OFDM系统稀疏信道估计研究

Research into algorithm for OFDM systems sparse channel estimation

由于许多通信系统的信道具有稀疏多径的特性,因此可以将信道估计问题归结为稀疏信号的恢复问题。提出一种新的基于压缩感知理论的正交频分复用系统信道估计方法,采用稀疏度自适应匹配追踪压缩感知算法对OFDM信道时域脉冲响应进行估计。克服了现有基于压缩感知理论的信道估计方法需要预先知道信道冲激响应稀疏度才能重构信道参数的不足,在信道稀疏度等信道先验知识未知情况下可得到较好的信道估计性能,降低系统复杂度。

Due to the sparse structure of channels in a number of communication systems,the sparse channel estimation problem can be formulated as the reconstruction problem of sparse signals.A new method of Orthogonal Frequency Division Multi-plexing（OFDM） sparse channel estimation based on Compressive Sensing（CS） is proposed.One of the CS algorithms,signal adaptive matching pursuit is used to estimate the channel impulse response of OFDM system.It overcomes shortcomings that the existing channel estimation methods based on the theory of compressed sensing can only reconstruct channel parameters under the circumstances of knowing sparse degrees of channel impulse response in advance.This algorithm can obtain good channel estimation performance without knowing such channel prior knowledge as sparse degrees and reduce the complexity of the system.