Delay Constrained Energy Minimization in UWB Wireless Networks

We study the optimal power control, rate adaptation and scheduling for energy minimization subject to delay, traffic demand, transmit power and SNIR constraints in Ultra-Wideband wireless networks. We first show that power control is not required for delay constrained energy minimization. We then formulate optimal scheduling problem as an exponential size Linear Programming (LP) problem for which we propose the Pricing Minimization based Column Generation Method (PM-CGM). PM-CGM decomposes the exponential size LP problem into two sub-problems Restricted Master Problem (RMP) and Pricing Problem (PP) and solves it iteratively. We solve the corresponding delay minimization problem for the initialization of the RMP and propose a pricing minimization based polynomial time algorithm to solve the non-linear integer PP formulation. Simulations illustrate that PM-CGM algorithm decreases the runtime required to solve the large scale LP problem considerably while performing very close-to-optimal for different network scenarios.