The Study On Synchronization Algorithms Of OFDM System

OFDM technology is that it divides the frequency band into sub channels, keeping frequency domain orthogonal. Comparing with the traditional serial modulating Communication System, OFDM has the advantages of efficient bandwidth, reducing multi-path interference, and simple in structure. As the needs for broadband, personality and mobility, people focuses on OFDM technology, which has became the key technology in the forth generation mobile communication systems.Synchronizing technology is the key technology in OFDM system. The method of OFDM system takes the symbol timing synchronization, carrier synchronization and sampling synchronization. Every sub- channel has narrow bandwidth in OFDM system and it distinct the frequency domains with orthogonalization, so the system is more sensitive for the frequency and synchronization error. If carrier frequencies happen to frequency offset, losing orthogonalization, it will causes the great disturb among the carrier frequencies, then reducing the function of whole system. Carrier Synchronization is the premise for OFDM working. This thesis is mainly study on the symbol timing recovery and carrier synchronization.This thesis firstly introduces the actualities, the advantage and the disadvantage and the elements of OFDM technology, then the effect on OFDM system form the symbol timing recovery, carrier synchronization and the deviation of sample value synchrony. On this basis it analyzes the ML Estimation Algorithm, schmidle&cox Algorithm and the improved program based on cyclic prefix in detail, and verificating the algorithm performance by emulation. On the base of the analysis and simulating the existing algorithms performance, we bring forward the symbol timing recovery and carrier synchronization base on the cycle, giving the simulation result, carrying the simulated verification and analysis and comparison of performance.