Abouth Multi-Threshold Decoding of Low-Density Parity-Check Codes

Low-density parity-check codes are one of the most common forward error-correction techniques used in many existing and perspective standards including 5G wireless transmission standards and ultra-high-rate (400 Gbit/s and more) fiber-optic transmission standards. These codes should combine scalability of codelength from dozens to dozens of thousands bits and of coderate from low to very high with outstanding error-correcting performance when operating under severe practical limitations both from the point of view of decoding error and complexity issues. In many practical cases most widely used decoders suffer either from complexity out of system restrictions or from error performance penalties. In this paper the performance-complexity trade-off approach is considered, based on improved hard-decision decoders. Decoding of low-density parity-check codes with bit-flip algorithm is considered. The multi-threshold decoder based on the bit inversion algorithm is described using dynamically changed threshold during the decoding iterations, as well as the simplest empirical method is proposed for thresholds calculation. Simulation results in Gaussian channel with hard decision demodulation are given.