Encoding And Implementation Of LDPC Codes In The DVB-S2

LDPC codes are a kind of check by the very sparse matrix definition of linear block error-correcting codes, which is approaching the performance of Shannon limit, has been widely used in mobile communications, deep-space communications and satellite communications, and other fields. The Digital Video Broadcasting (DVB) project organization released a new generation of digital video satellite broadcasting standards DVB-S2 adopted the BCH code with the LDPC cascade channel coding program by 2005.This coding scheme in performance with Shannon Limit has only 0.7 to 1 dB gap, the packet error rate (PER) is below 10^-7 on the set threshold noise.Researching the construction law and coding method of LDPC code, based on this, we study several LDPC codes used in communications standards and analyse IEEE802.16e in LDPC coding methods and coding complexity.On the basis of the map theoretical model, we analyse the structure of the IRA code and research two structures of the IRA Encoder. IRA code encoder has simple hardware structure and they can encod in linear time. Implementing universal IRA Encoder is of great significance. We put forward the type of IRA Turbo Codes encoder generating parity checking and compare their hardware resources and the occupation of the coding cycle.The encode rules of DVB-S2 standard and the structure of LDPC codes which the standard employed are anatomied in detail, then that the LDPC codes are a class of IRA codes is deduced. It can be gotten from simulation results that IRA codes used in DVB-S2 have good performance. The universal encoder of IRA codes is designed and implemented with FPGA.FPGA report shows that the encoder accords with the demands for two code length and eleven code rate LDPC code in DVB-S2 standard and can be used by the standard.Through researching the working principle of DVB-S2 modulator and combining the development and debugging needs of the various modules, we designed DVB-S2 modulator development boards. Development board to achieve DVB-S2 standard fixed modulation coding mode, single MPEG-2 TS stream input modulator function, and the modulator can be used to design and debug the the various modules of the DVB-S2 modulator.