MIMO-OFDM系统中基于RAMP及其改进的稀疏信道估计算法

研究了在MIMO-OFDM系统中的稀疏信道估计问题。将正则化稀疏度自适应匹配追踪算法（RAMP）运用到MIMO-OFDM稀疏信道估计中，并对该算法的迭代结束条件加以改进，取残差的能量之差小于设定的阈值来终止迭代过程，更加准确地估计出信道稀疏度，进而提高了稀疏信道的估计精度。仿真结果表明，在MIMO-OFDM系统中，相比RAMP算法与稀疏度自适应匹配追踪算法（SAMP），改进算法能够获得更好的MSE性能，在不需要稀疏度的前提下达到了与正交匹配追踪算法（OMP）算法相似的MSE性能。 

RAMP and An Improved Algorithm For Sparse Channel Estimation in MIMO-OFDM System

The sparse channel estimation in multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems was examined. Regularized adaptive matching pursuit (RAMP) was applied to the channel estimation, and the algorithm''s iteration termination condition was improved by taking the difference between the residual energy less than the set threshold to terminate the iterative process, ultimately obtain a more accurate estimation of the channel sparsity and improve the estimation accuracy of sparse channel. Simulation results demonstrate that compared to the sparsity adaptive matching pursuit (SAMP) and RAMP, the improved algorithm can obtain better MSE performance. Under the premise of unknown sparsity, the improved algorithm can reach the same MSE performance with orthogonal matching pursuit (OMP).