Automotive Radar Interference Mitigation via Dynamic Waveform Variation
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Solution Overview
Problem
Current automotive radar systems using frequency-modulated continuous-wave (FMCW) modulation lack effective interference mitigation solutions, leading to increased interference as more vehicles with advanced driver assistance systems (ADAS) are equipped with radar sensors, and existing solutions for phase-modulated continuous-wave modulation are complex, power-consuming, and costly.
Innovation Solution
The proposed solution involves generating and transmitting a series of wave frames with varying chirps, each with unique frequency characteristics, using a pseudo-random sequence and real-time clock values to dynamically change aspects like ramp rates and frequency ranges, allowing for interference mitigation while reusing existing FMCW algorithms and architecture, and enhancing signal-to-noise ratio through waveform variation and interpolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If FMCW modulation is used in automotive radar systems, then the system architecture remains cost-effective and simple, but interference mitigation capability deteriorates as more vehicles with radar sensors are deployed
Solution Approach 1:
The patent applies dynamics by making the FMCW waveform parameters dynamic rather than static. Specifically, the ramp rate, frequency range, and chirp duration are varied over time according to a pseudo-random sequence, allowing the radar to adapt its transmission characteristics dynamically. This dynamic variation enables interference mitigation while maintaining the cost-effective FMCW architecture, as the changes are implemented through software control of existing hardware components.
Solution Approach 2:
The patent implements parameter changes by modifying key FMCW waveform parameters including ramp rate, frequency range, and chirp duration. These parameters are adjusted according to a pseudo-random sequence to create time-varying waveforms that can distinguish between desired signals and interference. The parameter changes are achieved through digital signal processing in the existing FMCW architecture without requiring hardware modifications.
2Object-affected harmful factors
If phase-modulated continuous-wave (PMCW) modulation is used for interference mitigation, then interference mitigation capability improves, but hardware complexity, power consumption, and cost increase
Solution Approach 1:
The patent applies copying by using a pseudo-random sequence to generate reference waveforms that are copied and stored in memory. These reference waveforms are then used for correlation processing with received signals to identify and mitigate interference. The pseudo-random sequence acts as a unique fingerprint that can be replicated and used for signal identification without requiring complex hardware modifications, thus achieving interference mitigation while maintaining hardware simplicity.
Solution Approach 2:
The patent substitutes mechanical/hardware-based interference mitigation approaches with software-based signal processing. Instead of using complex hardware modulation schemes like PMCW, the invention uses digital signal processing techniques including pseudo-random sequence generation, correlation processing, and interference identification algorithms. This substitution achieves interference mitigation capability while maintaining the simplicity and cost-effectiveness of the FMCW hardware architecture.
3Reliability
If multiple vehicles with radar sensors are deployed, then ADAS coverage and safety improve, but interference severity increases
Solution Approach 1:
The patent implements feedback by using the received signal information to identify interference sources and adjust the waveform parameters accordingly. The correlation processing compares received signals with reference waveforms generated from pseudo-random sequences, enabling the system to detect interference patterns and adapt its transmission characteristics. This feedback mechanism allows multiple radar systems to coexist by enabling each system to identify and mitigate interference from other vehicles while maintaining ADAS safety functionality.
Data Source
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AI summary
Methods and apparatuses pertaining to radar interference mitigation are described. A processor associated with an apparatus may generate a plurality of wave frames such that one or more aspects of the plurality of wave frames vary from one wave frame to another wave frame of the plurality of wave frames. Each of the plurality of wave frames may respectively include a plurality of chirps. A wireless transmitter associated with the apparatus may transmit the plurality of wave frames. A wireless receiver associated with the apparatus may receive one or more reflected waves comprising at least a portion of one or more of the wave frames reflected by an object. The processor may determine a distance between the object and the apparatus, a speed of the objet, or both, based on an analysis of the one or more reflected waves.