A subcarrier average based block-by-block blind channel estimation algorithm for multi-user OFDM systems

In this paper, a block-by-block blind channel estimation algorithm is proposed for a multiuser orthogonal frequency division multiplexing (OFDM) system with an antenna array at the base station and a single antenna at each mobile unit. Provided that the channel is static within an OFDM block (i.e., block fading channel), based on the subcarrier averaging the proposed channel estimation algorithm can estimate all the channel parameters (directions of arrival, time delays and multipath gains of all the users) within only one OFDM block. Some simulation results are provided to justify the efficacy of the proposed channel estimation algorithm even when the total number of subcarriers is not very large.