Improved Sparse Multi-path Channel Estimation via Modified Orthogonal Matching Pursuit

Impulse response of sparse multi-path channel (SMPC) can be recovered from a short training sequence since most entries of SMPC are zeros. Though the ordinary orthogonal matching pursuit (OMP) algorithm provides a very fast implementation of SMPC estimation, it suffers from the coherence of atoms in dictionary, especially in the case of SMPC with a large delay spread and short training sequence. In this paper, a modified OMP method is proposed and a sensing dictionary is designed adaptively to improve the performance of the OMP algorithm. Numeral experiments illustrate that the proposed algorithm based on adaptive sensing dictionary outperforms the ordinary OMP algorithm.