An effective design of parity check matrix for LDPC codes using multi-objective gravitational search algorithm

The low-density parity-check (LDPC) code is an efficient contender for capacity approaching error correction over many important channels. In this paper, we design a parity check matrix for error correction using multi-objective gravitational search algorithm. The overall steps of the proposed technique are explained with three steps: 1) new objective function generation; 2) optimised parity check matrix generation using MGSA; 3) an LDPC encoding-decoding system design. At first, a multi-objective function is derived based on four efficient objectives like low density, maximum hamming minimum distance, maximum marginal entropy, and maximum cyclic lifting degree. Our GSA-based approach is developed with efficient agent representation, fitness computation along with usual GSA operators. Once the parity check matrix is computed, this matrix is utilised for LDPC encoding. The proposed approach is evaluated through bit error rate (BER) measure. From the results, we ensure that the proposed technique outperformed the existing technique by achieving the BER of 0.0513, 0.0348, and 0.0270 in fourth iteration.