System performance analysis of situation awareness messaging using narrow-band multi-user detection

This paper is concerned with enhancing situation awareness messaging using narrow-band multi-user detection techniques. Situation awareness messaging involves sending short packets of situation update data. Low latency is an important requirement. This paper focuses on using satellite communications which have a substantial propagation delay. These factors favour the use of a random access system such as Aloha. The main draw back of these systems is low channel utilisation. The capacity of an Aloha system using multi-user detection is analysed is this paper. The capacity is substantially improved by using multi-user detectors. Furthermore the distribution of user powers experienced at the ground station enhances the performance of a system based on multi-user detection.