Research On Single Carrier Time Domain Equalization In DTMB System

Single carrier modulation and demodulation have been applied widely in wireless digital communication system, and it is an important research aspect. How to design the time domain equalizer for single carrier modulation in DTMB system is studied in this paper. Firstly,we analyze the characteristics and computational complexity of equalizers and adopt fractionally-spaced decision feedback equalizer adapted by LMS as the basic whose operation is unified on symbol rate. Secondly,for the reason that when the channel presents multi-path, particularly strong multipath, error propagation in the feedback filter severely affects the performance of the equalizer, we use the blind equalization algorithm as a supplementary means to improve the convergence rate of decision feedback equalizer. Finally,according to the features of PN frame structure in DTMB system, by the adoption of different step control mechanisms and the further division of the equalizer workflow, we propose an improved algorithm based on the combination of blind equalization and decision feedback equalization. The simulation results demonstrate the effectiveness of the algorithm which can further improve the convergence rate and stable state performance.