Low-complexity multi-service power optimisation algorithm based on MOS models

In this study, the authors consider the power optimisation based on the MOS (mean of score) models of different services over multi-user femtocell systems. They first formulate a mathematic model to minimise the total power consumption, subject to the MOS requirements and the network resource constraint. To solve the formulated problem, they first propose an optimal power allocation (OPA) scheme, in which the optimal power allocation and RB (resource block) assignment can be obtained by employing the Lagrange dual decomposition method. However, iterative update of the Lagrange variables leads to high complexity. To deal with this, they further propose a utility-based suboptimal power optimisation algorithm (SPA). The utility of assigning each RB to each user is defined as the power consumption difference caused by adding the RB to the set of the RBs already assigned to the user. To calculate the utility, they develop a low-complexity optimal power allocation scheme. Based on the calculated utility, each RB is assigned to the user with the maximum utility. Experimental results demonstrate that OPA can indeed acquire an upper bound of the system performance. SPA can improve the MOS of the users with acceptable complexity compared with other existing algorithms.