OFDM快时变信道下的相位旋转调制技术

Phase Rotation Modulation Technique for Time-Varying OFDM Systems

由于发射端和接收端振荡器之间的频率偏差以及无线信道的时变性,OFDM系统各个子载波之间的正交性将会被破坏,从而产生载波间干扰(ICI)。该文利用发送端的多天线分集,提出了一种新型的相位旋转调制技术。它通过在频域对不同发送天线上的发送信号进行不同角度的旋转,使接收端等效信道频域响应产生的载波间干扰最小,达到抑制载波间干扰的作用。实验证明,这种新型的相位旋转调制技术不会改变OFDM系统的发送功率,能够在不占用额外系统带宽的情况下有效地消除快时变信道环境下系统的载波间干扰,达到较好的误码率性能。

Due to the time variation and frequency offset of mobile radio channels of the OFDM system, the orthogonality between sub-carriers will be destroyed. In this paper, a novel phase rotation technique is proposed which can suppress the Inter-Carrier Interference （ICI） efficiently. This new method can get the minimum of sub-carrier interference in frequency domain by rotating the phase properly on each sub-carrier. Simulation results show that this new scheme can suppress the ICI efficiently and achieve better system BER performance, while the frequency efficiency and transmitting power remain the same.