Downlink channel estimation algorithm in TD-LTE digital relay systems

In this paper, focusing on the downlink channel estimation of TD-LTE digital relay system, we present a new channel estimation method which is based on LS algorithm at scattered pilot frequencies with cascaded one-dimension linear interpolation both in time and frequency domains. Meanwhile, different algorithms for channel estimation, such as LS and LMMSE, are investigated and comparison of linear and DFT-based interpolation is made. By analyzing computer simulation results, it is concluded that the proposed method has a good performance on estimating and tracking the variance of OFDM channel through comparing with other channel estimation methods. Additionally, it also achieves a lower bit error rate (BER) at a lower computational complexity.