Power Allocation in Wireless Relay Networks: A Geometric Programming-Based Approach

In this paper, we consider an amplify-and-forward (AF) wireless relay system where multiple source nodes communicate with their corresponding destination nodes with the help of relay nodes. While each user is assisted by one relay, one relay can assist many users. Conventionally, each relay node is assumed to equally distribute the available bandwidth and power resources to all sources for which it helps to relay information. Realizing the sub-optimality of this approach, in this paper, we present efficient power allocation schemes to i) maximize the minimum end-to-end signal-to-noise ratio among all users; ii) minimize the total transmit power over all sources; iii) maximize the system throughput. Our approach is based on geometric programming (GP), a well-studied class of nonlinear and nonconvex optimization. Since a GP problem is readily transformed into an equivalent convex optimization problem, optimal power allocation can be obtained efficiently. Numerical results demonstrate the effectiveness of our proposed approach.

[1]  Daniel Pérez Palomar,et al.  Power Control By Geometric Programming , 2007, IEEE Transactions on Wireless Communications.

[2]  Min Chen,et al.  Distributed power allocation for parallel relay networks , 2005, GLOBECOM '05. IEEE Global Telecommunications Conference, 2005..

[3]  Raviraj S. Adve,et al.  Non-Coherent Code Acquisition in the Multiple Transmit/Multiple Receive Antenna Aided Single- and Multi-Carrier DS-CDMA Downlink , 2007 .

[4]  Mazen O. Hasna,et al.  End-to-end performance of transmission systems with relays over Rayleigh-fading channels , 2003, IEEE Trans. Wirel. Commun..

[5]  Branka Vucetic,et al.  Distributed Adaptive Power Allocation for Wireless Relay Networks , 2007, IEEE Transactions on Wireless Communications.

[6]  Raviraj S. Adve,et al.  Improving amplify-and-forward relay networks: optimal power allocation versus selection , 2006, IEEE Transactions on Wireless Communications.

[7]  Stephen P. Boyd,et al.  QoS and fairness constrained convex optimization of resource allocation for wireless cellular and ad hoc networks , 2002, Proceedings.Twenty-First Annual Joint Conference of the IEEE Computer and Communications Societies.

[8]  Gregory W. Wornell,et al.  Cooperative diversity in wireless networks: Efficient protocols and outage behavior , 2004, IEEE Transactions on Information Theory.

[9]  Ekram Hossain,et al.  Multihop Cellular Networks: Potential Gains, Research Challenges, and a Resource Allocation Framework , 2007, IEEE Communications Magazine.

[10]  Abbas Jamalipour,et al.  Wireless communications , 2005, GLOBECOM '05. IEEE Global Telecommunications Conference, 2005..

[11]  Alexander M. Haimovich,et al.  Power allocation for cooperative relaying in wireless networks , 2005, IEEE Communications Letters.