Interpolated Signal SNR Enhancement via Randomized Filter Coefficients
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing interpolation methods introduce noise into the signal, leading to a decrease in signal-to-noise ratio (SNR) due to frequency-dependent quantization noise and correlation effects caused by comb filters.
Innovation Solution
The method involves zero insertion and filtering with coefficients close to unity, randomly varying by a delta value, to generate interpolated signals with reduced noise and enhanced SNR, where the delta value is set within a range based on quantization noise to minimize correlation and maintain white noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional interpolation methods are used, then additional data points are generated, but noise is introduced and SNR decreases
Solution Approach 1:
The patent changes the filter coefficients from fixed values to random values drawn from a distribution with mean close to unity and standard deviation proportional to quantization noise. This parameter change transforms the deterministic comb filter into a randomized filter that maintains signal amplitude while decorrelating quantization noise, thereby improving SNR from potentially negative values to positive values.
Solution Approach 2:
The patent introduces an intermediary randomization step between the zero-insertion process and the final interpolated signal. By multiplying the zero-inserted signal by random coefficients, the quantization noise is decorrelated from the signal structure, preventing the noise enhancement that occurs with traditional deterministic filtering.
2Reliability
If comb filter is used for interpolation, then signal is filtered, but correlation effects increase noise
Solution Approach 1:
The patent transforms the static, deterministic comb filter coefficients into dynamic, randomized coefficients that vary for each interpolation operation. This dynamic approach prevents the fixed correlation patterns that cause noise enhancement in traditional comb filters, while still maintaining the essential filtering function.
Solution Approach 2:
The patent breaks the symmetry of the traditional comb filter by introducing asymmetric random variations in the coefficients. Instead of uniform unit coefficients, each coefficient becomes a random value with mean close to unity, creating an asymmetric filter response that decorrelates noise while preserving signal integrity.
Data Source
AI summary
Providing interpolated signals with enhanced signal-to-noise-ratio (SNR). In an embodiment, for each digital sample (of an analog signal) having strength Dn, N values are inserted, with the kth inserted value having a strength of Dn(1+/−Dk), wherein Dk is selected randomly from within a range set according to quantization noise. The received digital samples along with inserted digital values are provided as the interpolated signal corresponding to the input signal represented by the received digital samples.