Abstract:

An improved bit-flipping (BF) algorithm with low complexity for decoding structured lowdensity parity-check codes (LDPC) is proposed to improve the performance of the harddecision BF algorithm. The harddecision bits are divided into two groups based on the magnitudes of the received symbols, and at each iteration, the proposed algorithm can flip more than one bit with using two thresholds, and the flipping error probability is effectively decreased. The improved BF algorithm requires some real number comparisons before iterations and requires only logical operations during the iterations. Compared with the weighted bitflipping algorithm and its modifications, the new method is with significantly lower complexity. Simulations show that the proposed algorithm is provided with very fast convergence speed and excellent performance with significantly low complexity.

Key words: low-density parity-check codes, bit-flipping, iterative method