%0 Journal Article
%T SDR-Based Blind Channel Estimation of Time-varying OFDM Systems<br>基于半定松弛方法的时变OFDM系统盲信道估计
%A Fang Cheng-zhi Du Si-dan Ni Liang-fang
%A <br>方承志
%A 都思丹
%A 倪梁方
%J 电子与信息学报
%D 2008
%I 
%X Some Quadratic Programs (QP) have been presented for the blind channel estimation and signal detection of the time-varying OFDM systems. In this paper a method is proposed to turn the QP problem into the optimization of a Semi-Definite Program (SDP) based on the Semi-Definite Relaxation (SDR) technique. Compared to the original QPs which reach the optimal solution with exponential complexity, the SDP could be solved efficiently in polynomial time. In order to reduce the complexity involved in the transform from the solution of the SDPs to the solution of the original QPs, the correlation property of the OFDM time-frequency response between adjacent subchannels or time-slots is exploited to devise a novel randomization strategy. The simulation proves the effectiveness of the new method.
%K OFDM
%K Blind channel estimation
%K Semi-Definite Relaxation (SDR)
%K Correlation
%K Randomization<br>正交频分复用
%K 信道盲估计
%K 半定松弛
%K 相关性
%K 随机转换
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=1319827C0C74AAE8D654BEA21B7F54D3&jid=EFC0377B03BD8D0EF4BBB548AC5F739A&aid=F08D9ECB9B77158ACC49E746C6382265&yid=67289AFF6305E306&vid=340AC2BF8E7AB4FD&iid=5D311CA918CA9A03&sid=11CC1479731B5118&eid=EFCEB529E333AB35&journal_id=1009-5896&journal_name=电子与信息学报&referenced_num=0&reference_num=13