Energy Efficient Power Allocation in Generalized Distributed Antenna System

In this letter, we investigate the energy efficiency in the generalized distributed antenna systems (GDAS) with the frequency-selective fading. An energy efficient power allocation (EE-PA) problem, minimizing the Joule consumed per bit under per antenna power constraint, is formulated as a nonlinear fractional programming (FP) problem. Optimality conditions for the FP problem are first introduced with the generalized convex function. Then, we derive the analytical solutions for the antennas both with and without transmitting at full power. Finally, the general solution and the entire algorithm are obtained. Numerical results demonstrate that, in terms of energy efficiency, the proposed EE-PA scheme achieves a great improvement as compared to the scheme maximizing the sum throughput.