The Research And Implementation On Channel Estimation And Equalization Of Digital Television Terristrial Broadcasting System

Digital Television Terrestrial Broadcasting (DTTB) is recently one of hot points researched by universities and enterprises around the world. But DTTB has the stumbling block of serious signal fading, which is caused by high multi-path pervasion in wireless broadcasting channel; especially, it is more difficult to recovery signals in moving receiver environment, due to the fast time variable characteristic of the channel. DTTB basically represents the developing precursor of broad band digital communication. Its potential of product value arouses the most care among the industry. These days, China has come out with Digital Television Broadcasting-Terrestrial standard. Research on terrestrial transmission technique acording to digital television standard of our country has far-reaching meaning. Channel estimation and equalization are one of the core problems in the design of receivers in Digital Television Broadcasting-Terrestrial Standard. For the single carrier Digital Television Broadcasting-Terrestrial receiver, the method of direct adapt equalization can be used. For multi-carrier Digital Television Broadcasting-Terrestrial receiver, it's common to use indirect equalization method which combines channel estimation and frequency equalization, and some single carrier systems also use it. Therefore channel estimation and equalization have compact relationship. In this paper, the channel estimation and equalization in our country's Standard in Digital Television Broadcasting-Terrestrial are studied.Advanced Digital Television Broadcasting-Terrestrial (ADTB-T) system of Shanghai Jiaotong University, as one part of China's standard, has been mature digital television single-carrier system. Signal procession of time domain is adopted in system. Its time domain equalizer takes fraction space structure and overlap structure. Time domain equalizer estimates the channel through training sequence and updated the coefficients of equalizer through some self-adapting algorithm to track the channel chang. Orthogonal frequency divison mutiply (OFDM) is one special multiple-carrier scheme, whick can be taken as a modulating technique or a multiple techenique. Modulation and demodulation among each sub-carrier can be implemented through IDFT and DFT technique. If N is a big number, we can take fast fourier transform to implement it. General digital television multiple-carrier system takes channel estimation technique to conteract the multi-path in channel. This paper implements special system with time domain equalization technique.In the second chapter, two classes of channel models are summarized based on actual...