Performance analysis of cooperative multi-carrier relay-based UAV networks over generalized fading channels

• Published in: International journal of communication systems 2011-08, Vol.24 (8), p.1049-1064
• Main Authors: Abualhaol, Ibrahim Y., Matalgah, Mustafa M.
• Format: Article
• Language: English
• Subjects: adaptive modulation; cooperative UAVs; fading channels; finite mixture; multi-carrier systems; outage probability; relay based
• ISSN: 1074-5351; 1099-1131
• DOI: 10.1002/dac.1212

The outage probability in a network of cooperative unmanned airborne vehicles (UAVs) over generalized fading channels is studied analytically using finite mixture with expectation maximization technique. A relay‐based topology with one ground control unit (GCU) is considered, where the cooperative UAVs can communicate with the GCU directly or through relay. The application the UAV is assigned for specifies the minimum required transmission rate the UAV should achieve. The outage probability of the system is defined as the probability that either the transmission rate over any of the links drops below a predefined minimum threshold for that link or the Relay‐GCU link is not able to transmit the aggregate data from all relayed UAVs and the minimum rate required by the relay UAV itself. Throughout the paper, expressions for the outage probability and the average achievable bit rate of a cooperative multi‐carrier system are derived over generalized fading channels. Finite mixture with expectation maximization algorithm is utilized to derive a simple approximate expression for the probability density function (pdf) of the achievable bit rate assuming adaptive M‐ary quadrature amplitude modulation (M‐QAM). This pdf is used to derive closed‐form expressions for the outage probability and the average bit rate. Copyright © 2011 John Wiley & Sons, Ltd. The performance analysis in terms of outage probability of cooperative multicarrier relay‐based UAVs network over generalized fading channels is considered. General analytical expressions of cascaded weighted sums of wellknown Q‐function for the outage probability of both UAV‐relay and relay‐GCU links are derived. These expressions provide general tool to study the reliability of cooperative multicarrier relay‐based UAVs network over variety of fading scenarios. In our numerical demonstrations, we used Weibull, Nakagami‐m, and Rayleigh fading channels as examples. The expressions were validated using Monte Carlo simulation. Copyright © 2011 John Wiley & Sons, Ltd.