Evaluation Of Radio Link Design With Different Modulation And Antenna Schemes

Abstract

This article is devoted to microwave radio link design in order to provide communication between two locations and based on modelling of different radio link solutions with different modulation techniques, different antenna dimensions etc. by using PathLoss program software. Path loss test tool and modulation techniques for 256 quadrature amplitude modulation (QAM), 64 QAM, 16 QAM, and 4 QAM have been used in order to perform simultaneous simulations so that the best correlation of stated variables are characterized for the project. The variables are then simulated with various antenna sizes for the best throughput of 155 Mbit/s data transfer. Another design consideration for achieving better radio link availability and less transmission path interruption is to use automatic Adaptive Modulation feature of selected radio link equipment to fight against adverse weather. Adaptive Modulation can lower modulation level from 16 QAM in our study to 4 QAM level and this allows even smaller interruption time (0.18 minute) but with a bit smaller capacity (80 Mbps) for this short adverse weather conditions period.  In this study, the locations where we are unable to reach via fiber are considered for wireless transmission links. In the practical part of this study different modulation techniques and antenna sizes were analyzed in order to provide the most efficient way of data transmission.