Compressed MIMO chanel estimation and efficient pilot pattern over Doppler sparse environment

By exploiting the coherent sparsity of the fading channels, compressed sensing (CS) based channel estimation allows an increase in spectral efficiency through a reduction of the number of pilot symbols that have to be transmitted. In this paper, we consider the estimation of Doppler sparse time-selective channels in MIMO systems. The Doppler sparsity is used by CS method to reduce the number of pilots. Different pilot patterns are analyzed in terms of mean square error (MSE). Simulation results demonstrate that using the random pilot pattern gives much better estimation performance than other pilot patterns. Furthermore, the number of pilots required for CS-based method no longer increases linearly with the number of transmit antennas relative to conventional channel estimation methods.