中文摘要：

为改善多天线系统误码率,提出一种基于加权分数傅里叶变换域的2天线发射方法.该方法在发射端将待发送信号送入信息调制及合成模块中进行加权分数傅里叶变换,按照时频域信号合并方式将变换后的四路信号分量合并为两路混合载波信号,经时延调整后由2根发射天线发射送入信道;接收端采用单天线接收,对接收信号进行加权分数傅里叶反变换处理后,可得到原发送信号估计值.仿真结果表明：在双弥散信道下,相比于使用空时码2天线发射方法,采用本文提出的发射方法在系统误码率及复杂度方面较有优势,可有效改善系统误码性能,抵抗信道衰落.

英文摘要：

A two-branch transmit method based on the weighted-type fractional Fourier transform（ WFRFT） is proposed to improve the bit error rate（ BER） performance of multi-input multi-output（ MIMO） systems. The signal to be transmitted is first sent into the information modulation and synthesis module of the transmitter. Then the proposed method is accomplished in a two-step manner. Specifically, the transmitter first decomposes the transmission signal into four way signals. Then,the four-way transmitting signals are combined into two-way signals by time-frequency combination and are transmitted via two independent antennas. The signal is received by single antenna at the receiver. And inverse-WFRFT is performed such that the transmission signal can be recovered reliably. Numerical results show that the proposed scheme leads to a significant performance advantage,in terms of both BER performance and robustness against doubly-dispersive fading,compared with the Alamouti space-time block coding.