Complementary-Pair STFM Radar Waveforms for Fast 4D Imaging

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Solution Overview

Problem

Current automotive radar systems face challenges in meeting ultra-high-resolution imaging requirements for autonomous driving due to hardware complexity and cost, with existing techniques either requiring extensive hardware upgrades or compromising on scan time and Doppler resolution.

Innovation Solution

Implementing space-time-frequency multiplexing (STFM) using complementary pair waveforms, such as Golay pairs, to efficiently scan multiple sectors with fewer Tx/Rx chains, reducing hardware complexity while maintaining fast scanning and high Doppler resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple Tx/Rx chains are used to achieve ultra-high-resolution imaging, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveimaging resolutionVSAvoidhardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple complementary pair sequences across different frequencies and spatial sectors into a unified STFM framework. By merging these sequences and using their complementary properties, the system achieves high-resolution imaging with fewer physical Tx/Rx chains, thus reducing hardware complexity while maintaining measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the radar system multi-functional by enabling a single Tx/Rx chain to perform multiple scanning sectors and process multiple complementary sequences. This universal approach allows the system to achieve ultra-high-resolution imaging capabilities that would traditionally require multiple dedicated chains, thereby reducing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Productivity

If more Tx/Rx chains are deployed to increase scanning speed, then productivity is improved, but device complexity increases

Engineering Contradiction:
Improvescanning speedVSAvoidhardware complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs periodic transmission of complementary pair sequences at different frequencies and sectors. By using periodic action with the STFM framework, the system achieves fast scanning through efficient time-multiplexed sequences, improving productivity without requiring proportional increases in hardware complexity.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent changes multiple parameters including frequency, time, and spatial sector to achieve fast scanning. By varying these parameters across different complementary sequences, the system accomplishes rapid multi-sector scanning with a reduced number of Tx/Rx chains, thus improving productivity while controlling device complexity.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If complementary pair sequences are transmitted at multiple frequencies and sectors, then measurement precision is improved, but use of energy increases

Engineering Contradiction:
ImproveDoppler resolutionVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent segments the overall radar operation into multiple complementary pair transmissions at different frequencies and sectors. By dividing the measurement task into these segmented complementary sequences, the system achieves high Doppler resolution through their combined processing while managing energy consumption more efficiently than continuous high-power transmission would require.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3983823B1Space time frequency multiplexing (STFM) for radar systems using complementary pair waveforms
Publication Date: 2025.08.13 QUALCOMM INC
  • EP3983823B1 patent drawingFigure 1
  • EP3983823B1 patent drawingFigure 2
  • EP3983823B1 patent drawingFigure 3

AI summary

Space-time-frequency multiplexing (STFM) schemes for radio frequency (RF) scanning are disclosed in which complementary pairs of sequences (or "Golay pairs") are transmitted at different times using multiple frequencies. The transmission and reception of the sequences can occur over multiple transmit (Tx) and/or receive (Rx) radio sectors to scan an entire area for range, azimuth, elevation, and (optionally) velocity of objects therein.