Sparse channel estimation based on L1/2 regularization in OFDM systems

This paper addresses the problem of sparse channel estimation in orthogonal frequency-division multiplexing (OFD-M) systems. A novel sparse channel estimatior using iterative half thresholding algorithm based on L_1/2 regularization is proposed. Compared with the traditional greedy pursuit and L₁ regularization, the merit of the new method is twofold. Firstly, the new method has robust capacity to combat the observation noise. Secondly, it can deeply exploits the sparsity of the channel to reduce the number of pilots and hence raises the spectral efficiency. Simulation results demonstrate the effectiveness of the proposed algorithm.