Abstract: Channel estimation which can acquire the channel fading information is a key technology to improve the performance in wireless channel transmission. In this paper, we consider the estimation of Doppler sparse time-selective channels in AF-TWRN. Compared to the traditional linear estimation method, the compressed sensing-based channel estimation method has taken the inherent sparseness of wireless channel into account, which reduces the number of pilots, improves the channel estimation performance and the system throughput, raises the spectrum efficiency. We firstly establish the Doppler sparse model of AF-TWRN , then analyze the channel estimation performances improved with the increase of pilot number and SNR. Different pilot patterns will affect the correlation of measurement matrix, which can furtherly affect the channel estimation. Simulation results demonstrate that using the random pilot pattern gives much better estimation performance than other pilot patterns. Furthermore, we analyze the influence of maximum Doppler frequency shift on estimation performance.