Sinusoidal Audio Coding With Phase Jitter for Natural Speech

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Solution Overview

Problem

Existing sinusoidal coding schemes face challenges in maintaining the natural quality of synthesized audio signals, particularly in voiced portions, due to the artificial synthesis of phase information, which can result in a buzzy or unnatural sound, and require higher bit-rates for transmitting original phase parameters for improved quality.

Innovation Solution

Incorporating a phase jitter parameter into the encoded signal, which represents the amount of phase jitter to be applied during decoding, allowing for more natural sound reconstruction without the need for local determination, and transmitting this parameter alongside frequency and amplitude information to minimize bit-rate increase.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If original phase parameters are transmitted to improve synthesized speech quality, then the natural quality of synthesized audio signals is improved, but the bit-rate increases significantly

Engineering Contradiction:

Improvesynthesized speech qualityVSAvoidbit-rate

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential phase jitter parameter from the complete phase information, transmitting only this statistical characteristic rather than full phase parameters. This extraction allows quality improvement through phase naturalization while minimizing bit-rate increase by transmitting a compact representation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter representation from transmitting complete phase parameters to transmitting a phase jitter parameter that characterizes phase variations. This parameter transformation reduces the amount of data required while preserving the essential information needed for natural sound reconstruction.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If phase jitter is determined locally in the decoder, then the system complexity is reduced, but the determination of phase jitter becomes less reliable and accurate

Engineering Contradiction:

Improvedecoder complexityVSAvoidphase jitter determination accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent performs preliminary determination of the phase jitter parameter in the encoder, where the original signal characteristics are available. This advance determination ensures accurate and reliable phase jitter values are established before transmission, eliminating the need for complex local determination in the decoder while maintaining high accuracy.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The phase jitter parameter acts as an intermediary that carries essential phase characterization information from the encoder to the decoder. This mediator enables the decoder to reconstruct natural-sounding phase without needing to perform complex analysis, bridging the gap between encoder knowledge and decoder capabilities.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS7739106B2Sinusoidal coding including a phase jitter parameter

Publication Date: 2010.06.15 KONINKLIJKE PHILIPS NV

AI summary

Encoding (2) a signal (A) is provided, wherein frequency and amplitude information of at least one sinusoidal component in the signal (A) is determined (20), and sinusoidal parameters (f,a) representing the frequency and amplitude information are transmitted (22), and wherein further a phase jitter parameter (p) is transmitted, which represents an amount of phase jitter that should be added during restoring the sinusoidal component from the transmitted sinusoidal parameters (f,a).