Abstract: Based on Space Time Coding（STC） from Coordinate Interleaved Orthogonal Designs（CIOD）, a novel Spatial Modulation（SM） scheme for 4 transmit antennas is presented. Compared with conventional SM, the novel scheme can not only improve the spectral efficiency of wireless communication system by using the transmit antenna number to carry information, but also achieve partial diversity gain by using STC. The use of conditional Maximum-
Likelihood（ML） algorithm at the receiver reduces the decoding complexity effectively. The Bit Error Rate performances（BER） of the proposed scheme, SM and Space-Time Block Codes（STBC） over independent and correlated channel are presented. The simulation results show that the BER performance of the proposed scheme is better than that of conventional STBC and SM.

Key words: Coordinate Interleaved Orthogonal Designs（CIOD）, Space Time Coding（STC）, Spatial Modulation（SM）, conditional Maximum-Likelihood（ML） algorithm

摘要： 基于坐标交织正交设计（CIOD）的空时编码，提出了一种新型的4发射天线空间调制（SM）方案。与传统的空间调制技术相比，该方案不仅利用天线序号携带信息，提高了无线通信系统的频带利用率，而且通过空时编码可获得较大的分集增益。接收端采用条件最大似然（ML）算法，大大降低了译码复杂度。在独立和相关信道情况下对所提方案、传统空间调制及空时分组码（STBC）的误比特（BER）性能进行了仿真，结果表明，所提方案的性能优于传统的空时分组码和空间调制。

关键词: 坐标交织正交设计, 空时编码, 空间调制, 条件最大似然算法