IOSR Journal of Engineering
This paper reviews the basics of error correcting codes like linear block codes and LDPC. The error correcting codes which are also known as channel codes enable to recover the original message from the message that has been corrupted by the noisy channel. These block codes can be graphically represented by factor graphs. The authors mention the link between factor graphs, graphical models like Bayesian networks, channel coding and compressive sensing. In this paper, they discuss an iterative decoding algorithm called Message Passing Algorithm that operates in factor graph, and compute the marginal function associated with the global function of the variables.