A novel pilot power allocation method based on energy efficiency maximization in massive MIMO systems for future generation wireless technologies

Abstract

In this paper, we propose a novel pilot power allocation method that focuses on the maximization of the energy efficiency. The core algorithm of this method, which is a dynamic approach that takes into account signal-to-interference-plus-noise ratio (SINR), is called pilot power allocation polarizing SINRs (PS-PPA). The aim is to maximize the energy efficiency of the system along with the proposed pilot power allocation method using this algorithm in a multi-cell multi-user massive multiple-input multiple-output (MIMO) system. The algorithm determines difference between average SINR per cell and SINRs of users individually, during the scan of the whole cells sequentially. Therefore, it always updates the allocation for the latest SINR of users in power updates to improve the energy efficiency of the system. In power updates, PS-PPA calculates weights using an exponential function of the SINR difference. This weighting function is defined for each real number, so it can always result in a specific number. In addition, the weighting function is performed in the [ρ min ,ρ max ] range where the power values are predefined. The energy efficiency of the system is measured in a number of simulations by calculating the average SINR per cell. Furthermore, all these performance results are obtained for equal pilot power allocation (EPPA) and water-filling pilot power allocation (WF-PPA) schemes. As a result of simulation results, proposed pilot power allocation method has proven to be more superior than EPPA and WF-PPA methods.