Voice Codec Encoder Background Noise Recalculation
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Solution Overview
Problem
Current scalable coding methods for broadband speech codecs lack efficient implementation of discontinuous transmission (DTX) with comfort noise generation, leading to issues with maintaining connection quality and accurate background noise reconstruction during speech pauses.
Innovation Solution
The encoder recalculates background noise parameters, including averaged energy and autocorrelation function, after a determined idle period, allowing for updated SID frame transmission without energy threshold comparison, and separates narrowband and broadband noise components for separate encoding and processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If discontinuous transmission (DTX) is implemented with energy threshold comparison for SID frame transmission, then data transmission rate is reduced during speech pauses, but connection reliability deteriorates due to idle channel detection and additional data exchange requirements
Solution Approach 1:
The patent implements periodic transmission of SID frames based on time intervals rather than continuous transmission. The encoder transmits SID frames at predetermined periodic intervals during speech pauses, ensuring connection maintenance while reducing overall data transmission rate. This periodic action eliminates the need for energy threshold comparisons and idle channel detection, resolving the contradiction between data rate reduction and connection reliability.
2Measurement precision
If background noise parameters are continuously updated and transmitted during speech pauses, then comfort noise synthesis accuracy is improved, but data transmission rate increases
Solution Approach 1:
The patent applies partial action by updating and transmitting background noise parameters only at predetermined periodic intervals rather than continuously. This partial updating strategy maintains sufficient accuracy for comfort noise synthesis while significantly reducing the data transmission rate during speech pauses, resolving the contradiction between noise characterization accuracy and data rate efficiency.
3Productivity
If energy threshold comparison is used to decide SID frame transmission, then data transmission rate is reduced, but manufacturing precision (coding accuracy) deteriorates due to insufficient background noise updates
Solution Approach 1:
The patent performs preliminary determination of background noise parameters at regular intervals before actual transmission decisions are needed. By pre-calculating and storing updated noise parameters at predetermined times, the system ensures accurate noise characterization is always available when needed, eliminating the need for energy threshold comparisons and preventing accuracy deterioration while maintaining low data rates.
Data Source
Figure 1
AI summary
The inventive method provides for an encoder in a voice codec to be designed such that after a particular idle time ("Idle Period") it recalculates the averaged energy and the autocorrelation function. Administrative points in the network inform the encoder about the idle time which has been set in the transmission network.