A novel ICI cancellation technique for OFDM systems using adaptive mapping signal constellation

We propose a novel intercarrier interference (ICI) reduction technique for OFDM systems. By partitioning a (2M)-point constellation into two disjoint M-point constellations, and adaptively mapping each log₂ M input data bits into either of these two constellations; this technique allows extra freedom to reduce the ICI. The ICI reduction of the proposed technique is comparable to the rate-half technique while the throughput of the former is higher than that of the latter. In this paper, three suboptimal methods, i.e., the random selection, the modified PTS, and the recursive partial sequence methods, are also proposed to lower the computational complexity. Their performances are evaluated and compared by simulations.