【摘要】 作者着重对泛欧数字移动通信系统（ＧＳＭ）规则脉冲激励长时预测（ＲＰＥ－ＬＴＰ）语音编码方案中的ＲＰＥ编码部分进行了研究。为了降低编码比特率，提出了一种每子帧１０个激励脉冲的新方案。对它进行了计算机模拟和性能分析，结果表明在１２ｋｂｉｔ／ｓ的编码率下，这种方案满足ＧＳＭ建议０６．１０，即对单个正弦波的帧信噪比要求。又用自适应差分脉冲编码调制（ＡＤＰＣＭ），代替ＲＰＥ－ＬＴＰ方案中的自适应脉冲编码调制（ＡＰＣＭ）对选择的ＲＰＥ序列进行的量化编码。计算机模拟和性能分析的结果表明，用ＡＤＰＣＭ对选择的ＲＰＥ序列进行量化编码，在１１．８ｋｂｉｔ／ｓ的编码比特率上，满足ＧＳＭ建议０６．１０对单正弦波的帧信噪比要求更多还原

【Abstract】 This paper concentrates on the RPE encoding section of the long term Prediction of Regular Pulse Excitation in the linear predictive speech coding scheme(RPE LTP), which is the standard of the Pan European Digital Mobile Radio Systems(GSM). In order to reduce the code rate, a new scheme with 10 excitation pulses in each subsegment is suggested. The simulation on computer and the performance analysis of this scheme have been executed. The results of the simulation also the performance analysis on computer, and the performance analysis of this scheme have been shown. The results of the simulation and the performance analysis on computer inddicate that at the code rate 12kbit/s, the scheme satisfies the GSM recommendation 06.10 requirement of the segmental signal to noise rations of single sine waves. The Adaptive Differential Pulse Code Modulation(ADPCM) algorithm has been used to replace the Adaptive Pulse Code Modulation(APCM) algorithm in the RPE-LTP scheme to quantize the selected RPE sequence. The results of the simulation on computer and the performance analysis show that at the code rate 11.8kbits/s, the ADPCM quantization of the selected RPE sequence satisfies the GSM recommundation 06.10 requirement of the segmental signal to noise rations of single sine waves.更多还原