Wireless Mobile Applications Research Articles

Toward enhancing the distributed video coder under a multiview video codec framework

The advance of video coding technology enables multiview video (MVV) or three-dimensional television (3-D TV) display for users with or without glasses. For mobile devices or wireless applications, a distributed video coder (DVC) can be utilized to shift the encoder complexity to decoder under the MVV coding framework, denoted as multiview distributed video coding (MDVC). We proposed to exploit both inter- and intraview video correlations to enhance side information (SI) and improve the MDVC performance: (1) based on the multiview motion estimation (MVME) framework, a categorized block matching prediction with fidelity weights (COMPETE) was proposed to yield a high quality SI frame for better DVC reconstructed images. (2) The block transform coefficient properties, i.e., DCs and ACs, were exploited to design the priority rate control for the turbo code, such that the DVC decoding can be carried out with fewest parity bits. In comparison, the proposed COMPETE method demonstrated lower time complexity, while presenting better reconstructed video quality. Simulations show that the proposed COMPETE can reduce the time complexity of MVME to 1.29 to 2.56 times smaller, as compared to previous hybrid MVME methods, while the image peak signal to noise ratios (PSNRs) of a decoded video can be improved 0.2 to 3.5 dB, as compared to H.264/AVC intracoding.

Guest Editorial Special Section on the 2016 International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH)

As guest editors for the special section on the 2016 International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH), we are pleased to present the readership of IEEE Transactions on Semiconductor Manufacturing with a selection of papers developed from presentations made at this year’s conference. While semiconductor wafer volume is dominated by technologies based on silicon, compound semiconductor devices and integrated circuits are important for a range of applications and markets. Compound semiconductors have traditionally found use in technological areas demanding maximum performance, often for high speed or high frequency applications. Examples include high-speed wired, fiber, and point-to-point communications infrastructure, defense-related sensing and communications, and high-efficiency RF power amplifiers in consumer mobile wireless applications. However, recent trends have been eroding these traditional distinctions, with emerging applications such as power control and commercial wireless infrastructure being increasingly addressed using GaN and related materials, while ultra-low-power analog–and even future CMOS nodes for logic–embracing narrow-band gap III-V materials.

Dual-Band Patch Antenna Based on Resonant-Type Composite Right/Left-Handed Transmission Lines for IMT2000 and WLAN Applications

This paper proposed a dual-band resonant-type composite right/left-handed transmission lines which consisting of complementary single multi-split-ring resonators and a series capacitive gaps. For characteristics, the equivalent circuit mode for the design of antenna is discussed. And the effect of different combining complementary split-ring resonators to zeroth-order frequency is also analyzed. Then, a dual-band patch antenna for International Mobile Telecommunication (IMT2000) and wireless area networks applications is proposed. The result of simulated and measured for antenna are used to verify the theoretical prediction. Simulation and measure results shown that the proposed antenna operates at 1.97 and 2.45 GHz for voltage standing wave ratio <2. Also these results shown the antenna has a stable radiation patterns and good gain. All the results for antenna obtained in this work have been simulated with CST Microwave Studio.

Realization of 4G Downlink Channel

Today’s era people have grown in every field, such that their needs are also growing linearly with their advancement. This rapid development of broadband wireless access technologies in recent years was the result of growing demand for mobile Internet and wireless multimedia applications. Now it is becoming difficult to meet the demands of these data hungry people. So, the wireless network is advancing after 3G and providing better coverage, higher data rate and by reducing Latency. It uses the frame structure as Time Division Duplexing (TDD) and Frequency Division Duplexing (FDD).LTE technology uses different channels in both uplink and downlink. This paper mainly focuses on the Downlink channels named as PDCCH, PBCH, PCFICH, PHICH and downlink Signals i.e., PSS and S-SS. The individual Downlink Channels are analyzed using Agilent SystemVue platform further it is synchronized with the Agilent Vector Signal Analyzer (VSA) to the check the Output Response of the individual downlink channels.

IMPACT OF MULTIPLAY TRANSMISSION IN MOBILE WIMAX USING OVERLAY SCANNING

The growing demand for mobile internet and wireless multimedia applications has motivated the development of broadband wireless-access technologies in recent years. There are several issues that could impact the base station handover as a serious problem in the mobile communication system. In hard handover, a short time break known as handover interruption decreases the quality-of-services (QoS) due to connection between mobile subscriber station (MS) and serving base station (BS) is closed and ranging hand initiation to establish new connection. Prolonged time of request and response due to number of neighbours to scan will cause delay in handover process. This research proposed performance analysis of WiMAX/IEEE 802.16 with mobility supported to scan the channels provided by the mobile station. The proposed strategy required the mobile station for operation with a scan that can be used to reduce the time when trying to establish a network connection or do between neighboring base station handover. A second type is the fast handover that is proposed to reduce the unnecessary surrender to six different access modes. The mobile WiMAX air interface utilizes orthogonal frequency division multiple access (OFDMA) as the preferred multiple-access method in the downlink (DL) and uplink (UL) for improved multipath performance and bandwidth scalability. All simulations are run using MATLAB software to develop a new Overlay Scanning Mechanism (OSMA) algorithm. OSMA mainly focus on when to perform a scan to estimate future needs. Simulation results are expected to show WiMAX coverage by using real world data to detect movement and show that there are strategies that reduce the time required for scanning operations significantly.

Connecting Food Courts in Mall using Mobile App

This paper represents a system to improve the performance of restaurants at the food courts in mall. The idea represented in the paper focuses on efficient design of system to save customer‟s time and avoid the situation of long queues and billing hassle. The system explained in this paper uses wireless communication and mobile application technology to enable communication between restaurants and their target customers for order management and billing that will ensure good customer relation management and improve overall performance of restaurants.

Performance analysis of hybrid WiMAX/DSRC scenarios for vehicular communication environment

Internet becomes a vital and important service being integrated in the current scenarios of competing technologies, therefore there is a need for higher speed broadband access. Emergence and evolutions of technologies from the first generation to 4G LTE then to the promising 5G and WiMAX. For achieving high data rates and services to multiple users, WiMAX is one of the competing technology, which was introduced by the Institute of Electrical and Electronic Engineers (IEEE) designated for fixed wireless and mobile wireless applications and Dedicated Short Range Communication (DSRC) is another technology which is a trend in the vehicular network in the current situations employed in the Intelligent Transportation System in the United States which supports high speed data rates. In this paper, the authors considered a hybrid scenario and compared the communication link taken place in the DSRC-to-DSRC traditional system with the hybrid DSRC-WiMAX system communication link namely DSRC-to-Fixed WiMAX and Mobile WiMAX-to-Fixed WiMAX, with evaluation of performance by considering certain parameters simulated in MATLAB.

Specific absorption rate analysis of broadband mobile antenna with negative index metamaterial

This paper presents a negative index metamaterial-inspired printed mobile wireless antenna that can support most mobile applications such as GSM, UMTS, Bluetooth and WLAN frequency bands. The antenna consists of a semi-circular patch, a 50Ω microstrip feed line and metamaterial ground plane. The antenna occupies a very small space of 37 × 47 × 0.508 mm3, making it suitable for mobile wireless application. The perceptible novelty shown in this proposed antenna is that reduction of specific absorption rate using the negative index metamaterial ground plane. The proposed antenna reduced 72.11 and 75.53 % of specific absorption rate at 1.8 and 2.4 GHz, respectively.

A metamaterial unit cell inspired antenna for mobile wireless applications

ABSTRACTThe article reveals the design of a metamaterial cell inspired triple band antenna for DCS 1800, PCS 1900, WCDMA, Bluetooth, WLAN 2400, WiMAX 2.5, and WLAN 5 GHz frequency band applications. The overall antenna size is 48 × 48 × 1.575 mm3 where the electrical dimension is 0.26 λ × 0.26 λ × 0.0084 λ at 1.6 GHz lower frequency band. The proposed antenna consists of a microstrip feed line and metamaterial unit cell providing a negative index of refraction, which indicates both negative magnetic value of permeability and negative electrical value of permittivity. The proposed antenna achieves triple −10 dB measured impedance bandwidth of 370 MHz (1.6–1.97), 380 MHz (2.34–2.72), and 1.48 GHz (3.89–5.37). The measured gain of the proposed antenna at 1.9 GHz is 1.64 dB, 2.45 GHz is 2.07 dB, and 5 GHz is 4.06 dB with radiation efficiency of 66.2%, 77.15%, and 87.6%, respectively. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:263–267, 2016

Delay-Sensitive Communication Over Fading Channels: Queueing Behavior and Code Parameter Selection

This paper examines the queueing performance of communication systems that transmit encoded data over unreliable channels. A fading formulation suitable for wireless mobile applications is considered, where errors are caused by a discrete channel with correlated behavior over time. For carefully selected channel models and arrival processes, a tractable Markov structure composed of queue length and channel state is identified. This facilitates the analysis of the stationary behavior of the system, leading to evaluation criteria such as bounds on the probability of the queue exceeding a threshold. Specifically, this paper focuses on system models with scalable arrival profiles, which are based on Poisson processes, and finite-state channels with memory. These assumptions permit the rigorous comparison of system performance for codes with arbitrary block lengths and code rates. Based on the resulting characterizations, it is possible to select the best code parameters for delay-sensitive applications over various channels. Random codes and BCH codes are then employed as a means to study the relationship between code parameter selection and the queueing performance of point-to-point data links. The methodology introduced herein offers a new perspective on the joint queueing–coding analysis of finite-state channels with memory, and it is supported by numerical simulations.

A Double-Negative Metamaterial-Inspired Mobile Wireless Antenna for Electromagnetic Absorption Reduction.

A double-negative metamaterial-inspired antenna is presented for mobile wireless applications. The antenna consists of a semi-circular radiating patch and a 3 × 4 hexagonal shaped metamaterial unit cell array in the ground plane. The antenna is fed with a 50 Ω microstrip feed line. The electric dimensions of the proposed antenna are 0.20λ × 0.26λ × 0.004λ, at the low-end frequency. The proposed antenna achieves a −10 dB impedance with a bandwidth of 2.29 GHz at the lower band and 1.28 GHz at the upper band and can operate for most of the mobile applications such as upper GSM bands, WiMAX, Bluetooth, and wireless local area network (WLAN) frequency bands. The focused novelties of the proposed antenna are its small size, multi-standard operating bands, and electromagnetic absorption reduction at all the operating frequencies using the double-negative metamaterial ground plane.

Specific absorption rate reduction of multi‐standard mobile antenna with double‐negative metamaterial

A printed multi-standard mobile wireless antenna loaded with double-negative metamaterial that achieves an impedance bandwidth of 2.29 GHz (1.66 to 3.95 GHz) and 1.28 GHz (4.45 to 5.73 GHz) is presented. The proposed antenna can operate in the frequency bands of GSM (1800, 1900, 2100), WiMAX (3.2–3.6 GHZ), WLAN, Bluetooth (2.4 GHz) and WLAN (5.47–5.9 GHz). The antenna is assimilated with a semi-circular shape radiating patch, a metamaterial loaded ground plane and a 50 Ω microstrip feed line. The antenna exhibits a planar structure and occupies a very small space of 37 × 47 × 0.8 mm3, making it suitable for mobile wireless applications. The perceptible novelties exhibited in this proposed antenna is reduction of electromagnetic absorption with the metamaterial loaded ground plane. The proposed metamaterial antenna achieved 66.47 and 66.52% of 10 g specific absorption reduction at 1.8 and 2.4 GHz, respectively.

A Compact Multiband Hybrid Fractal Antenna for Multistandard Mobile Wireless Applications

This paper presents a compact Multiband hybrid fractal antenna designed for mobile wireless applications it has planar structure and suitable for mobile applications at low cost. The proposed antenna structure is obtained by integrating a Koch curve and Minkowski curve. It exhibits multiband behavior, acceptable values of return loss, VSWR and gain in-spite of its compact size and less complexity. The proposed antenna design has been examined up to 2nd iteration of the new fractal geometry. The simulated results exhibited seven bands of operation covering some important frequency bands like GPS (L1 = 1227.60 MHz), bluetooth (2.41---2.49 GHz) of ISM band, WLAN 802.11 a/b (5.15---5.35 GHz) and other bands covers applications like mobile/fixed satellite and aeronautical navigation (3.876---4.375, 6.6188---7.0045, 7.9698---8.3373 and 9.1648---9.6214 GHz). Proposed antenna is designed by using scripting method of HFSS using MATLAB.

Triple band circularly polarized compact microstrip antenna with defected ground structure for wireless applications

Asymmetric slits loaded irregular shaped microstrip patch antenna with three different ground structures is proposed. All three antennas show triple band characteristics. First antenna with regular ground plane resonates at 1.95, 2.4, and 4.90 GHz with good radiation characteristics and shows right-hand circular polarization at 1.95 GHz. 18.75% of compactness is achieved with triple band characteristics. Further, same patch is used with different defected ground structures. Second antenna resonates at 1.85, 2.4, and 4.85 GHz with suppressed cross-polarization level and antenna shows right-hand circular polarization at 1.85 and 4.85 GHz. Compactness is further improved to the value of 22.91%. The third antenna resonates at 1.95, 2.4, and 4.85 GHz with better gain and radiation characteristics and antenna shows right-hand circular polarization at 1.95 and 2.4 GHz. The small frequency ratio f2/f1 is achieved and the value of f2/f1 is 1.29 and 1.23 for second and third configuration, respectively. Proposed structures show right-hand circularly polarized with suppressed left-hand circularly polarized radiations and suitable for fixed mobile wireless communication applications. All structures are analyzed using Ansoft HFSS v.14 based on finite element method and measured results satisfy the simulated results.

Combined Effect of Block interleaving and FEC on BER Performance of OFDM based WiMAX (IEEE 802.16d) System

In this World of Digital era the demand of mobile Internet and wireless multimedia applications are growing faster than ever. To satisfy the user requirements and to overcome the limitations of existing wireless technologies, have led the researchers to come up with more advanced and efficient technology. Orthogonal Frequency Division Multiplexing (OFDM) based WiMAX (Worldwide Interoperability for Microwave Access ) is the outcome in this direction which promises to solve the last mile access technology to provide high speed internet access in the residential as well as small and medium sized enterprise sectors. In this paper we have analyzed the effect of Block Interleaving on the Bit Error Rate (BER) performance of the WiMAX Physical layer baseband system conforming to the parameters established by IEEE 802.16 standards for different digital modulation schemes. From the analysis it was observed that addition of interleaving with forward error correction (FEC) improves the system performance by reducing the burst errors during transmission.

Survey of Digital Forensics Technologies and Tools for Android based Intelligent Devices

During the rapid development of mobile wireless technologies and applications, the Android operating system, due to its open-source characteristics, has become the most popular development platform in the smartphone market. Meanwhile, as Android-based intelligent mobiles devices experience a rapid increase in numbers, high-tech crimes involving such devices have become more versatile, affecting an ever increasing amount of data, thus making digital evidence an indispensable part of the evidence that needs to be seriously dealt with during crime investigations. Consequently, understanding the internal structure of Android and the various data operations in the file systems becomes necessary in Android-based digital forensics. In this paper, we survey the state-of-the-art of technologies in Android-based digital forensics and some popular tools in the aspects of data recovery and acquisition, file system analysis and data analysis. We also discuss some technical challenges and point out future research directions in Android-based digital forensics.

Wideband, Multiband, Tunable, and Smart Antenna Systems for Mobile and UWB Wireless Applications 2014

Wideband, Multiband, Tunable, and Smart Antenna Systems for Mobile and UWB Wireless Applications 2014

Adaptive Scheduling in MIMO-Based Heterogeneous Ad Hoc Networks

The demands for data rate and transmission reliability constantly increase with the explosive use of wireless devices and the advancement of mobile computing techniques. Multiple-input and multiple-output (MIMO) technique is considered as one of the most promising wireless technologies that can significantly improve transmission capacity and reliability. Many emerging mobile wireless applications require peer-to-peer transmissions over an ad hoc network, where the nodes often have a different number of antennas, and the channel condition and network topology vary over time. It is important and challenging to develop efficient schemes to coordinate transmission resource sharing among a heterogeneous group of nodes over an infrastructure-free mobile ad hoc network. In this work, we propose a holistic scheduling algorithm that can adaptively select different transmission strategies based on the node types and channel conditions to effectively relieve the bottleneck effect caused by nodes with smaller antenna arrays, and avoid the transmission failure due to the violation of lower degree of freedom constraint resulted from the channel dependency. The algorithm also takes advantage of channel information to opportunistically schedule cooperative spatial multiplexed transmissions between nodes and provide special transmission support for higher priority nodes with weak channels, so that the data rate of the network can be maximized while user transmission quality requirement is supported. The performance of our algorithm is studied through extensive simulations and the results demonstrate that our algorithm is very effective in handling node heterogeneity and channel constraint, and can significantly increase the throughput while reducing the transmission delay.

Design and analysis of non-uniform shaped RF MEMS switch

In this paper, we present a novel non-uniform shaped cantilever based DC contact radio frequency microelectromechanical systems (RF MEMS) switch. This switch can be employed for various wireless mobile applications in frequency range of DC-10 GHz as it shows excellent RF characteristics with low actuation voltage. The design is optimized in the terms of electrostatic actuation mechanism, which included switch beam thickness, beam gap, spring shape and materials. Also, it's optimized shape and size of contact geometry and material ensures the high reliability, high isolation and very low insertion loss. The main features of this switch are simplicity of structure, reliability of contact, excellent RF characteristics, low actuation voltage and excellent figure of merit. We investigate the proposed design with Coventorware software for electromechanical and electromagnetic analysis and, get very promising results. The paper briefly outlines the design of RF MEMS switch and also focuses on the analysis of various switching parameters.

Dual Polarized Aperture Coupled Stacked Element for Base Station Antenna

The demand towards broad band efficient antennas for base station and mobile wireless applications have increased dramatically over the last few years. Today there is a huge increase in the number of subscribers and demand for equipments that is capable of handling cost-effective network capacity solutions in Spectrum limited markets. Our Paper describes the design of dual polarized antenna element which can be implemented in a base station antenna array using IE3D Zeland Software. The Element is based on aperture coupled architecture with stacked patch, maintaining the symmetry needed for dual polarization operation. Most of common antenna elements are linearly polarized with narrow band resonators. Our design has Broad-band and dual-polarized characteristics of traditional aperture coupled architecture. The Bandwidth for Return Loss &gt; 10 dB of the element covers 1710-2170 MHz frequency spectrum. The Isolation between the ports corresponding to the two different polarizations is greater than 32 dB over the bandwidth.