Research And Implementation Of Synchronization Algorithms In MPPSK Communication System

Synchronization is the precondition for successful realization of digital communications, and possesses important study value and wide application fields. The carrier synchronization and the bit synchronization, two sorts in synchronization research, are emphasized in this thesis.Firstly, the paper gave a full description about different sorts of synchronization.The principle of the MPPSK communication system was mainly discussed,then simulated and analyzed the demodulation in coherent and incoherent ways.Secondly,on the base of the classic carrier synchronization which was based on the COSTAS loop,data-aided frequency synchronization algorithms and data-aided phase synchronization algorithm were studied respectively.Results can be summed up through the data-aided frequency synchronization algorithms'simulations:the signal to noise ratio is a key factor affecting the performance of the algorithm, when the signal to noise ratio is high, the M&M algorithm and the Kay algorithm have great offset estimation range, and good estimation performance, but also the M&M algorithm performance is slightly better than the Kay algorithm; the Fitz algorithm and the L&R algorithm are suitable for use in poor communication environment situation, but compared to the Kay algorithm, due to a increased computing step of auto-correlation function, not only no advantage in calculation, the frequency estimation is also small. So the M&M algorithm performance is generally more suitable for use herein communications system. Results can be summed up through data-aided phase synchronization algorithm's simulation: Estimate performance of the DA algorithm is independent of modulation order and has a high resistance to noise, the estimated mean square error curve fitted well with MCRB curve.Finally,after studying the exciting bit synchronization methods of the MPPSK communication system receiver,the paper proposed a bit synchronization method for the MPPSK communication system receiver based on Gardner timing error estimate algorithm.