segments 412. Mean absolute error, correlation coefficient, or some other process can be used to match the pattern. In example 400, the matching pattern of the adjacent segments is determined to be matching segment 414. Once matching segment 414 is determined, replacement segment 416 is identified. Just as adjacent segment 412 precedes corrupted segment 410, matching segment 414 precedes replacement segment 416. Alternatively, if adjacent segment 412 follows corrupted segment 410, then matching segment 414 will follow replacement segment 416.

[0033] If the matching segment 414 is highly correlated with the adjacent segment 412, that is, if the correlation coefficient between the adjacent segment 412 and the matching segment 414 is higher than a threshold (e.g., a threshold determined through data training), then the replacement segment 416 can be used to replace the damaged segment 410. In Example 400, the modified beat signal 418 is generated by the preprocessing submodule 216. The modified beat signal 418 is output to the object tracking submodule 218 and includes segment 420, where samples from the replacement segment 416 have replaced samples in the damaged segment 410. In the modified beat signal 418, it is assumed that the damaged segments of the interference bursts 404 and 406 have also been replaced. The modified beat signal 418 can represent the mitigated beat signal 402 and can be received by the object tracking submodule 218 such that the radar data output from the radar system 104 reflects an increase in sensitivity (e.g., a lower noise floor) and has robustness against interference and noise.

[0034] Figure 5 Example 500 shows the spectrum of a beat signal 510 without mitigation, a beat signal 512 with zero-forcing mitigation, and a beat signal 516 with radar interference mitigation using signal pattern matching, according to the technology of this disclosure.

[0035] In Example 500, targets 502, 504, 506, and 508 are present in the environment. An unmitigated beat signal 510 may have a spectrum with a larger noise floor than the signal reflected from target 508. In this case, the unmitigated radar signal may fail to detect target 508. The dashed line represents a beat signal 512 mitigated using zero-forcing. Due to the zero-forcing technique, beat signal 512 may have a spectral spread characteristic 514. This spectral spread characteristic can lead to false detections. Beat signal 516 is an example of a mitigated signal output from preprocessing submodule 216 and is represented by a solid line. In Example 500, beat signal 516 has a similar noise floor to beat signal 512 but lacks any spectral spread characteristic similar to spectral spread characteristic 514. Because the spectral spread is minimized, beat signal 516 can be more sensitive compared to the output of other radar systems that have failed to mitigate interference or otherwise mitigate it, resulting in improved quality of radar data inferred from beat signal 516 generated by radar system 104. Example Method

[0036] Figure 6 An example method 600 for radar interference mitigation using signal pattern matching according to the technology of this disclosure is illustrated. Operations (or steps) 602 to 608 are performed, but are not necessarily limited to the order or combination of operations shown herein. Furthermore, any one or more operations may be repeated, combined, or reorganized to provide other operations. As an example, radar system 104, radar tracking module 108, preprocessing submodule 216, and / or object tracking submodule 218 may perform operations 602 to 608 based on instructions stored on CRM 214 and executed by processor 212.

[0037] At step 602, the radar system's processor determines that interference is present in the radar signal. The radar signal is transmitted and, after being reflected from an object, is received by the radar system. Interference may be introduced into this radar signal from other radar signals transmitted by radar systems in the environment. The greater the number of other radar systems in the environment, the higher the likelihood that interference can be introduced.

[0038] At 604, before generating radar data based on the radar signal, one or more preprocessing steps (e.g., steps 604-1 to 604-5) can be performed to mitigate interference from the radar signal. At 604-1, damaged segments of the radar signal corresponding to the interference are identified. In some aspects, multiple damaged segments can be identified. In some implementations, a threshold can be determined by applying adaptive thresholding to the amplitude (or squared amplitude) of the radar signal to identify damaged segments. If the amplitude (or squared amplitude) of the radar signal is greater than the threshold, a segment of the radar system can be considered damaged.

[0039] At step 604-2, adjacent segments of the radar signal adjacent to the damaged segment are determined. These adjacent segments can be before or after the damaged segment (e.g., in the time domain). In some implementations, a trained model can be used to analyze the portion of the radar signal immediately before or after the damaged segment to identify adjacent segments to be used for identifying the damaged segment. The trained model can be a neural network or other model trained using machine learning to learn to identify the damaged segment and, from it, adjacent segments that identify suitable matching segments.

[0040] In step 604-3, matching segments of radar signals with similar signal characteristics to adjacent segments are identified. The radar signals can be analyzed to obtain possible matching segments with signal characteristics highly correlated with those of adjacent segments. In some aspects, the mean absolute error between possible matching segments and adjacent segments can be determined. If this mean absolute error is below a threshold, the possible matching segment is defined as a matching segment. In other aspects, the correlation coefficient between adjacent segments and possible matching segments can be determined. If this correlation coefficient is above a threshold, the possible matching segment is defined as a matching segment.

[0041] At step 604-4, a replacement segment of the radar signal adjacent to the matching segment is determined. In some aspects, the replacement segment can be before or after the matching segment, depending on whether the adjacent segment precedes or follows the damaged segment. That is, if the adjacent segment precedes the damaged segment, the replacement segment follows the matching segment. Similarly, if the adjacent segment follows the damaged segment, the replacement segment precedes the matching segment.

[0042] At steps 604-5, the signal characteristics of the damaged segment are adjusted based on the replacement signal. In some respects, this adjustment is based on how well the matching segment correlates with adjacent segments.

[0043] In one example, if the matching segment and its adjacent segments have a correlation coefficient greater than a threshold, the signal characteristics of the replacement segment are used to adjust the signal characteristics of the corrupted segment. Otherwise, another method, such as zero-forcing, can be used to adjust the corrupted segment. In this non-limiting example, the threshold used to determine whether the signal characteristics of the replacement segment will be used to adjust the signal characteristics of the corrupted segment can be the same as the threshold used to determine whether a possible matching segment is defined as a matching segment. In another example, the threshold used to determine whether the signal characteristics of the replacement segment are used to adjust the signal characteristics of the corrupted segment can be greater than the threshold used to determine whether a possible matching segment is defined as a matching segment. Other combinations of thresholds and filtering can be used to identify matching segments.

[0044] At step 606, radar data is generated based on the mitigated radar signal. Once the preprocessing steps are complete, the mitigated radar signal can be processed to obtain radar data relating to objects in the environment of the radar system. The mitigated radar signal generated based on these steps so far can have a lower noise floor and result in fewer false affirmations than conventional mitigation methods.

[0045] At step 608, radar data is output for at least detecting and tracking objects in the environment of the radar system. For example, if the radar system is equipped on a vehicle, the radar data can be used to detect and track objects in the vehicle's path. Because this radar data can include fewer false positives than radar data generated by conventional means, it can be more accurate, resulting in a safer user experience for vehicle users. Additional examples

[0046] Example 1: A method comprising: determining, by a processor of a radar system, that interference exists in a radar signal; mitigating the interference from the radar signal by, before generating radar data based on the radar signal, by: identifying a damaged segment of the radar signal corresponding to the interference; determining an adjacent segment of the radar signal adjacent to the damaged segment; determining a matching segment of the radar signal having signal characteristics similar to the adjacent segment; determining a replacement segment of the radar signal adjacent to the matching segment; and adjusting the signal characteristics of the damaged segment of the radar signal based on the signal characteristics of the replacement segment to generate a mitigated radar signal free of the interference; and generating the radar data based on the mitigated radar signal; and outputting the radar data for at least detecting or tracking objects in the environment of the radar system.

[0047] Example 2: The method of Example 1, wherein identifying the damaged segment of the radar signal corresponding to the interference includes: applying adaptive thresholding to at least one of the amplitude of the radar signal or the squared amplitude of the radar signal to determine a threshold; and identifying the damaged segment of the radar signal as a segment greater than the threshold in response to a segment of at least one of the amplitude of the radar signal or the squared amplitude of the radar signal being greater than the threshold.

[0048] Example 3: In any of the previous examples, the method of determining the adjacent segments of the radar signal adjacent to the damaged segment further includes: using a trained model to analyze portions of the radar signal immediately before and immediately after the damaged segment to identify the adjacent segments to be used to identify the matching segment.

[0049] Example 4: In any of the previous examples, the method of determining the matching segment of the radar signal having signal characteristics similar to the adjacent segment includes: determining the mean absolute error between the possible matching segment and the adjacent segment; and defining the possible matching segment as having signal characteristics similar to the adjacent segment in response to the mean absolute error between the possible matching segment and the adjacent segment being below a threshold.

[0050] Example 5: A method in any of the preceding examples, wherein determining the matching segment of the radar signal having signal characteristics similar to the adjacent segment comprises: determining a correlation coefficient between a possible matching segment and the adjacent segment; and defining the possible matching segment as having signal characteristics similar to the adjacent segment in response to the correlation coefficient between the possible matching segment and the adjacent segment being higher than a first threshold.

[0051] Example 6: The method of Example 5, wherein mitigating the interference from the radar signal further comprises: determining whether a correlation coefficient between the adjacent segment and the matching segment is higher than a second threshold; and in response to determining that the correlation coefficient is higher than the second threshold, adjusting the signal characteristics of the damaged segment of the radar signal by replacing the signal characteristics of the damaged segment with the signal characteristics of the replacement segment to generate the mitigated radar signal.

[0052] Example 7: The method of Example 5, wherein mitigating the interference from the radar signal further comprises: determining whether the correlation coefficient between the adjacent segment and the matched segment is lower than a second threshold; and in response to determining that the correlation coefficient is lower than the second threshold, adjusting the signal characteristics of the damaged segment of the radar signal by applying a zero-forcing function to the signal characteristics of the damaged segment.

[0053] Example 8: A method in any of the previous examples, wherein: the adjacent segment precedes the damaged segment of the radar signal; and the replacement segment follows the matching segment of the radar signal.

[0054] Example 9: A method in any of the previous examples, wherein: the adjacent segment follows the damaged segment of the radar signal; and the replacement segment precedes the matching segment of the radar signal.

[0055] Example 10: A system comprising: a processor configured to: determine that interference exists in a radar signal; before generating radar data based on the radar signal, mitigate the interference from the radar signal by: identifying a damaged segment of the radar signal corresponding to the interference; determining an adjacent segment of the radar signal adjacent to the damaged segment; determining a matching segment of the radar signal having signal characteristics similar to the adjacent segment; in response to identifying the matching segment, determining a replacement segment of the radar signal adjacent to the matching segment; and adjusting the signal characteristics of the damaged segment of the radar signal based on the signal characteristics of the replacement segment to generate a mitigated radar signal free of the interference; and generating the radar data based on the mitigated radar signal; and outputting the radar data for at least detecting or tracking objects in the environment of the radar system.

[0056] Example 11: The system of Example 10, wherein the processor is further configured to identify the damaged segment of the radar signal corresponding to the interference by at least the following operations: applying adaptive thresholding to at least one of the amplitude of the radar signal or the squared amplitude of the radar signal to determine a threshold; and identifying the damaged segment of the radar signal corresponding to the interference as a segment greater than the threshold in response to a segment of at least one of the amplitude of the radar signal or the squared amplitude of the radar signal being greater than the threshold.

[0057] Example 12: A system of any one of Examples 10 or 11, wherein the processor is further configured to determine the adjacent segments of the radar signal adjacent to the damaged segment by at least the following operations: using a trained model to analyze portions of the radar signal immediately before and immediately after the damaged segment to identify the adjacent segments to be used to identify the matching segment.

[0058] Example 13: A system of any one of Examples 10 to 12, wherein the processor is further configured to determine the matching segment of the radar signal having signal characteristics similar to the adjacent segment by at least the following operations: determining the mean absolute error between the possible matching segment and the adjacent segment; and defining the possible matching segment as the matching segment having signal characteristics similar to the adjacent segment in response to the mean absolute error between the possible matching segment and the adjacent segment being lower than a threshold.

[0059] Example 14: A system of any one of Examples 10 to 13, wherein the processor is further configured to determine the matching segment of the radar signal having signal characteristics similar to the adjacent segment by at least the following operations: determining a correlation coefficient between a possible matching segment and the adjacent segment; and defining the possible matching segment as the matching segment having signal characteristics similar to the adjacent segment in response to the correlation coefficient between the possible matching segment and the adjacent segment being higher than a first threshold.

[0060] Example 15: The system of Example 14, wherein the processor is further configured to mitigate the interference from the radar signal by at least the following operations: determining whether the correlation coefficient between the adjacent segment and the matching segment is higher than a second threshold; and in response to determining that the correlation coefficient is higher than the second threshold, adjusting the signal characteristics of the damaged segment of the radar signal by replacing the signal characteristics of the damaged segment with the signal characteristics of the replacement segment to generate the mitigated radar signal.

[0061] Example 16: The system of Example 14, wherein the processor is further configured to mitigate the interference from the radar signal by at least: determining whether the correlation coefficient between the adjacent segment and the matched segment is lower than a second threshold; and in response to determining that the correlation coefficient is lower than the second threshold, adjusting the signal characteristics of the damaged segment of the radar signal by applying a zero-forcing function to the signal characteristics of the damaged segment.

[0062] Example 17: A system of any one of Examples 10 to 16, wherein: the adjacent segment precedes the damaged segment of the radar signal; and the replacement segment follows the matching segment of the radar signal.

[0063] Example 18: A system of any one of Examples 10 to 17, wherein: the adjacent segment follows the damaged segment of the radar signal; and the replacement segment precedes the matching segment of the radar signal.

[0064] Example 19: A system of any one of Examples 10 to 18, wherein the system is part of a vehicle system.

[0065] Example 20: A computer-readable storage medium comprising instructions that, when executed, configure at least one processor to: determine that interference exists in a radar signal; before generating radar data based on the radar signal, mitigate the interference from the radar signal by: identifying a damaged segment of the radar signal corresponding to the interference; determining an adjacent segment of the radar signal preceding or following the damaged segment; determining a matching segment of the radar signal having signal characteristics similar to the adjacent segment; in response to identifying the matching segment, determining a replacement segment of the radar signal preceding or following the matching segment; and adjusting the signal characteristics of the damaged segment of the radar signal based on the signal characteristics of the replacement segment to generate a mitigated radar signal free of the interference; and generating the radar data based on the mitigated radar signal; and outputting the radar data for at least detecting or tracking objects in the environment of the radar system. Conclusion

[0066] While various embodiments of this disclosure have been described in the foregoing description and illustrated in the accompanying drawings, it should be understood that this disclosure is not limited thereto, but can be practiced in various ways within the scope of the following claims. It will be apparent from the foregoing description that various modifications can be made without departing from the spirit and scope of this disclosure as defined by the following claims. Problems associated with radar interference mitigation may occur in other systems. Therefore, although described as one way to improve radar interference mitigation in vehicle-based radar, the techniques described above can be applied to other systems requiring electromagnetic interference mitigation. Furthermore, the techniques described herein have been described in the context of digital signal processing. In theory, similar techniques can be applied using analog signal processing.

[0067] Unless the context explicitly states otherwise, the use of "or" and grammatically related terms indicates an unrestricted, non-exclusive alternative. As used herein, the phrase referring to "at least one" of a list of items means any combination of those items, including a single member. As an example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

Claims

1. A method for a means of transport, the method comprising: The radar system's processor determines that interference exists in the radar beat signal, wherein the radar beat signal is the time difference between the transmitted chirp and the reflected chirp; Before generating radar data based on the radar beat signal, the interference from the radar beat signal is mitigated by the following operations: Identify the damaged segments of the radar beat signal corresponding to the interference; Identify adjacent segments of the radar beat signal that are adjacent to the damaged segment; Identify matching segments of the radar beat signal that have similar signal characteristics to the adjacent segments; Determine the replacement segment of the radar beat signal adjacent to the matching segment; as well as Based on the signal characteristics of the replacement segment, the signal characteristics of the damaged segment of the radar beat signal are adjusted to generate a mitigated radar beat signal without the interference. as well as The radar data is generated based on the mitigated radar beat signal; as well as The radar data is output for at least the detection or tracking of objects in the environment of the radar system.

2. The method as described in claim 1, characterized in that, The damaged segments of the radar beat signal corresponding to the interference include: Adaptive thresholding is applied to at least one of the amplitude of the radar beat signal or the squared amplitude of the radar beat signal to determine a threshold; and In response to a segment of at least one of the amplitude of the radar beat signal or the squared amplitude of the radar beat signal being greater than the threshold, the damaged segment of the radar beat signal is identified as the segment being greater than the threshold.

3. The method as described in claim 1, characterized in that, Determining the adjacent segments of the radar beat signal adjacent to the damaged segment further includes: The trained model is used to analyze the portions of the radar beat signal immediately before and immediately after the damaged segment to identify the adjacent segments to be used to identify the matching segment.

4. The method as described in claim 1, characterized in that, Determining the matching segment of the radar beat signal that has similar signal characteristics to the adjacent segment includes: Determine the mean absolute error between possible matching segments and the adjacent segments; and In response to the mean absolute error between the possible matching segment and the adjacent segment being below a threshold, the possible matching segment is defined as the matching segment having signal characteristics similar to the adjacent segment.

5. The method as described in claim 1, characterized in that, Determining the matching segment of the radar beat signal that has similar signal characteristics to the adjacent segment includes: Determine the correlation coefficients between possible matching segments and the adjacent segments; and In response to the correlation coefficient between the possible matching segment and the adjacent segment being higher than a first threshold, the possible matching segment is defined as the matching segment having signal characteristics similar to the adjacent segment.

6. The method as described in claim 5, characterized in that, Mitigating the interference from the radar beat signal further includes: Determine whether the correlation coefficient between the adjacent segments and the matching segments is higher than a second threshold; and In response to determining that the correlation coefficient is higher than the second threshold, the signal characteristics of the damaged segment of the radar beat signal are adjusted by replacing the signal characteristics of the damaged segment with the signal characteristics of the replacement segment to generate the mitigated radar beat signal.

7. The method as described in claim 5, characterized in that, Mitigating the interference from the radar beat signal further includes: Determine whether the correlation coefficient between the adjacent segments and the matching segments is lower than a second threshold; and In response to determining that the correlation coefficient is below the second threshold, the signal characteristics of the damaged segment of the radar beat signal are adjusted by applying a zero-forcing function to the signal characteristics of the damaged segment.

8. The method as described in claim 1, characterized in that: The adjacent segment precedes the damaged segment of the radar beat signal; and The replacement segment follows the matching segment of the radar beat signal.

9. The method as described in claim 1, characterized in that: The adjacent segment follows the damaged segment of the radar beat signal; and The replacement segment precedes the matching segment of the radar beat signal.

10. A system for a vehicle, the system comprising: Processor, the processor being configured to: It is determined that interference exists in the radar beat signal, wherein the radar beat signal is the time difference between the transmitted chirp and the reflected chirp; Before generating radar data based on the radar beat signal, the interference from the radar beat signal is mitigated by the following operations: Identify the damaged segments of the radar beat signal corresponding to the interference; Identify adjacent segments of the radar beat signal that are adjacent to the damaged segment; Identify matching segments of the radar beat signal that have similar signal characteristics to the adjacent segments; In response to identifying the matching segment, a replacement segment of the radar beat signal adjacent to the matching segment is determined; as well as Based on the signal characteristics of the replacement segment, the signal characteristics of the damaged segment of the radar beat signal are adjusted to generate a mitigated radar beat signal without the interference. as well as The radar data is generated based on the mitigated radar beat signal; as well as The radar data is output for at least the detection or tracking of objects in the environment of the radar system.

11. The system as claimed in claim 10, characterized in that, The processor is further configured to identify the damaged segments of the radar beat signal corresponding to the interference by at least the following operations: Adaptive thresholding is applied to at least one of the amplitude of the radar beat signal or the squared amplitude of the radar beat signal to determine a threshold; and In response to a segment of at least one of the amplitude of the radar beat signal or the squared amplitude of the radar beat signal being greater than the threshold, the damaged segment of the radar beat signal corresponding to the interference is identified as the segment being greater than the threshold.

12. The system as described in claim 10, characterized in that, The processor is further configured to determine the adjacent segments of the radar beat signal adjacent to the damaged segment by at least the following operations: The trained model is used to analyze the portions of the radar beat signal immediately before and immediately after the damaged segment to identify the adjacent segments to be used to identify the matching segment.

13. The system as described in claim 10, characterized in that, The processor is further configured to determine the matching segment of the radar beat signal having signal characteristics similar to the adjacent segment by at least the following operations: Determine the possible matching segments and the mean absolute error between the adjacent segments; as well as In response to the mean absolute error between the possible matching segment and the adjacent segment being below a threshold, the possible matching segment is defined as the matching segment having signal characteristics similar to the adjacent segment.

14. The system as claimed in claim 10, characterized in that, The processor is further configured to determine the matching segment of the radar beat signal having signal characteristics similar to the adjacent segment by at least the following operations: Determine the correlation coefficients between possible matching segments and the adjacent segments; as well as In response to the correlation coefficient between the possible matching segment and the adjacent segment being higher than a first threshold, the possible matching segment is defined as the matching segment having signal characteristics similar to the adjacent segment.

15. The system as described in claim 14, characterized in that, The processor is further configured to mitigate the interference from the radar beat signal by at least the following operations: Determine whether the correlation coefficient between the adjacent segments and the matching segments is higher than a second threshold; as well as In response to determining that the correlation coefficient is higher than the second threshold, the signal characteristics of the damaged segment of the radar beat signal are adjusted by replacing the signal characteristics of the damaged segment with the signal characteristics of the replacement segment to generate the mitigated radar beat signal.

16. The system as claimed in claim 14, characterized in that, The processor is further configured to mitigate the interference from the radar beat signal by at least the following operations: Determine whether the correlation coefficient between the adjacent segments and the matching segments is lower than a second threshold; as well as In response to determining that the correlation coefficient is below the second threshold, the signal characteristics of the damaged segment of the radar beat signal are adjusted by applying a zero-forcing function to the signal characteristics of the damaged segment.

17. The system as claimed in claim 10, characterized in that: The adjacent segment precedes the damaged segment of the radar beat signal; and The replacement segment follows the matching segment of the radar beat signal.

18. The system as claimed in claim 10, characterized in that: The adjacent segment follows the damaged segment of the radar beat signal; and The replacement segment precedes the matching segment of the radar beat signal.

19. The system as claimed in claim 10, characterized in that: The system is part of the vehicle system.

20. A computer-readable storage medium comprising instructions that, when executed, configure at least one processor to: It is determined that interference exists in the radar beat signal, wherein the radar beat signal is the time difference between the transmitted chirp and the reflected chirp; Before generating radar data based on the radar beat signal, the interference from the radar beat signal is mitigated by the following operations: Identify the damaged segments of the radar beat signal corresponding to the interference; Identify adjacent segments of the radar beat signal before or after the damaged segment; Identify matching segments of the radar beat signal that have similar signal characteristics to the adjacent segments; In response to identifying the matching segment, a replacement segment of the radar beat signal before or after the matching segment is determined; as well as Based on the signal characteristics of the replacement segment, the signal characteristics of the damaged segment of the radar beat signal are adjusted to generate a mitigated radar beat signal without the interference. as well as The radar data is generated based on the mitigated radar beat signal; as well as The radar data is output for at least the detection or tracking of objects in the environment of the radar system.

Images