Device and method for expanding speech bandwidth based on G.711.1

Abstract

The invention discloses a device and a method for expanding speech bandwidth based on G.711.1. The method of the invention comprises the steps of: further compressing the high frequency speech code stream in a G.711.1 protocol, embedding the compressed data in the encoded code stream of narrow band speech by a lowest significant digit watermark embedding algorithm, and synthesizing the high frequency part of the wide band speech by the extracted high frequency code stream at a decoding end so as to obtain wide band speech. The invention provides a novel scheme of layered encoding of creating a hidden channel in the narrow band speech transmission for transmitting the encoded code stream of high frequency signals in the layered encoding protocol, thereby not only utilizing the advantages of good vision effect of wide band speech obtained by layered encoding, but also not changing the transmission rate of the current network. As shown in a simulation test, the high frequency noise introduced by the wide band speech obtained by the method is small, and the vision effect has small difference with the original wide band speech.

Description

technical field [0001] The invention relates to the field of speech processing, in particular to a device and method for expanding speech bandwidth based on G.711.1. Background technique [0002] Typically, human speech contains the majority of perceivable energy at frequencies between 50Hz and 8kHz. However, the voice transmission bandwidth in the current telephone network is less than 4 kHz, and the frequency band is limited between 300 Hz and 3400 Hz, and the voice of this bandwidth is narrow-band voice. Narrowband speech reduces the requirement for communication bandwidth while ensuring a certain intelligibility, but because narrowband speech does not have the high-frequency components of the original speech, this kind of speech does not sound natural enough. With the development of technology, broadband voice communication has begun to be used in occasions that require high voice quality, such as teleconferencing. During an upgrade to broadband voice communications, e...

AI Technical Summary

Problems solved by technology

[0007] Disadvantages of the existing technology: Although the prediction-based speech bandwidth extension technology does not change the original narrowband speech coding format and bit rate, but because the high frequency part of the wideband speech is predicted by the narrowband speech, the result obtained by this method The wideband voice is quite different from the original wideband voice, and will introduce larger high-frequency noise at the same time

The broadband voice auditory effect obtained by the voice bandwidth expansion technology based on layered coding is better, but this is at the cost of occupying additional communication channel bandwidth, which cannot be realized without changing the original network equipment and protocols.

Images