Pilot allocation for doubly selective channel estimation in OFDM systems

This paper investigates deterministic pilot allocation for compressed sensing (CS) based channel estimation of doubly selective channel in Orthogonal Frequency Division Multiplexing (OFDM) systems. Based on minimizing the coherence of submatrix of two-dimensional Discrete Fourier Transform (2D-DFT) matrix, the optimum pilot location criterion for greedy reconstruction methods is derived. However, it is difficult to find such optimum pilot location set. A greedy method is proposed to search a suboptimal pilot allocation solution. What´s more, considering the special structure of doubly selective channel, an improved reconstruction method based on Orthogonal Matching Pursuit (OMP) is proposed. Simulation results demonstrate a significant improvement of channel estimation performance by using the proposed pilot allocation and the improved reconstruction method.