Masood Ur-Rehman

Interference Mitigation in D2D Communication Underlaying LTE-A Network

The mobile data traffic has risen exponentially in recent days due to the emergence of data intensive applications, such as online gaming and video sharing. It is driving the telecommunication industry as well as the research community to come up with new paradigms that will support such high data rate requirements within the existing wireless access network, in an efficient and effective manner. To respond to this challenge, device-to-device (D2D) communication in cellular networks is viewed as a promising solution, which is expected to operate, either within the coverage area of the existing eNB and under the same cellular spectrum (in-band) or separate spectrum (out-band). D2D provides the opportunity for users located in close proximity of each other to communicate directly, without traversing data traffic through the eNB. It results in several transmission gains, such as improved throughput, energy gain, hop gain, and reuse gain. However, integration of D2D communication in cellular systems at the same time introduces new technical challenges that need to be addressed. Containment of the interference among D2D nodes and cellular users is one of the major problems. D2D transmission radiates in all directions, generating undesirable interference to primary cellular users and other D2D users sharing the same radio resources resulting in severe performance degradation. Efficient interference mitigation schemes are a principal requirement in order to optimize the system performance. This paper presents a comprehensive review of the existing interference mitigation schemes present in the open literature. Based on the subjective and objective analysis of the work available to date, it is also envisaged that adopting a multi-antenna beamforming mechanism with power control, such that the transmit power is maximized toward the direction of the intended D2D receiver node and limited in all other directions will minimize the interference in the network. This could maximize the sum throughput and hence, guarantees the reliability of both the D2D and cellular connections.

NUMERICAL MODELLING OF HUMAN BODY FOR BLUETOOTH BODY-WORN APPLICATIONS

The human body has got a pivotal role in portable devices operating in Body-centric Wireless Networks (BCWNs). Electromagnetic interaction between lossy human body tissues and wearable antennas degrades the system performance. E-cient deployment of such systems necessitates thorough understanding of these efiects. Numerical analysis is a powerful tool that provides useful information of such scenarios fairly quicker than the actual measurements giving the user full control of the design environment. This paper investigates usefulness of numerical analysis based on the comparison of three difierent homogeneous models of the human body. Efiectiveness of a numerical model is evaluated in terms of its resolution, computational e-ciency, time consumption and accuracy of the results in software followed by experimental veriflcations.

A compact multi-band slot-ring microstrip patch antenna for wireless applications

Design of a printed microstrip patch antenna operating at multiple frequency bands is presented in this paper. The antenna has a very simple structure combining a microstrip patch, two rings and a slot. The antenna covers GPS (1.575 GHz), 4G/LTE/CDMA (2.1 GHz), and Wi-Fi (3.6/5.3 GHz) frequency bands with good impedance matching (2:1 VSWR) and radiation pattern performance. It has an omni-directional radiation pattern at most of the desired frequencies of operation. The antenna has good efficiency ranging from 60% to 98% and exhibits high peak gain values of 4.1 dBi, 5.7 dBi, 5.1 dBi and 7.9 dBi at 1.575 GHz, 2.1 GHz, 3.68 GHz and 5.37 GHz, respectively.

A Low Profile Antenna for Millimeter-Wave Body-Centric Applications

Millimeter-Wave (mm-Wave) frequencies are a front runner contender for the next generation body-centric wireless communications. In this paper, the design of a very low-profile antenna is presented for body-centric applications operating in the mm-Wave frequency band centered at 60 GHz. The antenna has an overall size of

Millimetre-Wave Antennas and Systems for the Future 5G

14\times 10.5\times 1.15~\text {mm}^{3}

Energy Management in LTE Networks

and is printed on a flexible printed circuit board. The performance of the antenna is evaluated in off-body, on-body, and body-to-body communication scenarios using a realistic numerical phantom and verified through measurements. The antenna has a bandwidth of 9.8 GHz and offers a gain of 10.6 dBi in off-body (free space) configuration, while 12.1 dBi in on-body configuration. It also achieves an efficiency of 74% in off-body and 63% in on-body scenario. The small and flexible structure of the antenna along with excellent impedance matching, broad bandwidth, high gain, and good efficiency makes it a suitable candidate to attain simultaneous data transmission/reception at mm-Wave frequencies for the 5G body-centric applications.

Green Communications: Techniques and Challenges

1Centre for Wireless Research, University of Bedfordshire, Luton LU1 3JU, UK 2Texas A &M University at Qatar, Doha, Qatar 3School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK 4Department of Electrical & Computer Engineering, North South University, Dhaka, Bangladesh 5Department of Electrical Engineering, Faculty of Engineering, Islamic University in Madinah, Al-Madinah, Saudi Arabia 6Department of Electrical and Electronic Engineering, Institute Teknologi Brunei, Gadong, Brunei Darussalam

A low profile penta-band antenna for portable devices

Wireless cellular networks have seen dramatic growth in number of mobile users. As a result, data requirements, and hence the base-station power consumption has increased significantly. It in turn adds to the operational expenditures and also causes global warming. The base station power consumption in long-term evolution (LTE) has, therefore, become a major challenge for vendors to stay green and profitable in competitive cellular industry. It necessitates novel methods to devise energy efficient communication in LTE. Importance of the topic has attracted huge research interests worldwide. Energy saving (ES) approaches proposed in the literature can be broadly classified in categories of energy efficient resource allocation, load balancing, carrier aggregation, and bandwidth expansion. Each of these methods has its own pros and cons leading to a tradeoff between ES and other performance metrics resulting into open research questions. This paper discusses various ES techniques for the LTE systems and critically analyses their usability through a comprehensive comparative study.

Study of a novel multi-band antenna for body-centric wireless networks

Green technology has drawn a huge amount of attention with the development of the modern world. Similarly with the development in communication technology the industries and researchers are focusing to make this communication as green as possible. In cellular technology the evolution of 5G is the next step to fulfil the user demands and it will be available to the users in 2020. This will increase the energy consumption by which will result in excess emission of co2. In this paper different techniques for the green communication technology and some challenges are discussed. These techniques include device-to-device communication (D2D), massive Multiple-Input Multiple-Output (MIMO) systems, heterogeneous networks (HetNets) and Green Internet of Things (IoT).

Design of a compact wearable single-arm spiral antenna for satellite communications

Recent years have seen a rapid growth of portable wireless communication systems. Limited form factor and operation at multiple frequencies of these devices require novel solutions of efficient embedded antennas. It has increased the demand of microstrip patch antennas due to their inherent properties of being low profile, simple design, small size and ease of fabrication and integration. Miniaturisation requirements have seen rise of multiband patch antennas. This paper presents the design and analysis of a novel multiband microstrip patch antenna. The antenna consists of a rectangular slot with two E-shaped stubs on both of its sides. An inverted T-shaped stub is present on the upper side of the slot while an I-shaped stub is there on the bottom side. A T-shaped feeding line feeds the antenna. The slot, stubs and feed collectively produce five frequency bands centred at 1.5 GHz, 2.2 GHz, 3.1 GHz, 4.2 GHz and 5.3 GHz for LTE/4G/5G, WiBro/WiMax, Satcomm and WLAN applications. The antenna offers small size, good impedance bandwidth and high gain at all operating frequencies.