Multi-Objective Optimization of Massive MIMO 5G Wireless Networks towards Power Consumption, Uplink and Downlink Exposure

Abstract

The rapid development of the number of wireless broadband devices requires that the induced uplink exposure be addressed during the design of the future wireless networks, in addition to the downlink exposure due to the transmission of the base stations. In this paper, the positions and power levels of massive MIMO-LTE (Multiple Input Multiple Output-Long Term Evolution) base stations are optimized towards low power consumption, low downlink and uplink electromagnetic exposure and maximal user coverage. A suburban area in Ghent, Belgium has been considered. The results show that the higher the number of BS antenna elements, the fewer number of BSs the massive MIMO network requires. This leads to a decrease of the downlink exposure (−12% for the electric field and −32% for the downlink dose) and an increase of the uplink exposure (+70% for the uplink dose), whereas both downlink and uplink exposure increase with the number of simultaneous served users (+174% for the electric field and +22% for the uplink SAR). The optimal massive MIMO network presenting the better trade-off between the power consumption, the total dose and the user coverage has been obtained with 37 64-antenna BSs. Moreover, the level of the downlink electromagnetic exposure (electric field) of the massive MIMO network is 5 times lower than the 4G reference scenario.

Electromagnetic Field Levels in Built-up Areas with an Irregular Grid of Buildings: Modeling and Integrated Software

“…Given this experimental evidence, and since the development of 5G technology already resulted in the deployment of RBS stations, it is questionable if our modified C231WI model could be extended to the 3.6-3.8 GHz band, for both monitoring and coverage issues [35][36][37]. Indeed, in the literature, there is a lack of models and experimental strategies for EM propagation in urban environments [38], such as those investigated in this work, even though several studies which cover the synthesis of antennas, protocols, and systems for 5G exist [39][40][41]. Future work may deal with the definition and correction of the model parameters for EM signals of higher frequency, with the goal of ensuring the same accuracy and reliability of the estimated electric field levels.…”

Issues, Challenges, and Research Trends in Spectrum Management: A Comprehensive Overview and New Vision for Designing 6G Networks

“…For the mmWave spectrum, M-MIMO is expected to deliver better results in the TDD mode rather than in FDD mode; for sub-6 GHz, FDD provides remarkable results [215,216]. In the FDD communication mode, the uplink and downlink transmissions usually occur in the same channel simultaneously, thus suppressing a great deal of the spectrum gain, as shown in Figure 6 [217,218]. The FDD is designed for paired uplink/downlink spectrum channel access, which requires two dedicated channels with constant spacing between them.…”

A Comprehensive Study on Simulation Techniques for 5G Networks: State of the Art Results, Analysis, and Future Challenges

“…The three main constraints of coverage, capacity, and cost were studied for a range of cases that reflected scenarios from dense to ultra-dense network deployments in order to achieve high capacity. In [75], a joint optimization algorithm is proposed of a multi-cell massive MIMO network towards three objectives: the power consumption, the downlink (DL) Electromagnetic (EMF) exposure, and the uplink (UL) EMF exposure. Both the DL and UL EMF exposure have been addressed in a different context.…”