Abstract: Based on the tower control communication simulation system, the function of multi-voice mixing is designed and implemented. The sending parts use the mechanism of double threads and multi-buffer to guarantee real-time data transmission; the introduction of more than one buffer queues in synchronization mechanism creates good conditions for the implementation of synchronization for mixing; some improvements are proposed for the key mixing algorithms, and mixing efficiency is significantly improved. The system uses Speex voice compression library which is specially designed for sound decompression. Its high decompression efficiency of voice signal has been well reflected in the application. Simulation results show that the set of multi-voice mixing is feasible, and has a certain validity and superiority.

Key words: multi-voice mixing, simular voice communication system, synchronization mechanism, buffer queue;attenuation factor

摘要： 基于塔台管制模拟语音通讯系统，设计并实现了多路混音功能。发送端采用双线程多缓冲区机制保证数据的实时即时发送；在混音同步机制中引入了多个缓冲队列，为成功实现同步混音创造了良好条件；在最为重要的混音算法中做了一些改进，混音效率有明显提高。在该系统中使用了专门为声音解压缩研究设计的Speex语音解压缩库，其高性能的语音解压缩效率，在应用中得到了很好的体现。系统仿真实验结果表明该套多路混音实现方式切实可行，具有一定的有效性和优越性。

关键词: 多路语音混合, 模拟语音通讯系统, 同步机制, 缓冲队列, 衰减因子