Low-Complexity Energy Efficient Power Allocation with Buffer Constraint for Downlink DAS in HSR Scenarios

In this paper, we investigate the low-complexity energy efficient (EE) power allocation with buffer constraint for downlink distributed antenna system (DAS) in high speed railway (HSR) communication. Then, we formulate the EE optimization power allocation problem with the requirement of buffer size. Because the traditional method is used to solve this optimization problem, multi-layer iteration is needed, which leads to the low efficiency of the solving process. Therefore, to deal with multiple iterations, we present a low-complexity algorithm by analyzing the feasible region of the optimal solution. Simulation results demonstrate that the low-complexity algorithm can achieve the same EE performance as the optimal algorithm based on the bisection method and reduce the number of iterations.