Energy Efficiency in C-RAN using Rate Splitting and Common Message Decoding
Alaa Alameer Ahmad, Bho Matthiesen, Aydin Sezgin, Eduard A. Jorswieck
Abstract
Energy efficiency (EE) has become vital in assessing the performance of modern communication network. With a tremendous increase in the data traffic it is important to keep the energy consumption manageable. This paper studies the EE maximization problem in C-RAN which adopts rate splitting (RS). The cloud is connected to a set of base stations (BSs) via limited capacity fronthaul links. To this end, the paper considers optimization of the power control in the BSs subject to common fronthaul constraints capacity and per-BS transmit power constraints. The problem is non-convex and difficult to solve. We propose to solve the problem using iterative approach merging Dinkelbach Algorithm and successive convex approximations (SCA). The solution is guaranteed to converge to a stationary point of the original problem. To evaluate the quality of the first-order optimal approach, we employ the recently proposed mixed monotonic programming framework to solve this problem with global optimality. Numerical results show a gain of up to 97% in EE when employing RS instead of simply treating interference as noise and good performance of the polynomial complexity algorithm compared to the global optimal solution.