Wideband Speech Coding for Harmonic Switching Continuity

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Solution Overview

Problem

Wideband switching in speech/audio signal processing often results in discontinuous signals at the decoder, degrading communication service quality due to changes in network bandwidth and the need to switch between high-frequency and low-frequency signals.

Innovation Solution

A method and apparatus that determine whether a wideband speech/audio signal is a harmonic signal before switching, adjusting the harmonic signal determining condition to ensure consistency in signal type after switching, thereby maintaining continuity and improving communication quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If wideband switching is performed to adapt to network bandwidth changes, then adaptability of the speech/audio signal transmission is improved, but signal continuity is degraded causing discontinuous signals at the decoder

Engineering Contradiction:
Improveadaptability to network bandwidth changesVSAvoidsignal continuity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The encoder performs preliminary classification of the high-frequency signal type (harmonic or non-harmonic) before wideband switching occurs. This preliminary classification information is used to guide the decoder in selecting the appropriate decoding method, ensuring continuous and correct signal reconstruction after switching.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The encoder sends feedback information about the signal type classification to the decoder. This feedback mechanism ensures that the decoder has the necessary information to maintain signal continuity by selecting the correct decoding method based on the encoded signal type, preventing discontinuities after wideband switching.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If different decoding methods are used for harmonic and non-harmonic signals, then decoding accuracy is improved, but system complexity increases due to multiple decoding paths

Engineering Contradiction:
Improvedecoding accuracyVSAvoiddecoding system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The decoding system dynamically selects the appropriate decoding method based on the signal type information received from the encoder. Rather than implementing all possible decoding methods simultaneously, the system adaptively chooses between harmonic and non-harmonic decoding paths, maintaining high decoding accuracy while reducing operational complexity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the decoding parameters and methods based on the signal type classification. By adjusting the decoding approach according to whether the signal is harmonic or non-harmonic, the system achieves high decoding accuracy for different signal types without requiring a permanently complex multi-path decoding architecture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3748634B1Speech/audio signal processing method and coding apparatus
Publication Date: 2022.08.10 HUAWEI TECH CO LTD
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  • EP3748634B1 patent drawingFigure 2
  • EP3748634B1 patent drawingFigure 3

AI summary

Embodiments of the present invention provide a speech/audio signal processing method based on wideband switching and a coding apparatus. The method includes: if a first wideband speech/audio signal is a harmonic signal, adjusting a determining condition for determining that a second wideband speech/audio signal is a harmonic signal, to obtain a first determining condition, so as to raise a possibility of determining that the second wideband speech/audio signal is a harmonic signal, where the first wideband speech signal is a signal before wideband switching, and the second wideband speech/audio signal is a signal after the wideband switching; and determining, according to the first determining condition, whether the second wideband speech/audio signal is a harmonic signal. In the embodiments of the present invention, in the case of wideband switching, signal types of speech/audio signals remain as consistent as possible before and after the switching, so that continuity of the speech/audio signal decoded by a decoder device is ensured as much as possible, further improving speech communication service quality.