Performance of Modified Iterative Decoding Algorithm for Multilevel codes

In this paper, performance of Modified Iterative Decoding Algorithm (MIDA) is investigated for decoding of Multi-level codes. MIDA is a hard decision decoder that was initially proposed for decoding of Product codes, by same authors. In this paper same concept is being extended for Multi-level codes. The basic iterative decoder has a huge complexity which is unaffordable for long constituent codes especially when used in real time systems. In MIDA, the idea of Syndrom Decoding is used for search space reduction. Moreover, it is found that complexity reduction factor increases with each iteration. The worst case complexity of MIDA is closed to that of basic algorithm but in average case there is hung reduction in complexity, with negligible performance degradation. Performance of the proposed algorithm is investigated over an OFDM system. Additive White Gaussian Noise (AWGN) channel and Reyleigh fading channel are used for simulations.