Research On Timing Synchronization Algorithm To Burst QPSK Signal Open Loop Structure

Synchronization is a critical function in digital communications. Its failure may have catastrophic effects on the system performance. In burst communications, rapid acquisition of the synchronization parameters is essential. The central topic of this thesis is to discuss feedforward synchronization techniques using a PN preamble, which are well suited for burst communication.The best synchronization algorithms for digital communication systems are based on the maximum likelihood estimation theory,and interpolation can be applied to the timing phase compensation. Therefore, these subjects are discribed in detail.For the study of symbol timing recovery, this thesis presents a new feedforward data-aided estimation algorithm using a PN preamble based on the maximum likelihood estimation theory. The proposed method needs just two samples per symbol period and it exhibits good performance even for signals employing small excess bandwidth. Simulation results show that its performance is close to MCRB. The feedforward algorithm using a short preamble provides very fast acquisition and low complexity, well suitable for point-multipoint QPSK TDMA systems.The main hardware structures of timing recovery are also presented.