الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Transmission over hybrid communication channels such as radio frequency (RF),
power line communications (PLC), and underwater optical wireless communication (UOWC)
has been investigated under the umbrella of heterogeneous future generations of communication networks such as 5G, Beyond 5G (B5G), and 6G. On the other hand, nonorthogonal multiple access (NOMA) is a key technology for enhancing system performance in terms of spectral efficiency.
The mixture of RF and PLC is vital for implementing new applications in smart grid
and vehicular communications. In this Thesis, the performance of NOMA-based dualhop hybrid communication systems with decode-and-forward (DF) relay is investigated.
The wireless channel is characterized by Nakagami-m fading under an additive white
Gaussian noise (AWGN), while the PLC channels are characterized by Log-normal distribution with Bernoulli Gaussian noise including both background and impulsive noise
components. New closed-form expressions for the outage probability, the asymptotic
outage probability and ergodic capacity are derived and verified via extensive representative simulations. For more insights on the outage performance, the diversity order is
analyzed. Additionally, a power allocation optimization technique to achieve an outageoptimal performance is proposed. The results show that the system outage probability
is improved as the impulsive noise index and the arrival probability of the impulsive
component of the PLC additive noise is decreased, while their effect is negligible on the
ergodic capacity. Finally, the performance of the proposed system is compared against a
benchmark OMA-based system.
Furthermore, the hybrid combination UOWC and RF is a vital demand for enabling
communication through the air-water boundary. In the second part of this thesis, a
downlink NOMA-based dual-hop hybrid RF-UOWC with DF relaying is proposed. The
UOWC channels are characterized by exponential-generalized Gamma (EGG) fading,
while the RF channel is characterized by Rayleigh fading. Exact closed-form expressions
i
of outage probabilities and approximated closed-form expressions of ergodic capacities
are derived, for each NOMA individual user and the overall system as well, under the
practical assumption of imperfect successive interference cancellation (SIC). These expressions are then verified via Monte-Carlo simulation for various underwater scenarios.
To gain more insights on the system performance, the asymptotic outage probabilities
and the diversity order are analyzed. Moreover,a power allocation optimization problem
to obtain an outage-optimal performance is formulated and solved. For the sake of comparison and to highlight the achievable gain, the system performance is compared against
a benchmark OMA-based system.
Finally, an experimental implementation of the NOMA-based transmitter is provided.
NI USRP-2942 with NI-LabVIEW software is utilized to experimentally implement a
two-user downlink NOMA-based Quadrature amplitude modulation (QAM) transmitter.