Over recent years, the research and studies have focused on innovative solutions in various aspects
and phases related to the high demands on data rate and energy for fifth-generation and beyond
(B5G). This thesis aims to improve the energy efficiency, error rates, low-resolution
ADCs/DACs, antenna array structures and sum-rate performances of a single cell downlink
broadband millimetre-wave (mmWave) systems with orthogonal frequency division multiplexing
(OFDM) modulation and deploying multi-user massive multiple inputs multiple outputs (MU mMIMO) by applying robust beamforming techniques and detection algorithms that support
multiple streams per user (UE) in various environments and scenarios to achieve low complexity
system design with reliable performance and significant improvement in users perceived quality
of service (QoS).
The performance of the four 5G candidate mmWave frequencies, 28 GHz, 39 GHz, 60 GHz, and
73 GHz, are investigated for indoor/outdoor propagation scenarios, including path loss models
and multipath delay spread values. Results are compared to confirm that the received power and
delay spread is decreased with increasing frequency. The results were also validated with the
measurement findings for 60 GHz.
Then several proposed design models of beamforming are studied and implemented modified
algorithms of Hybrid Beamforming (HBF) approaches in indoor/outdoor scenarios over large
scale fading wideband mmWave /Raleigh channels. Firstly, three beamforming based diagonalize
the Equivalent Virtual Channel Matrix (EVCM) schemes with the optimal linear combining
methods are presented to overcoming the self-interference problems in Quasi-Orthogonal-Space
Time Block Code (QO-STBC) systems over narrowband mmWave Single-User mMIMO (SU mMIMO). The evaluated results show that the proposed beamforming based- Single Value
Decomposition (SVD) outperforms the conventional beamforming and standard QO-STBC
techniques in terms of BER and spectrum efficiency.
Next, the proposed HBF algorithm approaches with the fully/ partially connected structures are
developed and applied for sum-rate and symbol error rate (SER) performance maximization MU mMIMO-OFDM system, including HBF based on block diagonalization (BD) method Constraint/Unconstraint RF Power, Codebook, Kalman schemes. In addition, the modified near optimal linear HBF-Zero Forcing (HBF-ZF) and HBF-Minimum Mean Square Error (HBF MMSE) schemes, considering both fully-connected and partially-connected structures.
Finally, Simulation results using MATLAB platform, demonstrate that the proposed HBF based codebook and most likely HBF based-unconstraint RF power algorithms achieve significant
performance gains in terms SER and sum-rate efficiency as well as show high immunity against
the deformities and disturbances in the system compared with other HBF algorithm schemes. / Ministry of Higher Education and Scientific Research, the Republic of Iraq
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/19280 |
| Date | January 2021 |
| Creators | Alabdullah, Ali AbdulMohsin S. |
| Contributors | Abd-Alhameed, Raed |
| Publisher | University of Bradford, Faculty of Engineering and Informatics |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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