公开(公告)号：WO2003098598A1

公开(公告)日：2003-11-27

申请号：PCT/US2003/006335

申请日：2003-02-26

Applicant: CONEXANT SYSTEMS, INC.

Inventor： BENYASSINE, Adil ,  SHLOMOT, Eyal ,  SU, Huan-Yu ,  THYSSEN, Jes ,  GAO, Yang

IPC: G10L11/04

CPC classification number: H04W88/181 ,  G10L19/173

Abstract: There is provided transcoding of speech in a packet network environment. A decoder configured to receive a first bit-stream encoded according to a first coding scheme. The decoder decodes the bit-stream according to the first coding scheme, generates a plurality of first speech samples, and extracts a plurality of first speech parameters, which may include spectral characteristics, energy, pitch and/or pitch gain. A converter then converts the plurality first speech samples and plurality of first speech parameters to a plurality of second speech samples and a plurality of second speech parameters for use according to a second coding scheme. The first and second coding schemes may be, for example, G.711, G.723.1, G.726 or G.729, and may be parametric or non-parametric. An encoder receives the plurality of second speech samples and plurality of second speech parameters and generates a second bit-stream according to the second coding scheme.

Abstract translation: 在分组网络环境中提供语音转码。 解码器，被配置为接收根据第一编码方案编码的第一比特流。 解码器根据第一编码方案解码比特流，产生多个第一语音样本，并且提取多个第一语音参数，其可以包括频谱特性，能量，音调和/或音调增益。 然后，A转换器将多个第一语音样本和多个第一语音参数转换为多个第二语音样本和多个第二语音参数，以便根据第二编码方案使用。 第一和第二编码方案可以是例如G.711，G.723.1，G.726或G.729，并且可以是参数或非参数的。 编码器接收多个第二语音样本和多个第二语音参数，并根据第二编码方案生成第二比特流。

公开(公告)号：WO2000007178A1

公开(公告)日：2000-02-10

申请号：PCT/US1999017329

申请日：1999-07-29

Applicant: CONEXANT SYSTEMS, INC.

Inventor： CONEXANT SYSTEMS, INC. ,  THYSSEN, Jes ,  SU, Huan-Yu

IPC: G10L21/02

CPC classification number: G10L21/0364

Abstract: In a cellular telephone system where a digital cellular telephone is connected to a regular telephone through the public switched telephone network (PSTN), a speech encoder/decoder is used with an A/'mu'-Law encoder/decoder causing annoying audible noise at very low levels because of the quantization characteristics of the A/'mu'-Law encoder/decoder. This noise is eliminated by adding a digital constant to the output of the speech coder, shifting the low level signal away from zero. The resulting DC level added to the speech signal is inaudible to the PSTN telephone user and does not degrade speech quality.

Abstract translation: 在数字蜂窝电话通过公共交换电话网（PSTN）连接到普通电话的蜂窝电话系统中，语音编码器/解码器与A /μ-Law编码器/解码器一起使用，导致令人讨厌的可听噪声非常低 因为A /μ-Law编码器/解码器的量化特性。 通过向语音编码器的输出添加数字常数，将低电平信号从零移开来消除该噪声。 所产生的直流电平加到语音信号对于PSTN电话用户听不到，并且不降低语音质量。