att_abstract={{We consider a wireless relay network (WRN) where
multiple mobile stations (MSs) try to send their data to a base
station (BS) either directly or via a set of fixed relay stations
(RSs). For this network, we study the problem of joint optimal
MS and RS power allocation and relay selection with the objective
of minimizing the total transmitted power of the system. The joint
optimization algorithm must satisfy the minimum data demand of
each MS. We formulate the problem as a mixed integer nonlinear
programming (MINLP) problem and find the solution under
different relaying architectures and spatial diversity schemes. The
optimal solution of the MINLP problem is exponentially complex
due to its combinatorial nature. We use the MATLAB based
commercial software TOMLAB to find a near optimal solution
of the MINLP problem. We also find an approximate solution of
the original problem by applying a simple relay selection scheme
based on the channel gains between MSs and RSs. Numerical
results are presented to show the performance of this simple
scheme with respect to the optimal one in terms of total power
	att_authors={md6393, rj2124},
	att_copyright={{Wireless Innovation Forum European conference on Communications Technologies and Software Defined Ra}},
	att_copyright_notice={{The definitive version was published in Mobile VCE Green Radio, Software Defined Radio - Wincomm. {{, 2011-06-23}}{{, http://europe.wirelessinnovation.org/mc/page/MobileVCE }}
	att_tags={relay,  cooperative communications},
	author={Md Habibul Islam and Zbigniew Dziong and Kazem Sohraby and Mahmoud Daneshmand and Rittwik Jana},
	institution={{Mobile VCE Green Radio, Software Defined Radio - Wincomm}},
	title={{Joint Optimal Power Allocation and Relay Selection with Spatial Diversity in Wireless Relay Networks}},