Interference Cancellation and Joint Decoding for Collision Resolution in Slotted ALOHA

Abstract

We present a novel decoding scheme for slotted ALOHA which is based on concepts from physical-layer network coding (PNC) and multi-user detection (MUD). In addition to recovering individual user packets from a packet collision as it is usually done with MUD, the receiver applies PNC to decode packet combinations that can be used to retrieve the original packets using information available from other slots. We evaluate the novel scheme and compare it with another scheme based on PNC that has been proposed recently and show that both attain important gains compared to basic successive interference cancellation. This suggests that combining PNC and MUD can lead to significant gains with respect to previously proposed methods on either one or the other.