Polyphase Digital Beamforming for Variable Sampling Rates
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Solution Overview
Problem
Existing digital beamforming systems face challenges in flexible and accurate signal sampling when the sampling rate exceeds the processing clock frequency, limiting their ability to adapt to changing data rates and perform effective multi-phase processing.
Innovation Solution
A multi-channel, multi-phase digital beamforming method that pre-configures a delay filtering coefficient storage table and calculates weighting coefficients to perform weighted synthesis and filtering, allowing for flexible signal processing by dividing the signal into multiple phases and using a filtering coefficient storage table to determine appropriate filter coefficients based on subarray arrangements and beam directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the sampling rate of the array signal exceeds the processing clock frequency, then the signal processing capability is improved, but the flexibility and accuracy of signal sampling deteriorates
Solution Approach 1:
The patent divides the high-rate signal into multiple lower-rate parallel streams using polyphase decomposition. The filtering operation is segmented into P separate polyphase filters, each operating at the lower clock frequency fclk. This segmentation allows the system to process high sampling rate signals (fs > fclk) by distributing the processing across multiple parallel channels, thereby maintaining both high productivity and sampling accuracy without requiring the entire system to run at the high sampling rate.
2Productivity
If the sampling rate exceeds the processing clock frequency, then the data rate handling capability is improved, but the system complexity increases
Solution Approach 1:
The patent creates a universal processing architecture where the same polyphase filter bank and combiner structure can handle any sampling rate that is an integer multiple of the clock frequency. By setting P = fs/fclk, the system universally adapts to different data rates without requiring separate processing paths. The delay filtering coefficient storage table is pre-configured to accommodate multiple phase quantities, making the system multi-functional across different operating conditions while maintaining a single unified processing framework.
3Adaptability or versatility
If the quantity of signal phases is changed to adapt to different sampling rates, then the adaptability is improved, but the processing architecture complexity increases
Solution Approach 1:
The patent implements a dynamic system where the number of polyphase filters P can be adjusted based on the input sampling rate fs according to the relationship P = fs/fclk. When the sampling rate changes, the system dynamically reconfigures the number of active polyphase filter channels without requiring a complete architectural redesign. The delay filtering coefficient storage table is designed to store coefficients for multiple phase quantities, allowing the system to adaptively select the appropriate number of phases while maintaining the same fundamental processing architecture.
Data Source
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AI summary
A multi-channel multi-phase digital beamforming method and apparatus is provided. The multi-channel multi-phase digital beamforming method includes following steps: S1: pre-configuring a delay filtering coefficient storage table; S2: calculating a filter coefficient and a weighting coefficient; and S3: performing weighted synthesis and filtering processing on a multi-phase signal to form a multi-phase digital beam. When a data rate of an input signal changes, the multi-channel multi-phase digital beamforming method can perform weighted synthesis for the signal at different sampling rates by changing a quantity of signal phases without changing a processing architecture. Based on a multi-phase finite impulse response (FIR) filtering technology, a fractional multiple delay processing architecture that can flexibly adapt to a plurality of phase quantities of the input signal is proposed.