Novel multiple access for non-geostationary orbit communications

Abstract

The task of multiple access strategy is to link users as flexible as possible with limited spectrum and power resources as far as possible. The design and implementation of appropriate multiple access scheme are of great importance for satellite networks since their on-board resource is severely limited while the service requirements of terminal devices are ever-increasing, especially in rural areas. In this case, novel multiple access schemes, such as non-orthogonal multiple access (NOMA) and enhanced ALOHA, have been introduced in non-geostationary orbit (NGSO) communication to further improve resource utilization efficiency in recent years. This chapter focuses on these two novel access schemes which are relevant for future satellite systems.Section 7.1 introduces and compares three commonly used orthogonal multiple access (OMA) schemes. Section 7.2 is devoted to the performance analysis of a NOMA-based NGSO satellite system, where the key points of the NOMA scheme are specifically addressed. Section 7.3 focuses on the performance improvement brought by the enhanced ALOHA. Finally, the last section summarizes the content of this chapter.