Radar Receiver Decoupling Range and Doppler Processing
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Solution Overview
Problem
Waveform diversity in radar systems leads to clutter range sidelobe modulation (C-RSM), which reduces target detection performance due to increased computational complexity in implementing optimal receiver filters for pulse agile and waveform diverse radar emissions.
Innovation Solution
A radar receiver is designed with reduced computational complexity by decoupling range and Doppler processing, using a block Toeplitz structure for the interference covariance matrix to efficiently compute and apply optimal filters, allowing for efficient processing of radar signals with varying waveforms both pulse-to-pulse and coherent processing interval-to-interval.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If joint range-Doppler processing is implemented to maximize SINR for waveform diverse radar emissions, then target detection performance is improved, but computational complexity becomes prohibitive
Solution Approach 1:
The patent segments the joint range-Doppler processing into separate range processing and Doppler processing stages. Range processing is performed first using matched filtering for each waveform type, followed by Doppler processing across the coherent processing interval. This segmentation reduces computational complexity while maintaining target detection performance.
Solution Approach 2:
The patent extracts and processes different waveform types separately using waveform-specific matched filters. By taking out the waveform diversity aspect and handling it through dedicated filters before Doppler processing, the system avoids the prohibitive complexity of joint processing while preserving detection performance.
2Adaptability or versatility
If waveform diversity is increased for radar-embedded communication, then communication capacity is improved, but clutter range sidelobe modulation increases and reduces detection performance
Solution Approach 1:
The patent introduces waveform-specific matched filters as intermediary processing elements that compensate for the clutter range sidelobe modulation caused by waveform diversity. These filters act as mediators that restore detection performance while allowing waveform diversity to maintain communication capacity.
Solution Approach 2:
The patent changes the processing parameters by applying different matched filter responses corresponding to different waveform types. This parameter change approach allows the system to handle waveform diversity for communication while compensating for the resulting clutter modulation effects on target detection.
3Object-affected harmful factors
If pulse agile radar is used to reduce clutter effects, then clutter resistance is improved, but computational complexity increases for optimal filtering
Solution Approach 1:
The patent segments the pulse agile radar processing into range filtering using waveform-specific matched filters followed by Doppler filtering. This segmentation reduces the computational complexity of optimal filtering while maintaining the clutter resistance benefits of pulse agile operation.
Data Source
AI summary
A receiver method and apparatus provides a more efficient computation and application of optimal filters. Range and Doppler processing in the receiver are decoupled and, as a result, computational complexity required for both filter computation and filtering stages are significantly reduced. In one embodiment, a response to an emitted signal is demodulated and sampled to provide baseband samples. The response includes a component due to interaction of the emitted signal with a target, The baseband samples are filtered in a bank of N parallel range filters to provide N filter outputs for each of the baseband samples. For one or more Doppler phase shifts ϕ, a discrete Fourier transform of the N filter outputs is computed to produce Doppler components that may be analyzed to determine at least one of a presence, range and speed of the target.