Abstract:
The impact of digital modulation techniques used in Long Term Evolution (LTE) when applied to
Radio over Fibre (RoF) has been analysed and evaluated in this research. The analyses are based
on the measured Bit Error Rate (BER) and the observed eye diagram in conjunction with the
Quality Factors (Q-Factors) for the different modulation techniques such as QPSK, 16 QAM, 64
QAM, and 256 QAM. A fibre length between 5 km and 100 km is adopted to showcase the best
configuration at a particular length that can support Fifth Generation (5G) systems. The analysis
majored on a transmitted millimeter-wave signal on the RoF topology based on the aforementioned
modulation techniques. The modulation techniques are the ones that are currently in use on the
Long-Term Evolution (LTE) network and the best of these techniques are fitted to the 5G mobile
technology. The technology demonstrated in this work follows the merging of optical networks
and microwaves to provide a possible solution to increase channel capacity, mobility, and reduced
the cost of the access network for customers’ comfort. The analysis and impact of the digital
modulations applied on LTE are successfully implemented on the RoF transmission link and an
evaluation based on Q-factor, BER, and eye diagrams for the 5G data threshold of 10Gbps based
on Optisystem 17.However, it is important to point out that the nexus of length and wavelength of
the transmission optical medium plays an important role in the overall performance of the system
which has been dealt with in this work Generally, 256 QAM modulations is observed to be suitable
for 5G networks but the core station should be about 5 km from the base station to achieve the
desired throughput and 1550 nm for an ideal wavelength in the radio over fibre setup.
