Implementation of Message Passing Algorithm for LDPC Codes

Abstract

Error correcting codes (ECC) enable the communication systems to have a low Power, reliable transmission over noisy channels. Low Density Parity Check codes are the best-known ECC code that can achieve data rates very close to Shannon limit. Low-density parity-check (LDPC) codes are a class of linear block codes. The name comes from the characteristic of their parity-check matrix, which contains only a few 1’s in comparison to the amount of 0’s. LDPC is an Iterative algorithm. Basically there are two different possibilities to represent LDPC codes. All linear block codes they can be described via matrices and the second possibility is a graphical representation. My aim is to implement the message passing decoding algorithm for LDPC codes. A modified version of Min-Sum algorithm has been used for the decoder, which has the advantage of simpler computations compared to Sum-Product algorithm without any loss in performance. To balance the area-time trade-off of the design, a special structure is proposed for the parity-check matrix.