In view of the characteristics of the two-dimensional sparse channel of the time and frequency domains of the LTE-A systems in Doppler environment and in line with the distribution of pilot in the time and frequency domains and its correlation with them

this paper presents an Orthogonal Matching Pursuit（OMP）algorithm-based improved compressed sensing channel estimation by decomposing the search space into ranges between OFDM symbols in time domain and between subcarriers in frequency domain.Simulation results show that the improved OMP algorithm has still lower Mean Square Error（MSE）than the original one.