Performance Analysis based on Density Evolution on Fault Erasure Belief Propagation Decoder

TL;DR

This paper analyzes the performance of fault erasure belief propagation decoders using density evolution, revealing how faults affect error probabilities and thresholds, and proposing encoding techniques to improve fault tolerance.

Contribution

It derives density evolution equations for fault erasure BP decoders and investigates their asymptotic error behaviors, highlighting the impact of faults and encoding methods.

Findings

Error probabilities converge to positive values under faults

Fault BP thresholds are lower than fault-free cases

Encoding techniques can improve fault thresholds

Abstract

In this paper, we will present an analysis on the fault erasure BP decoders based on the density evolution. In the fault BP decoder, messages exchanged in a BP process are stochastically corrupted due to unreliable logic gates and flip-flops; i.e., we assume circuit components with transient faults. We derived a set of the density evolution equations for the fault erasure BP processes. Our density evolution analysis reveals the asymptotic behaviors of the estimation error probability of the fault erasure BP decoders. In contrast to the fault free cases, it is observed that the error probabilities of the fault erasure BP decoder converge to positive values, and that there exists a discontinuity in an error curve corresponding to the fault BP threshold. It is also shown that an message encoding technique provides higher fault BP thresholds than those of the original decoders at the cost of increased circuit size.