Configurable Digital Filter Array for Real-Time Voice Clarity
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Solution Overview
Problem
Existing voice communication terminals face challenges in achieving clear voice transmission due to fixed filter qualities and delays caused by calculating filter coefficients, especially in noisy conditions and real-time communication requirements.
Innovation Solution
A noise-canceling device with a digital filter array and a filter quality designator that allows for real-time adjustment of filter qualities by selecting from pre-defined filter coefficient arrays, minimizing delays and improving voice clarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If filter coefficients are calculated in accordance with detected noise level to change digital filter qualities, then voice clarity is improved, but transmission delay increases making real-time conversation difficult
Solution Approach 1:
Filter coefficient arrays are pre-calculated and stored in the filter coefficient storage unit for various noise levels and frequency bands. When noise is detected, the system simply retrieves the appropriate pre-calculated coefficients rather than calculating them in real-time, thus achieving fast response without compromising voice clarity
Solution Approach 2:
The filter coefficients are segmented into multiple pre-calculated arrays corresponding to different noise levels and frequency bands. This segmentation allows the system to quickly select the appropriate coefficient array based on current conditions without performing complex calculations during voice transmission
2Device complexity
If a single fixed-quality filter is used to simplify the device, then device complexity is reduced, but voice clarity under varying noise conditions deteriorates
Solution Approach 1:
The filter quality is made dynamic through the noise-level-dependent selection of filter coefficient arrays. The filter automatically adjusts its characteristics based on the detected noise level and frequency band, transitioning from a fixed-quality filter to an adaptive system that optimizes voice clarity under varying conditions
Solution Approach 2:
The filter coefficients are organized into multiple arrays with different parameters (noise levels and frequency bands). By changing which coefficient array is active based on detected conditions, the system achieves multiple filter qualities using the same physical filter structure, improving voice clarity without significantly increasing device complexity
Data Source
AI summary
A noise-canceling device of a voice communication terminal that removes noise elements included in received voice signals. The device comprises: a digital filter array that exhibits filter qualities in response to a coefficient setting signal showing each supplied arrays of filter coefficients, and includes a first-stage filter that receives the received voice signals as well as multiple later-stage filters connected thereto in a straight line; a filter qualities designator that generates input designation that designates each qualities of the multiple digital filters forming the digital filters array; and a filter coefficient setter that retains multiple arrays of filter coefficients, extracts a filter coefficient array corresponding to the designation input from among the multiple filter coefficient arrays, and supplies to each multiple digital filters. The noise-canceling device for a voice communication terminal provided to obtain desired filter qualities in real-time without calculation of filter coefficients.