Research On The Key Techniques Of A Baseband Demodulator For DVB-H Receiver

As the standard derived from DVB, which is the most widely used standard for Digital Television Systems in the world, DVB-H has attracted more and more attention all around the world cause of its compatibility and flexibility.For the purpose of withstanding the poor characteristic of the wireless channel, DVB-H utilizes COFDM as the method for channel coding and modulation, which makes it possible to realize the mobile inception, SFN setting up and various applications more expediently. For OFDM system, synchronization and FFT play very important roles in the whole system. So the research on these key techniques of a baseband demodulator for DVB-H system is very significant for the system development.In this dissertation, the recent situations of mobile digital video broadcasting all over the worldwide are introduced, the presentations of the framing structure, channel coding and modulation in DVB-H system are following in brief. Then the synchronization algorithms and FFT scheme in existence for DVB-H are analyzed in detail. Synchronization and FFT schemes of DVB-H channel demodulator suited for DSP implementation are also presented. The synchronization scheme includes the following parts: coarse symbol synchronization, fractional carrier frequency estimation and compensation, integral carrier frequency estimation and compensation, joint algorithm of fine symbol timing recovery and sampling clock adjustment. As the result, the synchronization modules and FFT modules implemented by DSP in DVB-H channel modulator are also described finally.