Digital Microphone Signal Compression for Low-Bit Bus Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digital microphone systems face challenges in efficiently transmitting audio signals over digital buses due to the need for numerous quantization levels, which increases communication throughput and susceptibility to noise.
Innovation Solution
A digital microphone system that converts analog audio signals into digital signals with a plurality of quantization levels and processes them to compress into signals with fewer levels, using a delta-sigma modulator and quantizer to represent each level by transitions or absences of bits, thereby reducing the number of bits required for transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If numerous quantization levels are used to represent audio signal with sufficient quality, then signal fidelity is improved, but communication throughput decreases and noise susceptibility increases
Solution Approach 1:
The patent segments the audio signal processing into two distinct stages: first, an analog-to-digital converter creates a high-resolution digital signal with numerous quantization levels for accurate representation; second, a compressor processes this digital signal to reduce the number of quantization levels. This segmentation allows the system to maintain signal fidelity during conversion while reducing bit depth for transmission, thereby resolving the contradiction between signal quality and communication throughput
Solution Approach 2:
The patent applies preliminary action by performing analog-to-digital conversion with high quantization levels before compression. The system first captures the audio signal with sufficient quality using numerous quantization levels, then subsequently compresses the digital signal to reduce bit depth. This preliminary high-resolution capture ensures that signal fidelity is preserved during the critical conversion phase, while the subsequent compression reduces communication overhead
2Measurement precision
If numerous quantization levels are used to represent audio signal with sufficient quality, then signal fidelity is improved, but noise susceptibility increases
Solution Approach 1:
The patent segments the signal processing into conversion and compression stages. The analog-to-digital converter stage uses numerous quantization levels to ensure high signal fidelity with minimal quantization noise. The subsequent compression stage reduces the number of quantization levels only for transmission purposes. This segmentation isolates the high-resolution processing to where it's most needed (conversion) while reducing noise susceptibility in the transmission path by using fewer bits
Solution Approach 2:
The patent introduces an intermediary compression process between the high-resolution analog-to-digital conversion and the transmission stage. This intermediary compressor acts as a mediator that takes the high-fidelity digital signal and creates a compressed version with fewer quantization levels for transmission. The intermediary process allows the system to maintain high signal fidelity during conversion while reducing noise susceptibility during transmission by using a compressed representation
3Measurement precision
If digital codes with many bits are transmitted over digital bus, then signal fidelity is maintained, but communication efficiency decreases
Solution Approach 1:
The patent segments the digital signal transmission process into two parts: first, the analog-to-digital converter generates a high-resolution digital signal with many bits to maintain signal fidelity; second, a compressor processes this digital signal to reduce the number of bits before transmission over the digital bus. This segmentation allows the system to maintain signal fidelity during conversion while improving communication efficiency during transmission by using compressed, lower-bit representations
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the number of quantization levels based on the processing stage. The analog-to-digital converter uses a high number of quantization levels to maintain signal fidelity, while the compressor reduces the number of quantization levels for transmission. This parameter change from high to low bit depth resolves the contradiction between maintaining signal fidelity and improving communication efficiency
Data Source
AI summary
In accordance with embodiments of the present disclosure, a digital microphone system may include a microphone transducer and a digital processing system. The microphone transducer may be configured to generate an analog input signal indicative of audio sounds incident upon the microphone transducer. The digital processing system may be configured to convert the analog input signal into a first digital signal having a plurality (e.g., more than 3) of quantization levels, and in the digital domain, process the first digital signal to compress the first digital signal into a second digital signal having fewer quantization levels (e.g., +1, 0, −1) than that of the first digital signal.