Combined Ray-Tracing/FDTD and Network Planner Methods for the Design of Massive MIMO Networks

Abstract

The design of a massive MIMO network requires a channel model that captures the Spatio-temporal dimensions of the propagation environment. In this paper, we propose a novel method combining Hybrid Raytracing -Finite difference time domain (FDTD) and network planner tools to address this requirement. This method provides accurate and realistic EMF exposure models for the design of a massive MIMO network. Using this method, we proceed with the optimization of the BS's locations under the low power consumption and low EMF exposure constraints. Assuming equal preference of the optimization objectives, the simulations show that the uplink localized 10g dose appears to be the dominant factor of the localized 10g EMF exposure. Moreover, a massive MIMO network designed to serve 224 simultaneous active users at the same time-frequency resource is subject to an increase of the total whole-body dose (2 times higher in downlink and +18% in uplink), compared to a design with 14 active users. However, in the same conditions, the downlink localized 10g dose reduces (20 times lower) whereas the uplink localized 10g dose increases (+23%) in comparison with the scenario with fewer users (14). Besides, the electromagnetic field strength in all locations obtained with this new method is 2 times weaker compared to a 4G LTE network, while complying with the international guidelines.INDEX TERMS 5G, antenna arrays, beamforming, EMF exposure, massive MIMO, power consumption, network planner, precoding, ray-tracing.

Multi-objective optimisation of human exposure for various 5G network topologies in Switzerland

“…The increment of BS antenna elements contributed to 12% DL exposure reduction while UL rises by 70% [17] 5G values with the measured EMF values to evaluate the spherical formula of the far field, obtaining similar results if the traffic beam patterns are known. [27] presents a multibeam multi-user 5G test-bed where the exposure values measured are far lower than the exposure limits.…”

“…Results show that the increment of the number of 5G BS due the increased traffic tend to reduce the DL exposure by 12% while the UL exposure is increased by 70%. [17] introduced a Ray tracking (RT) method into the 5G network planner, in order to obtain detailed knowledge of the propagation environment. The exposure values reported show that the localised 𝐷𝐿 10𝑔 and the 𝐷𝐿 𝑤𝑏𝑎 from a BS with 64 antenna elements is 31% higher and 46% lower respectively, compared with a BS with 16 antenna elements.…”

Evaluating 60 GHz FWA Deployments for Urban and Rural Environments in Belgium

“…We implement a two bouncing ray tracing method, where each ray launches a ray every 5 degrees, looking for an intersection in a circumference with a 10 m radius. Up to two wall bounces are accounted until a ray is discarded [ 68 ]. We select two types of walls: bricks and concrete, representing the material of the reflecting wall.…”

Towards Environmental RF-EMF Assessment of mmWave High-Node Density Complex Heterogeneous Environments

“…The authors in Reference [7] presented a computational method based on ray tracing techniques (RT) to estimate human EMF exposure in DL 5G base stations at sub-6 GHz frequencies in outdoor macrocell environments. The same authors presented in References [8][9][10] a combined numerical approach based on RT and Finite Difference Time Domain (FDTD) techniques, which estimates EMF exposure for 5G massive MIMO in different environments, such as an industrial environment [8], an urban microenvironment (UMi) [9] or an urban macro-environment (UMa) [10], all of them at 5G frequencies below 6 GHz. The work in Reference [11] presented a statistical approach to obtain realistic maximum power levels of 5G gNodeB (gNB) for the assessment of EMF exposure, employing massive MIMO for DL scenarios.…”

“…As it can be seen from the table, there were few works in the literature that presented an approximation in which simulation estimations were simultaneously combined with measurement results. References [6][7][8][9][10][11] presented different methodologies based only on simulation techniques, all for DL and sub-6 GHz frequency bands. Conversely, the works in References [12][13][14] presented EMF exposure assessment methodologies based on measurements campaigns, again at sub-6 GHz frequency bands and DL assessments.…”