根据香农信源和信道分离编码理论进行的分离信源和信道编码在时变信道时不能充分利用系统资源。正是在这种情况下 ,提出了信源信道联合编码 ,可以跟随信道的变化充分利用通信系统的资源 ,达到最好的端对端的通信效果。本文首先阐述了联合信源信道编码的原理 ,然后介绍了常用的实现方法 ,最后 ,提出了在设计联合信源信道编码系统时的改进方法。 Separate source and channel coding based on Shannon’s source and channel separation coding theory can not fully utilize system resources in time-varying channels. It is under such circumstances, the joint proposed source channel coding, you can follow the channel changes to make full use of communication system resources to achieve the best end-to-end communication. This paper first describes the principle of joint source channel coding, and then introduces the commonly used methods. Finally, we propose an improved method in the design of joint source channel coding system.