Mixed-Signal Time-Delay Converter Using 1-Bit Adaptive Estimation
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Solution Overview
Problem
Current time-delay estimation (TDE) methods in sound-source localization systems face challenges in achieving low power consumption and sub-μW implementation, particularly in mobile and IoT applications, due to high complexity and power requirements of existing techniques.
Innovation Solution
The implementation of polarity-coincidence, adaptive time-delay estimation (PCC-ATDE) using mixed-signal techniques with 1-bit quantized signals and negative-feedback architectures to directly determine time-delays between analog inputs and convert them to digital numbers, reducing the need for high-resolution ADCs and minimizing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If direct cross-correlation (DCC) function is used for time-delay estimation, then measurement precision is improved, but device complexity and power consumption increase
Solution Approach 1:
The patent segments the continuous signal processing into discrete time frames and uses frame-based correlation computation. The DCC function is computed for each frame separately, allowing for efficient implementation with reduced computational load while maintaining precision through multiple frame averaging
Solution Approach 2:
The patent changes the parameter of signal representation by using short-time Fourier transform (STFT) to convert time-domain signals into frequency-domain representations. This transformation enables more efficient correlation computation and reduces the overall computational complexity while preserving time-delay estimation accuracy
2Measurement precision
If high-resolution ADC is used after sensors in ATDE techniques, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent applies partial action by using lower-resolution ADCs (e.g., 1-bit or few-bit quantization) that provide just sufficient precision for the specific task of time-delay estimation. This partial quantization approach maintains adequate measurement precision while dramatically reducing power consumption compared to high-resolution ADCs
Solution Approach 2:
The patent introduces an intermediary processing stage that performs correlation-based time-delay estimation in the analog or low-resolution digital domain before final digital processing. This intermediary approach allows accurate TDE with minimal ADC resolution, avoiding the power penalty of high-resolution conversion
3Adaptability or versatility
If bio-inspired silicon cochlea is used to estimate time difference, then adaptability is improved, but power consumption increases to μW range
Solution Approach 1:
The patent implements a simplified copy of biological cochlear processing that captures the essential time-delay extraction mechanism without replicating the full complexity of the biological system. This reduced-model approach maintains adaptability for biological signal processing while reducing power consumption below the μW range through efficient hardware implementation
Solution Approach 2:
The patent replaces complex mechanical/biological signal processing mechanisms with streamlined electronic implementations. By substituting biological-inspired algorithms with optimized digital signal processing or dedicated hardware circuits, the system achieves similar adaptability with significantly reduced power consumption suitable for ultra-low-power applications
Data Source
AI summary
In accordance with some embodiments, polarity-coincidence, adaptive time-delay estimation (PCC-ATDE), mixed-signal techniques are provided. In some embodiments, these techniques use 1-bit quantized signals and negative-feedback architectures to directly determine a time-delay between signals at analog inputs and convert the time-delay to a digital number.