Convex Optimization
Power Control in Wireless Cellular Networks
Foundations and Trends® in Networking
IEEE Journal on Selected Areas in Communications - Special issue on broadband access networks: Architectures and protocols
Downlink scheduling and resource allocation for OFDM systems
IEEE Transactions on Wireless Communications
Distributed power control in femtocell-underlay cellular networks
GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
Joint scheduling and resource allocation in CDMA systems
IEEE Transactions on Information Theory
Power Control By Geometric Programming
IEEE Transactions on Wireless Communications
Dynamic spectrum allocation in composite reconfigurable wireless networks
IEEE Communications Magazine
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Efficient radio resource management is a key issue in a multi-channel femtocell system, where femtocell base stations are deployed randomly and will generate interference to each other. In this research, we formulate multi-channel power allocation as a convex optimization problem, in order to maximize the overall system throughput under complex transmit power constraint. We apply the Lagrangian duality techniques to make the problem decomposable and propose a distributed iterative subgradient algorithm, namely Multi-channel Power Allocation and Optimization (McPAO). Specifically, McPAO consists of two phases: (I) a gradient projection algorithm to solve the optimal power allocation for each channel under a fixed Lagrangian dual cost; and (II) a subgradient algorithm to update the Lagrangian dual cost by using the power allocation results from Phase I. This two-phase iteration process continues until the Lagrangian dual cost converges to the optimal value. Numerical results show that our McPAO algorithm can improve the overall system throughput by 18 %, comparing to with fixed power allocation schemes. In addition, we study the impact of errors in gradient direction estimation (Phase I), which are caused by limited or delayed information exchange among femtocells in realistic situations. These errors will be propagated into the subgradient algorithm (Phase II) and, subsequently, affect the overall performance of McPAO. A rigorous analytical approach is developed to prove that McPAO can always achieve a bounded overall throughput performance very close to the global optimum.