中文摘要：

在双向中继系统中,针对采用SSK传输不能获得发射分集且频谱效率较低的问题,提出了一种对角空时码空间调制算法,简称为DSTC-SM。该算法在源节点处采用DSTC-SM码字发送信号,在中继节点处配置单根天线对接收到的信号进行放大并将其转发至目的节点。DSTC-SM码字的构造中以对角码作为基本码块,并与空间调制（SM）技术相结合,采用循环结构来激活不同的天线。此外,通过对旋转角度的优化使该方案在即使只激活一根天线的情况下仍然可以获得发射分集增益。仿真结果表明,所提的算法比现有的算法具有较好的误码性能。

英文摘要：

In two-way relay system, focusing on the problem that using SSK transmission can not achieve the transmit diversity and has lower spectral efficiency, a diagonal space-time coded spatial modulation scheme called DSTC-SM scheme was proposed. In the DSTC-SM scheme, the source nodes transmit signals to the relay node by using the DSTC-SM codewords, and then the relay node equipped with one antenna amplifies the received signals and broadcasts them to the destination nodes. The proposed scheme uses the diagonal space-time codes as the core space-time block code（STBC） to construct the DSTC-SM codewords, and combines with SM technology to take advantage of the benefits of DSTC and SM. The antenna pairs activated in different codewords are moving cyclically along the total transmit antenna array. In addition, the rotation angles are further optimized to maximize the diversity and coding gains of the DSTC-SM codewords, so the proposed scheme can still obtain diversity gain even though only one transmit antenna is activated. Simulation results show that the proposed scheme outperforms the existing schemes.