Search Results

Survivability of systems is a very important system property and consists major concern for organizations and companies. Survivable systems should maintain their critical services functional in a timely manner. There are several approaches, proposed in the literature, on how to develop survivable telecommunication systems, but the majority is based on node outages or path failures,…

The main advantage of software-defined visible light communication (VLC) systems is that they allow us to reuse modulation, coding, synchronization and medium access techniques used in conventional radio systems. This article focuses on the implementation of an uplink alternative using an infrared (IR) light communication system. For this goal, analog front-ends are designed and implemented.…

The automated Global System for Mobile Communication Signal Strength and Radio Climatological (GSM-RC) measuring device is an integration of different electronic sensors in a box for an in-situ measuring system. The sensor, data logging, and communication subsystems are integrated for transmitting information on meteorological parameters (MPs) and GSM signal strength level (SSL). The goal is…

With the significant spread of 5G telecommunication systems, the demand for high quality of service and better coverage is growing rapidly. Multiple-input–multiple-output is planned to be among the key technologies in 5G telecommunication’s field. In this article, a new fully digital 2×2 MIMO testbed is implemented, using USRP B210 and 2 pairs of microstrip antennas…

This paper represents analysis of principles providing maximally reliable delay estimation of signal synchronization devices in telecommunication. Clock synchronization schemes on the base of stochastic models, graph-analytic interpretation, analytical functional description and their parameters selection in case of real complex hindrance are analyzed. Dependences between dispersion of maximally reliable estimation of synchronization devices and signal…

Orthogonal Frequency Division Multiplexing (OFDM) is a modulation format that has recently attracted lots of consideration interior the long-haul fiber-optic transmission community. The most important advantage of optical OOFDM is its unlimited capability of canceling Inter-Symbol Interference (ISI) caused by Chromatic Dispersion (CD) and Polarization-Mode Dispersion (PMD). Specifically, Coherent OOFDM (CO-OFDM) presents a good and…

Wireless communication opens up new avenues in the field of intelligent vehicle systems, including monitoring, guidance and warning applications. In order to determine more precisely the feasibility of using the 802.11n standard in vehicular communication systems, this paper describes a process for evaluating the propagation performance of the 802.11n and 802.11p standards. To do that,…

The increased motivation (by service providers) to offer user-centric and seamless communication services – that satisfies users’ quality of experience (QoE), has manifested a myriad of challenges in the field of wireless communication; and given the increased traffic capacity and sudden explosion of cellular devices, communication systems are constantly threatened by performance related issues –…

Recently, the Multiple-input multiple-output (MIMO) antennas have been used a lot and attracted many researchers in advanced high-speed wireless communication systems. MIMO antennas are an essential part not only in access points but also in end-user devices. This technology allows a significant increase in channel capacity, but also lead to a challenge of minimize mutual…

In the time past, virtually all the contemporary communication systems depend on distinct source and channel encoding schemes for data transmission. Irrespective of the recorded success of the distinct schemes, the new developed scheme known as joint source channel coding technique has proven to have technically outperformed the conventional schemes. The aim of the study…

In the present paper, a universal approach for determining the maximum flow problem in directed graph for solving different problems is applied. It can be considered as a heuristic and it can be used as a denomination for analyzing an arbitrary system with a mathematical description as a directed graph. The physical nature of the…

Stop and Wait (SW) ARQ, Go Back N (GBN) ARQ, and Selective Repeat (SR) ARQ are the main ARQ (Automatic-Repeat-reQuest) protocols used to ensure reliable delivery of digital data at correct sequence. These protocols are implemented at the DLC (Data Link Control) sub layer of Data Link Layer (DLL) of OSI (Open System Interconnection) network…

Automatic Repeat reQuest (ARQ) protocols are used to control transmission errors in data communications. They are used at Data Link Control (DLC) sublayer of Data Link Layer (DLL) of OSI (Open Systems Interconnection) network model to achieve flow and error control and provide smooth and reliable transmission between network nodes. ARQ protocols use acknowledgments and…

The data transmitted over wireless communication systems are affected by various elements as noise, interference or distortion, and to be able to combat these factors the paper propose the utilization of Redundant Residue Number System (RR NS) coding as a Forward Error Correction (FEC) technique to enhance the performance of MIMO-OFDM communication system compared to…

In this paper, a hybrid system solar cell antenna was studied. Our contribution lies in the combination of both optical and radio-frequency signals in a solar cell antenna. Hence, we propose a new method to merge antenna and solar cell. The leaf- shaped patch solar cell antenna was dedicated at a time to the energy…

In this paper we focus on the adaptive modulation and coding (AMC) techniques, makes use of the channel state information (CSI) to improve the spectral efficiency (SE) in wireless communication systems. To achieve higher data rates and lower bit error rate (BER’s) channel coding can be carried out in OFDM, called COFDM. The NLMS channel…

Due to the increasing bandwidth requirement of modern wireless communication systems, developing antenna having wider bandwidth have been receiving significant attention in the recent years. In this paper, a comparative analysis of the contacting feed (micro strip line and coaxial probe) and non-contacting feed mechanism (both Aperture Coupling and Proximity Coupling) in micro strip patch…

Direction dependent antenna modulation (DAM), as a potential physical-layer security technique, is able to enhance the security of wireless communication systems by virtue of the capability of its direction-dependent signal modulation format transmission. In this paper, DAM using frequency diverse array (FDA) to produce the modulation is presented. By phase shifting each element, the desired…