Nael A.  Al-Shareefi, Mohanad S.  Alkhazraj, Sarah Yahya Ali  Al-Abbasi, Sura Adil  Abbas, 
    Evaluation of OFU Techniques for Optical Generation of mm-W Signals in
Future Broadband Cellular Communication Networks,
    Journal of Engineering and Applied Sciences,
    Volume 14,Issue 10,
    2019,
    Pages 3463-3471,
    ISSN 1816-949x,
    jeasci.2019.3463.3471,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2019.3463.3471)
    Abstract: Cellular networks that use the millimeter-Wave (mm-W) spectrum holds a great promise to revolutionize wireless industry. Nevertheless, the generation and transportation of mm-W signals in the
electrical-domain are unfeasible owing to the high air link loss and electromagnetic interference. Generating mm-W signals in the optical-domain, i.e., over an optical fiber will allow sending wireless signals for a long distance. This study presents an evaluation of the Optical Frequency Upconversion (OFU) techniques based on advanced Mach-Zehnder Modulator (MZM) for optical generation and transportation of mm-W
wireless signals. Four types of OFU techniques will be compared: frequency-doubling, frequency-quadrupling, frequency-sixtupling and frequency-octupling. We begin by reviewing selected OFU techniques that enable to double, quadruple, sixtuple or octuple an Radio Frequency (RF) and highlighting drawbacks and benefits. Then, a comparison in terms of modulation index, bias drifting and modulation efficiency is presented to show the trade-off between OFU techniques complexity and cost. Comparison of OFU techniques and results from simulation analysis reveal that the frequency quadrupling technique is a robust and more desirable choice for optical generation and transportation of mm-W wireless signals.
    Keywords: OFU techniques;optical mm-W signal generation;5G;frequency quadrupling;MZM;wireless
signals