Radar Signal Detection Using Phase-Code Modulation in Multi-Radar Networks
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Solution Overview
Problem
Existing radar systems face challenges in accurately detecting real targets due to interference from false alarms caused by multi-radar networks, with current methods either reducing distance resolution, wasting time resources, or failing to fully eliminate interference.
Innovation Solution
A signal detection method involving phase code modulation of sounding signals in different time periods to determine false alarm targets and improve target detection reliability and distance resolution without affecting bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If frequency staggering is used to resolve interference, then interference signals are pushed outside receiver bandwidth, but distance resolution is severely affected
Solution Approach 1:
The patent segments the interference resolution process into two independent stages: frequency domain filtering (to remove interference) and time domain correlation (to preserve distance resolution). By separating these functions, the system can suppress interference signals outside the bandwidth while maintaining accurate distance measurement through temporal signal analysis.
Solution Approach 2:
The patent transitions from relying solely on frequency domain separation to incorporating time domain processing. By adding the time dimension to signal analysis through correlation processing, the system achieves interference rejection without sacrificing distance resolution, effectively moving the problem solution from one dimension to another.
2Object-affected harmful factors
If time synchronization is used to resolve interference, then interference is reduced, but time resources are wasted and working period is prolonged
Solution Approach 1:
The patent applies partial time synchronization by aligning only the critical portions of multi-radar signals that contain target information, rather than synchronizing entire frame structures. This selective approach reduces interference effectively while minimizing the time overhead, avoiding the excessive time consumption of complete frame synchronization.
Solution Approach 2:
The patent extracts and processes only the relevant signal components that contain both target information and interference, separating them through correlation analysis. By focusing computation on extracted signal portions rather than entire synchronized frames, the system reduces interference while minimizing time resource consumption.
3Object-affected harmful factors
If code division multiple access is used to suppress interference, then interference is reduced by about 10 dB, but false alarm cannot be totally eliminated and low noise increases
Solution Approach 1:
The patent introduces cross-correlation processing as an intermediary step between signal reception and target detection. This intermediary operation compares received signals with expected radar signal patterns, providing a reliable mechanism to distinguish true targets from false alarms caused by interference, thereby eliminating false alarms completely rather than merely suppressing them.
4Object-affected harmful factors
If code division multiple access is used to suppress interference, then interference is reduced, but side lobe is raised
Solution Approach 1:
The patent replaces code-based interference suppression with a correlation-based approach that uses temporal signal matching instead of code orthogonality. This substitution eliminates the side lobe raising effect inherent in code division methods, as correlation processing naturally produces sharp peaks with minimal side lobes, improving measurement precision while maintaining interference suppression.
Data Source
AI summary
This application provides a signal detection method and apparatus. One example method includes: transmitting, by a first radar, a first sounding signal in a first time period of a first frame; transmitting, by the first radar, a second sounding signal in a second time period of the first frame; receiving, by the first radar, reflected signals corresponding to the first sounding signal and the second sounding signal; and determining, by the first radar, a false alarm target based on a difference between a first distance-velocity spectrum and a second distance-velocity spectrum, wherein the second sounding signal is a signal obtained through first phase code modulation based on the first sounding signal, the first distance-velocity spectrum is obtained based on a first reflected signal corresponding to the first sounding signal, and the second distance-velocity spectrum is obtained based on a second reflected signal corresponding to the second sounding signal.