A Design Of DVB-C STB With CA Module

With the development of the technology of digital cable television, it is inevitable that the digital cable television will take the place of the analogy cable television gradually. Which standard should apply to the digital cable television system has become a very important question of it. The standard of DVB-C has been proved to be the best one of many of them. And many provinces and cities have taken the standard to try to broadcast in our country now.The title mainly introduces a design method of single-directional DVB-C STB based on CA system. The design process emphases on the managing of the scrambled signal, which involves the channel processing, the demux, and the descramble of the signal.The first part of it mainly introduces current development of the digital cable television, then the different standards which applied to them, and comparison of their performance.The second part mainly introduces the whole thoughts of the STB design and the structure of the software and hardware of it. It includes a standard design of the digital cable STB, the functions that will come true base on the condition of our province and the design circumstance, and the analysis of the software and hardware design.The third part first analyzes the theory of channel encoder and digital modulating, then analyzes the theory of the channel decoder and digital demodulating accordingly. And last introduce the hardware design and software flow and arithmetic of them.The forth part introduces the concept and the theory of CA system first, then it describes the protocol of the communication between the host and the smartcard. Last it introduces the communication between the user interface module, the demux module, and the CA module, and how they harmonize to work in the design.The fifth part mainly introduces the problem that we had meet in our experiment and how we resolved it. Except that, it also provides the result, the waveform and the picture of the desrambled TV program to the reader.The design has realized the requirement of DVB-C STB, It provides the consumers a friendly operation interface, and it can descramble and decoder the program continuously and normally.