Error Performance of Decoding of LDPC over AWGN Channel

The design of future communication systems with high throughput demands will become a critical task, especially when sophisticated channel coding schemes have to be applied. Low-Density Parity-Check(LDPC) codes are among the most powerful forward error correcting codes, since they enable to get as close as a fraction of a dB from the Shannon limit. A simplified decoding algorithms for decoding Low-Density Parity-Check (LDPC)codes is proposed with a view to reduce the implementation complexity. The algorithm is based on simple hard-decisiondecoding techniques while utilizing the advantages of soft channel information to improve decoder performance . This astonishing performance combined with their relatively simple decoding algorithm makes these codes very attractive for the next digital transmission system generations.The parity check matrix used for the LDPC codes is sparse. The complexity and performance of codes are improved by the modifications in the decoding algorithm. This work deals with study and implementation of LDPC coding system over AWGN Channel. Keywords— LDPC Low Density Parity Check, AWGN Additive White Gaussian Niose, BER Bit error Rate, SPA Sum Product Algorithm,MPA Message Passing Algorithm, BP Belief Propagation, MS Min-sum Algorithm