# Variational Optimization for Sustainable Massive MIMO Base Station Switching

## TL;DR

This paper introduces a new energy-saving method for massive MIMO networks by optimizing base station switching using variational optimization.

## Contribution

The novelty lies in formulating energy efficiency in massive MIMO as a constrained variational problem and proving the solution's uniqueness and boundedness.

## Key findings

- Variational optimization achieved optimal base station switching with significant energy savings.
- The method maintained user capacity demand while minimizing handover overhead signaling.
- The proposed base station selection criteria provided suboptimal handover overhead.

## Abstract

Massive MIMO networks are a promising technology for achieving ultra-high capacity and meeting future wireless service demand. Massive MIMO networks, on the other hand, consume intensive energy. As a result, energy-efficient operation of massive MMO networks became a requirement rather than a luxury. Many NP-hard concavity search algorithms for optimal base station switching on-off scheme have been developed. This paper demonstrates the formulation of massive MIMO networks energy efficiency as a constrained variational problem. Our proposed method solution’s uniqueness and boundedness are demonstrated and proven. The developed system is a total energy optimization problem formulation. Furthermore, the order in which the base stations are switched on and off is specified for minimal handover overhead signaling and fair user capacity sharing. Results showed that variational optimization yielded optimal base station switching on and off with considerable energy saving achieved and maintaining the user capacity demand. Moreover, the proposed base station selection criteria provided suboptimal handover overhead signaling.