Cognitive Radio Overlay Paradigm Towards Satellite Communications

Abstract

In this paper, we investigate the application of cognitive radio techniques within the overlay paradigm toward satellite communications, where the primary and cognitive users transmit concurrently at the same frequency, time and space. By means of dirty paper coding (DPC) and superposition techniques, a low complexity scheme is proposed when compared to classical precoding for interference pre-subtraction. The system performance is evaluated in different realistic scenarios, resulting in no degradation for primary user and a significant recovery of the shaping loss for the cognitive user.