FMCW Radar Signal Processing Device for Interference Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
FMCW radar devices face interference issues due to radio wave interference from other devices of the same type, leading to increased noise in beat signals, which can bury the reflected wave component from the measurement object, making it difficult to detect the object accurately.
Innovation Solution
A signal processing device that reduces the amplitude of beat signals at specific phase shift timings using a phase shift control signal, converting the signal into a frequency domain to differentiate between transmission and interference waves, thereby reducing noise and enhancing signal clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If phase modulation is applied to transmit waves from multiple FMCW radar devices, then interference waves are generated that increase noise in beat signals, but if no phase modulation is applied, then all devices transmit at the same frequency causing severe radio wave interference
Solution Approach 1:
The patent applies phase modulation to transmit waves, analogous to changing color characteristics, to differentiate between signals from different radar devices. This allows the receiving device to identify and filter out interference waves from other devices while maintaining reliable detection of reflected waves from measurement objects.
Solution Approach 2:
The patent changes the phase parameter of transmit waves using phase modulation codes. By varying the phase parameter according to predetermined codes, the system enables distinction between signals from different radar devices, reducing noise in beat signals while maintaining detection reliability.
2Object-affected harmful factors
If amplitude reduction is applied at phase shift timings, then noise from interference waves is reduced, but signal processing complexity increases
Solution Approach 1:
The patent applies preliminary action by reducing the amplitude of the local wave at phase shift timings before it is used for beat signal generation. This preprocessing step prevents interference waves with specific phase characteristics from contributing to noise, simplifying subsequent signal processing while effectively reducing interference.
Data Source
AI summary
A signal processing device includes: an amplitude reducing unit to reduce, when a phase shift control signal indicating a phase shift of a transmission wave whose frequency is modulated is output, among amplitudes of a beat signal having a difference frequency between the transmission wave and a reception wave, an amplitude of the beat signal at a timing at which a phase of the transmission wave is shifted in accordance with the phase shift control signal; and a signal converting unit to convert the beat signal whose amplitude at the timing at which the phase of the transmission wave is shifted is reduced by the amplitude reducing unit into a signal in a frequency domain.