@conference {Gmira2016,
	title = {A game theoretic approach for an hybrid overlay-underlay spectrum access mode},
	booktitle = {2016 IEEE International Conference on Communications, ICC 2016},
	year = {2016},
	note = {cited By 0},
	abstract = {Cognitive radio is emerging as a promising technique to improve the utilization of the radio frequency spectrum in wireless networks. In this paper, we propose a hybrid CR (cognitive radio) system where underlay and overlay CR approaches are combined under SINR (Signal to Interference plus Noise Ratio) constraints. This new access type allows to optimize the spectrum sensing time with throughput improvement. The goal of this paper is to provide a new access mode in order to enhance the cognitive system performance while reducing the power spent for detecting the presence of the primary user and the spectrum holes. We consider the problem of spectrum sharing among primary (or licensed) users (PUs) and secondary (or unlicensed) users (SUs). In this scheme, the spectrum allocation problem is modeled as a non cooperative game, with each CR user acting as a player. Nash equilibrium is considered as the solution of this game. {\textcopyright} 2016 IEEE.},
	doi = {10.1109/ICC.2016.7511026},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84981337899\&doi=10.1109\%2fICC.2016.7511026\&partnerID=40\&md5=b33c0dff4da1e3292042d7b39a65c27e},
	author = {Gmira, S.a and Kobbane, A.a and Sabir, E.b and Ben-Othman, J.c}
}
@conference {Gmira2015,
	title = {A new optimal hybrid spectrum access in cognitive radio: Overlay-underlay mode},
	booktitle = {International Conference on Wireless Networks and Mobile Communications, WINCOM 2015},
	year = {2015},
	note = {cited By 2},
	abstract = {In this paper, we propose a hybrid cognitive radio (CR) system where underlay and overlay CR approaches are combined under SIRN constraints. This new access type allows to optimize the spectrum sensing time with throughput improvement. Our proposed access type is based on a merger of these two modes depending on the number of secondary users (SU) in the Underlay Mode and on the access probabilities for these two modes. The number of all users in the Underlay access mode should not exceed a certain number of users. When a new SU arrives and if the number of SUs in Underlay mode is already equal to the predifined max number, the SU decides to switch to the Overlay mode to access the canal using this method. The SU states will be modeled with a Markov chain, the aim of this work is attempting to show that this new method allows to increase the throughput of the SU with energy optimization. The exact outage probability of secondary system is also derived for this model. Simulation results show that the performance, especiallay the throughput can be significantly increased by the proposed hybrid system. {\textcopyright} 2015 IEEE.},
	doi = {10.1109/WINCOM.2015.7381314},
	url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84965043094\&doi=10.1109\%2fWINCOM.2015.7381314\&partnerID=40\&md5=5d077bbb24ef8194362f761a7665f204},
	author = {Gmira, S.a and Kobbane, A.a and Sabir, E.b}
}
