Optimal Pilot Pattern Design for Compressed Sensing-Based Sparse Channel Estimation in OFDM Systems

The frequency selective channel estimation problem in orthogonal frequency division multiplexing (OFDM) systems is investigated from the perspective of compressed sensing (CS). By minimizing the mutual coherence or the modified mutual coherence of the measurement matrix in CS theory, two criteria for optimizing the pilot pattern for CS-based channel estimation are proposed. Simulation results show that using the pilot pattern designed by either of the two criteria gives a much better performance than using other pilot patterns in terms of the mean-squared error of the channel estimate as well as the bit error rate of the system. Moreover, the optimal pilot pattern designed by minimizing the modified mutual coherence offers a larger performance gain than that obtained by minimizing the mutual coherence.