Iterative Sequential OFDM Symbol Estimation Algorithm over Time-Frequency-Selective Fading Channels

Time-frequency-selective, i.e., time-variant multipath, fading in orthogonal frequency division multiplexing (OFDM) systems destroys subcarrier orthogonality, resulting in intercarrier interference (ICI). In general, the previously proposed estimation schemes to resolve this problem are only applicable to slowly time-variant channels or suffer from high complexity due to large-sized matrix inversion. In this letter, we propose and develop efficient symbol estimation schemes, called the iterative sequential neighbor search (ISNS) algorithm and the simplified iterative sequential neighbor search (S-ISNS) algorithm. These algorithms achieve enhanced performances with low complexities, compared to the existing estimation methods. key words: OFDM, symbol estimation, time-frequency-selective fading channel