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dc.contributor.authorLatunde, Abayomi Temitope
dc.date.accessioned2019-10-30T09:22:02Z
dc.date.available2019-10-30T09:22:02Z
dc.date.issued2019-03-19
dc.identifier.urihttp://hdl.handle.net/2299/21820
dc.description.abstractThe unprecedented growth in mobile data traffic, driven primarily by bandwidth rich applications and high definition video is accelerating the development of fifth generation (5G) mobile network. As mobile access network evolves towards centralisation, mobile fronthaul (MFH) architecture becomes essential in providing high capacity, ubiquitous and yet affordable services to subscribers. In order to meet the demand for high data rates in the access, Millimetre-wave (mmWave) has been highlighted as an essential technology in the development of 5G-new radio (5G-NR). In the present MFH architecture which is typically based on common public radio interface (CPRI) protocol, baseband signals are digitised before fibre transmission, featuring high overhead data and stringent synchronisation requirements. A direct application of mmWave 5G-NR to CPRI digital MFH, where signal bandwidth is expected to be up to 1GHz will be challenging, due to the increased complexity of the digitising interface and huge overhead data that will be required for such bandwidth. Alternatively, radio over fibre (RoF) technique can be employed in the transportation of mmWave wireless signals via the MFH link, thereby avoiding the expensive digitisation interface and excessive overhead associated with its implementation. Additionally, mmWave carrier can be realised with the aid of photonic components employed in the RoF link, further reducing the system complexity. However, noise and nonlinearities inherent to analog transmission presents implementation challenges, limiting the system dynamic range. Therefore, it is important to investigate the effects of these impairments in RoF based MFH architecture. This thesis presents extensive research on the impact of noise and nonlinearities on 5G candidate waveforms, in mmWave 5G fibre wireless MFH. Besides orthogonal frequency division multiplexing (OFDM), another radio access technology (RAT) that has received significant attention is filter bank multicarrier (FBMC), particularly due to its high spectral containment and excellent performance in asynchronous transmission. Hence, FBMC waveform is adopted in this work to study the impact of noise and nonlinearities on the mmWave fibre-wireless MFH architecture. Since OFDM is widely deployed and it has been adopted for 5G-NR, the performance of OFDM and FBMC based 5G mmWave RAT in fibre wireless MFH architecture is compared for several implementations and transmission scenarios. To this extent, an end to end transmission testbed is designed and implemented using industry standard VPI Transmission Maker® to investigate five mmWave upconversion techniques. Simulation results show that the impact of noise is higher in FBMC when the signal to-noise (SNR) is low, however, FBMC exhibits better performance compared to OFDM as the SNR improved. More importantly, an evaluation of the contribution of each noise component to the overall system SNR is carried out. It is observed in the investigation that noise contribution from the optical carriers employed in the heterodyne upconversion of intermediate frequency (IF) signals to mmWave frequency dominate the system noise. An adaptive modulation technique is employed to optimise the system throughput based on the received SNR. The throughput of FBMC based system reduced significantly compared to OFDM, due to laser phase noise and chromatic dispersion (CD). Additionally, it is shown that by employing frequency domain averaging technique to enhance the channel estimation (CE), the throughput of FBMC is significantly increased and consequently, a comparable performance is obtained for both waveforms. Furthermore, several coexistence scenarios for multi service transmission are studied, considering OFDM and FBMC based RATs to evaluate the impact inter band interference (IBI), due to power amplifier (PA) nonlinearity on the system performance. The low out of band (OOB) emission in FBMC plays an important role in minimising IBI to adjacent services. Therefore, FBMC requires less guardband in coexistence with multiple services in 5G fibre-wireless MFH. Conversely, OFDM introduced significant OOB to adjacent services requiring large guardband in multi-service coexistence transmission scenario. Finally, a novel transmission scheme is proposed and investigated to simultaneously generate multiple mmWave signals using laser heterodyning mmWave upconversion technique. With appropriate IF and optical frequency plan, several mmWave signals can be realised. Simulation results demonstrate successful simultaneous realisation of 28GHz, 38GHz, and 60GHz mmWave signals.en_US
dc.language.isoenen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.rightsAttribution 3.0 United States*
dc.rights.urihttp://creativecommons.org/licenses/by/3.0/us/*
dc.subject5Gen_US
dc.subject5G New Radioen_US
dc.subject5G Mobile Fronthaulen_US
dc.subjectFBMCen_US
dc.subjectOFDMen_US
dc.subjectMillimetre-waveen_US
dc.subjectRadio-over-Fibreen_US
dc.subjectMillimetre-wave Heterodyne Upconversionen_US
dc.subjectUncorrelated Optical Sources for Millimetre-wave upconversionen_US
dc.subject28 GHzen_US
dc.subject60 GHzen_US
dc.subjectFibre-Wireless Integrationen_US
dc.subjectMobile Fronthaul Millimetre-wave Radio Access Technologyen_US
dc.subjectNovel 5G waveformen_US
dc.subject5G Small Cellsen_US
dc.titleMillimetre-Wave Fibre-Wireless Technologies for 5G Mobile Fronthaulen_US
dc.typeinfo:eu-repo/semantics/doctoralThesisen_US
dc.identifier.doidoi:10.18745/th.21820*
dc.type.qualificationlevelDoctoralen_US
dc.type.qualificationnamePhDen_US
dcterms.dateAccepted2019-03-19
rioxxterms.funderDefault funderen_US
rioxxterms.identifier.projectDefault projecten_US
rioxxterms.versionVoRen_US
rioxxterms.licenseref.urihttps://creativecommons.org/licenses/by/4.0/en_US
rioxxterms.licenseref.startdate2019-10-30
herts.preservation.rarelyaccessedtrue
rioxxterms.funder.projectba3b3abd-b137-4d1d-949a-23012ce7d7b9en_US


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