Noise-Mitigated Radar Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radar systems face reduced ability to determine relevant information due to noise in received signals, such as amplitude and phase noise from interferer signals, and existing noise-mitigation methods only improve noise figure when the power difference between these noises exceeds a threshold.
Innovation Solution
An apparatus that includes a transmitter, receiver, multiplier, and signal shifter, where the imaginary portion of the baseband signal is multiplied by a value β based on the power difference between amplitude and phase noise, and the interferer signal is shifted to approximately zero frequency, allowing both real and imaginary parts to be used for signal processing, thereby improving the signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal shifting is performed to isolate amplitude noise into real part and phase noise into imaginary part, then noise figure is improved, but only when power difference between amplitude noise and phase noise exceeds a threshold
Solution Approach 1:
The patent applies dynamics by making the selection between real and imaginary parts adaptive rather than static. The system dynamically determines which part (real or imaginary) has less noise based on the actual noise characteristics of the received signal, and selectively processes only that part. This dynamic adaptation allows the noise mitigation to work effectively across different noise conditions, not just when a specific power difference threshold is met.
Solution Approach 2:
The patent changes the processing parameter based on noise conditions. Instead of always processing both real and imaginary parts or always selecting one fixed part, the system changes which part is selected for processing based on the measured noise characteristics. This parameter change (selecting real or imaginary part) is driven by the actual noise power levels, making the noise figure improvement applicable across varying noise scenarios.
2Device complexity
If only one part (real or imaginary) is processed to reduce noise, then processing complexity is reduced, but noise mitigation effectiveness is limited to cases with sufficient power difference
Solution Approach 1:
The patent applies partial action by processing only the necessary part (either real or imaginary) rather than both parts. This reduces processing complexity while maintaining detection accuracy. The system performs partial processing (only one part) but does so selectively based on noise conditions, ensuring that the reduced complexity does not compromise measurement precision when the selection is made correctly.
Solution Approach 2:
The system uses feedback by measuring the noise characteristics of the received signal and using this information to determine which part (real or imaginary) should be processed. This feedback loop ensures that the simplified processing approach (partial action) maintains measurement precision by adapting to the actual noise conditions rather than using a fixed processing path.
3Measurement precision
If both real and imaginary parts are processed, then object detection accuracy is maintained, but noise figure improvement is not achieved when power difference is small
Solution Approach 1:
The patent uses dynamics to adapt the processing approach based on noise conditions. When noise power difference is large, it dynamically selects only the cleaner part for processing, achieving noise figure improvement. When power difference is small, it dynamically switches to processing both parts to maintain detection accuracy. This dynamic adaptation resolves the contradiction between noise figure improvement and detection accuracy across different operating conditions.
Solution Approach 2:
The patent applies partial action (processing only one part) when it provides noise figure improvement, and excessive action (processing both parts) when it provides detection accuracy. This flexible application of partial or excessive action based on conditions resolves the contradiction by using the appropriate level of processing for each scenario.
Data Source
AI summary
An apparatus comprises a transmitter that transmits a signal, a receiver, a multiplier, and a signal shifter included in one of the transmitter and the receiver. The receiver receives a reflected signal comprising an interferer signal with at least one of an amplitude noise or a phase noise and generates a baseband signal comprising a real portion and an imaginary portion. The multiplier multiplies the imaginary portion by a value β chosen based on a power difference α between the amplitude noise and the phase noise, resulting in a modified baseband signal. The signal shifter shifts the interferer signal and the modified baseband signal. An estimator can process the reflected signal and estimate a frequency and phase of the interferer signal for the signal shifter. The value β can be represented as:β=1α2where α represents the power difference between the amplitude noise and the phase noise.