Multi-Radar Chirp Phase Coding for Interference-Resilient Coexistence

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Solution Overview

Problem

Existing radar systems in autonomous vehicles face challenges in efficiently transmitting and receiving encoded information bits due to interference and multipath effects, which can lead to misdetection and inaccurate object detection.

Innovation Solution

Implementing phase-shift keying (PSK) modulation and demodulation techniques for radar signals, using phase-coded symbols to convey encoded information bits and determine phase differences between transmitter and receiver radars, enabling accurate decoding of radar signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If radar systems transmit encoded information bits using conventional modulation techniques, then the system can communicate between vehicles, but interference and multipath effects cause misdetection and inaccurate object detection

Engineering Contradiction:
Improvedetection accuracyVSAvoidinterference and multipath effects
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies phase-shift keying (PSK) modulation to encode information bits onto radar signals by varying the phase of the signal. This parameter change enables reliable communication between vehicles while maintaining radar detection functionality, allowing the system to distinguish between direct signals and multipath reflections through phase analysis

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces reference symbols with known phase modulation as intermediaries to enable phase difference determination between transmitter and receiver radars. These reference symbols serve as a mediator to calculate phase offsets, which are then used to equalize and correct multipath interference effects, improving detection accuracy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If radar systems use phase-coded symbols to convey information, then communication reliability improves, but the complexity of signal processing increases

Engineering Contradiction:
Improveinformation transmission reliabilityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the radar signal into chirps, with some chirps carrying encoded information bits and others containing reference symbols with known phase modulation. This segmentation allows the receiver to process and equalize phase differences using reference symbols while decoding information from data-chirps, reducing overall processing complexity through structured division of signal components

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback through the use of reference symbols that provide known phase information. The receiver uses this feedback to determine phase differences between transmitter and receiver radars, equalize phase errors, and correct multipath effects. This feedback mechanism enables reliable information decoding while managing processing complexity through systematic phase correction

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the accuracy of radar systems in autonomous vehicles by improving the detection of objects and reducing misdetection, thereby enhancing safety and reliability in autonomous driving scenarios.

Implementation Method 1

generating a first set of phase-shift keying (PSK) modulated phase-coded symbols to convey the plurality of encoded information bits

Methodology Applied
Scientific EffectPhase-shift keying (PSK) modulation: Phase Modulation

Implementation Method 2

determining a phase difference between the receiver radar and the transmitter radar based on a phase of the plurality of chirps of the radar signal phase coded according to the second set of PSK modulated phase-coded symbols

Methodology Applied
Scientific EffectPhase detection: Phase Modulation

Implementation Method 3

a radar system for transmitting a FMCW radar sensor signal

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 4

the radar echoes are phase-demodulated

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4038407B1Radar coordination for multi-radar coexistence
Publication Date: 2026.03.18 QUALCOMM INC
  • EP4038407B1 patent drawingFigure 1
  • EP4038407B1 patent drawingFigure 2A
  • EP4038407B1 patent drawingFigure 2B

AI summary

Disclosed are techniques for transmitting and receiving a plurality of encoded information bits on a radar signal. In an aspect, a transmitter radar generates a first set of modulated phase-coded symbols to convey the plurality of encoded information bits, generates a second set of modulated phase-coded symbols as reference symbols having a known phase modulation, phase codes a plurality of chirps of the radar signal according to the first and second sets of modulated phase-coded symbols, and transmits the plurality of chirps according to the phase coding. A receiver radar determines a phase difference between the receiver and transmitter radars based on a phase of the plurality of chirps, equalizes the phase based on the determined phase difference, determines a phase code of the first set of symbols based on the equalized phase, and decodes the encoded information bits based on the phase code of the first set of symbols.