Radar Phase Shift Interference Suppression
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Solution Overview
Problem
Conventional radar apparatuses face challenges in suppressing interference between sector radars without synchronizing transmission cycles, leading to decreased signal-to-interference and noise power ratio (SNIR) and reduced target positioning accuracy.
Innovation Solution
A radar apparatus design that uses phase-shifted baseband signals for transmission, where the phase shift for one radar is opposite to that of another, allowing for interference suppression without synchronizing transmission cycles, utilizing complementary code sequences to minimize range sidelobes and maintain target detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase-shifted baseband signals with opposite phase shifts are used for transmission, then interference between sector radars is suppressed and SNIR is maintained, but transmission timing synchronization becomes unnecessary and device complexity increases
Solution Approach 1:
The patent applies parameter changes by modifying the phase shift parameter of baseband signals. Specifically, it sets the phase shift of one radar's baseband signal to be the opposite of another radar's phase shift (e.g., +90 degrees and -90 degrees). This parameter modification enables interference suppression without requiring transmission timing synchronization, thereby maintaining high SNIR while simplifying system coordination.
2Measurement precision
If complementary code sequences are used to minimize range sidelobes, then target detection accuracy is maintained, but signal processing complexity increases
Solution Approach 1:
The patent employs complementary code sequences (such as Barker codes or pseudo-random codes) and modifies the phase parameter of the coded signals. By combining complementary coding with opposite phase shifts, the system achieves low range sidelobes and high target detection accuracy. The complementary codes provide inherent sidelobe suppression, while the phase shift differentiation further enhances interference rejection between radars.
3Adaptability or versatility
If transmission cycles are not synchronized between sector radars, then system operation flexibility is improved, but interference suppression becomes difficult and measurement precision deteriorates
Solution Approach 1:
The patent applies local quality by making each radar's signal have a unique local characteristic through opposite phase shifts. Each radar transmits with a distinct phase signature (e.g., one with +90 degrees, another with -90 degrees), allowing the receiving radar to identify and separate its own echoes from interference by detecting the phase characteristic. This enables asynchronous operation while maintaining measurement precision through local signal identification.
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
This configuration effectively suppresses interference between sector radars, maintaining high SNIR and target detection accuracy without the need for synchronized transmission cycles, thus enhancing the radar's ability to detect targets in overlapping measurement areas.
Implementation Method 1
a first radar transmission signal generated using a first code sequence having a prescribed code length from a first transmission antenna as a first radio-frequency signal; and a second radar transmission signal generated using a second code sequence having a prescribed code length from a second transmission antenna as a second radio-frequency signal, wherein the first radar transmission signal is a signal generated by modulating a first baseband signal that has been phase-shifted on the basis of a first transmission timing signal; the second radar transmission signal is a signal generated by modulating a second baseband signal that has been phase-shifted on the basis of a second transmission timing signal; and a phase shift given to the first baseband signal is opposite to a phase shift given to the second baseband signal
Data Source
AI summary
A radar transmitter Txs (s=1) generates a baseband transmission signal by modulating a first code sequence having a prescribed code length on the basis of a first transmission timing signal and gives a first transmission phase shift corresponding to each transmission cycle to the transmission signal. A radar receiver Txs (s=2) generates a baseband transmission signal by modulating a second code sequence having the prescribed code length on the basis of a second transmission timing signal and gives, to the transmission signal, a second transmission phase shift that correspond to each transmission cycle and opposite to the first transmission phase.