Application of sphere decoding in intercarrier-interference reduction for OFDM systems

While fast variations of wireless channel characteristics cause intercarrier interference (ICI) in orthogonal frequency-division multiplexing systems, they also introduce frequency diversity, which can be exploited to improve the demodulation performance. An ICl-reduction algorithm is proposed based on a sphere decoding (SD) algorithm. By considering channel information, a new search strategy is developed to reduce the computational complexity of the SD algorithm. Design examples are presented which demonstrate that the proposed algorithm outperforms several existing algorithms in terms of BER performance.