Exploiting self-interference suppression for improved spectrum awareness/efficiency in cognitive radio systems

• Published in: 2013 Proceedings IEEE INFOCOM pp. 1258 - 1266
• Main Authors: Afifi, Wessam, Krunz, Marwan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.04.2013
• Subjects: High definition video; Interference; Measurement; Receivers; Sensors; Signal to noise ratio; Throughput
• ISBN: 9781467359443; 1467359440
• ISSN: 0743-166X
• DOI: 10.1109/INFCOM.2013.6566918

Inspired by recent developments in full-duplex communications, we propose and study new modes of operation for cognitive radios with the goal of achieving improved primary user (PU) detection and/or secondary user (SU) throughput. Specifically, we consider an opportunistic PU/SU setting in which the SU is equipped with partial/complete self-interference suppression (SIS), enabling it to transmit and receive/sense at the same time. Following a brief sensing period, the SU can operate in either simultaneous transmit-and-sense (TS) mode or simultaneous transmit-and-receive (TR) mode. We analytically study the performance metrics for the two modes, namely the detection and false-alarm probabilities, the PU outage probability, and the SU throughput. From this analysis, we evaluate the sensing-throughput tradeoff for both modes. Our objective is to find the optimal sensing and transmission durations for the SU that maximize its throughput subject to a given outage probability. We also explore the spectrum awareness/efficiency tradeoff that arises from the two modes by determining an efficient adaptive strategy for the SU link. This strategy has a threshold structure, which depends on the PU traffic load. Our study considers both perfect and imperfect sensing as well as perfect/imperfect SIS.