135 research outputs found
Low-complexity antenna selection techniques for massive MIMO systems
PhD ThesisMassive Multiple-Input Multiple-Output (M-MIMO) is a state of the art technology
in wireless communications, where hundreds of antennas are exploited at the base
station (BS) to serve a much smaller number of users. Employing large antenna
arrays can improve the performance dramatically in terms of the achievable rates
and radiated energy, however, it comes at the price of increased cost, complexity,
and power consumption.
To reduce the hardware complexity and cost, while maintaining the advantages of
M-MIMO, antenna selection (AS) techniques can be applied where only a subset of
the available antennas at the BS are selected. Optimal AS can be obtained through
exhaustive search, which is suitable for conventional MIMO systems, but is prohibited
for systems with hundreds of antennas due to its enormous computational
complexity. Therefore, this thesis address the problem of designing low complexity
AS algorithms for multi-user (MU) M-MIMO systems.
In chapter 3, different evolutionary algorithms including bio-inspired, quantuminspired,
and heuristic methods are applied for AS in uplink MU M-MIMO systems.
It was demonstrated that quantum-inspired and heuristic methods outperform
the bio-inspired techniques in terms of both complexity and performance.
In chapter 4, a downlink MU M-MIMO scenario is considered with Matched Filter
(MF) precoding. Two novel AS algorithms are proposed where the antennas are
selected without any vector multiplications, which resulted in a dramatic complexity
reduction. The proposed algorithms outperform the case where all antennas are
activated, in terms of both energy and spectral efficiencies.
In chapter 5, three AS algorithms are designed and utilized to enhance the performance
of cell-edge users, alongside Max-Min power allocation control. The
algorithms aim to either maximize the channel gain, or minimize the interference
for the worst-case user only.
The proposed methods in this thesis are compared with other low complexity AS
schemes and showed a great performance-complexity trade-off
Energy Efficiency Based Load Balancing Optimization Routing Protocol In 5G Wireless Communication Networks
A significant study area in cloud computing that still requires attention is how to distribute the workload among virtual machines and resources. Main goal of this research is to develop an efficient cloud load balancing approach, improve response time, decrease readiness time, maximise source utilisation, and decrease activity rejection time. This research propose novel technique in load balancing based network optimization using routing protocol for 5G wireless communication networks. the network load balancing has been carried out using cloud based software defined multi-objective optimization routing protocol. then the network security has been enhanced by data classification utilizing deep belief Boltzmann NN. Experimental analysis has been carried out based on load balancing and security data classification in terms of throughput, packet delivery ratio, energy efficiency, latency, accuracy, precision, recall
A metaheuristic optimization approach for energy efficiency in the IoT networks
© 2020 John Wiley & Sons, Ltd. Recently Internet of Things (IoT) is being used in several fields like smart city, agriculture, weather forecasting, smart grids, waste management, etc. Even though IoT has huge potential in several applications, there are some areas for improvement. In the current work, we have concentrated on minimizing the energy consumption of sensors in the IoT network that will lead to an increase in the network lifetime. In this work, to optimize the energy consumption, most appropriate Cluster Head (CH) is chosen in the IoT network. The proposed work makes use of a hybrid metaheuristic algorithm, namely, Whale Optimization Algorithm (WOA) with Simulated Annealing (SA). To select the optimal CH in the clusters of IoT network, several performance metrics such as the number of alive nodes, load, temperature, residual energy, cost function have been used. The proposed approach is then compared with several state-of-the-art optimization algorithms like Artificial Bee Colony algorithm, Genetic Algorithm, Adaptive Gravitational Search algorithm, WOA. The results prove the superiority of the proposed hybrid approach over existing approaches
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Contextually and identity aware 5G services
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonThe fifth generation (5G) mobile networks aim to be ten times faster than the existing 4G connection, whilst providing low latency, and flexibility. Hence, various alterations are planned to the existing network infrastructure to be able to reach the 5G expected performance levels. The main technologies that were used, to ensure high performance, flexible network, and efficient resource allocation, are Software Defined Network and Network Function Virtualization. As these technologies are replacing the device-based architecture with, a service-based architecture.
This thesis provides a design of location database interactive web interface and interactive mobile application. The implementation of real time video streaming location server, the streaming system's performance parameters demonstrated a high level of QoS (0.07ms jitter and 9.53ms delay). In regard to experimental examination, it measured the localisation coverage, accuracy measurements and a highly scalable security solution. The localisation coverage and accuracy measurements were achieved through the mmWave and VLC link transmitters. The proposed simulated annealing algorithm aimed at data optimisation for location measurements accuracy showed results of the average location error of x and y which showed significant improvement from x= 22.5 and y=21.6 to x=11.09 and y= 11.63.
The proposed indoor location security solution showed significant results, as it provides a high scalability solution using the VNF. The solution showed that it was not 100% effective, as some of the fake discover packets still reached the DHCP server. This was due to the high load of traffic passing through the network. Nonetheless, 90% of the fake DHCP discover packets never reached the DHCP server because the scripts began blocking all fake discover packets after realising it was an attack. This conveys that the proposed system was able to run successfully without crashing or overloading the controller.
Overall, the main challenges facing 5G have been addressed with their proposed solutions, which showed promising results. Conclusively showing that there is a lot more space for technological advancements to support the future of mobile networks.European Union’s Horizon 2020 research program - the Internet of Radio-Light (IoRL) project H2020-ICT 761992
Contributions to the development of the CRO-SL algorithm: Engineering applications problems
This Ph.D. thesis discusses advanced design issues of the evolutionary-based
algorithm \textit{"Coral Reef Optimization"}, in its Substrate-Layer (CRO-SL)
version, for optimization problems in Engineering Applications. The problems
that can be tackled with meta-heuristic approaches is very wide and varied, and
it is not exclusive of engineering. However we focus the Thesis on it area, one
of the most prominent in our time. One of the proposed application is battery
scheduling problem in Micro-Grids (MGs). Specifically, we consider an MG that
includes renewable distributed generation and different loads, defined by its
power profiles, and is equipped with an energy storage device (battery) to
address its programming (duration of loading / discharging and occurrence) in a
real scenario with variable electricity prices. Also, we discuss a problem of
vibration cancellation over structures of two and four floors, using Tuned Mass
Dampers (TMD's). The optimization algorithm will try to find the best solution
by obtaining three physical parameters and the TMD location. As another related
application, CRO-SL is used to design Multi-Input-Multi-Output Active Vibration
Control (MIMO-AVC) via inertial-mass actuators, for structures subjected to
human induced vibration. In this problem, we will optimize the location of each
actuator and tune control gains. Finally, we tackle the optimization of a
textile modified meander-line Inverted-F Antenna (IFA) with variable width and
spacing meander, for RFID systems. Specifically, the CRO-SL is used to obtain
an optimal antenna design, with a good bandwidth and radiation pattern, ideal
for RFID readers. Radio Frequency Identification (RFID) has become one of the
most numerous manufactured devices worldwide due to a reliable and inexpensive
means of locating people. They are used in access and money cards and product
labels and many other applications.Comment: arXiv admin note: text overlap with arXiv:1806.02654 by other author
Differential Evolution in Wireless Communications: A Review
Differential Evolution (DE) is an evolutionary computational
method inspired by the biological processes of evolution and mutation. DE has
been applied in numerous scientific fields. The paper presents a literature review
of DE and its application in wireless communication. The detailed history,
characteristics, strengths, variants and weaknesses of DE were presented. Seven
broad areas were identified as different domains of application of DE in wireless
communications. It was observed that coverage area maximisation and energy
consumption minimisation are the two major areas where DE is applied.
Others areas are quality of service, updating mechanism where candidate positions
learn from a large diversified search region, security and related field applications.
Problems in wireless communications are often modelled as multiobjective
optimisation which can easily be tackled by the use of DE or hybrid of
DE with other algorithms. Different research areas can be explored and DE will
continue to be utilized in this contex
Machine Learning for Unmanned Aerial System (UAS) Networking
Fueled by the advancement of 5G new radio (5G NR), rapid development has occurred in many fields. Compared with the conventional approaches, beamforming and network slicing enable 5G NR to have ten times decrease in latency, connection density, and experienced throughput than 4G long term evolution (4G LTE). These advantages pave the way for the evolution of Cyber-physical Systems (CPS) on a large scale. The reduction of consumption, the advancement of control engineering, and the simplification of Unmanned Aircraft System (UAS) enable the UAS networking deployment on a large scale to become feasible. The UAS networking can finish multiple complex missions simultaneously. However, the limitations of the conventional approaches are still a big challenge to make a trade-off between the massive management and efficient networking on a large scale.
With 5G NR and machine learning, in this dissertation, my contributions can be summarized as the following: I proposed a novel Optimized Ad-hoc On-demand Distance Vector (OAODV) routing protocol to improve the throughput of Intra UAS networking. The novel routing protocol can reduce the system overhead and be efficient. To improve the security, I proposed a blockchain scheme to mitigate the malicious basestations for cellular connected UAS networking and a proof-of-traffic (PoT) to improve the efficiency of blockchain for UAS networking on a large scale. Inspired by the biological cell paradigm, I proposed the cell wall routing protocols for heterogeneous UAS networking. With 5G NR, the inter connections between UAS networking can strengthen the throughput and elasticity of UAS networking. With machine learning, the routing schedulings for intra- and inter- UAS networking can enhance the throughput of UAS networking on a large scale. The inter UAS networking can achieve the max-min throughput globally edge coloring. I leveraged the upper and lower bound to accelerate the optimization of edge coloring.
This dissertation paves a way regarding UAS networking in the integration of CPS and machine learning. The UAS networking can achieve outstanding performance in a decentralized architecture. Concurrently, this dissertation gives insights into UAS networking on a large scale. These are fundamental to integrating UAS and National Aerial System (NAS), critical to aviation in the operated and unmanned fields. The dissertation provides novel approaches for the promotion of UAS networking on a large scale. The proposed approaches extend the state-of-the-art of UAS networking in a decentralized architecture. All the alterations can contribute to the establishment of UAS networking with CPS
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