Research On Channel Coding And Modulation Technique In COFDM Transmission System

In this paper, we first introduce the development of high definition television in our country and the principle of COFDM technique, followed by comparing the two channel transmission standards between ATSC and DVB-T for digital terrestrial television. After describing channel coding and modulation system based on COFDM transmission scheme, we study the methods of circuit design in all blocks, including front control, randomization, Reed-Solomon code, outer interleaving, inner interleaving, mapping and frame shaping. These methods of system design can also be applied to other systems similar to the scheme we adopt. Finally, we using some software and hardware, such as Matlab Quartus II and Logic Analysis System, to realize the whole circuit function by FPGA. Presently our system is tested in Beijing and Shanghai, and the circuit operates reliably.