Coded Domain Adaptive Gain Control for Voice Quality
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Solution Overview
Problem
In telecommunications networks, particularly in wireless and VOIP systems, performing voice quality enhancement (VQE) in the coded domain without intermediate decoding and re-encoding is challenging due to speech quality degradation and increased computational resources required for encoding, which affects echo suppression, noise reduction, adaptive level control, and adaptive gain control.
Innovation Solution
The method involves modifying parameters of encoded signals using Joint Codebook Scaling (JCS) to achieve voice quality enhancement directly in the coded domain, avoiding intermediate decoding and re-encoding, thereby maintaining speech quality and reducing computational resources needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the signal is decompressed to linear domain for voice quality enhancement, then voice quality enhancement can be performed, but speech quality degradation occurs due to intermediate decompression and re-compression
Solution Approach 1:
The patent changes the domain in which VQE operations are performed from linear domain to coded domain by modifying encoding parameters (LPC coefficients, gain values, codebook indices) directly. This allows voice quality enhancement to be achieved without intermediate decompression, preventing speech quality degradation while maintaining enhancement effectiveness.
2Reliability
If the signal is decompressed and re-encoded for voice quality enhancement, then voice quality enhancement can be achieved, but computational resources are significantly increased
Solution Approach 1:
The patent extracts and modifies only the essential encoding parameters (LPC coefficients, gain values, codebook indices) needed for voice quality enhancement operations such as echo suppression, noise reduction, and gain control. This selective parameter modification approach achieves VQE without requiring full decompression and re-encoding, significantly reducing computational resource consumption.
3Reliability
If the signal is decompressed and re-encoded for voice quality enhancement, then voice quality enhancement can be achieved, but system delay is significantly increased
Solution Approach 1:
The patent performs voice quality enhancement operations directly on the encoded signal parameters before decomposition occurs. By modifying LPC coefficients, gain values, and codebook indices in advance, the system achieves echo suppression, noise reduction, and adaptive gain control without waiting for decompression, thereby minimizing system delay while maintaining enhancement performance.
Data Source
AI summary
Adaptive Gain Control (AGC) is performed directly in a coded domain. A Coded Domain Adaptive Gain Control (CD-AGC) system modifies at least one parameter of a first encoded signal, resulting in corresponding modified parameter(s). The CD-VQE system replaces the parameter(s) of the first encoded signal with the modified parameter(s), resulting in a second encoded signal. In a decoded state, the second encoded signal approximates a target signal that is a function of two signals, including the first encoded signal and a third encoded signal, in at least a partially decoded states. Thus, the first encoded signal does not have to go through intermediate decode/re-encode processes, which can degrade overall speech quality. Computational resources required for a complete re-encoding are not needed. Overall delay of the system is minimized. The CD-AGC system can be used in any network in which signals are communicated in a coded domain, such as a Third Generation (3G) wireless network.