Common Phase Estimation in Coherent OFDM System Using Image Processing Technique

In a coherent orthogonal frequency division multiplexing system, the possible rotation of the rectangular signal constellation, due to common phase error, is shown to be effectively compensated by applying an skew compensation technique adopted in image processing area. We further propose an improved technique to further reduce the complexity of the algorithm and investigate the effect of the number of required test phases, via numerical simulations. The proposed improved algorithm is also compared with the conventional blind phase searching algorithm. It is shown that by employing only two bits of overhead, it can achieve a comparable performance to that of the traditional pilot aided method.