Second-order statistics of system with N-branch microdiversity and L-branch macrodiversity operating over gamma shadowed Nakagami-m fading channels
Article first published online: 10 MAY 2012
Copyright © 2012 John Wiley & Sons, Ltd.
International Journal of Communication Systems
How to Cite
Sekulović, N. M., Stefanović, M. Č., Milović, D. M. and Stanojčić, S. Ž. (2012), Second-order statistics of system with N-branch microdiversity and L-branch macrodiversity operating over gamma shadowed Nakagami-m fading channels. Int. J. Commun. Syst.. doi: 10.1002/dac.2369
- Article first published online: 10 MAY 2012
- Manuscript Accepted: 15 APR 2012
- Manuscript Revised: 30 MAR 2012
- Manuscript Received: 28 FEB 2011
- Nakagami-m fading;
- gamma shadowing;
- average level crossing rate;
- average fade duration
The problem concerning short-term fading and long-term fading (shadowing) and their deleterious effects on wireless systems performance has been in focus for a long time. In this paper, motivated by the results of propagation measurements in land-mobile and indoor-mobile systems, and by the fact that gamma distribution can describe shadowing reliably, Nakagami-m distribution is used to model the signal envelope and gamma distribution is used to model the average signal power. Receive diversity with maximal-ratio combining and selection combining is implemented at the microlevel and macrolevel, respectively. The general case is explored, which assumes that microdiversity and macrodiversity are provided through arbitrary number of channels. Because shadowing has larger correlation distance than short-term fading, correlated macrodiversity channels are studied. This paper investigates the dynamics of the received signal. A novel rapidly converging infinite-series expression for average level crossing rate and average fade duration are obtained. Numerical results are graphically presented to examine the impact of fading severity, shadowing severity, number of diversity branches at the microlevel, number of base stations and correlation between base stations to the system's performance. Computer simulations are also performed to verify the validity and the accuracy of proposed theoretical analysis. Copyright © 2012 John Wiley & Sons, Ltd.