Orthogonal Two-Phase Radar Coding for Ambiguity and Occlusion
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Solution Overview
Problem
Radar systems face issues of range ambiguity and occlusion due to pulse repetition frequency and transceiving switching, which traditional methods fail to adequately address.
Innovation Solution
A method utilizing orthogonal two-phase coded signals, optimized through a walsh matrix and genetic algorithm, to minimize transmission pulse width and employ multiple pulse repetition frequencies for echo processing, ensuring accurate range and velocity measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high pulse repetition frequency (HPRF) working mode is used to solve velocity ambiguity, then velocity measurement precision is improved, but range ambiguity and range occlusion occur
Solution Approach 1:
The patent segments the pulse repetition frequency into multiple discrete values (first PRF and second PRF) rather than using a single HPRF. This segmentation allows the system to switch between different PRFs to resolve range ambiguity while maintaining velocity measurement capability through the orthogonal two-phase coded signals.
Solution Approach 2:
The patent dynamically adjusts the pulse repetition frequency between two different values (first PRF and second PRF) based on detection needs. The system switches between these PRFs to eliminate range ambiguity and occlusion while maintaining accurate velocity measurement through the dynamic variation in transmission parameters.
2Measurement precision
If multiple different pulse repetition intervals (PRIs) are used to solve range ambiguity, then range measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent changes the pulse repetition interval parameter between two specific values (first PRI and second PRI) to resolve range ambiguity. By using only two discrete PRI values rather than multiple or continuous variations, the system achieves range ambiguity resolution while keeping the complexity of signal processing manageable through the orthogonal two-phase coded signal framework.
3Measurement precision
If transmission pulse width is minimized to reduce range blind area, then range resolution is improved, but energy transmission is reduced
Solution Approach 1:
The patent optimizes the transmission pulse width to a specific minimum value that balances range resolution and energy transmission. By carefully selecting this parameter within the orthogonal two-phase coded signal framework, the system achieves improved range resolution while maintaining adequate energy transmission through the efficient use of the two-phase coding structure.
Data Source
AI summary
Provided is a method for solving radar ambiguity and occlusion based on an orthogonal two-phase coded signal. The method includes: generating and optimizing an orthogonal two-phase coded signal set by means of a walsh matrix and a genetic algorithm, and alternatively, obtaining an orthogonal two-phase coded signal set through an exhaustive method, depending on a chip length; determining the radar period and the number m of transmission pulses in a period according to the radar farthest detection range and the pulse repetition interval (PRI), and selecting m signals from the orthogonal two-phase coded signal set, to constitute a group of orthogonal two-phase coded pulse signals; and accumulating echoes of transmitted pulse signals, to generate an echo matrix, performing frequency domain pulse compression, to obtain a processed new matrix, and performing moving target detection on the matrix.