Interference Mitigation on WLANs Using Smart Antennas

This paper investigates the performance of a fixed Wireless LAN in which nodes are equipped with fully adaptive smart antennas. The considered smart antenna system is a uniform circular array of microstrip patch elements in which the weights are updated using the unconstrained LMS algorithm. The behavior of a new directional MAC protocol for spatial multiplexing is analyzed and compared with IEEE 802.11 DCF. The paper purpose is the evaluation of interference and multipath effects on SDMA, using realistic models for the channel and for the smart antenna system. The link model takes into account path loss, cochannel interference and multipath, using a modified Jakes model. Results show that the performance of the WLAN are strictly dependent on the interferer characteristics and on the angular spread of the channel. Fulvio Babich was born in Trieste, Italy. He received the doctoral degree in electrical engineering, from the University of Trieste, in 1984. From 1984 to 1987 he was with the Research and Development Department of Telettra (Vimercate), working on optical communications. From 1987 to 1992 he was with Research and Development Department of Zanussi (Zeltron), where he held the position of Company Head in the Home System European projects. In 1992, he joined the Department of Electrical Engineering (DEEI) of the University of Trieste, where he is associate professor of digital communications. His current research interests are in the field of wireless networks and personal communications. Massimiliano Comisso was born in Trieste, Italy. He received the degree of “Laurea" in Electronic Engineering from the University of Trieste. Currently, he is a PhD student at the Department of Electrical Engineering (DEEI) at University of Trieste in information technology. His research interests include wireless networks, adaptive arrays and small antennas. Marco D'Orlando was born in Tolmezzo, Italy, in September 1978. He received the Electronic Engineering degree (summa cum laude) from the University of Trieste, Italy, in December 2003. He is currently working toward the Ph.D. degree in the Department of Electrical and Electronic Engineering (DEEI) at University of Trieste. His research interests are in the field of multimedia communications, networking, joint source channel coding and resource allocation. Lucio Manià was born in Ronchi dei Legionari, Italy, in 1942. He received the Electronic Engineering degree from the University of Trieste, Italy, in 1968. Since 1970 he has been an Assistant Professor with the Department of Electrical and Electronic Engineering, where he is currently an Associate Professor. From 1975 to 1985 he was a consulting engineer with Co.El. S.p.A., where he was involved in antenna design for FM and TV broadcasting systems. His current scientific interests include electromagnetic compatibility for safety purposes, wireless communications and numerical techniques for electromagnetic simulations.