NCSA: A New Protocol for Random Multiple Access Based on Physical Layer Network Coding

摘要

This paper introduces a random multiple access method for satellitecommunications, named Network Coding-based Slotted Aloha (NCSA). The goal is toimprove diversity of data bursts on a slotted-ALOHA-like channel thanks toerror correcting codes and Physical-layer Network Coding (PNC). This scheme canbe considered as a generalization of the Contention Resolution DiversitySlotted Aloha (CRDSA) where the different replicas of this system are replacedby the different parts of a single word of an error correcting code. Theperformance of this scheme is first studied through a density evolutionapproach. Then, simulations confirm the CRDSA results by showing that, for atime frame of $400$ slots, the achievable total throughput is greater than$0.7\times C$, where $C$ is the maximal throughput achieved by a centralizedscheme. This paper is a first analysis of the proposed scheme which openseveral perspectives. The most promising approach is to integrate collidedbursts into the decoding process in order to improve the obtained performance.