中文摘要：

在信源-信道联合编码／调制中，通过优化信源和信道调制符号间的映射关系，在端到端均方误差的失真度量标准下，可以得到比传统级联编码系统更好的性能。且通过类似BSA的交换算法求得局部最优映射方式，有更高的重建信噪比，系统复杂度低。

英文摘要：

By optimizing the mapping scheme between source and channel modulation symbols in a joint source-channel coding/modulation system, under the distortion measurement of end-to-end mean square error, the proposed scheme has better performance than that of the traditional tandem coding system. With the local optimization mapping founded by switch algorithm which is similar to the Binary Switching Algorithm, it can reach higher SNR in reconstruction and lower complexity in system realization.