Design And Implementation Of BCH Codec In DVB-S2

BCH code,a very good kind of linear error correction code that has been found by now,is widely applied to mobile communications, wireless paging systems, fiber optical communications, and so on. DVB-S2 ,the new generation transmission specification for satellite broad-band applications, issued by the Digital Video Broadcasting (DVB) Project in 2005,adopts a scheme of channel coding which carrys out concatenation of BCH outer codes and LDPC(Low Density Parity Check) inner codes. Advanced channel coding scheme combined with high-order modulation such as 16APSK and 32APSK makes DVB-S2 achieve about 30 % capacity increase over DVB-S. For DVB-S2's advanced technology and excellent performance, it is important for establishing the Armed Police Force satcom system.In this paper, the BCH codes in DVB-S2 are researched deeply and the conclusion that 21 kinds of BCH code in DVB-S2 are shortened codes of 4 binary primitive BCH codes respectively, is drawed. The coding and decoding algorithms are researched, especially for Berlekamp-Massey iterative decoding algorithm and Euclid iterative decoding algorithm including their modified algorithms which are Inversion-free BM iterative decoding algorithm and Modify Euclid algorithm. Secondly,C language is used to implement BCH coding and decoding under VC++6.0 environment. In this foundation, a simulation software is developed and used to simulate the performance of BCH codes in DVB-S2 in AWGN channel. Then the simulation results is analyzed. Finally,a design scheme of BCH codes in DVB-S2 encoding circuit for general purpose and decoding circuit based on Inversion-free BM iterative decoding algorithm is presented.