中文摘要：

该文使用矩生成函数方法推导了时间和频率选择性多输入多输出瑞利衰落信道上采用矩形M进制正交幅度调制的空时频分组编码正交频分复用系统的平均误符号率精确闭合表达式。数值计算和模拟结果表明,空时频分组码的误码性能分别优于时间选择性衰落信道上的空时分组码和频率选择性信道上的空频分组码。

英文摘要：

Based on moment generating function approach,this paper derives the exact closed-form expressions for the average symbol error rate（SER） of space-time-frequency block coded orthogonal frequency division multiplexing（STFBC-OFDM） system with rectangular M-ary quadrature amplitude modulation（MQAM） on time and frequency selective multiple-input multiple-output Rayleigh-fading channels.Numerical and simulation results show that the SER performance of STFBC outperforms STBC in time-selective channels and SFBC in frequency-selective fading channels,respectively.