Speed ​​fft In The Receiver Of The Dvb-t Modulator To Achieve

Nowadays, technology changes every passed day, and the development of communication and information make the whole television broadcast industry a noticeable evolution. The digital televison should be a key point of this evolution. As the digital television broadcast becomes more abroad, traditional TV media will use some other means of information and communication in their technology and function. So that, a totally new and huge industry of digital TV would be founded. Recent years, DVB-T, a digital terrestrial TV broadcast standard, is used in much occasion. Meanwhile, it provides the possibility of electronic commerce, banking operation and web browsing over the TV network.DVB-T standard adopts OFDM to be the key technology of transmission. As a multi-carrier modulation, OFDM may avoid high-speed equalization, and could confront impulse noise and propagation fading, and more importantly, it saves frequence spectrum resource. At the year of 1971, Weinstein and Ebert applied DFT in parallel transmission system, as a part of modulation and demodulation. In that way, it could carry out FDM without band-pass filter, but only need deal with it at base band. In the implementation, not any more sub-carrier oscillators are needed, and it could be completed alone with FFT processor.DFT, the form of Fourier Transform in the digital region, points out the relationship of discrete signal in time domain and frequence domain. DFT makes it easily that transforming discrete signal between time domain and frequence domain, so that it becomes an important mathematic tool in many aeras. In another hand, calculation DFT directly will take a lot of operation. To deal with this, researching the fast way to calculate DFT makes sense to implementing OFDM system.This thesis consists of five chapters. At the beginning, it is an introduction to digital TV and ASIC design. Then it analyzes the character of OFDM system and the architecture of a DVB-T modulator/demodulator. The means of FFT algorithm and how to apply it to the OFDM system is discussed in the following chapters. Finally, a most proper way is found out and described with particular block diagrams and formulas. Some other applications of FFT processor is also gave out at the last chapter.