8.0kbit／sACELP声码器的GSM平台仿真

研究恶劣传输环境下８．０ｋｂｉｔ／代数码激励线性预测声码器的译码算法的改进及其在ＧＳＭ典型信道的传输性能。方法在集成软件仿真平台中引入稳信道编码模块，以消除衰落噪声和高斯噪声的影响，并完成ＡＣＥＬＰ声码器到ＧＳＭ全速率语音业务信道（ＴＣＨ／ＦＳ）的速率适配任务；在ＡＣＥＬＰ译码器中引入错误帧隐藏单元（ＥＣＵ），以提高恶劣信道环境下的合成语音质量。结果与结论错误隐藏单元与相应的高效稳健的信道编码相结

Simulation of 8.0 kbit/s ACELP over GSM Platform

Aim To improve the decoding algorithm of 8.0 kbit/s ACELP vocoder against the badly deteriorated transmission, and evaluate its performance over typical GSM transmission platforms. Methods A robust and efficient channel coding module was constructed to integrate the ACELP vocoder into GSM TCH/FS platform; and an ECU (error concealment unit) was introduced to ameliorate the quality of its synthetic speech by canceling the sharp noises in it that caused by fading and AWGN transmission channels. Results and Conclusion By combining the robust channel code and the ECU unit, the sharp noises emerged in the synthetic speech are almost eliminated, and the sound effect is improved obviously; the simulations show that the 8.0 kbit/s ACELP GSM platform has better performance than GSM TCH/FS at low SNR values.