Asymptotic Performance of Coded Slotted ALOHA with Multi Packet Reception

TL;DR

This paper derives a theoretical upper bound on the maximum load for coded slotted ALOHA with multi-packet reception, revealing that increasing reception capability improves performance, and demonstrates how spatially-coupled CSA can approach this bound.

Contribution

It introduces a converse bound on the load threshold for CSA with multi-packet reception and shows how spatial coupling can approach this theoretical limit.

Findings

Normalized load threshold increases with K

Converse bound derived using density evolution

Spatially-coupled CSA approaches the bound

Abstract

In this letter, we develop a converse bound on the asymptotic load threshold of coded slotted ALOHA (CSA) schemes with K-multi packet reception capabilities at the receiver. Density evolution is used to track the average probability of packet segment loss and an area matching condition is applied to obtain the converse. For any given CSA rate, the converse normalized to K increases with K, which is in contrast with the results obtained so far for slotted ALOHA schemes based on successive interference cancellation. We show how the derived bound can be approached using spatially-coupled CSA.