@article{lu_duel-hallen_2016, place={USA}, title={Channel-Aware Spectrum Sensing and Access for Mobile Cognitive Radio Ad Hoc Networks}, volume={65}, ISSN={["1939-9359"]}, url={http://dx.doi.org/10.1109/TVT.2015.2421913}, DOI={10.1109/tvt.2015.2421913}, abstractNote={In hardware-constrained cognitive radio (CR) ad hoc networks, secondary users (SUs) with limited sensing capabilities strive to discover and share available spectrum resources without impairing primary-user (PU) transmission. Sensing strategy design objectives include high CR network throughput, resolved SU competition, distributed implementation, and reliable performance under node mobility. However, these objectives have not been realized by previously investigated sensing strategies. A novel sensing strategy is analyzed, where the reward is adapted to the SU-link channel state information (CSI) prior to sensing, thus randomizing sensing decisions and boosting the network throughput. Moreover, CSI-aided sensing is combined with a novel first-come-first-served (FCFS) medium access control (MAC) scheme that resolves SU competition prior to sensing. Finally, a pilot-based CSI prediction method is developed to enable the proposed CSI-aided sensing strategies for mobile scenarios. Analytical and numerical results demonstrate that the proposed sensing and access methods significantly outperform nonadaptive sensing strategies for practical mobile CR scenarios with CSI mismatch and pilot overhead.}, number={4}, journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY}, author={Lu, Yuan and Duel-Hallen, Alexandra}, year={2016}, month={Apr}, pages={2471–2480} }
 @inproceedings{fairness.}_{yuan lu and duel-hallen, a.}_copyright=_2015, title={A two-layer coalitional game among rational cognitive radio users}, url={http://dx.doi.org/10.1109/CISS.2015.7086824}, DOI={10.1109/ciss.2015.7086824}, abstractNote={In cognitive radio (CR) networks, secondary users (SUs) sense the spectrum to identify and possibly transmit over temporarily unoccupied channels that are licensed to primary users (PUs). However, when the received PU signal is weak, spectrum sensing by individual SUs becomes unreliable. To improve sensing accuracy, SUs can form disjoint coalitions and cooperate to discover idle time slots. These spectrum opportunities are then shared among the coalition members in a coordinated manner. It is proposed to decouple the coalition formation and the access (payoff) allocation problems by modeling these processes as a two-layer coalitional game. This game fosters cooperation by providing each SU with the access opportunities it deserves. Numerical results demonstrate that the proposed game outperforms previously investigated collaborative sensing and access approaches in terms of energy efficiency, throughput, and fairness.}, note={Keywords= {cognitive radio;energy conservation;game theory;radio spectrum management;signal detection;wireless channels;two-layer coalitional game;rational cognitive radio users;CR networks;secondary users;spectrum sensing accuracy improvement;primary users;received PU signal;individual SU;disjoint coalition member;idle time slots;coalition formation;access allocation problems;collaborative sensing;access approach;energy efficiency;temporarily unoccupied channels;}, Pages= {6}, booktitle={2015 49th Annual Conference on Information Sciences and Systems (CISS). Proceedings}, author={fairness.}, Address= {Piscataway, N.J., U.S.A.} and {Yuan Lu and Duel-Hallen, A.}, Author= and Copyright=}, year={2015}, pages={– ,} }
 @inproceedings{lu_duel-hallen_2013, place={Piscataway, NJ, USA}, title={Channel-adaptive sensing strategy for Cognitive Radio ad hoc networks}, url={http://dx.doi.org/10.1109/CCNC.2013.6488485}, DOI={10.1109/ccnc.2013.6488485}, abstractNote={In Cognitive Radio (CR) ad hoc networks, secondary users (SU) attempt to utilize valuable spectral resources without causing significant interference to licensed primary users (PU). While there is a large body of research on spectrum opportunity detection, exploitation, and adaptive transmission in CR, most existing approaches focus only on avoiding PU activity when making sensing decisions. Since the myopic sensing strategy results in congestion and poor throughput, several collision-avoidance sensing approaches were investigated in the literature. However, they provide limited improvement. A channel-aware myopic sensing strategy that adapts the reward to the fading channel state information (CSI) of the SU link is proposed. This CSI varies over the CR spectrum and from one SU pair to another due to multipath and shadow fading, thus randomizing sensing decisions and increasing the network throughput. The proposed joint CSI adaptation at the medium access control (MAC) and physical layers provides large throughput gain over randomized sensing strategies and/or conventional adaptive transmission methods. The performance of the proposed CSI-aided sensing strategy is validated for practical network scenarios and demonstrated to be robust to CSI mismatch, sensing errors, and spatial channel correlation.}, booktitle={2013 IEEE 10th Consumer Communications and Networking Conference (CCNC)}, author={Lu, Yuan and Duel-Hallen, A.}, year={2013}, pages={466–71} }