Browsing by Author "Sheikh, Muhammad"
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Item Ambient Backscatter Communications for Future Ultra-Low-Power Machine Type Communications: Challenges, Solutions, Opportunities, and Future Research Trends(IEEE, 2020-02-14) Duan, Ruifeng; Wang, Xiyu; Yigitler, Huseyin; Sheikh, Muhammad; Jäntti, Riku; Han, Zhu; Department of Communications and Networking; Communication Engineering; University of HoustonThe widespread applications of massive MTC are limited by energy availability, spectrum congestion, and device costs. The emerging AmBC not only addresses these bottlenecks but also opens opportunities for new applications. This article aims to explore AmBC-enhanced future ultra-low-power MTC. In this context, we present the development trends in AmBC prototype designs and discuss potential applications, highlight the specific features of the AmBC technology, and review AmBC receiver designs. Finally, we investigate and outline the future research challenges and trends from the practical aspects of AmBC systems.Item DAS and UDN Solutions for Indoor Coverage at Millimeter Wave (mmWave) Frequencies(2019) Sheikh, Muhammad; Ruttik, Kalle; Jäntti, Riku; Department of Communications and Networking; Communication Engineering; Wireless & Mobile CommunicationsThe future 5th Generation (5G) wireless networks are expected to support a variety of bandwidth hungry applications. Millimeter wave (mmWave) communications, and Ultra Dense Network (UDN) deployment along with smart Distributed Antenna System (DAS) can be considered as a tempting solution for cellular networks. The aim of this paper is to analyze the performance of different UDN and DAS configurations in an indoor environment i.e. real university office building at 3.5 GHz, 28 GHz, and 60 GHz frequency. System performance is analyzed by performing ray launching simulations using a three dimensional floor plan. The obtained results show the incapability of basic indoor solution in providing the ubiquitous Quality of Service (QoS) in an indoor environment at higher frequencies. Simulation results shows that it is inevitable to have a dedicated indoor network with UDN or DAS configuration to provide homogeneous coverage in an indoor condition. It is found that despite of more interference the UDN deployment provides a higher system capacity compared with DAS due to more number of cells. However, the gain of cell densification saturates with the increasing number of cells.Item Drone Detection and Classification Using Cellular Network: A Machine Learning Approach(2019) Sheikh, Muhammad; Ghavimi, Fayezeh; Ruttik, Kalle; Jäntti, Riku; Department of Communications and Networking; Communication Engineering; Wireless & Mobile CommunicationsThe main target of this paper is to propose a preferred set of features from a cellular network for using as predictors to do the classification between the flying drone User Equipments (UEs) and regular UEs for different Machine Learning (ML) models. Furthermore, the target is to study four different machine learning models i.e. Decision Tree (DT), Logistic Regression (LR). Discriminant Analysis (DA) and K- Nearest Neighbour (KNN) in this paper, and evaluate/compare their performance in terms of identifying the flying drone UE using three performance metrics i.e. True Positive Rate (TPR), False Positive Rate (FPR) and area under Receiver Operating Characteristic (ROC) curve. The simulations are performed using an agreed 3GPP scenario, and a MATLAB machine learning tool box. All considered ML models provide high drone detection probability for drones flying at 60 m and above height. However, the true drone detection probability degrades for drones at lower altitude. Whereas, the fine DT method and the coarse KNN model performs relatively better compared with LR and DA at low altitude, and therefore can be considered as a preferable choice for a drone classification problem.Item Performance Evaluation of Switched Beam Antenna with Different Configurations at 28 GHz(2019) Sheikh, Muhammad; Ruttik, Kalle; Jäntti, Riku; Department of Communications and Networking; Communication Engineering; Wireless & Mobile CommunicationsThe main target of this paper is to evaluate the performance of a switched beam antenna in a macro-cellular environment at 28 GHz frequency. Another objective of this study is to compare the performance of a cellular system equipped with 7-beams switched beam antenna with conventional system implemented with wide 65◦ horizontal HPBW antenna. A campaign of 3D ray tracing simulations was carried out by using realistic 3D building data. Performance metrics considered for this study are RX level, SINR, system spectral efficiency, and the relative gain. Different configurations of 7-beams antenna is studied and the advantages and the disadvantages of considered configurations are highlighted in this paper. It is learned from the acquired results that an optimal configuration of 7-beams antenna can provide upto only 209.72 % of relative gain with respect to a traditional 3-sector site deployment. However, the relative performance gain of a 7-beam antenna can be negative under certain circumstances.Item Usability Benefits and Challenges in mmWave V2V Communications: A Case Study(2019) Sheikh, Muhammad; Hämäläinen, Jyri; Gonzalez Gonzalez, David; Jäntti, Riku; Gonsa, Osvaldo; Department of Communications and Networking; Communication Engineering; Wireless & Mobile Communications; Continental AGRecently, an active discussion on the feasibility of Millimeter Wave (mmWave) frequencies for the Vehicle-to-Vehicle (V2V) communication have been carried out in research community. We contribute to this discussion by providing a comparison between explicit three-dimensional ray-tracing simulations and field trial measurements on 39 GHz frequency. Three basic practical and relevant cases for V2V communications are considered covering several important scenarios of daily life traffic. A close match between the measured and simulated results is found through explicit ray tracing simulations; thus validating the feasibility of the simulation model and underlying assumptions. Moreover, these outcomes also shed light on the potential and challenges of using mmWave frequencies for V2V communication. The acquired results indicate that the Reference Signal Received Power (RSRP) levels are sufficiently above the noise level even up to 100 m distance between TX and RX in case of a single obstructing car. Results also reveal the impact of moving vehicle intersecting the LOS between the TX and RX vehicle at road intersection, and they indicate a notable blockage loss in case of short TX-RX separation.