Coordinated frequency modulated continuous wave radar coexistence with artificial waveform phase ramps

Abstract

The present disclosure provides methods and systems for radar detection of coordinated interference using artificially introduced phase ramps. A radar device transmits a frequency modulated continuous wave (FMCW) radar waveform having artificially introduced phase ramps on a plurality of chirps within each of a plurality of frames. The radar device receives a signal including a reflection of the FMCW radar waveform. The radar device calculates respective distances and respective velocities of the one or more detected objects based on phases of chirps in the received signals. The radar device attempts to associate each of the one or more detected objects with a trajectory based on the respective distance and the respective velocity. The radar device discards one or more detected objects or corresponding trajectories in response to a change in speed between frames of the detected objects being greater than a threshold.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Greek Application No. 202340100209, filed on March 10, 2023, entitled “COORDINATED FREQUENCY MODULATED CONTINUOUS WAVE RADAR CO-EXISTENCE WITH ARTIFICIAL WAVEFORM PHASE RAMPS,” which is hereby incorporated by reference in its entirety. Background Art

[0003] Aspects of the present disclosure relate generally to radar, and more particularly, to frequency modulated continuous wave (FMCW) radar waveforms for radar.

[0004] FMCW radar is used in a vehicle environment to detect objects around the vehicle. The FMCW transmits a radar waveform consisting of multiple frames, each frame consisting of multiple chirps. If a target is present, the FMCW radar waveform returns to the radar after a propagation delay based on the distance and the speed of light. Therefore, the radar can determine the distance to the object based on the measured propagation delay and simple signal processing. Furthermore, the radar can track detections over multiple frames. Consecutive frame detections are combined to produce a time series of detections, which are input into data association and track detection filters. In the case of a single target, the filter smooths out noise-corrupted detections and forms a clean trajectory or track of the target. In the case of multiple targets, the filter can associate each target with a track and add or discard detections based on their respective associations with the track.

[0005] In a vehicular environment, interference with FMCW radars from other FMCW radars on other vehicles is a possibility, especially as more vehicles are equipped with radars, such as for autonomous driving operations. In scenarios where multiple radars operate on the same frequency, a signal transmitted by one radar will be received by a second radar nearby. This direct signal from the first radar can cause the second ("victim") radar to experience an increased noise floor (making target detection less reliable) and to detect "phantom" targets—i.e., targets that are not actually present in the detected location (also known as "false alarms"). Both of these effects are undesirable. Therefore, it may be desirable to improve radar detection in the presence of interfering signals. Summary of the Invention

[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of these aspects. This summary is not an extensive overview of all contemplated aspects and is neither intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the detailed description that is presented later.

[0007] In one aspect, the present disclosure includes a method for radar detection. The method may include transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames. The method may include receiving a signal including reflections of the FMCW radar waveform. The method may include calculating respective ranges of one or more detected objects based on the timing of the received signal. The method may include calculating respective velocities of the one or more detected objects based on the phases of the chirps in the received signal. The method may include attempting to associate each of the one or more detected objects with a track based on the respective ranges and the respective velocities. The method may include discarding the track of the one or more detected objects or an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

[0008] In another aspect, the present disclosure provides a radar comprising one or more antennas, a memory storing executable instructions, and at least one processor communicatively coupled to the plurality of antennas and the memory. The at least one processor may be configured to transmit, via the one or more antennas, an FMCW radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames. The at least one processor may be configured to receive, via the one or more antennas, a signal comprising reflections of the FMCW radar waveform. The at least one processor may be configured to calculate respective ranges of one or more detected objects based on the timing of the received signals. The at least one processor may be configured to calculate respective velocities of the one or more detected objects based on the phases of the chirps in the received signals. The at least one processor may be configured to attempt to associate each of the one or more detected objects with a track based on the respective ranges and the respective velocities. The at least one processor may be configured to discard the track of the one or more detected objects or an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

[0009] In another aspect, the present disclosure provides a radar comprising means for transmitting an FMCW radar waveform having artificially introduced phase slopes across a plurality of chirps within each of a plurality of frames. The radar comprises means for receiving a signal comprising reflections of the FMCW radar waveform. The radar comprises means for calculating respective ranges of one or more detected objects based on the timing of the received signal. The radar comprises means for calculating respective velocities of the one or more detected objects based on the phases of the chirps in the received signal. The radar comprises means for attempting to associate each of the one or more detected objects with a track based on the respective ranges and the respective velocities. The radar comprises means for discarding the track of one or more detected objects or an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

[0010] In another aspect, the present disclosure provides a computer-readable medium storing instructions executable by a processor of a radar device. The computer-readable medium includes code for transmitting a frequency-modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames. The computer-readable medium also includes code for receiving a signal comprising reflections of the FMCW radar waveform. The computer-readable medium also includes code for calculating respective ranges of one or more detected objects based on the timing of the received signals. The computer-readable medium also includes code for calculating respective velocities of the one or more detected objects based on the phases of the chirps in the received signals. The computer-readable medium also includes code for attempting to associate each of the one or more detected objects with a track based on the respective ranges and velocities. The computer-readable medium also includes code for discarding the track of one or more detected objects or an erroneously detected object among the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

[0011] To accomplish the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of but a few of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The disclosed aspects will be described below with reference to the accompanying drawings, which are provided to illustrate and not to limit the disclosed aspects, wherein like designations represent like elements, and in which:

[0013] Figure 1 is a schematic diagram of an example operating environment of a radar device for detecting an object.

[0014] Figure 2 This is a conceptual diagram of an example of a frequency modulated continuous wave (FMCW) waveform.

[0015] Figure 3 is a conceptual diagram illustrating an example of a transmitted FMCW signal and a corresponding returned FMCW signal.

[0016] Figure 4 is a diagram showing an example of an FMCW signal with an artificially introduced phase ramp.

[0017] Figure 5 is a schematic diagram of an example of signal processing for a received FMCW signal.

[0018] Figure 6 is a flow chart illustrating an example of a method of radar detection. DETAILED DESCRIPTION

[0019] Various aspects will now be described with reference to the accompanying drawings. In the following description, for purposes of explanation and to provide a thorough understanding of one or more aspects, numerous specific details are set forth. However, it will be apparent that such aspects may be practiced without these specific details. Additionally, as used herein, the term "component" may refer to a portion of a system, hardware, firmware, and / or software stored on a computer-readable medium, and may be divided into other components.

[0020] The present disclosure relates generally to radar sensors, and in particular to radar sensors that use a frequency modulated continuous wave (FMCW) radar waveform.A radar system can detect and track multiple targets located in an operating environment of the radar system.

[0021] More specifically, the present disclosure addresses at least issues associated with interference between multiple FMCW radars operating in an environment, such that a signal transmitted by a first radar is received as interference at a second radar.

[0022] Various signal processing techniques have been proposed to discard observation samples contaminated by interference, or to identify the portion of received energy that is due to interference and cancel that interference. Sample discarding methods may not be feasible in conditions with a large number of interference sources, as there is a high probability that most or all samples will be contaminated by interference. Interference cancellation methods can be computationally intensive and may only handle a limited number of interference sources. Furthermore, these methods may not be backwards compatible with currently deployed radars.

[0023] In one aspect, the present disclosure provides interference mitigation using a combination of coordinated jamming and waveform shaping, which allows for the identification of phantom targets using simple signal processing. Coordinated jamming may refer to the use of identical FMCW parameters across multiple radars, including a jamming radar. Coordinated jamming can make the jamming signal appear as if it were a returning signal, causing the jamming signal to be detected as a potential target (a "phantom" target). Waveform shaping can include adding an artificial phase ramp to the transmitted signal. This artificial phase ramp varies (i.e., changes) between consecutive frames and, when received as a jamming signal, causes the waveform to appear as an object moving at a rapidly changing speed. In other words, each radar effectively adds an artificial velocity offset to each frame that changes between frames. Signal processing may include conventional correlation and tracking filters. When a jamming signal includes an artificial phase ramp, the velocity of a potential detection may appear to vary between frames in a manner that is unrealistic for an actual physical object. Consequently, detections due to jamming signals with artificial phase ramps may be discarded by the correlation and tracking filters. For example, a detection may not establish a track, or an established track may be discarded. In contrast, the artificial phase slope of the returned signal can be canceled during the mixing operation with the transmitted signal, allowing the target's true velocity to be measured. Thus, the correlation and tracking filter can track the actual object that reflected the returned signal.

[0024] In one aspect, the present disclosure improves radar performance by discarding detections of jamming signals that result in phantom targets. The radar continues to track detections based on returned signals from actual targets. Additionally, because detections based on transmitted FMCW signals that include artificial phase ramps are discarded by the correlation and tracking filters, the disclosed radar is backward compatible with currently deployed FMCW radars.

[0025] The following reference Figures 1 to 6 The following description provides examples and is not intended to limit the scope, applicability, or examples set forth in the claims. The functions and arrangements of the elements discussed may be modified without departing from the scope of the present disclosure. Various examples may omit, replace, or add various procedures or components as appropriate. For example, the methods described may be performed in a different order than described, and various steps may be added, omitted, or combined. In addition, features described with respect to some examples may be combined in other examples.

[0026] Figure 1An example operating scenario 100 for a radar device 110 is illustrated. In one aspect, radar device 110 may be used in an automotive scenario to track surrounding objects 102 (such as other vehicles). Objects 102 may be designated herein as objects 102-a, 102-b, 102-c, ..., 102-k, where k is the number of trackable objects. However, radar device 110 may be used in other scenarios where it is desirable to track multiple objects (e.g., aircraft, drones, or robots).

[0027] Radar device 110 may include one or more antennas 112, which may be designated herein as antennas 112-a, 112-b, ..., 112-n, where n is the total number of antennas. Generally, radar device 110 may transmit an FMCW radar beam 104 with an artificial phase slope via a first set of antennas 112. Radar beam 104 may reflect from object 102, and radar device 110 may receive reflected radar signal 106 via a second, different set of antennas 112. Radar device 110 may also receive interfering radar signal 108, which may be generated by a radar at object 102 (e.g., another vehicle). In one aspect, interfering radar signal 108 may also be an FMCW radar beam with an artificial phase slope different from that of radar beam 104. Radar device 110 may analyze reflected radar signal 106 and interfering radar signal 108 to detect and track object 102, while discarding the track of a phantom target based on the detection of interfering radar signal 108.

[0028] Radar device 110 may include a processor 114 that executes instructions stored in memory 116. For example, processor 114 may execute an operating system and / or one or more applications, which may include artificial phase ramp component 120. Processor 114 may be communicatively coupled to one or more of antennas 112 and to memory 116.

[0029] Memory 116 may be configured to store data and / or computer-executable instructions defining and / or associated with artificial phase ramp component 120, and processor 114 may execute artificial phase ramp component 120. Memory 116 may represent one or more hardware memory devices accessible to radar device 110. Examples of memory 116 may include, but are not limited to, any type of computer-usable memory, such as random access memory (RAM), read-only memory (ROM), magnetic tape, magnetic disk, optical disk, volatile memory, non-volatile memory, and any combination thereof. Memory 116 may store a local version of an application being executed by processor 114. In one specific implementation, memory 116 may include a storage device, which may be a non-volatile memory.

[0030] The processor 114 may include one or more processors for executing instructions. Examples of the processor 114 may include, but are not limited to, any processor specifically programmed as described herein, including a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a system on a chip (SoC), or other programmable logic component or state machine. The processor 114 may include other processing components such as an arithmetic logic unit (ALU), registers, and a control unit. The processor 114 may include multiple cores and may be capable of using multiple cores to concurrently process different instruction sets and / or data to execute multiple threads.

[0031] Radar device 110 may include an artificial phase ramp component 120 that generates an FMCW waveform including an artificial phase ramp. Typically, the FMCW waveform has the same parameters as the FMCW waveform transmitted by the potentially interfering radar. For example, the FMCW waveform of beam 104 may use the same carrier frequency, chirp duration, and chirp bandwidth as the potentially interfering radar. Furthermore, radar device 110 may synchronize with other potentially interfering radars to concurrently transmit FMCW waveforms. The artificial phase ramp used for the FMCW waveform of radar device 110 may differ from the phase ramp applied by the potentially interfering radar. For example, the artificial phase ramp may be randomly generated or selected from a codebook. The artificial phase ramp may also change with each frame.

[0032] Conceptually, an artificial phase ramp can be considered an artificial velocity offset introduced into the transmitted FMCW waveform. In one aspect, when the FMCW radar waveform lacks an artificial phase ramp, the FMCW radar can detect the relative velocity between the radar and object 102 based on the naturally occurring phase ramp of reflected radar signal 106. The naturally occurring phase ramp of reflected radar signal 106 may be caused by the Doppler effect, which is applied to the FMCW waveform and manifests as a linear increase in the phase of the chirp. When the FMCW radar waveform has an artificial phase ramp, the mixing operation of the FMCW radar waveform and reflected radar signal 106 can cancel the artificial phase ramp of reflected radar signal 106, leaving behind the naturally occurring phase ramp due to the Doppler shift, and the FMCW radar can still detect the relative velocity of object 102. When the FMCW radar receives a jamming signal 108 that includes the second artificial phase ramp, the detected relative velocity will be based on the first artificial phase ramp transmitted by the radar, the second artificial phase ramp, and any phase ramp that naturally forms due to the non-zero actual relative velocity between the radar and the jamming radar. The artificial phase ramp can be designed so that the detected relative velocity based on the jamming signal will vary significantly between consecutive frames.

[0033] Artificial phase ramping component 120 may include a signal generation component 130 configured to transmit an FMCW radar waveform having an artificially introduced phase ramp across a plurality of chirps within each of a plurality of frames. Signal generation component 130 may optionally include a phase ramp selection component 132 configured to set the artificially introduced phase ramp based on the radar's velocity offset. Signal generation component 130 may optionally include a communication component 134 configured to coordinate the transmission of the FMCW radar waveform with other devices. For example, communication component 134 may synchronize radar and / or receive phase ramp patterns.

[0034] Radar device 110 may include a signal detection component 140 configured to detect the respective ranges and respective velocities of one or more objects based on the received signals. For example, artificial phase ramp component 120 may include a distance component 142 configured to calculate the respective ranges of one or more detected objects based on the timing of the received signals. For another example, artificial phase ramp component 120 may include a velocity component 144 configured to calculate the respective velocities of the one or more detected objects based on the phase of the chirp in the received signals.

[0035] Radar device 110 may include an associating component 150 configured to associate each of the one or more detected objects with a track based on a respective distance and a respective speed.

[0036] Radar device 110 may include a tracking component 160 configured to discard a track of an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the erroneously detected object being greater than a threshold.

[0037] Figure 2 An example FMCW waveform 200 is illustrated that includes a plurality of chirps 210 (eg, chirps 210-a, 210-b, 210-c, and 210-n). Each chirp 210 may include a duration (T up ) 222 over a bandwidth (B) 220. Each chirp 210 may also be associated with a chirp period (T) between the start of each chirp 210. c ) 224. Bandwidth 220 can be associated with a carrier frequency (f c ). The chirp can be expressed mathematically according to equation (1):

[0038] (1)

[0039] Where c is a constant complex scalar that captures aspects such as the phase of the phase-locked loop (PLL). A single frame waveform can be expressed as:

[0040] (2)

[0041] in is the mth chirp in the frame, and T c ≥T up is the chirp sending period.

[0042] Figure 3 3 is a diagram 300 illustrating an example transmitted FMCW signal 310 and a returned FMCW signal 350. The FMCW signal 310 may follow the FMCW waveform 200 in each frame 312 (e.g., frames 312-a, 312-b, and 312-c). The returned FMCW signal 350 may have the same FMCW waveform 200, but may have different propagation delays due to radar-to-target propagation delays ( 352. The distance component 142 can calculate the distance of the object 102 that reflected the returned FMCW signal 350 based on the propagation delay 352. The distance component 142 can use the following equation:

[0043] (3)

[0044] where d is the distance of the target from the radar, and c0 is the speed of light.

[0045] Figure 4 is a diagram of the FMCW instantaneous phase of example signals 410, 420, and 430 including artificial phase ramps. Attached is the transmitted FMCW signal 310 ( Figure 3 ) is provided for reference. The transmitted FMCW signal 310 can be mathematically represented as follows for the mth chirp waveform:

[0046] (4)

[0047] in , .

[0048] The transmitted FMCW signal 410 includes an artificial phase ramp 414 that varies between frames 412. For example, in a first frame 412-a, the phase of each chirp increases according to the slope of phase ramp 414-a (e.g., in a manner similar to the relative velocity toward the radar). In contrast, in a second frame 412-b, the phase of each chirp decreases according to the slope of phase ramp 414-b (e.g., in a manner similar to the relative velocity away from the radar). Again, in a third frame 412-c, the phase of each chirp increases according to the slope of phase ramp 414-c.

[0049] The transmitted FMCW signal 410 can be mathematically represented as follows for the mth chirp waveform:

[0050] (5)

[0051] in is the phase artificially introduced into the mth chirp, π and e are known constants. The sequence applied to each chirp in the frame is Can be increased or decreased linearly to produce a phase ramp. For example, in the first frame 412-a, the sequence may be increased, and in the second frame 412-b, the sequence Can be reduced.

[0052] sequence It can be expressed mathematically for the i-th frame. For example, the phase ramp sequence can be chosen as:

[0053] ,(6)

[0054] in is the carrier frequency, is the chirp period within the frame, is the speed of light, is the velocity offset of the i-th frame, and π is a known constant. Velocity offset is a parameter that specifies the phase ramp of the frame. The other parameters can be constants or set based on common FMCW configurations for coordinated interference. Can take any (positive or negative) value.

[0055] Returning FMCW signal 420 (e.g., reflected from a relatively stationary object) includes the same artificial phase ramp as transmitted FMCW signal 410. The chirp is delayed by radar-to-target-to-radar propagation delay 422, which is similar to propagation delay 352 discussed above. Therefore, the distance to the object can be calculated based on propagation delay 422.

[0056] Interfering FMCW signal 430 may be generated by another radar that includes artificial phase ramp component 120. Artificial phase ramp 434 of interfering FMCW signal 430 differs from phase ramp 414 of transmitted FMCW signal 410 in each frame. Additionally, in first frame 412-a, phase ramp 434-a of each chirp decreases, while in second frame 412-b, phase ramp 434-b in each chirp remains constant, and in third frame 412-c, phase ramp 434-c in each chirp decreases at a different rate than in first frame 412-a. Furthermore, interfering FMCW signal 430 is associated with propagation and synchronization delay 436 from the jammer to the radar. Propagation and synchronization delay 436 may be based on the distance to the jammer and the timing difference between the radar and the jammer. Therefore, determining distance based on propagation and synchronization delay 436 may result in a distance that does not correspond to the actual distance to the jammer (i.e., the phantom target).

[0057] In some implementations, the transmitted FMCW signal 410 and the interfering FMCW signal 430 can be synchronized. While the disclosed technology can operate without synchronization, when synchronized, the interfering FMCW signal 430 may be more likely to be correctly identified as a phantom target rather than noise. Synchronization does not need to be exact, but the radars should transmit concurrently so that the interfering radar arrives within the same time window as the returned signal. For example, the interfering radar may begin its frame close enough in time to ensure that the first chip of the interfering frame is received at the victim radar at any time within the interval of the first chip of the victim radar's frame. In some implementations, the radars can achieve synchronization based on a common reference time, for example, based on a global navigation satellite system (GNSS) such as the Global Positioning System (GPS). As another example, the radars can synchronize via a direct communication protocol such as V2X.

[0058] In one aspect, to allow other radars to filter out interfering signals (e.g., interfering FMCW signal 430), each FMCW radar should select a different velocity offset for each frame. Several schemes can be used to select the velocity offset for any frame. For example, in a first option, the phase ramp selection component 132 can randomly and independently of any other factors select the velocity offset for any frame i. The randomly selected velocity offsets of the interfering signal 430 may cause the phantom target to appear to have random velocities in each frame, jumping within the range of detected velocities at the victim radar. Such random velocities may be rejected as noise artifacts by the correlation / tracking filter. For another example, each radar may select a deterministic pattern of velocity offsets from a system-wide codebook. The codebook may be distributed via a standard specification or government regulation. The phase ramp selection component 132 may randomly select a pattern from the codebook. Using a codebook may prevent the possibility of randomly selected velocities appearing similar to real movement. For another example, the FMCW radars (e.g., via the communication component 134) may communicate via a radio network to assign a codebook pattern to each FMCW radar. For example, a network entity such as a roadside unit (RSU) or a base station may signal the assigned codebook pattern via signaling such as a radio resource control (RRC) message, a medium access control (MAC) control element (CE), a physical downlink control channel (PDCCH), or a physical downlink shared channel (PDSCH). As another example, FMCW radars can use direct link communications such as vehicle-to-everything (V2X) signaling to ensure that no two radars use the same mode.

[0059] Figure 5 is a diagram 500 of example signal processing of a received radar signal. Received radar signal 510 may be received at antenna 112 of radar device 110. The mth chirp of radar signal 510 will be received at the radar as , where h represents the propagation loss and channel attenuation, which is assumed to be constant over the entire frame duration. At the mixer 520, the waveform of the received signal 510 is mixed with the waveform of the transmitted FMCW signal 410, and the mixer output 522 for the mth chirp duration will be approximately equal to:

[0060] ,

[0061] where, slightly abusing notation, the constant h contains the value that does not depend on m or t All factors of .

[0062] At filter 530, the mixer output 522 is filtered (to remove broadband noise) and then The sampling frequency is sampled, which produces a 2D discrete-time signal 532, which can be expressed as:

[0063]

[0064] for ,in is the number of samples in the up-chirp interval considered by the receiver per chirp. The discrete-time signal 532 is a signal with (2D) frequency 2D complex exponential (harmonic signal), parameter and is "coded" in it.

[0065] 2D-FFT processing 540 provides identification of 2D harmonic signals (a standard estimation / detection theory problem) and also provides target range and velocity. Typically, the 2D frequency is estimated via a 2D FFT with size 540 in the "m" dimension. and in the "n" dimension are 2D FFT of . For example, may represent the "bin" index of the 2D FFT with the maximum power. The distance to the target can then be estimated as and the velocity can be estimated as When there are multiple targets, for example, K>1, the 2D signal K harmonics are included that are identified via a single 2D-FFT, and for each harmonic, the range-velocity of each target is identified as described above.The range and velocity of each target may be provided as detections to the correlation / tracking filter 550 .

[0066] The association / tracking filter 550 is tasked with processing the temporal sequence of detections identified per frame. It examines the detections' properties (e.g., distance and velocity) and groups detections in consecutive frames as originating from the same target. Multiple targets (tracks) can be detected. The association / tracking filter 550 will also identify new tracks (e.g., corresponding to new detections with properties that do not match the current track) and discard tracks (since detections with the track's properties are no longer recognized). Finally, when the detections' properties indicate they are noise artifacts, the association / tracking filter 550 will discard detections entirely (without associating them with a track).

[0067] Different selections of artificial phase ramps for the two radars allow each radar to filter out interfering signals. Assuming that both radars follow the same FMCW parameters and have synchronized frame transmissions, radar #1 transmits with a velocity offset of The phase ramp is applied to frame i, and radar #2 transmits a signal with a velocity offset of Frame i of the applied phase ramp. For simplicity, it can be assumed that the only target present to radar #1 is radar #2. Generalization to multiple targets and interference sources is straightforward. Parameters Represents the relative velocity of the two radars (assumed to be constant for the frame duration). Radar #1 RX will generate a 2D signal , which is the superposition of two harmonics: (1) the reflection of the signal sent by itself at the target: (e.g., signal 420) and (2) from the interference signal: (For example, signal 430). Since radar #1 will receive the signal ( ) is mixed with its own signal, which cancels the phase slope of the target reflection (harmonic 1 / signal 420). However, because the phase slope of radar #1 (velocity offset ) is generally related to the phase slope of radar #2 (velocity offset ) are different, so the harmonics caused by the interference signal appear as corresponding to the speed - (Harmonic 2 / Signal 430). Similarly, the effect of Radar #1 on Radar #2 will be of velocity - 's phantom target. Because and If the velocity is chosen randomly or according to a codebook that assigns unrealistically varying velocities between frames, the velocity of the phantom target will appear to vary significantly and unrealistically between frames. For example, physical objects to be detected by radar have significant mass and inertia that cannot change from positive to negative velocity within a frame on the order of milliseconds. Therefore, the correlation and tracking filters may discard detections based on interfering signals.

[0068] Figure 6 is a flow chart illustrating an example method 600 of operation of radar device 110. Method 600 may be performed by radar device 110 to detect objects 102 in the vicinity of radar device 110.

[0069] At block 610, method 600 may optionally include synchronizing the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms. In one aspect, for example, radar device 110 and / or processor 114 may execute signal generation component 130 and / or communication component 134 to synchronize radar device 110 with one or more potentially interfering radars 180 to concurrently transmit FMCW radar waveforms. Thus, radar device 110 and / or processor 114 executing signal generation component 130 and / or communication component 134 may provide components for synchronizing the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

[0070] At block 620, method 600 may include transmitting an FMCW radar waveform having an artificially introduced phase slope across the plurality of chirps within each frame of the plurality of frames. In one aspect, for example, radar device 110 and / or processor 114 may execute signal generation component 130 and / or phase slope selection component 132 to transmit an FMCW radar waveform of signal 410 having an artificially introduced phase slope 414 across the plurality of chirps 210 within each frame 312 of the plurality of frames.

[0071] In one aspect, at sub-block 622, block 620 may include generating an FMCW radar waveform for signal 410 based on a common set of parameters applicable to the potentially interfering radar. For example, the common set of parameters may include carrier frequency, chirp duration, and chirp bandwidth. Using common parameters may result in coordinated interference, where interfering signals from other radars are detected as targets (e.g., phantom targets). In one aspect, at sub-block 624, block 620 may include setting artificially introduced phase ramp 414 based on the velocity offset of radar device 110. For example, artificially introduced phase ramp 414 may be based on parameters that differ for radar device 110 from those for the potentially interfering radar.

[0072] In one aspect, at sub-block 626, block 620 may include selecting a different artificially introduced phase slope for each of the plurality of frames. In some implementations, sub-block 626 may include selecting a phase slope 414 for each frame 412 based on the random velocity offset. In some implementations, sub-block 626 may include selecting the phase slope 414 based on a pattern specified in a codebook. The phase slope selection component 132 may randomly select the pattern specified in the codebook, or the communication component 134 may communicate with the network or other radar 180 to select a unique pattern specified in the codebook.

[0073] In view of the foregoing, radar device 110 and / or processor 114 executing signal generation component 130 and / or phase ramp selection component 132 may provide means for transmitting an FMCW radar waveform having an artificially introduced phase ramp across a plurality of chirps within each of a plurality of frames.

[0074] At block 630, method 600 includes receiving a signal comprising a reflection of the FMCW radar waveform. In one aspect, for example, radar device 110 and / or processor 114 may implement signal detection component 140 to receive a signal comprising a reflection of the FMCW radar waveform (e.g., returned signal 420 and possible interfering signal 430). Thus, radar device 110 and / or processor 114 implementing signal generation component 130 and / or communication component 134 may provide components for receiving a signal comprising a reflection of the FMCW radar waveform.

[0075] At block 640, method 600 includes calculating the respective distances of one or more detected objects based on the timing of the received signals. In one aspect, for example, radar device 110 and / or processor 114 may execute signal detection component 140 and / or distance component 142 to calculate the respective distances of one or more detected objects 102 based on the timing of the received signals. Thus, radar device 110 and / or processor 114 executing signal detection component 140 and / or distance component 142 may provide means for calculating the respective distances of one or more detected objects based on the timing of the received signals.

[0076] At block 650, method 600 includes calculating the corresponding speeds of the one or more detected objects based on the phase of the chirp in the received signal. In one aspect, for example, radar device 110 and / or processor 114 may execute signal detection component 140 and / or speed component 144 to calculate the corresponding speeds of the one or more detected objects based on the phase of the chirp in the received signal. In one aspect, at sub-block 652, block 650 may include mixing the received signal (e.g., signals 420 and / or 430) with the transmitted FMCW radar waveform of signal 410 (e.g., at mixer 520) to produce mixer output 522. In some implementations, the linear phase ramp 414 of the reflection of the FMCW radar waveform (e.g., signal 106 or signal 420) from the actual target is canceled by the mixing. The slope of the linear phase ramp of mixer output 522 corresponding to the actual target is proportional to the corresponding speed of the actual target. In some implementations, the linear phase slope 434 of a received signal (e.g., jammer signal 430) transmitted by a different radar (e.g., radar 180) does not cancel the artificially introduced phase slope 414 during mixing. The slope of the linear phase slope of the mixer output 522 corresponding to the received signal 108 transmitted by the different radar 180 depends on the speed of the jammer radar, the artificially introduced phase slope 414 of the FMCW radar waveform of signal 410, and the phase slope 434 of the received signal 430. At sub-block 654, block 650 may further include identifying one or more linear phase slopes of respective potential targets across the chirp of the mixer output. At sub-block 656, block 650 may include calculating the respective speed of each respective potential target based on the corresponding linear phase slope. The respective speeds corresponding to the received signals from the different radars may depend on the actual speed of the different radars, the speed offset of the artificial phase slope of the transmitted FMCW waveform, and the speed offset of the phase slope of the received signal's waveform. Thus, radar device 110 and / or processor 114 executing signal detection component 140 and / or velocity component 144 may provide means for calculating the respective velocities of the one or more detected objects based on the phase of the chirp in the received signal.

[0077] At block 660, method 600 includes attempting to associate each of the one or more detected objects with a track based on the corresponding distance and corresponding speed. In one aspect, for example, radar device 110 and / or processor 114 may execute association component 150 to associate each of the one or more detected objects with a track based on the corresponding distance and corresponding speed. The detected object may be associated with the track that most closely matches the corresponding distance and corresponding speed. For some targets, the detected object may not be associated with any track because the corresponding distance or corresponding speed may not match any track. Such a detected object may be a first detection or a phantom target. Therefore, radar device 110 and / or processor 114 executing association component 150 may provide a component for associating each of the one or more detected objects with a track based on the corresponding distance and corresponding speed.

[0078] At block 670, method 600 includes discarding one or more detected objects or tracks of erroneously detected objects among the one or more detected objects in response to a change in velocity between frames of the detected objects being greater than a threshold. In one aspect, for example, radar device 110 and / or processor 114 may execute tracking component 160 to discard the track of the erroneously detected object among the one or more detected objects in response to a change in velocity between frames of the erroneously detected object being greater than a threshold. For example, the erroneously detected object may be based on signal 108 from second radar 180, which transmits jammer signal 430 using a second FMCW radar waveform with a different phase slope 434. The different phase slopes cause the corresponding velocity to change unrealistically between frames (e.g., a velocity change greater than a threshold). In some implementations, block 670 may include feeding the corresponding distance and corresponding velocity of each of the one or more detected objects to a correlation and tracking filter. The correlation and tracking filter may discard detected objects that cannot be associated with a track. The correlation and tracking filter may also discard the track of the erroneously detected object when the corresponding velocity between frames is unrealistic. For example, when the corresponding velocity increases, the rapid change in direction is inconsistent with the movement of the physical object. Thus, radar device 110 and / or processor 114 executing tracking component 160 may provide means for discarding tracks of one or more detected objects or erroneously detected ones of the one or more detected objects in response to a change in velocity between frames of the detected objects being greater than a threshold.

[0079] Some further example clauses

[0080] Specific implementation examples are described in the following numbered clauses:

[0081] 1. A method for object tracking for a radar, the method comprising:

[0082] transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames;

[0083] receiving a signal comprising a reflection of the FMCW radar waveform;

[0084] calculating respective distances of one or more detected objects based on a timing sequence of the received signals;

[0085] calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal;

[0086] attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; and

[0087] In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

[0088] 2. The method of clause 1 , wherein transmitting the FMCW radar waveform comprises generating the FMCW radar waveform based on a common parameter set applicable to potentially interfering radars.

[0089] 3. The method of clause 2, wherein the common set of parameters comprises carrier frequency, chirp duration, and chirp bandwidth.

[0090] 4. A method according to any of clauses 1 to 3, wherein the falsely detected object is based on a signal from a second radar, the second radar transmitting a second FMCW radar waveform having a different phase slope.

[0091] 5. The method of any of clauses 1 to 4, wherein calculating the respective speeds of one or more detected objects based on the phase of the chirp in the received signal comprises:

[0092] mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output;

[0093] one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and

[0094] The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

[0095] 6. The method of clause 5, wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

[0096] 7. The method of clause 5, wherein the linear phase slope of the received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein the slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on the speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

[0097] 8. A method according to clause 7, wherein the respective speed corresponding to the received signal from the different radar depends on the actual speed of the different radar, the speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and the speed offset of the phase slope of the received signal.

[0098] 9. The method of any of clauses 1 to 8, further comprising setting the artificially introduced phase ramp based on a velocity offset of the radar.

[0099] 10. The method of any of clauses 1 to 9, wherein transmitting the FMCW radar waveform comprises selecting a different phase ramp for each frame in the plurality of frames.

[0100] 11. The method of clause 10, wherein selecting the different phase slope for each frame of the plurality of frames comprises selecting the artificially introduced phase slope for each frame based on a random velocity offset.

[0101] 12. The method of clause 10, wherein selecting the different phase slope for each frame in the plurality of frames comprises selecting the artificially introduced phase slope based on a pattern specified in a codebook.

[0102] 13. The method of any of clauses 1 to 12, further comprising synchronizing the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

[0103] 14. A method according to any one of clauses 1 to 13, wherein discarding the trajectory of the one or more detected objects or the erroneously detected object among the one or more detected objects comprises feeding the corresponding distance and the corresponding speed of each of the one or more detected objects to an association and tracking filter.

[0104] 15. A radar, comprising:

[0105] one or more antennas;

[0106] a memory storing executable instructions; and

[0107] at least one processor communicatively coupled to the one or more antennas and the memory, the processor configured to:

[0108] transmitting, via the one or more antennas, a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames;

[0109] receiving, via the one or more antennas, a signal comprising a reflection of the FMCW radar waveform;

[0110] calculating respective distances of one or more detected objects based on a timing sequence of the received signals;

[0111] calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal;

[0112] attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; and

[0113] In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

[0114] 16. The radar of clause 15, wherein the at least one processor is configured to generate the FMCW radar waveform based on a common set of parameters applicable to potentially interfering radars.

[0115] 17. The radar of clause 16, wherein the common set of parameters comprises carrier frequency, chirp duration, and chirp bandwidth.

[0116] 18. A radar according to any of clauses 15 to 17, wherein the falsely detected object is based on a signal from a second radar transmitting a second FMCW radar waveform having a different phase slope.

[0117] 19. The radar of any of clauses 15 to 18, wherein the at least one processor is configured to:

[0118] mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output;

[0119] one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and

[0120] The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

[0121] 20. The radar of clause 19, wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

[0122] 21. The radar of clause 19, wherein the linear phase slope of a received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein the slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on the speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

[0123] 22. The radar of clause 21 , wherein the respective speed corresponding to the received signal from the different radar depends on the actual speed of the different radar, the speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and the speed offset of the phase slope of the received signal.

[0124] 23. The radar of any of clauses 15 to 22, wherein the at least one processor is configured to set the artificially introduced phase ramp based on a velocity offset of the radar.

[0125] 24. The radar of any of clauses 15 to 23, wherein the at least one processor is configured to select a different phase ramp for each frame of the plurality of frames.

[0126] 25. The radar of clause 24, wherein the at least one processor is configured to select the artificially introduced phase ramp for each frame based on a random velocity offset.

[0127] 26. The radar of clause 24, wherein the at least one processor is configured to select the artificially introduced phase ramp based on a pattern specified in a codebook.

[0128] 27. The radar of any of clauses 15 to 26, wherein the at least one processor is configured to synchronize the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

[0129] 28. The radar of any of clauses 15 to 26, wherein the at least one processor is configured to feed the respective range and the respective velocity of each of the one or more detected objects to a correlation and tracking filter.

[0130] 29. A radar, comprising:

[0131] means for transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp across a plurality of chirps within each of a plurality of frames;

[0132] means for receiving a signal comprising a reflection of said FMCW radar waveform;

[0133] means for calculating respective distances of one or more detected objects based on the timing of the received signals;

[0134] means for calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal;

[0135] means for attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; and

[0136] means for discarding the track of one or more detected objects or an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

[0137] 30. The radar of clause 29, wherein the means for transmitting the FMCW radar waveform is configured to generate the FMCW radar waveform based on a common set of parameters applicable to potentially interfering radars.

[0138] 31. The radar of clause 30, wherein the common set of parameters comprises carrier frequency, chirp duration, and chirp bandwidth.

[0139] 32. A radar according to any of clauses 29 to 31, wherein the falsely detected object is based on a signal from a second radar transmitting a second FMCW radar waveform having a different phase slope.

[0140] 33. A radar according to any of clauses 29 to 32, wherein the means for calculating the respective velocities of one or more detected objects based on the phase of the chirp in the received signal is configured to:

[0141] mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output;

[0142] one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and

[0143] The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

[0144] 34. The radar of clause 33, wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

[0145] 35. The radar of clause 33, wherein the linear phase slope of a received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein the slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on the speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

[0146] 36. A radar according to clause 35, wherein the respective speed corresponding to the received signal from the different radar depends on the actual speed of the different radar, the speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and the speed offset of the phase slope of the received signal.

[0147] 37. A radar according to any of clauses 29 to 36, further comprising means for setting the artificially introduced phase slope based on a velocity offset of the radar.

[0148] 38. The radar of any of clauses 29 to 37, wherein the means for transmitting the FMCW radar waveform is configured to select a different phase slope for each of the plurality of frames.

[0149] 39. The radar of clause 38, wherein selecting the different phase slope for each frame of the plurality of frames comprises selecting the artificially introduced phase slope for each frame based on a random velocity offset.

[0150] 40. The radar of clause 38, wherein the means for transmitting the FMCW radar waveform is configured to select the artificially introduced phase ramp based on a pattern specified in a codebook.

[0151] 41. A radar according to any of clauses 29 to 40, further comprising means for synchronising the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

[0152] 42. A radar according to any one of clauses 29 to 41, wherein the component for discarding the track of the one or more detected objects or the erroneously detected object among the one or more detected objects is configured to feed the corresponding distance and the corresponding speed of each of the one or more detected objects to a correlation and tracking filter.

[0153] 43. A non-transitory computer-readable medium storing computer-executable code that, when executed by a processor of a radar, causes the processor to:

[0154] transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames;

[0155] receiving a signal comprising a reflection of the FMCW radar waveform;

[0156] calculating respective distances of one or more detected objects based on a timing sequence of the received signals;

[0157] calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal;

[0158] attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; and

[0159] In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

[0160] 44. The non-transitory computer-readable medium of clause 43, wherein the code for transmitting the FMCW radar waveform comprises code for generating the FMCW radar waveform based on a common set of parameters applicable to potentially interfering radars.

[0161] 45. The non-transitory computer-readable medium of clause 44, wherein the common set of parameters comprises carrier frequency, chirp duration, and chirp bandwidth.

[0162] 46. ​​The non-transitory computer-readable medium of any of clauses 43-45, wherein the falsely detected object is based on a signal from a second radar that transmits a second FMCW radar waveform with a different phase slope.

[0163] 47. The non-transitory computer-readable medium of any of clauses 43 to 46, wherein the code for calculating the respective velocities of one or more detected objects based on the phase of the chirp in the received signal comprises code for:

[0164] mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output;

[0165] one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and

[0166] The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

[0167] 48. The non-transitory computer-readable medium of clause 47, wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

[0168] 49. The non-transitory computer-readable medium of clause 47, wherein a linear phase slope of a received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein a slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on a speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

[0169] 50. A non-transitory computer-readable medium according to clause 49, wherein the respective speeds corresponding to the received signals from the different radars are dependent on the actual speeds of the different radars, the speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and the speed offset of the phase slope of the received signals.

[0170] 51. The non-transitory computer-readable medium of any of clauses 43 to 50, further comprising code for setting the artificially introduced phase ramp based on a velocity offset of the radar.

[0171] 52. The non-transitory computer-readable medium of any of clauses 43 to 51, wherein the code for transmitting the FMCW radar waveform comprises code for selecting a different phase ramp for each frame in the plurality of frames.

[0172] 53. The non-transitory computer-readable medium of clause 52, wherein the code for selecting the different phase slope for each frame of the plurality of frames comprises code for selecting the artificially introduced phase slope for each frame based on a random velocity offset.

[0173] 54. The non-transitory computer-readable medium of clause 52, wherein the code for selecting the different phase slope for each frame in the plurality of frames comprises code for selecting the artificially introduced phase slope based on a pattern specified in a codebook.

[0174] 55. The non-transitory computer-readable medium of any of clauses 43 to 54, further comprising code for synchronizing the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

[0175] 56. A non-transitory computer-readable medium according to any one of clauses 43 to 55, wherein the code for discarding the trajectory of the one or more detected objects or the erroneously detected object among the one or more detected objects includes code for feeding the corresponding distance and the corresponding speed of each of the one or more detected objects to an association and tracking filter.

[0176] The above detailed description, set forth above in conjunction with the accompanying drawings, describes examples and does not represent the only examples that can be implemented or fall within the scope of the claims. The term "example" as used in this description means "serving as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The detailed description includes specific details to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0177] Information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned in the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer executable code or instructions stored on a computer-readable medium, or any combination thereof.

[0178] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed using a specially programmed device designed to perform the functions described herein, such as, but not limited to, a processor, a digital signal processor (DSP), an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The specially programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The specially programmed processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration).

[0179] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted via a non-transitory computer-readable medium as one or more instructions or code. Other examples and implementations fall within the scope and spirit of this disclosure and the appended claims. For example, due to the nature of software, the functions described above may be implemented using hardware, firmware, hardwiring, software executed by a specially programmed processor, or a combination of any of these. Features implementing the functions may also be physically located at different locations, including being distributed so that various parts of the functions are implemented at different physical locations. Additionally, as used herein, including in the claims, the term "or" used in a list of items, such as beginning with "at least one of," indicates a dispersed list, so that, for example, a list such as "at least one of A, B, or C" means A or B or C or AB or AC or BC or ABC (i.e., A and B and C).

[0180] Computer-readable media includes both computer storage media and communication media, including any media that facilitates the transfer of computer programs from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer. By way of example and not limitation, computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, or any other medium that can be used to carry or store desired program code components in the form of instructions or data structures and can be accessed by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor. In addition, any connection is properly referred to as a computer-readable medium. For example, if the software is sent from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0181] The previous description of the present disclosure is provided to enable those skilled in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the essence or scope of the present disclosure. Furthermore, although elements of the described aspects and / or embodiments are described or claimed in the singular, the plural form may also be envisioned unless expressly stated to be limited to the singular. Additionally, unless otherwise stated, all or part of any aspect and / or embodiment may be used together with all or part of any other aspect and / or embodiment. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for object tracking for a radar, the method comprising: transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames; receiving a signal comprising a reflection of the FMCW radar waveform; calculating respective distances of one or more detected objects based on a timing sequence of the received signals; calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal; attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; as well as In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

2. The method of claim 1 , wherein transmitting the FMCW radar waveform comprises: The FMCW radar waveform is generated based on a common set of parameters applicable to potentially interfering radars.

3. The method of claim 2, wherein the common parameter set comprises carrier frequency, chirp duration, and chirp bandwidth.

4. The method of claim 1 , wherein the falsely detected object is based on a signal from a second radar that transmits a second FMCW radar waveform having a different phase slope.

5. The method of claim 1 , wherein calculating the respective velocities of one or more detected objects based on the phase of the chirp in the received signal comprises: mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output; one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

6. The method of claim 5 , wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

7. The method of claim 5 , wherein a linear phase slope of a received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein a slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on a speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

8. The method of claim 7 , wherein the respective speeds corresponding to the received signals from the different radars are dependent on an actual speed of the different radars, a speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and a speed offset of the phase slope of the received signal.

9. The method according to claim 1, further comprising: The artificially introduced phase ramp is set based on a velocity offset of the radar.

10. The method of claim 1 , wherein transmitting the FMCW radar waveform comprises: A different phase ramp is selected for each frame in the plurality of frames.

11. The method of claim 10 , wherein selecting the different phase ramp for each of the plurality of frames comprises: The artificially introduced phase ramp is selected for each frame based on a random velocity offset.

12. The method of claim 10 , wherein selecting the different phase ramp for each frame in the plurality of frames comprises: The artificially introduced phase ramp is selected based on a pattern specified in a codebook.

13. The method according to claim 1, further comprising: The radar is synchronized with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

14. The method of claim 1 , wherein discarding the one or more detected objects or the track of the erroneously detected object among the one or more detected objects comprises: The respective distance and the respective velocity of each of the one or more detected objects are fed to an association and tracking filter.

15. A radar, comprising: one or more antennas; a memory storing executable instructions; and at least one processor communicatively coupled to the one or more antennas and the memory, the processor configured to: transmitting, via the one or more antennas, a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames; receiving, via the one or more antennas, a signal comprising a reflection of the FMCW radar waveform; calculating respective distances of one or more detected objects based on a timing sequence of the received signals; calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal; attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; as well as In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

16. The radar of claim 15, wherein the at least one processor is configured to generate the FMCW radar waveform based on a common set of parameters applicable to potentially interfering radars.

17. The radar of claim 16, wherein the common parameter set includes carrier frequency, chirp duration, and chirp bandwidth.

18. The radar of claim 15, wherein the falsely detected object is based on a signal from a second radar transmitting a second FMCW radar waveform having a different phase slope.

19. The radar of claim 15, wherein the at least one processor is configured to: mixing the received signal with the transmitted FMCW radar waveform to produce a mixer output; one or more linear phase ramps across the chirp output by the mixer to identify corresponding potential targets; and The respective speed of each respective potential target is calculated based on the corresponding linear phase ramp of the respective potential target.

20. The radar of claim 19, wherein a linear phase slope of the reflection of the FMCW radar waveform from an actual target is canceled by the mixing, wherein a slope of the linear phase slope of the mixer output corresponding to the actual target is proportional to the corresponding speed of the actual target.

21. The radar of claim 19 , wherein a linear phase slope of a received signal from a different radar does not cancel the artificially introduced phase slope during the mixing, and wherein a slope of the linear phase slope of the mixer output corresponding to the received signal from the different radar depends on a speed of the different radar, the artificially introduced phase slope of the FMCW radar waveform, and the phase slope of the received signal.

22. The radar of claim 21 , wherein the respective speeds corresponding to the received signals from the different radars are dependent on an actual speed of the different radars, a speed offset of the artificially introduced phase slope of the transmitted FMCW waveform, and a speed offset of the phase slope of the received signal.

23. The radar of claim 15, wherein the at least one processor is configured to set the artificially introduced phase ramp based on a velocity offset of the radar.

24. The radar of claim 15, wherein the at least one processor is configured to select a different phase ramp for each frame in the plurality of frames.

25. The radar of claim 24, wherein the at least one processor is configured to select the artificially introduced phase ramp for each frame based on a random velocity offset.

26. The radar of claim 24, wherein the at least one processor is configured to select the artificially introduced phase ramp based on a pattern specified in a codebook.

27. The radar of claim 15, wherein the at least one processor is configured to synchronize the radar with one or more potentially interfering radars to concurrently transmit FMCW radar waveforms.

28. The radar of claim 15, wherein the at least one processor is configured to feed the respective range and the respective velocity of each of the one or more detected objects to a correlation and tracking filter.

29. A radar, comprising: means for transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp across a plurality of chirps within each of a plurality of frames; means for receiving a signal comprising a reflection of said FMCW radar waveform; means for calculating respective distances of one or more detected objects based on the timing of the received signals; means for calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal; means for attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; and means for discarding the track of one or more detected objects or an erroneously detected object of the one or more detected objects in response to a change in velocity between frames of the detected object being greater than a threshold.

30. A non-transitory computer readable medium storing computer executable code that, when executed by a processor of a radar, causes the processor to: transmitting a frequency modulated continuous wave (FMCW) radar waveform having an artificially introduced phase ramp on a plurality of chirps within each of a plurality of frames; receiving a signal comprising a reflection of the FMCW radar waveform; calculating respective distances of one or more detected objects based on a timing sequence of the received signals; calculating respective velocities of the one or more detected objects based on the phase of the chirp in the received signal; attempting to associate each of the one or more detected objects with a track based on the respective distance and the respective speed; as well as In response to a change in velocity between frames of the detected object being greater than a threshold, the trajectory of one or more detected objects or an erroneously detected object among the one or more detected objects is discarded.

Images