Technical Report, 8 Novembre 2019
In SIERRA, one of the overall purposes is to provide new technology solutions for extending the Quality of Service (QoS) and consequently opening new areas of applications and services in satellite communications on frequencies already used by terrestrial systems. This goal leads to the crucial development of an underlay satellite cognitive system and the related dynamic resource allocation techniques, where the main objective of SIERRA is to perform resource allocation to maximize the throughput while satisfying the interference temperature limits regarding the primary systems. Particularly, workpackage (WP) 2 addresses the most general case with multiple satellites belonging to multiple operators considering distributed resource allocation approaches. Its aim is to determine the appropriate level of coordination between secondary users leading to efficient and practical solutions for the considered cognitive configurations. In this report, we address the problem of resource allocation (RA) for spectrum underlay in a cognitive satellite (CogSat) communication system with multiple secondary operators sharing resource with an incumbent primary operator 1. The multiple secondary operator RA problem is well known to be especially challenging because of the inter-operator coupling constraints arising in the optimization problem, which render impractical inter-operator information exchange necessary. In the CogSat maturation regime, i.e. the period in which the secondary subscriber density is growing yet remains much below that of incumbent users, we show that in fact the inter-operator mutual constraints can be neglected, thus making distributed (i.e. across secondary operators) optimization possible. Furthermore, we establish analytically that the mutual constraints asymptotically vanish with the primary user density.