Fused Threshold Phase Modulation Pulse Detection
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Solution Overview
Problem
Digital radar receivers face limitations in pulse detection due to large size, weight, and power consumption, as well as sub-optimal processing of signals with mismatched bandwidth and frequency, leading to missed, false, and inaccurate pulse descriptor words, especially at low signal-to-noise ratios.
Innovation Solution
A fused detection method combining threshold detection and double-difference phase modulation detection, which continuously updates thresholds and window sizes to handle changing noise conditions, enabling accurate pulse detection across a wide range of signal-to-noise ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If threshold detection is used for pulse detection, then detection speed is fast and latency is low, but detection accuracy deteriorates at low signal-to-noise ratios
Solution Approach 1:
The detection process is segmented into two independent detection paths: a threshold detection path for fast detection and a phase modulation detection path for accurate detection. Each path processes signals independently and their results are fused to achieve both speed and accuracy across all SNR conditions.
Solution Approach 2:
The system dynamically changes detection parameters based on signal conditions. The threshold detector uses fixed parameters for speed, while the phase modulation detector adapts window size and threshold based on estimated SNR, allowing accurate detection across varying signal conditions.
2Reliability
If a channelizer with large filter bank is used for signal processing, then signal separation and noise reduction improve, but device size, weight and power consumption increase
Solution Approach 1:
The invention extracts and removes the channelizer component from the receiver architecture. Instead of using a large filter bank for signal separation, the system uses a simpler front-end followed by pulse-level processing that achieves similar separation quality without the bulky channelizer hardware.
Solution Approach 2:
The mechanical/filter-based signal separation approach of the channelizer is replaced with a computational approach using pulse detection and parameter estimation algorithms that achieve signal separation through software processing rather than physical filter banks.
3Reliability
If continuous processing by large filter banks is used, then signal detection capability improves, but power consumption increases
Solution Approach 1:
Instead of continuous processing through the filter bank, the system uses periodic pulse-level processing where detection is performed at discrete pulse events. This event-driven approach processes signals only when pulses are detected, dramatically reducing average power consumption while maintaining detection capability.
Solution Approach 2:
The system applies partial processing by using a simplified front-end that processes all signals, followed by selective detailed processing only for detected pulses. This partial action approach reduces overall computational load and power consumption compared to full continuous processing.
4Productivity
If threshold detection alone is used, then processing of high SNR pulses is efficient, but detection range is limited due to inability to detect low SNR pulses
Solution Approach 1:
The system merges two detection methods: threshold detection for efficient high SNR pulse processing and phase modulation detection for extended range low SNR pulse detection. The fusion of these complementary approaches achieves both processing efficiency and extended detection range across all SNR conditions.
Solution Approach 2:
The phase modulation detector acts as an intermediary that bridges the gap between threshold detection and low SNR signals. It processes signals that are too weak for reliable threshold detection and passes validated pulses to the main processing chain, effectively extending detection range.
Data Source
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AI summary
A threshold detection method is fused with a double-difference phase modulation detection method to provide a higher-performance method of pulse detection for any digital receiver. The first pulse detection technique uses a signal power threshold. When the square of the magnitude of a pulse crosses the signal power threshold, the beginning of a pulse is declared and pulse processing starts. The second pulse detection technique is model based and uses a windowed detector that crosses a phase difference threshold when the pulse has consistent second-order (in general d-th order) difference phase values within the window. The first technique has low latency and is independent of pulse width, but only operates well at SNR values greater than 15 dB. The second technique has higher latency and requires a minimum pulse width, but operates at lower (approximately 0 dB) SNR values.