New Channel Coding Lower Bounds for Noisy Permutation Channels
Lugaoze Feng, Xunan Li, Guocheng Lv, Ye jin
TL;DR
This work addresses finite-blocklength coding for noisy permutation channels where the channel is a strictly positive, full-rank square matrix combined with a random permutation. It introduces ε-packing-based divergence packing to construct a message set and derives a new nonasymptotic achievability bound that tightens prior results, complemented by a Gaussian approximation that yields a closed-form rate–blocklength tradeoff. The results are specialized to BSC and BEC permutation channels, with explicit expressions and effective numerical validation showing the new bounds outperform previous ones (e.g., Makur 2020). The combination of divergence-packing structure and Berry–Esseen-based analysis provides accurate predictions of maximal code sizes in moderate blocklengths and lays groundwork for future extension to non-full-rank or non-strictly-positive matrices.
Abstract
Motivated by the application of point-to-point communication networks and biological storage, we investigate new achievability bounds for noisy permutation channels with strictly positive and full-rank square matrices. Our new bounds use $ε$-packing with Kullback-Leibler divergence as a metric to bound the distance between distributions and are tighter than existing bounds. Additionally, Gaussian approximations of achievability bounds are derived, and the numerical evaluation shows the precision of the approximation.
