The Research And Realization Of Mobile Digital Television Receiver Based On DVB-T Standard

After experienced the mechanism television,the black and white television and color television time,the television is advancing to the high definition and the digitized direction,while the simulation electron television is being gradually retired from family during the world scope.Along with the technical development and the research being unceasingly thorough,people to the ground digital video broadcasting in motion reception, frequency spectrum efficiency, Single Frequency Network, disturbance,system aspect flexibility and so on have more profound understanding.At present in the European the DVB-T network is successfully realized the commercial operation, which depends on the characteristic of the mobile and the multimedia increment service. But in domestic, before the motion numeral television country standard doesn't appear, the most widespread DVB-T network in the world used by the majority city is applied to prosperous advertisement broadcast increment market in the the public place,such as the public transportation vehicle and the subway as well as the building.This paper develops the newest numeral television platform of Sigma Designs Inc.—EM8620L scheme, through studying DVB-T as well as the MPEG-2 related standard, and first grasping the MPEG-2 principle of the coding and the decoding, the system structure, the work way, the form and the decoding method. Next through studying the DVB-T signal characteristic,the frame structure, the transmission letter, the synchronization, the channel estimate and the modulation constellation, and detailedly elaborating the principle of the orthogonal code frequency divided multiplexing(COFDM),the method that DFT realizes the OFDM modulation, the reason which DFT realizes the OFDM modulation method and the OFDM protection gap which can do the anti-multi-diameters disturbance, this enable the development of the programming driver of the TU1216 tuner to have the good theory instruction.Secondly by absorbing,digesting and improving the general plan which the Sigma Corporation provides the numeral television platform, the own DVB-T hardware platform and the software movement platform are successfully designed. Finally in this software and hardware platform, the high frequency tuner signal of the DVB-T front end is successfully finished the signal reception, the frequency channelscanning as well as the channel demodulation.After the DVB-T signal is demodulated into standard TS stream,the process of PID filter implementation, the STC timer regeneration and PTS and DTS withdrew from the TS stream make it possible to the synchronization between video and audio,the correct demonstration of the frame order, the management of memory buffer overflowed or under overflows and the decoding of video stream and audio stream.