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The security of wireless communication systems has been the focal subject of research for more than a century. It is a topic of vital importance due to its effectiveness in many fields. Besides, the importance of sending data from one point to another without intercepting by unwanted third-party has become an essential requirement in conjunction with the widespread hacking technologies. This research paper is set out to explore a new technique used in internet of things applications that will ensure a secure wireless communication system. Additionally, it clarifies five distinct cryptographic methods: advanced encryption standard, elliptic curve cryptography, transposition, substitution, and Rivest, Shamir, and Adleman. In addition, the secure wireless communication system combines four of the prementioned techniques to build a highly secure system. Moreover, we managed to elucidate the critical points of our work on the long-range systems into a short yet informative and detailed summary. This paper will extensively cover the following topics: cryptography, cryptographic methods and techniques, software implementation, applications, and advantages of the system. [ABSTRACT FROM AUTHOR]

This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network that records environmental parameters such as temperature, humidity, wind speed, and carbon dioxide (CO2) concentration in the air, as well as taking infrared photos. The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected, processed, and uploaded to a cloud database at the gateway. An Android smartphone application that allows anyone to easily view the recorded data has been developed. When a fire is detected, the system will sound a siren and send a warning message to the responsible personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam, have been conducted to verify and evaluate the operation of the system. [ABSTRACT FROM AUTHOR]

Within the rapidly evolving landscape of wireless communication technologies, this scientific paper delves into an innovative approach by exploring the integration of the Bluetooth frequency band into a circular antenna design. Leveraging the capabilities of metamaterials. The Bluetooth frequency band a cornerstone for short-range communications, takes center stage in our study. Traditionally associated with wireless connectivity in diverse applications, its integration into a circular antenna structure opens up new avenues for optimizing performance and functionality. Our research aims to not only enhance the efficiency of short-range communication systems but also contribute to the broader discourse on antenna design evolution. The computer simulation technology (CST) studio suite is utilized to show the recommended antenna design. By scrutinizing the symbiotic relationship between the Bluetooth frequency band and the circular antenna augmented with metamaterial, our study endeavors to push the boundaries of current design paradigms. We believe that this exploration will not only address the contemporary challenges associated with wireless communication but also pave the way for the development of more sophisticated, adaptable, and compact devices in the ever-expanding realm of telecommunications. [ABSTRACT FROM AUTHOR]

The ocean environment monitoring system is of great significance to the researchers because the ocean is the storehouse of natural resources. It is critical to comprehend and assess the ocean's environmental conditions. Several studies have been conducted over the last several decades that use sophisticated information and communication techniques to ensure the ocean ecosystem. Wireless sensor networks (WSNs) are a promising technology to monitor the ocean environment, which delivers significant benefits such as enhanced accuracy and real-time observations. The advancements in sensor technology such as micro electromechanical systems (MEMS), integrated systems, distributed processing, wireless communications, and wireless sensor applications have contributed to the development of WSNs. This paper describes the utilization of WSN and analyzes the previous and existing project works and technologies used for ocean environment monitoring through WSNs, and also includes the MEMS sensor technology used for monitoring various ocean parameters such as ocean wave monitoring, water conductivity, temperature, and depth of ocean. [ABSTRACT FROM AUTHOR]

Acoustic underwater link due to low attenuation is employed for underwater sensor network (UWSN). Due to water changing physical properties and different environmental conditions, the sound propagation for every underwater channel are different. So, the most important parameters to design reliable UWSN are: the shadow zone determination, optimum nodes placement, high signal to noise ratio and more power efficiency of nodes. This paper simulates underwater channel for 7 KHz carrier frequency, with measured physical water properties and remote sensing data. Based on defined scenario, the research determines optimum nodes placement and link budget analysis based on bottom to surface acoustic link. The paper utilizes Bellhop acoustic toolbox as a simulator, GeoMapApp program to collects bathymetry data and Aviso+ database to determine wind speed on sea surface. As a result the paper based on simulation of sound propagation in channel and transmission loss determination in depth and range, finds the optimum nodes positions and link budget calculation to prove the results. [ABSTRACT FROM AUTHOR]

Microstrip patch antennas are becoming increasingly popular because they are small, have low profiles, are easy to integrate, are very cheap, and work well. For this reason, this antenna could be used for wireless communication systems. This research paper reviews and studies 28 GHz microstrip patch antenna for wireless applications. Different substrate materials have been used to make these antennas, such as FR-4 (loss), FR-4 Epoxy, Rogers RT/droid 5880, TLC-30, Rogers RT/droid 5880 LZ, and others. Different substrate materials and shapes were used to make microstrip patch antennas with a frequency of 28 GHz. This article discusses the different sizes of antennas, the other geometric shapes antennas can take, the different ways antennas' properties can be analyzed, and the different types of antennas. It will also talk about the material, thickness, loss tangent, return loss, bandwidth, voltage standing wave ratio (VSWR), gain, efficiency, and directivity of the substrate. This antenna is used for super-high-frequency (SHF), radars, commercial wireless local area networks (LANs), cell phones, and other wireless communications systems. [ABSTRACT FROM AUTHOR]

Copyright of Telkomnika is the property of Department of Electrical Engineering, Ahmad Dahlan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telkomnika is the property of Department of Electrical Engineering, Ahmad Dahlan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the microstrip antenna rectangular patch with beetle shaped slot is presented. The characterization results of the proposed antenna obtained by changing the dimensions of the ground plane. CST software is used to design and analyze this proposed antenna. The simulated results of proposed antenna show that the antenna works at the frequency of 2.1 GHz while the return loss of -32.18 dB with the bandwidth reaches 155.19 MHz and the gain of 3.895 dBi. [ABSTRACT FROM AUTHOR]

In the fifth generation of wireless communication systems (5G), the millimeter wave (mmWave) signal can be affected by many challenges in irregular environments such as dust and sand storms. In this paper, we investigate the attenuation that faces a mmWave link signal in a dusty environment for different sizes of dust particles. Further, we derive a model to calculate the total attenuation in mobile communication systems and/or internet of things (IoT) in different base stations highnesses. The obtained results show that in a dusty environment it is better to have high base station transmitters as the signal may escape the dense dust area. The paper also studies the case of the city of Mosul to find that not only the dry weather is increasing the attenuation, but wet weather also may impact more on the attenuation in the mmWave systems. [ABSTRACT FROM AUTHOR]

Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications. [ABSTRACT FROM AUTHOR]

Considering a dual-hop energy-harvesting (EH) non-orthogonal multiple access (NOMA) relaying system, this paper consider novel relaying protocols based on time power switching-based relaying (TPSR) architecture for amplify-and-forward modes. We introduce novel system model relaying network with impacts of energy harvesting fractions and derive analytical expressions for outage probability for the information transmission link. It confirmed that right selection of power allocation for NOMA to obtain optimal performance. Theoretical results show that, in comparison with the conventional solutions, the proposed model can achieve optimal throughput efficiency for sufficiently small threshold SNR with condition of controlling time switching fractions and power splitting fractions appropriately in TPSR protocol. We also explore impacts of transmission distances in each hop, transmission rate, the other key parameters of TPSR to outage performance for different channel models. Simulation results are presented to corroborate the proposed methodology. [ABSTRACT FROM AUTHOR]

Communication is one of essential elements in this life, including the people who live at rural areas. However, telecommunications in rural area especially in Indonesia have many constraints like expensive infrastructure, difficult terrain and electrical problem. This led to a lot of areas that uncovered by telecommunication access. In this paper, we proposed a design and architecture of mobile wireless communication based on modified openWRT as a solution for low-cost communication and telephony infrastructure in rural areas. The design combines VoIP over mesh ad-hoc network as a potential solution for cheap calls and use modified embedded device to save electrical resources as a node to connect each other with multi hop transmissions. With this approach, we get many advantages such as high mobility, easy to use, scalable, low-cost implementation, and low power consumption. This paper presents the measurement result of performance to provide access telecommunication in several conditions. In addition, this paper also shows benchmarking results and lifetime of the node that we use in this prototype. The results show that our node can provide telecommunications access in terms of making calls with good quality using wireless LAN. To sum this up, The OpenVoice node is expected to contribute bridging digital divide in rural areas. [ABSTRACT FROM AUTHOR]

It is known that high altitude platform system (HAPS) is one of the promising wireless technologies that exploit many advantages from cellular satellite system as well as from cellular terrestrial system. HAPS is envisaged to be a novel technology for communication, broadcasting, internet backbone, earth observation and surveillance, and also for navigation. One of upcoming technologies for communication is a long term term evolution (LTE) of a cellular forth generation (4G). Many techniques have been developed to make LTE come into real in the environment of cellular terrestrial. However, LTE that deployed through HAPS is a challenging due to different its geometry and channel. This paper aims at evaluating the performance of a pilot-based channel estimation for uplink LTE using SC-FDMA over Ricean HAPS communication channel. Pilot-based channel estimation is used to estimate an uplink channel of LTE users who transmit the data to HAPS as a base transceiver station (BTS). Analysis is performed to determine the effect of user's elevation angle with respect to user position inside HAPS coverage, LTE channel bandwidth, modulation type, and the Doppler frequency shift effect. We found that user's elevation angle contribute major effect to the pilot-based channel estimation of LTE SC-FDMA performance. System capability to overcome fading effect that users with low elevation angle would be needed to increase the performance. In particular to keep an acceptable performance, in this paper we compensate the channel bandwidth, changing modulation type, and limit the Doppler Effect through vehicle speed limitation. [ABSTRACT FROM AUTHOR]

The aim of this paper is to use defected ground structures (DGS) in order to miniaturize a microstrip patch antenna. The DGS structure is integrated in the ground plane to improve the performance of the planar antenna, and shifted the resonance frequency from 5.8 GHz to 2.5 GHz, with a miniaturization up to 83%.The antenna is designed, optimized and miniaturized by using the CST MWstudio, mounted on an FR-4 substrate having a dielectric constant 4.4, a loss tangent tan (ϕ) = 0.025,thickness of 1.6 mm with the whole area of 34 X 34 mm2.The proposed antenna is suitable for ISM (Industrial, Scientific and Medical) applications at 2.5 GHz with S11 ⩽(-10) dB. The antenna is fed by 50ohm input impedance and it has good performances in terms of matching input impedance and radiation pattern. The proposed antenna was fabricated and tested.Simulation and measurement results are in good agreement. [ABSTRACT FROM AUTHOR]

To design Visible Light Communication (VLC) system, there are several requirements that needs to be met. One of the requirements is an active component selection (e.g. Op Amp). As an ideal communication system, VLC system has to be able to provides wide bandwidth access with minimum noise. The Transimpedance amplifiers (TIAs) is one of main components in optical system which is placed in the first stage of receiver system. It is used to convert the current output from photodiode to voltage. We have designed a 1 MHz fGBW TIA with low noise (in μVrms range). This paper aims to explain the design and implementation of TIA circuit with photovoltaic topology which cover empirical calculations and simulation of TIA's bandwidth and its noise sources, i.e. resistor feedback noise, current noise, voltage noise and total noise based on RSS. The OP-AMP is chosen from Texas Instruments product, OPA 380, and photodiode is chosen from OSRAM, SFH213, then simulated by TINA-TI SPICE® software. The noise in TIA circuit is analyzed clearly. The developed kit is ready to be implemented in VLC system. [ABSTRACT FROM AUTHOR]

Over the last few years coverage and connectivity of wireless ad hoc networks have fascinated considerable attention. The presented paper analyses and investigates the issues of k-connectivity probability and its robustness in wireless ad hoc-network while considering fading techniques like lognormal fading, Rayleigh fading, and nakagami fading in the ad hoc communication environment, by means of shadowing and fading phenomenon. In case of k-connected wireless sensor network (WSNs), this technique permits the routing of data packets or messages via individual (one or more) of minimum k node disjoint communication paths, but the other remaining paths can also be used. The major contribution of the paper is mathematical expressions for k-connectivity probability. [ABSTRACT FROM AUTHOR]

With the demand for mobile data traffic, multi-carrier transmission techniques are highly attractive for all-new wireless communication systems, which divides data into many components and sends each of these components via a different carrier signal. So far, orthogonal frequency division multiplexing (OFDM) and filter bank multi-carrier (FBMC) techniques are the dominant waveform contenders. A number of studies have been made and failed to give a complete comparison where they did not consider various conditions altogether. Therefore, this paper addresses a complete comparative analysis of OFDM and FBMC, performed based on spectral efficiency, modulation, demodulation, power spectral densities, and peak to average power ratio comparison, all simulated using Matlab and GNU's not unix radio (GNU-radio) software. [ABSTRACT FROM AUTHOR]

Spectrum scarcity is an emerging issue in wireless communication systems due to the increasing demand of broadband services like mobile communications, wireless internet access, IoT applications, among others. The migration of analog TV to digital systems (a.k.a. digital TV switchover) has led to the release of a significant spectrum share that can be used to support said additional services. Likewise, TV white spaces emerge as spectral opportunities that can also be explored. Hence, cognitive radio (CR) presents itself as a feasible approach to efficiently use resources and exploit gaps within the spectrum. The goal of this paper is to unveil the state of the art revolving around the usage of TV white spaces, including some of the most important methods developed to exploit such spaces, upcoming opportunities, challenges for future research projects, and suggestions to improve current models. [ABSTRACT FROM AUTHOR]

The requirement for applications operating at a variety of frequencies in a unified wireless device has greatly enhanced in recent years. For this purpose, multi-functional wireless components are essential. This paper presents a new design of a wideband circularly-polarized microstrip antenna array with defected ground structure (DGS). A previous design was introduced which cover the C-band at 5.8 GHz and operates in the industrial scientific medical (ISM) band for wireless communication applications. The proposed antenna has excellent performances which include good input impedance matching with a fed of the circular polarization at 5.8 GHz. The proposed design is validated and optimized by adding a new design of defected ground structure. This aperture geometry enables the antenna to operate in a wideband. The obtained results show that the modified antenna has a good performance in terms of return loss, bandwidth, gain and radiation pattern and demonstrate that the proposed antenna offers a good solution for multi-standard wireless communication applications. [ABSTRACT FROM AUTHOR]

Vehicular cloud computing (VCC) is a new hybrid technology which has become an outstanding area of research. VCC combines salient features of cloud computing and wireless communication technology to help drivers in network connectivity, storage space availability and applications. VCC is formed by dynamic cloud formation by moving vehicles. Security plays an important role in VCC communication. Key management is one of the important tasks for security of VCC. This paper proposes a novel key management protocol for VCC security. Proposed scheme is based on Elliptical Curve Cryptography (ECC). The simulation results demonstrated that the proposed protocol is efficient compared to existing key management algorithms in terms of key generation time, memory usage and cpu utilization. [ABSTRACT FROM AUTHOR]

Wireless Body Area Network (WBAN) is a device developed mainly for the purpose of monitoring the medical condition of a human. WBAN is worn on the surface or in the human body, and it contains a wireless communication device. A WBAN device is required to be small-sized, with limited power and high data reliability. The data reliability can be obtained by using a carefully designed channel coding scheme so that the energy consumed can be maintained at a low level. In this paper, data transmission in Rayleigh, Rician, and Nakagami-m fading channels using Raptor and BCH codes is simulated. Simulation results show that Raptor-coded data transmission consumes lower energy compared to BCH-coded transmission for various fading channels if the transmission distance exceeds 10 meters. Therefore, Raptor code is a good candidate for the channel coding scheme for WBAN. [ABSTRACT FROM AUTHOR]

A novel single layer, microstrip line fed compact wideband monopole antenna using open loop resonator has been designed and analyzed. The proposed antenna occupies a compact size of only 30 36.5 1.6 mm3. A partial ground plane is employed to enhance the operating bandwidth and reflection coefficient of the proposed antenna. The variations in operating bandwidth of the proposed antenna can be easily controlled by properly adjusting the position of the gap in the open loop resonator.The antenna prototype is fabricated on FR4 substrate with a dielectric constant 4.2. In this design, the antenna exhibits 10dB wide impedance bandwidth of 61% from 2.0174 to 3.7903 GHz.The antenna can be easily fed using a 50 Ω microstrip feed line and it covers the bandwidth requirements of a number of modern wireless communication systems such as IEEE 502.11b WLAN band (2.4 2.5 GHz), extended UMTS (2.5 2.69 GHz), IMT (2.7 2.9 GHz), and IEEE 802.16 Wi MAX band (3.3 3.6 GHz) applications. The desired antenna is designed and simulated using Computer Simulation Technology (CST). An extensive analysis of the antenna parameters (reflection coefficient, radiation pattern, directivity, and VSWR) including surface current distributions is presented and discussed in this paper. Good agreement between simulated and measured result is obtained. [ABSTRACT FROM AUTHOR]

A dual-band harmonic suppression dipole antenna suitable for energy harvesting system is presented in this paper. A linear dipole with two parasitic elements is designed and fabricated with a capability to eliminate the harmonic of higher order modes. At first, the antenna resonates at 900 MHz and 2.7 GHz. Therefore, a parasitic element is added into each of the dipole's arm to tune the second frequency band to 2.4 GHz to fit into wireless application. However, the presence of two parasitic elements has generated an unwanted harmonic at 4.0 GHz. Thus, a stub has been integrated into the antenna's terminal (feed line) to suppress the 4.0 GHz frequency. This technique is suitable for developing a multiband antenna with harmonic suppression. The antenna is fabricated on a FR-4 board with the size of 72×152 mm2 which operates efficiently at 0.8 GHz and 2.4 GHz which is suitable for wireless communication applications. The prototype can suppress the undesired harmful harmonics present within the frequency range of 3 to 5 GHz. The antenna has a good potential to be used in a rectenna system with a dual-band frequency operation but with better performance. Simulation and measurement results obtained are in a good agreement, which have confirmed the proposed design concept. [ABSTRACT FROM AUTHOR]

This paper analyzes the weight of impact factors on selection the antenna places for mobile telecommunication system in Jordan. The new technique plays a lead role in divided area and selects the place of antennas' sites. The main objective of this research is to minimize the antenna numbers in order to reduce the cost. Research follows flowcharting categories and stages as: The first stage aim to classify the effective factors on the: signal radius, better position of antenna from candidate points, reserved area, and non-preferring position. The second stage focuses on finding the effective weight of these factors on the decision. The third stage suggest the new proposed approach by implement the MCLP and P-center problems in linear function. The last stage has the pseudo code for the proposed approach, where the proposed approach provides the solution that helps the planners in telecommunication industry and in related government agencies make informed position of the antennas. [ABSTRACT FROM AUTHOR]

Vivaldi antenna has been considered as a mitigation to the scattering effect of an antenna. However, the current performance of Vivaldi antenna suffers from multipath effect, interfering signals and radiation pattern control. This paper proposed an improved Vivaldi antenna which combined triple radiating slot to enable control of radiation pattern features. This is accomplished by controlling the position of the radiating element through the asymmetric arrangement of ideal switches to steer the beam in three desired-directions. The Using operating frequency lied between 900 MHz and 2.5GHz, the proposed design was fabricated and tested. Depending on the radiating element, the proposed anten na covered about ±90° with an almost equal gain at the three different focal in contrast to ±45° coverage of traditional rectangular microstrip antenna beam. The results satisfied pattern reconfigurability and the proposed design can be very useful for wireless communications where multipath fading problems are frequently encountered. [ABSTRACT FROM AUTHOR]

Providing simple and low complexity algorithms for estimating the direction of arrival in large systems using Massive MIMO is considered an important issue. In this paper a method with reduced complexity was proposed to estimate the direction of arrival in FD- MMIMO. The Separated Steering Matrix (SSM) algorithm uses two separated equations for estimating elevation and azimuth angles of Multi-users. This method reduces the complexity of calculating the covariance matrix by decreasing the size of this matrix. This technique is tested using 2D-MUSIC algorithm. Since the mobility of devices affects the accuracy of direction estimation, thus the effect of the initial phase of transmitted signal from mobile device is tested. [ABSTRACT FROM AUTHOR]

Cognitive radio (CR) technology has emerged as a realistic solution to the spectrum scarcity problem in present day wireless networks. A major challenge in CR radio networks is the hidden node problem, which is the inability of the CR nodes to detect the primary user. This paper proposes energy detector-based distributed sequential cooperative spectrum sensing over Nakagami-m fading, as a tool to solve the hidden node problem. The derivation of energy detection performance over Nakagami-m fading channel is presented. Since the observation represents a random variable, likelihood ratio test (LRT) is known to be optimal in this type of detection problem. The LRT is implemented using the Neyman-Pearson Criterion (maximizing the probability of detection but at a constraint of false alarm probability). The performance of the proposed method has been evaluated both by numerical analysis and simulations. The effect of cooperation among a group of CR nodes and system parameters such as SNR, detection threshold and number of samples per CR nodes is investigated. Results show improved detection performance by implementing the proposed model. [ABSTRACT FROM AUTHOR]

This paper presented the design of integrated open loop resonator bandpass filter with notch type antenna for the use in microwave applications. Chebyshev type filter is selected as the filter characteristics and cascaded design with the antenna to produce a single module, Integrated Filter Antenna (IFA). Special feature of the antenna is the implementation of notch on the patch antenna to improve the efficiency. IFA is then simulated in electromagnetic simulation tool, Agilent Advance Design System (ADS) version 2016 and measured using R&S Vector Network Analyzer. It shows that the proposed IFA produced good measured return loss >-30dB with both vertical and horizontal gain of 9.11dBi and 8.01dBi respectively. [ABSTRACT FROM AUTHOR]

In this paper, we suggested two approaches to minimizing the CH packet size by considering the accuracy of prediction of sensed data at the base station. The proposed coding schemes based relative difference (CS-RD) and based the factor of precision (CS-FP) instead of the absolute change method that has been used in recent work. The aim is to enhance the accuracy of prediction data at the base station. Therefore, the performance metric was evaluated in term of the accuracy of prediction data at the base station. Simulation results showed that the proposed approaches performed better in term of the accuracy of prediction data at the base station. Specifically, the distortion percentage and average Absolut error in the CS-RD and CS-FP method decreased by 50% and 88% better than the current new aggregation method (ADATDC). However, our proposed CS-FP showed a low reduction ratio for some states. [ABSTRACT FROM AUTHOR]

This paper proposed a new design of Minkowski Island microstrip antenna fed by proximity coupling with partial ground plane. The design was consisted of two layers of substrate, on the top substrate was the antenna patch and on the bottom substrate was the proximity feed line and the partial ground. At the first stage, the normal square patch antenna was mainly designed. Then, the Minkowski patch antenna was designed using 1st iteration technique and 2nd iteration technique. The Minkowski fractal shape slot was embedded in the center of the patch to form a Minkowski Island patch antenna. Using the Minkowski Island fractal technique, the dimension of the patch can be reduced up to 58.7%. The proximity feed line in this design was used to increase the impedance bandwidth, and from the measurement the impedance bandwidth of the proposed antenna was 240 MHz with return loss of -24.54 dB and VSWR of 1.126. [ABSTRACT FROM AUTHOR]

Signal detection in cognitive radio network (CRN) is influenced by several factors. One of them is malicious user that emulate primary user (PU) signal. Emulation of PU signal causes detection error. This paper investigates the impact of malicious user attack to PU signal detection. A number of malicious users are randomly deployed around secondary user (SU) at a certain distance. They attempt to attack primary signal detection that is transmitted from 100 km to SU receiver. Then, the received signal power at secondary receiver and the performance of probability of false alarm and probability of miss detection under two hypothesis of Neyman Pearson criterion are studied. The derived results show that a number of malicious users has a significant impact to the performance of received power at SU and detection error rate. [ABSTRACT FROM AUTHOR]

This paper presents a slotted design for ultra-wideband (UWB) antenna. Design of a rectangular UWB antenna covering the frequency range 3.1-10.6 GHz, to achieve notch characteristics in the bands at 3.1-8.4 GHz and 8.6- 10.6 GHz. By changing the direction of distribution of current to apply this technique by inserting three C-shaped holes and two pairs of rectangular notches below the antenna. The simulation results reveal that the proposed structure is in good accord with the simulation results. The proposed UWB antenna size is (100x90x1.6 mm)3. This proposed design could provide a solution to eliminating bands that interfere in a UWB band depending on the aperture design. The simulated findings reveal that the UWB antenna operates in the 8.5 GHz center frequency range and rejects all frequency bands utilizing slits. This antenna design can provide a solution to remove UWB bands from 3.1-10.6 except for 8.5 GHz which only works. By using the notch, we got a large increase in the gain. makes to be a suitable candidate for X-band-UWB applications. [ABSTRACT FROM AUTHOR]

Copyright of Telkomnika is the property of Department of Electrical Engineering, Ahmad Dahlan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wireless network state varies with the surrounding environment, however, the existing resource allocation algorithm cannot adapt to the varying network state, which results to the underutilization of frequency and power resource. Therefore, in this paper, we propose an adaptive resource allocation algorithm which can efficiently adapt to the varying network state by building an optimal mathematical model and then changing the weighted value of the objective function. Furthermore, the optimal allocation of subcarrier and power is derived by using the Lagrange dual decomposition and the subgradient method. Simulation results show that the proposed algorithm can adaptively allocate the resource to the users according to the varying user density which represents the network state. [ABSTRACT FROM AUTHOR]

The primary objective of cognitive radio network is to effectively utilize the unused spectrum bands. In cognitive radio networks, spectrum sharing between primary and secondary users is accomplished using either underlay or interweave cognitive radio approach. Non orthogonal multiple access (NOMA) is the proven technology in the present wireless developments, which allows the coexistence of multiple users in the same orthogonal block. The new paradigm cognitive radio NOMA (CR-NOMA) is one of the potential solutions to fulfill the demands of future wireless communication. This paper emphasizes on practical implementation of NOMA in cognitive radio networks to enhance the spectral efficiency. The goal is to increase the throughput of the secondary users satisfying the quality of service (QOS) requirements of primary users. To achieve this, we have presented the optimized power allocation strategy for underlay downlink scenario to support the simultaneous transmission of primary and secondary users. Furthermore, we have proposed QOS based power allocation scheme for CR-NOMA interweave model to support the coexistence of multiple secondary networks. Also, the changes adopted in implementing superposition coding (SC) and successive interference cancellation (SIC) for CR-NOMA are highlighted. Finally, simulation results validate the mathematical expressions that are derived for power allocation coefficient and outage probability. [ABSTRACT FROM AUTHOR]

The body area networks (BAN) structure is one of the advancements in health monitoring innovations and the sharp rise in healthcare demand. With the help of a network of constantly running sensors, BAN technology aims to monitor vital physiological and physical features like accessibility, respiration, and blood sugar levels. The achievement of BAN technology depends on wireless communication since it gives the user flexibility and versatility. Most BAN solutions have effectively employed radio frequency (RF) wireless technology, although these systems are battery-intensive, prone to electromagnetic interference, and have security weaknesses. The human body is the signal transmission medium in the alternative wireless communication technology called human body communication (HBC). HBC possesses traits that could logically deal with the problems with RF for wireless body area networks (WBAN) technology. This overview looks at the ongoing research in this field and highlights the principles of the HBC, the most recent studies of HBC, human body coupling approaches, the designs of HBC transceivers, and the unresolved research issues. HBC provides promising future possibilities for making WBAN technologies more useful. [ABSTRACT FROM AUTHOR]

The traditional load balancing optimization scheme cannot guarantee the user's QoS in the C-RAN wireless communication networks when all the neighboring macrocells are under the situation of overload. In order to resolve this problem, we implement the femtocell to the macrocell network, which considers the advantages of femtocell, i.e., small coverage, low cost and better signal quality. Therefore, in this paper, the joint load balancing mechanism is proposed to achieve the joint optimization of femtocell and macrocell network by allowing the users of overloaded macrocell to handover to the femtocell. Finally, the simulation results show that the proposed mechanism greatly improves the user satisfaction as well as the resource utilization rate of the femtocell network while decreases the blocking rate and dropping rate. [ABSTRACT FROM AUTHOR]

In the past decades, there has been a growing interest in unmanned aerial vehicles (UAVs) for educational, research, business, and military purposes. The most critical data for a flight system is the telemetry data from the GPS and wireless transmitter and also from the gyroscope and accelerometer. The objective of this paper is to develop a control system for UAV using long-range wireless communication and GPS. First, Matlab simulation was conducted to obtain an optimum PID gains controller. Then LoRa wireless was evaluated during clear and rainy days. Static and dynamic points measurement was conducted to validate and optimize GPS accuracy. GeoMapping in Matlab and Google GPS GeoPlanner were then used to analyze the traveled UAV flight path. [ABSTRACT FROM AUTHOR]

In this paper, a tuneable rectangular microstrip patch antenna (MPA) is simulated and optimized to operate in four frequency bands of the next generation of wireless communication systems. The proposed design incorporates a copper radiating patch with four implanted graphene strips for tuning purposes. The reconfigurable surface impedance of graphene can easily be altered by applying a DC voltage bias directly to the graphene strips, allowing the operating frequency of the antenna to be tuned as desired. The capability of the applied voltage to tune the operating frequency band of the proposed antenna is studied via computer simulation technology (CST) microwave studio (MWS). Frequency selective surfaces (FSSs) are introduced in order to improve the radiation parameters of the antenna. The operating frequency band of the tuneable rectangular MPA increases directly as the applied DC voltage bias is increased. Based on the simulation results, a tuneable rectangular MPA placed between two FSSs is proposed for fifth-generation applications. [ABSTRACT FROM AUTHOR]

This paper introduces the design and implementation of a wireless communication system with MATLAB based on orthognal frequency division multiplexing technique (OFDM). The constructed system is consisting of transmitter, fading channel and receiver. At the transmitter, the transmitted signal first modulated with PSK modulation, and then multiplexed with OFDM technique to achieve a higher bit rates transmission. The signal was then transmitted through a frequency selective channel with 6 taps. In the receiver parity. The received faded signal processed to be de-multiplexed and de-modulated. Then, a frequency domain equalizer was adopted to remove the fading noise and the inter-symbol interference from the received signal that introduced due to the fading channel. In order to inspect the performance of the frequency equilizer, bit error rate for the overall system was calculated at the receiving point and to recover the original information signal. The simulation results of the designed system as well as the frequency equilizer showed a robustness against the frequency selective faded channel effects. The maximum obtained bit error rate was around 10-5, which means that original signal was effectively recovered. [ABSTRACT FROM AUTHOR]

Spectrum sharing (SS) is a promising solution to enhance spectrum utilization in future cellular systems. Reducing the energy consumption in cellular networks has recently earned tremendous attention from diverse stakeholders (i.e., vendors, mobile network operators (MNOs), and government) to decrease the CO2 emissions and thus introducing an environment-friendly wireless communication. Therefore, in this paper, joint energy-efficient user association (UA) mechanism and fully hybrid spectrum sharing (EE-FHSS) approach is proposed considering the quality of experience QoE (i.e., data rate) as the main constraint. In this approach, the spectrum available in the high and low frequencies (28 and 73 GHz) is sliced into three portions (licensed, semi-shared, and fully-shared) aims to serve the users (UEs) that belong to four operators in an integrated and hybrid manner. The performance of the proposed QoE-Based EE UA-FHSS is compared with the well-known maximum signal-to-interference-plus-noise ratio (max-SINR UA-FHSS). Numerical results show that remarkable enhancement in terms of EE for the four participating operators can be achieved while maintaining a high degree of QoE to the UEs. [ABSTRACT FROM AUTHOR]

The widespread popularity of Wireless Local Area Network (WLAN) is recognized as an effective approach to complementing cellular networks for the high data rate and cost effective connectivity delivered to mobile users. Efficient handover and offloading schemes for integrated WLAN and cellular networks, referred to as Heterogeneous Wireless Networks, have thus attracted lots of attentions from both academia and industry. This paper proposes a novel Multiple-Threshold based Triggering (MTT) scheme for Cellular-to-WLAN handover control. Aiming at minimizing the probability of handover failures and unnecessary handovers, three thresholds are calculated based on a variety of network parameters such as system performance requirements, radius of the WLAN coverage, user mobility and handover delays. The thresholds are then compared against the predicted user residence time and estimated channel holding time inside WLAN to make vertical handover decisions (VHDs). Simulations were carried out to evaluate the effectiveness of MTT and results show that MTT minimizes handover failures and avoids unnecessary handovers in integrated cellular and WLAN networks, thus providing satisfactory Quality of Service (QoS) to users and improving system resource utilization. [ABSTRACT FROM AUTHOR]

Telemedicine promises a great opportunity for health care service improvement. However, it has several issues for its implementation in certain area. They include communication service quality, infrastructure and operational cost. Since Wireless Mesh Network (WMN) is designed to reduce the infrastructure cost and operational cost, an investigation of network performance for implementation of telemedicine is required. In this paper, a simulation to investigate the wireless mesh network quality of service. Using network simulator 2, The QoS performance analysis was performed in different routing protocol scenarios of proposed system. It showed that OLSR protocol for Mesh Network maintained the time transfer of the EPT data. The field testing of the proposed system to measure the distance with various time has already been done. The infrastructure has been also implemented using low cost 5.8 GHz transceiver for backhauls and low cost 2.4 GHz transceiver for clients. Test result shows that the low cost telemedicine system is able to do real time communication between patient and medical staff with medical data rate up to 2 Mbps. It shows that telemonitoring system using wireless mesh network can give a low cost application in emergency time with acceptable medical data transfer quality. [ABSTRACT FROM AUTHOR]

Copyright of Telkomnika is the property of Department of Electrical Engineering, Ahmad Dahlan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Energy harvesting relay network is considered as the promising solution for a wireless communication network in our time. In this research, we present and demonstrate the system performance of the energy harvesting based two-way full-duplex relaying network over Nakagami-m fading environment. Firstly, we propose the analytical expressions of the achievable throughput and outage probability of the proposed system. In the second step, the effect of various system parameters on the system performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte-Carlo simulation. The numerical results demonstrated and convinced the analytical and the simulation results are agreed with each other. [ABSTRACT FROM AUTHOR]

Copyright of Telkomnika is the property of Department of Electrical Engineering, Ahmad Dahlan University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cellular CDMA systems are usually affected by interference experienced by users in adjacent cells that decrease the Quality of Services in wireless communication network. Hence, interference is the limiting factor of capacity in CDMA cellular and it is one of the problems fighting against the high efficiency of any mobile network. In this paper, a mathematical model to estimate the average number of users contributing in inter-cell interference at the busy hours of CDMA network is proposed. As the power exponent value has significant affect on interferer signal attenuation and hence other-cells interference, measurements were carried through a drive test to determine the received power level at various distance from CDMA base stations at Baghdad. The results obtained show that the power exponent was 2.71. This value was applied in dual-slop path loss model to determine the expected interference factor, and the number of users that can be hold at each cell. Simulations showed that users at a boundary cell generate more interference than those close to the base station. Furthermore, it was denoted that greater number of users caused to increase the interference factor, and greater power exponent value result in interference factor reduction. [ABSTRACT FROM AUTHOR]

In this paper a P-shaped microstrip antenna array is proposed for X-band applications in the frequency range (8.1567-9.3811) GHz .The gain obtained in this frequency range is about 8.305 dBi. The reflection coefficient is less than - 10 dB in the above frequency range. The simulation results were obtained for the optimum parameters using the CST software while the practical test was carried out using Vector Network Analyzer (VNA). The microstrip antenna was manufactured using FR-4 substrate with relative dielectric constant of 4.3 and loss tangentδ = 0.002.The simulation and practical results were compared. The size of the antenna array is (33 × 70 × 1.6)mm33. This array is suitable for satellite communication, radar application. [ABSTRACT FROM AUTHOR]

In this paper presents the design and manufacture of a new broadband elliptical patch antenna with a microstrip feed line and optimum antenna parameters. The antenna dimension of (30 × 21 × 1.6)mm3 and fabricated on an FR-4 epoxy substrate having relative dielectric constant 𝜀εr𝑟=4.3, loss tangent tan (δ)=0.002 and the feed line used has characteristic impedance of 50Ω.The designed antenna has the capability of operating in the bandwidth (6.95-30.94) GHz and the gain (6.8) dBi. The antenna performance was modified by inserting a slots in the ground plane to achieve impedance bandwidth (when S11≤-10dB) and slots to patch to improve the gain. The modified antenna was designed to be used for fifth generation (5G) mobile communication. The simulation results are obtained using CST software. [ABSTRACT FROM AUTHOR]