基于专用CVSD芯片MC34115的单工话音基带传输设计

Design of Simplex Direction Voice Baseband Transmission Based on Specific CVSD Chip MC34115

在话音信号的数字基带传输过程中,为了设计一种电路结构简单、占据频带较窄、可靠性高的数字话音通信系统,调制解调方式的选取是一个重要环节.对CVSD芯片编译码原理、引脚功能以及实际应用电路结构进行了介绍和分析;同时采用信道HDB3编码传输,设计了以CVSD芯片为核心的低误码率,单工通话时不需要严格收发同步的长距离数字电话系统,此系统在极大地简化了电路结构的基础上还降低了数字信号的带宽.

In the process of the digital baseband transmission of the voice signal,the chip of demodulation is an important part to ensure communication availability.The continuously variable slope delta( CVSD) demodulation can either code with the lower error rate or transfer signal in simplex direction without strictly receive-transmission synchronous ,accordingly lowers the bandwidth of the digital signal in the base of predigesting circuit structure , so the digital telephone system for core with the CVSD chip has got its extensive application when the frequency resource is very limited .At the same time, the design adopts the code transmission of HDB3 ,thereby puts up the dependability of long-distance communication.