Coding method and decoding method for ultra wide band expansion, coder and decoder as well as system for ultra wide band expansion

Abstract

The invention relates to a coding method and a decoding method for ultra wide band expansion, a coder and a decoder as well as a system for the ultra wide band expansion, wherein the coding method and the coder obtain a coding parameter of a reconstructed 7-8 kHz signal through wide band enhancement, perform perception weighting on the base, obtain a frequency band expansion parameter of a reconstructed 8-14 kHz high frequency signal according to a principle of the smallest mean square error; and a decoding end reconstructs a 7-14 kHz high frequency signal through coding transmission so as to achieve the expansion of a 7-14 kHz ultra wide band. The decoding method and the decoder decode a residual error MDCT coding parameter to obtain a 7-8 kHz residual error MDCT recovery coefficient, perform perception weighting on the base, and reconstruct a 8-14 kHz signal according to the principle of the smallest mean square error so as to achieve the reconstruction of the 7-14 kHz high frequency signal and obtain a 0-14 kHz ultra wide band signal.

Description

technical field [0001] The invention relates to voice communication technology, in particular to an ultra-wideband extension encoding and decoding method, a codec and an ultra-wideband extension system. Background technique [0002] In real-time voice communication, because the transmission quality of voice signals is affected by factors such as sampling rate and bandwidth, existing voice and audio codecs usually use methods such as reducing the sampling rate and losing high-frequency content to ensure the codec process. realization. This is especially true for the transmission of wideband voice signals (50Hz ~ 7kHz). In order to avoid aliasing effects, the wideband signal is usually converted into a band-limited signal and then encoded. In this way, when the code rate is determined, especially for Medium and low bit rates, ensuring enough bits to encode low-frequency content. However, the high-frequency part of the broadband signal contains rich content, and the lack of t...

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventor found that the prior art has at least the following problems: the prior art extends the narrowband speech signal from 0 to 3.4kHz to 0 to 7kHz, and only completes the frequency band extension of less than 4kHz, and the decoded The voice signal lacks ultra-wideband signals above 7kHz, so that the audio quality still cannot be greatly improved; the excitation signal used in the frequency band extension is derived from the speech generation model, which cannot accurately describe the music signal, and the coding effect for the music-like signal is relatively poor , the reuse effect is not good in the ultra-broadband part

Images