Dual-pulse excited linear prediction for speech coding

Abstract

The present invention proposes a Dual-Pulse Excitation Model; wherein two pulses of each pair of pulses are always adjacent each other. Only one position index for each pair of pulses needs to be sent to the decoder, which saves bits to code all pulse positions. The magnitudes of each pair of pulses have limited number of patterns. Because the two pulses are adjacent each other, each pair of pulses with different magnitudes can produce different high-pass and / or low-pass effect. Since the magnitudes have enough variation, it is possible to assign the candidate positions of each pair of pulses within a small range in order to save the searching complexity.

Description

technical field [0001] The present invention belongs to the field of signal coding. Specifically in the field of speech coding; especially coding for improved excitation signals. Background technique [0002] Traditionally, all parametric speech coding methods often use the redundancy of the speech signal itself to reduce the amount of information that must be transmitted and estimate the parameters of the speech signal in a short period of time. This redundancy is firstly caused by the periodic repetition of the speech waveform and the slow change of the spectrum envelope. [0003] The redundancy of different forms of speech waveforms corresponds to different types of speech signals, such as voiced and unvoiced. In the case of voiced speech, the speech signal is essentially periodic; however, this periodicity varies within speech segments, and the periodic waveform varies slowly between speech segments. Speech coding at low bit rates can greatly benefit from this periodi...

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However, there is little chance that these parameter values ​​will change significantly within a few milliseconds

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