压缩ICI的延迟分集算法

针对在正交频分复用(OFDM)系统中,时变信道引起符号内子载波间传输的数据出现ICI,引起系统性能下降[1]。提出在时域延迟分集即循环延迟发送、分集接收的算法来压缩子载波间干扰(ICI)。其思想是:将OFDM符号时域循环延迟,再以正常的发送方式发送这些符号,经空中信道后,这些经历不同衰落,在接收端通过分集接收能压缩ICI,增强系统性能。通过性能分析和仿真表明,时域自干扰删除(TDSIC-OFDM)系统和其他系统如PCC-OFDM系统相比,能有效对抗时变信道,并且能获得极大的系统性能增益。

ICI Suppression Method for OFDM System Using Cyclic Delay Diversity

In OFDM system,the time variance of channel destroys orthogonality among the sub-carriers,and introduces Inter-Carriers Interference （ICI）,so degrades the system performance severely.A method of suppressing ICI for OFDM based on cyclic delay diversity （CDD） is proposed to combat the influence of time-varying channel,which is called time-domain self-interference cancellation （TDSIC） algorithm.The TDSIC symbols are transmitted cyclically with delay,and received with diversity methods.The main idea of TDSIC is that,in a cyclically extended OFDM system,the fading characteristics of these OFDM symbols with different cyclic delay are different,so diversity collection can be used to improve the system performance.The performance is enhanced at the expense of time.Through performance analysis and simulation,it is proved that TDSIC can effectively combat the influence of time-varying channel and achieve perfect system performance.