Abstract: OFDM blind channel estimation technique can estimate the information of channel mode without the pilot. It can also save bandwidth and improve the spectrum efficiency. This paper analyzes a kind of blind channel estimation technique which is based on subspace SVD method and proposes a method for estimating time-varying channel on the basis of blind channel estimation technique. In the light of low accuracy of existing methods for estimating, this paper also raises an optimization algorithm to carry out λ weighting using channel’s interrelated property. It does Monte Carlo simulation to this algorithm. The simulation results show that this algorithm can improve the performance of channel estimation effectively, and has lower complexity.

Key words: blind channel estimation, subspace, Orthogonal Frequency Division Multiplexing（OFDM）, correlation

摘要： OFDM盲信道估计技术可以在不需要导频的情况下，估计出信道的状态信息，能有效节约带宽，提高频谱利用率。分析了一种基于子空间SVD方法的盲信道估计技术，在此算法基础上提出了针对时变信道的估计方法，并就现有方法估计精度较低的问题，提出了一种利用信道相关特性进行λ加权的优化算法。对算法进行了蒙特卡罗仿真，仿真结果表明该算法能够有效改善信道估计性能，并且具有较低的复杂度。

关键词: 盲信道估计, 子空间, 正交频分复用, 相关