Synchronization Technology In OFDM System With Applications To DVB-C2

Due to its high spectrum efficiency, high data rate, and effectiveness in combatingthe multipath interference, OFDM (Orthogonal Frequency Division Multiplexing) hasattracted wide attention and applied in many fields. While OFDM system is verysensitive to synchronization, synchronization error will degrade the system performance.Therefore, an accurate synchronization is necessary to construct a high-performanceOFDM system. The second generation of digital video broadcasting transmissionsystem (DVB-C2) has high spectrum efficiency and flexible data allocation ability,using OFDM technology as its physical layer modulation scheme, combining with thephysical-layer-pipe technology and the powerful FEC coding system.The work is unfolded as two aspects: the synchronization algorithms for OFDMsystem and a synchronizer design for DVB-C2system. The main content includes:1. The basic principle of OFDM system is investigated. Then the influence ofsynchronization error on the system performance is analyzed, which explains thenecessity of research.2. Two kinds of synchronization algorithms are discussed, including non-data aidedand data aided algorithm. The principle of ML and MC algorithms based on cyclicprefix is analyzed. Data aided synchronization algorithms are introduced, which can bedivided into training sequence and pilot sequence. Algorithms based on trainingsequence are researched respectively. Then their characteristics are analyzed throughsimulation. After that, an algorithm based on pilot sequence is discussed.3. The characteristics of the Constant Amplitude Zero Auto Correlation (CAZAC)sequence are investigated and then a typical algorithm based on this sequence isintroduced. Under the analysis above, an algorithm based on CAZAC sequence isdesigned. Compared with other algorithms, it turns out that the designed algorithm hasmore accurate timing performance, higher accuracy of carrier frequency offsetestimation, and the estimation rang can cover the entire signal band.4. The transmission standard of DVB-C2is introduced. And a synchronizer for DVB-C2is designed, including symbol timing, carrier frequency and samplingfrequency synchronization. With the MATLAB-based simulation software platform, theperformance of the synchronizer is analyzed under the environment of cable channel.Simulation results indicate that the design scheme exactly meet the implementationrequirements.