“A novel combined algorithm for 32-QAM carrier recovery"

In this paper a novel method to realize the synchronization process in case of 32-QAM will be presented. The system is based on the times-n carrier recovery and doesn't depend on data decision. Starting from the Park and Ahn method which tracks, after a non linearity, the carrier recovery only for the in-phase symbols of a 16-QAM modulation, the proposed method combines a Phase Lock Loop and a Costas loop to use also in-quadrature symbols to solve the problem of tracking process. Moreover the algorithm has been extended to a 32 QAM modulation and it has been tested with received symbols corrupted by phase noise and thermal noise. Numerical results are presented to support the effectiveness of the proposed algorithm.