Phase-Modulated Sensing Signals for Low-Sidelobe SFCW Radar
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Solution Overview
Problem
Stepped frequency continuous wave (SFCW) radar sensing has poor auto-correlation performance and high impulse response sidelobes, leading to non-ideal sensing performance.
Innovation Solution
Implement phase modulation and control information to vary the phase of sensing signals continuously over time, reducing impulse response sidelobes and improving sensing performance by using phase modulation and control information to determine the phase of the first sensing signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If stepped frequency continuous wave (SFCW) is used for radar sensing, then hardware requirements are reduced and integration with OFDM communication hardware is facilitated, but auto-correlation performance deteriorates and impulse response sidelobes increase
Solution Approach 1:
The patent applies phase modulation to the SFCW signal, changing the phase parameter continuously over time according to a predetermined phase sequence. This transforms the original SFCW signal into a phase-modulated SFCW signal that maintains the frequency stepping characteristics while introducing continuous phase variation, thereby improving auto-correlation performance and reducing impulse response sidelobes without increasing hardware complexity
Solution Approach 2:
The patent combines SFCW frequency modulation with phase modulation to create a composite waveform. The signal incorporates both the frequency stepping characteristic (Δf per symbol) and continuous phase variation (φ[n]), forming a composite modulated signal that leverages the advantages of both modulation techniques while mitigating their individual drawbacks
2Device complexity
If stepped frequency continuous wave (SFCW) is used for radar sensing, then hardware requirements are reduced and integration with OFDM communication hardware is facilitated, but impulse response sidelobes increase
Solution Approach 1:
The patent modifies the phase parameter of the SFCW signal by applying continuous phase modulation according to a predetermined phase sequence. This phase parameter change suppresses the impulse response sidelobes while maintaining the frequency stepping structure that enables simple hardware implementation and OFDM integration
3Measurement precision
If phase modulation with continuous phase variation is applied to sensing signals, then auto-correlation performance improves and impulse response sidelobes reduce, but signal processing complexity increases
Solution Approach 1:
The patent employs a predetermined phase sequence that is determined in advance and stored in the system. This preliminary preparation of the phase modulation pattern simplifies the real-time signal processing, as the phase variations follow a pre-planned sequence rather than requiring complex real-time calculation, thereby reducing processing complexity while maintaining improved auto-correlation performance
Data Source
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AI summary
This application provides a sensing method and apparatus. The method may include: A sensing transmit end determines phase modulation and control information of a first sensing signal, where the phase modulation and control information is used to control a phase of the first sensing signal to continuously vary over time; and the sensing transmit end sends the first sensing signal to a sensing target. In this solution, a waveform expression of the first sensing signal includes the phase modulation and control information, and the phase modulation and control information can be used to control the phase of the first sensing signal to continuously vary over time. Because phases are strongly related to auto-correlation performance of signals, using signals whose phases continuously varies over time for sensing can enhance auto-correlation performance of the signals, reduce impulse response sidelobes of the signals, and improving sensing performance.