A channel coder design for a high speed and less complex communication system using QC - LDPC codes

Forward error correcting codes are successfully implemented in high speed communication for error-free transmission with high data rate. One such code is Low Density Parity Check (LDPC) code. In this paper, Quasi Cyclic (QC) construction of LDPC code is used and we investigate the performance of various decoding algorithms of QC-LDPC code. Their performances in terms of error correction and complexity are compared. The speed of convergence of various decoding algorithms of LDPC code is analyzed by using the Density Evolution theory. With this thresholding in iterations, the BER performances of different algorithms are simulated. Our results show that the same BER performance can be achieved with reduced number of iterations or the speed of the system can be improved without much sacrifice in BER performance.