重点研究了低时延１６ｋｂｐｅ语音编码器标准Ｇ．７２８，在此基础上用软件仿真实现了一种高质量的编解码器，其单通道编码延迟在２ｍｓ以下。该编码器基本上是码激励线性预测编码器的后向自适应版本。对各功能块作了剖析和一些改进，得出的仿真结果证明，采用ＬＤ＿ＣＥＬＰ方案可以得到预期的１６ｋｂｐｓ的码率，以及低算法时延，高的语音音质。文中还讨论了实时软件设计的一些关键问题。 Focus on the low-delay 16kbpe speech encoder standard G. 728, on this basis, using software simulation to achieve a high-quality codecs, the single-channel encoding delay of 2ms or less. The encoder is basically a backward-adaptive version of a code-excited linear predictive encoder. The functional blocks are analyzed and some improvements are made. The simulation results show that using LD_CELP scheme can get the expected bit rate of 16kbps, as well as low algorithm delay and high voice quality. The article also discusses some of the key issues in real-time software design.