Error Floor Analysis of Coded Slotted ALOHA over Packet Erasure Channels

TL;DR

This paper develops an analytical framework to predict the error floor of coded slotted ALOHA over packet erasure channels by identifying dominant stopping sets, enabling accurate low to moderate load performance estimation.

Contribution

It introduces a method to analyze the error floor of CSA by enumerating dominant stopping sets, which was previously a complex problem.

Findings

Accurately predicts error floor at low to moderate loads.

Identifies dominant stopping sets affecting performance.

Characterizes unequal error protection in CSA.

Abstract

We present a framework for the analysis of the error floor of coded slotted ALOHA (CSA) for finite frame lengths over the packet erasure channel. The error floor is caused by stopping sets in the corresponding bipartite graph, whose enumeration is, in general, not a trivial problem. We therefore identify the most dominant stopping sets for the distributions of practical interest. The derived analytical expressions allow us to accurately predict the error floor at low to moderate channel loads and characterize the unequal error protection inherent in CSA.