一种基于压缩感知的正交频分复用信道估计中确定性导频方案

Optimal Definite Pilot Pattern for Orthogonal Freguency Division Multiplexing Compressed Channel Estimation

基于压缩感知的正交频分复用(OFDM)信道估计方法通过充分利用信道冲激响应在时域的稀疏特性,在感知矩阵满足可重构条件下,能近似完美的重构信道并显著降低导频开销。基于感知矩阵相关系数最小化准则,设计了一种最优的确定性导频方案,在无虚子载波的OFDM系统中,采用正交匹配跟踪算法时,实现了与随机导频方案相同的信道估计性能;而在实际的存在大量虚子载波的OFDM系统中,获得比随机导频方案更优的性能。

When the sensing matrix holds the restricted isometry property （RIP）, the compressed sensing-based OFDM channel estimation can greatly reduce pilot overhead and approximately ideally recover the channel state information （CSI） as well by exploiting the sparsity of channel impulse response （CIR）. An optimal deterministic pilot pattern is proposed under the principle of minimizing the mutual correlation coefficient of the sensing matrix. With the aid of the designed optimal definite pilot pattern, the mutual correlation coefficient of the sensing matrix is analyzed, and the mean square error （MSE） performance of orthogonal matching pursuit （OMP） algorithm is simulated for OFDM systems with large amount of virtual subcarriers. Both the analysis and the simulation results show that the designed optimal definite pilot pattern outperforms the other reference pilot patterns.