The Narrow Band Cofdm System Synchronization And Channel Estimation Research And Hardware Implementation

DTTB (Digital Television Terrestrial Broadcasting) technology is a newly developed technology which has comprehensively combined with many Hi-tech productions such as Digital Television, Coding theory, Digital Signal Processing, Computer Technology, SLSI (Super Large-Scale Integration), Communication Technology and so on. In view of current complex terrestrial transmission environment, limited spectrum resource and dispersed users, there is no undisputed international standard of Digital Television Terrestrial Broadcasting up till now. Therefore, rich research potential has been remained in this field. Researching and designing a narrow band Digital Television Terrestrial Broadcasting transmitting system is significant as soon as MPEG-4 AVC standard was put forward.This project has been focused on the research of basic theory of narrow band Digital Television Broadcasting transmitting system and its practical realization on SOC (system on Chip). The system has taken advantage of many advanced technologies including MPEG-4 AVC theory, narrow band coding and modulation, update digital up transducer, and digital down transducer. The application of so many advanced technologies has improved the ability of Rayleigh fading and saved frequency resource. Meanwhile, the capability of system burst interruption and the comprehensive performance of this system has been obviously upgraded. In final analysis, this narrow band coding and modulation system has injected new energy into the weak field of domestic mobile video.The design of Narrow Band Coded Orthogonal Frequency Multiplexing system contains Signal resource encoding and Channel encoding. The order of Signal resource encoding is transferring image and sound signal to electric signal, and the order of channel encoding is making sure of effectual transmission of electric signal. In this paper, the design of Channel encoding is disserted. It contains RS code,convolutional code,the realization of OFDM with IFFT/FFT,DDC/DUC,Synchronization and channel estimator and so on. The scheme of the system is introduced firstly, and then Synchronization and channel estimator are expatiated. Based on the simulation with Matlab, it expatiates signal theory, common arithmetic and typical arithmetic. In the end, FPGA circuit is designed of Synchronization and channel estimator module in ISE6.1i, and the circuit was checked on PCB board.