Ray-tracing based atmospheric propagation simulator for a 2x2 LOS MIMO system
Ladda ner
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Communication Engineering (MPCOM), MSc
Publicerad
2023
Författare
Zhou, Yongan
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
A microwave radio system with multiple antennas is one popular technology for
backhaul network deployment to reach the capability increase required for 5G and
6G. Antenna separations at transmit and receive sites should be carefully designed
to ensure a proper phase relation, in this Multiple Input Multiple Output (MIMO)
system with long Line-of-Sight (LoS) paths between transmitter and receiver. The
LOS MIMO system may fail to operate under an extremely refractive atmosphere
due to a lack of sufficient system gain which is determined by the power level and
phase condition of the received sub-streams.
The contribution of the thesis is to provide a simulator that can model radio’s at mospheric propagation, and it can be further used to verify real link measurement
data. It is tested that the simulator has minor accuracy loss over the propagating
distance concerned in this study. The simulation of electromagnetic wave propa gation is based on Forward Ray Tracing (FRT). The results demonstrate that the
simulator is capable of predicting channel performance (MIMO gain, MIMO phase,
etc.) for a 2-by-2 LOS MIMO system over a refractive atmosphere. The results
also demonstrate that the simulator is found to be in good agreement with the lit erature and with Parabolic Equation (PE) methods, validating its potential use for
predicting the outage probability for the MIMO link.
This study, to the author’s best knowledge, is the first work that models the im pact of atmospheric refractivity on LOS MIMO channels using FRT. It is found
that for a 2x2 LOS MIMO system the antenna separation calculated assuming free
space propagation is also valid for the case of standard refractivity. For other re fraction conditions, the link will more likely experience an outage due to variation
in phase condition than loss of power. In addition, atmospheric multipath may in duce random MIMO phase variation. However, the simulator cannot yet properly
tackle surface-induced effects on the signals; this requires further development of
the software.
Beskrivning
Ämne/nyckelord
Line-of-Sight, radio propagation, troposphere duct, wireless backhaul, atmospheric refraction, microwave link planning