Performance improvement of channel estimation based on pilot structure variations for cellular OFDMA systems

An increasing number of systems are adopting orthogonal frequency division multiple access (OFDMA) as their high-speed wireless transmission method supporting multiple users, and impacts on performance of OFDMA systems under mobile cellular environments are currently being investigated. In this paper, channel state and quality estimation performance issues are addressed for varying types of pilot structures in the transmitted burst. It is demonstrated that significant performance variations can occur in estimation of the state and quality of the wireless link depending on the pilot pattern used in the preamble symbol. In particular, advantages of using disjoint patterns for downlink transmission from adjacent cells are quantitatively presented, by evaluating the bit error rate and the carrier-to-interference ratio (CIR) estimation performance.