Probabilistic bit method cuts error rates in LDPC code decoding
Error-Rate Reduction in LDPC Decoding via Bit-Aligned Temporal Reinforcement in Parallel Probabilistic-Bit Dynamics
Information TheoryEmerging Technologies
Summary
Decoding messages accurately is important for reliable communication. The authors studied a new method to improve how low-density parity-check (LDPC) codes are decoded using probabilistic bits with a special memory technique. This new approach reduces errors by storing and reusing information from earlier steps, making the decoding process more stable. Their tests show significant error reductions compared to standard methods across different message lengths.
What this means in practice
- •For communication systems engineers: Improve error correction in communication devices by integrating bit-aligned temporal reinforcement in LDPC decoders to reduce bit error rates effectively.
- •For hardware architects: Design hardware implementations of LDPC decoders that incorporate memory of previous bit responses to enhance decoding stability and performance.
Authors
Naoya Onizawa, Takahiro Hanyu
Abstract
Probabilistic bits (p-bits) provide a physical and algorithmic primitive for stochastic inference, but highly parallel updates can alter their collective dynamics. We study the decoding of random-regular (3, 6) low-density parity-check (LDPC) codes using Jacobi-type p-bit annealing with stochastic partial activation. An additive response-path rule stores each bit's saturated response and reuses it before stochastic readout. High-statistics simulations with independent parameter optimization for each method show pooled bit-error-rate reductions of 33.5%, 74.8%, and 81.8% relative to memoryless probabilistic simulated annealing (pSA) for representative codes of block lengths 96, 192, and 288, respectively. Static gain, normalized averaging, response shuffling, and same-bit binary-state feedback with only its coefficient tuned under the same nonmemory parameters do not reproduce the full saturated-response benefit. Trajectory analysis links the improvement to acquisition of the channel-consistent valid-codeword basin and enhanced post-acquisition stability; the acquisition advantage persists from random and channel-hard-decision starts under the tested conditions. Across all 30 independent code realizations, fixed additive parameter-and-readout packages achieve lower bit- and frame-error rates than separately optimized pSA-specific packages, with neither package retuned for individual codes. These results show that the computational effect of temporal state depends on the retained quantity and its reinjection into stochastic dynamics.