Title: Cooperative sensing with transmit diversity based on randomised STBC in CR networks

Authors: Telex Magloire Nkouatchah Ngatched; Attahiru Sule Alfa; Jun Cai

Addresses: Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada ' Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada ' Department of Electrical and Computer Engineering, University of Manitoba, Winnipeg, MB R3T 5V6, Canada

Abstract: In this paper, a cognitive radio (CR) network composed of K secondary users (SUs) who cooperatively sense a channel using the k-out-of-K fusion rule to determine the presence of the primary user is studied. The sensing-throughput tradeoff problem is investigated in a realistic environment where both the sensing channels and reporting channels are characterised by fading channels. It is observed that taking into consideration the probability of reporting error in the CR network increases the sensing time and reduces the maximum average throughput of the SUs. To mitigate the effect of the probability of reporting error, a transmit diversity-based cooperative spectrum sensing method using randomised space-time block coding (RSTBC) is proposed. Simulations results show that the spatial diversity gain induced by RSTBC significantly decreases the sensing time and improves the throughput of the SUs.

Keywords: cognitive radio; CR networks; cooperative transmission; diversity technique; sensing-throughput trade-off; space-time coding; spectrum sensing; throughput maximisation; fading channels; randomised STBC; space-time block coding; RSTBC; simulation; spatial diversity gain; sensing time; secondary user throughput.

DOI: 10.1504/IJAACS.2013.056823

International Journal of Autonomous and Adaptive Communications Systems, 2013 Vol.6 No.4, pp.403 - 416

Published online: 13 Sep 2014 *

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