Integer frequency offset estimation by pilot subset selection for OFDM system with CDD

Cyclic delay diversity (CDD) is a simple transmit diversity technique for an OFDM system using multiple transmit antennas. However, the performance of post-FFT estimation, i.e. integer frequency offset (IFO) is deteriorated by high frequency selectivity introduced by CDD. Proposed is an IFO estimation scheme for an OFDM system with CDD. Based on the pilot subset partitioning, the proposed IFO estimation scheme reduces the effect of frequency selective fading by adopting the CDD.