Radar-Unique Phase Codes for Fleet Interference Mitigation
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Solution Overview
Problem
Radar-to-radar interference in autonomous vehicle fleets is challenging due to the use of the same waveforms by multiple radars, leading to increased 'ghost' detections and interference that conventional methods fail to adequately address.
Innovation Solution
Implementing a common phase code for all radar transmitters within a vehicle, which is unique or quasi-unique, and compensating this phase on the receive side to introduce incoherence, thereby spreading interfering energy in the Doppler domain and reducing false detections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional radar waveforms are used by multiple radars in a fleet, then radar systems can detect and classify objects, but radar-to-radar interference increases causing ghost detections and false positives
Solution Approach 1:
The patent applies parameter changes by modifying the phase code parameter of radar waveforms. Each radar in the fleet is assigned a unique phase code that modulates the transmitted signal, changing the waveform characteristics while maintaining compatibility with existing radar infrastructure. This allows differentiation between multiple radars and eliminates interference-induced ghost detections.
2Object-affected harmful factors
If unique phase codes are assigned to each radar transmitter, then intra-fleet interference is mitigated, but device complexity increases due to additional phase management
Solution Approach 1:
The patent implements preliminary action by pre-assigning unique phase codes to each radar transmitter in the fleet before operation. This phase code assignment is configured in advance and remains static during normal operation, eliminating the need for complex real-time phase management while still providing interference mitigation benefits.
3Measurement precision
If phase codes are compensated on the receive side, then false detections are reduced, but signal processing complexity increases
Solution Approach 1:
The patent applies the taking out principle by extracting the phase code information from the received signal through correlation processing. The known phase code sequence is used as a reference to selectively extract the desired signal component while rejecting interference, achieving precise detection without requiring complex full-signal processing.
Data Source
AI summary
A radar system comprises transmit antennas configured to transmit a radar signal and receive antennas that receive a radar return. The radar system further comprises circuitry configured to perform acts, the acts comprising generating a phase-shifted radar signal using a unique phase code that is commonly assigned to all transmitters included in the radar system. The acts further comprise transmitting the phase-shifted radar signal from transmit antennas and receiving a radar return at receive antennas. Additionally, the acts comprise, during signal processing, performing phase compensation by multiplying a radar signal received in the radar return by a phase compensation value that is commonly assigned to all receivers included in the radar system in order to remove the phase shift. The acts also comprise outputting an un-shifted processed radar signal.