Multi-slot Coded ALOHA with Irregular Degree Distribution

TL;DR

This paper introduces an improved multi-slot coded ALOHA scheme for satellite communication that uses irregular degree distributions to significantly enhance throughput and spectral efficiency over existing methods.

Contribution

It proposes an irregular degree distribution for MuSCA, achieving higher throughput and better spectral efficiency than prior CRDSA and MuSCA schemes.

Findings

Normalized throughput up to 1.43 achieved

Significant gain over CRDSA and MuSCA

Analysis of spectral efficiency and implementation issues

Abstract

This paper proposes an improvement of the random multiple access scheme for satellite communication named Multislot coded ALOHA (MuSCA). MuSCA is a generalization of Contention Resolution Diversity Slotted ALOHA (CRDSA). In this scheme, each user transmits several parts of a single codeword of an error correcting code instead of sending replicas. At the receiver level, the decoder collects all these parts and includes them in the decoding process even if they are interfered. In this paper, we show that a high throughput can be obtained by selecting variable code rates and user degrees according to a probability distribution. With an optimal irregular degree distribution, our system achieves a normalized throughput up to 1.43, resulting in a significant gain compared to CRDSA and MuSCA. The spectral efficiency and the implementation issues of the scheme are also analyzed.