本文研究了存在载波频率偏移的分布式空时分组编码(DSTBC)正交频分复用(OFDM)系统(DSTBC-OFDM)的性能。首先给出存在多个载波频率偏移的DSTBC-OFDM系统的接收信号模型,然后提出一种频域均衡技术来抑制符号检测时的载波间干扰(ICI)以及符号间干扰(ISI)。仿真结果表明这种均衡技术在各分布式发送端间的载波频率之差较小时具有优异的性能,同时,通过把接收端的频率设置为各发送端频率的平均值可以获得更好的性能。
In this paper, we investigate the performance of distributed space-time block coded (DSTBC) orthogonal frequency-division multiplexing (OFDM) system (DSTBC-OFDM) with the presence of carrier frequency offsets. Received signal model of DSTBC-OFDM system with multiple carrier frequency offsets is given. Then a frequency-domain equalization technique is proposed to mitigate the inter-carrier interference (ICI) and the inter-symbol interference (ISI) when detecting the symbols. Simulation results show that the equalization technique is quite effective when the carrier frequency difference between the distributed transmitters is small, and moreover, by setting the receiver's frequency to the mean value of the transmitters' frequencies, a better performance can be obtained.