Research Of Adaptive Equalization For ATSC 8-VSB Systems

Single carrier modulation is adopted in ATSC 8-VSB systems, in which equalization technique is critical to the ATSC 8-VSB receivers. First, the ATSC terrestrial transportation standard and the characteristics of wireless communications channel are introduced. A study of channel equalization including the equalization algorithms and structure of equalizer are made. According to the characteristics of ATSC 8-VSB systems, proper algorithms and structure of equalizer are analyzed. Also channel estimation methods which are used to initialize the tap weights of the filters are compared and sparse taps algorithum is used to reduce the extra mean square error. A decision feedback equalizer (DFE) implemented in real and base-band domain is used in the receivers. Much attention was paid to the techniques used to improve the performance of equalizer such as data recycling algorithm, virtual training technique, channel matched filter, non-causal filter, joint equalization and decoding technique and so on. Furthermore new methods, which are joint equalization and decoding with multiple decoding depth and construction of non-causal filter, are proposed to improve the performance of equalizer. Simulation with Matlab and C are made in this thesis and the symbol error rate (SER) curves of the receivers under the ensembles of Brazil channel are given.