A robust least square channel estimation algorithm for OFDM systems under interferences

Conventional channel estimation algorithms devised for OFDM systems suffer from significant performance degradation in the presence of interference. This paper develops a robust least square (LS) channel estimation scheme with low complexity. The received pilot symbols are first separated into several groups, then each group is divided into two parts. After that, we apply the conventional LS algorithm to estimate the channel of the first part, then combine the result of each group to get the final estimation result. Meanwhile, the second part is utilized to determine the weight matrix of this combining operation. We mainly analyze the performance under 2 typical interferences, the worst interference (WI) and the narrow-band interference (NBI). Both theoretical analysis and simulations indicate that the proposed algorithm can achieves better performance than the conventional LS algorithm under both the WI and the NBI.