title: Impact of Beamforming on the Path Connectivity in Cognitive Radio Ad Hoc Networks.
abstract: This paper investigates the impact of using directional antennas and beamforming schemes on the connectivity of cognitive radio ad hoc networks (CRAHNs). Specifically, considering that secondary users use two kinds of directional antennas, i.e., uniform linear array (ULA) and uniform circular array (UCA) antennas, and two different beamforming schemes, i.e., randomized beamforming and center-directed to communicate with each other, we study the connectivity of all combination pairs of directional antennas and beamforming schemes and compare their performances to those of omnidirectional antennas. The results obtained in this paper show that, compared with omnidirectional transmission, beamforming transmission only benefits the connectivity when the density of secondary user is moderate. Moreover, the combination of UCA and randomized beamforming scheme gives the highest path connectivity in all evaluating scenarios. Finally, the number of antenna elements and degree of path loss greatly affect path connectivity in CRAHNs.
authors.affiliation: Department of Radio and Communication Engineering, Chungbuk National University, Cheongju City, Chungbuk 28644, Korea. dung.t.le@ieee.org.
authors.forename: Le The
authors.initials: LT
authors.lastname: Dung
authors.affiliation: Department of Electronics and Computer Engineering in Graduate School, Hongik University, Sejong City 30016, Korea. trandinhhieu1989@gmail.com.
authors.forename: Tran Dinh
authors.initials: TD
authors.lastname: Hieu
authors.affiliation: Department of Radio and Communication Engineering, Chungbuk National University, Cheongju City, Chungbuk 28644, Korea. sgchoi@cbnu.ac.kr.
authors.forename: Seong-Gon
authors.initials: SG
authors.lastname: Choi
authors.affiliation: Department of Computer and Information Communication Engineering, Hongik University, Sejong City 30016, Korea. jsnbs@hongik.ac.kr.
authors.forename: Byung-Seo
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Computer and Information Communication Engineering, Hongik University, Sejong City 30016, Korea. beongku@hongik.ac.kr.
authors.forename: Beongku
authors.initials: B
authors.lastname: An
keywords: beamforming scheme; cognitive radio ad hoc networks; directional antenna; path connectivity; uniform circular array antenna; uniform linear array antenna