UWB communication Research Papers - Academia.edu (original) (raw)

Keywords: MIMO antenna UWB antenna Model predictive Control Non-uniform microstrip line Printed monopole antenna a b s t r a c t A novel ultra wideband (UWB) printed monopole multiple-input multiple-output (MIMO) antenna with non-uniform transmission line using nonlinear model predictive control (NMPC) is presented. The proposed antenna is superior to conventional antennas in terms of dimensions, gain, and efficiency while maintaining the impedance bandwidth. In order to improve the results, a non-uniform transmission line has been used for impedance matching between the radiated patch element and the coaxial cable. For designing the non-uniform transmission line, it has been expanded using cosine terms. Regarding the presence of differential equation for the variation in the impedance of the transmission line and its transformation to the state-space equation, NMPC has been employed to design the transmission line and determine the cosine expansion coefficients. Two base antennas, as MIMO, were simulated configuration and fabricated. The surface area of the proposed MIMO antenna is 0.99 k 2 g , the wavelength has been obtained for the center frequency of the 3.16 GHz to 10.6 GHz range, and its mutual coupling, peak gain, channel capacity loss (CCL), total active reflection coefficient (TARC), mean effective gain (MEG) and diversity gain (DG), envelope correlation (ECC) are acceptable. The simulation and measurement results are in good agreement, and the proposed antenna is suitable for MIMO applications. Ó 2020 The ''Authors". Karabuk University. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

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- Antennas, Wireless Communications, Model Predictive Control, Model Predictive Control (MPC)

В данной работе предлагаются три различные модели для описания диаграмм направленности TEM рупора в E-плоскости в сверхширокой полосе частот. Каждая из предлагаемых моделей различаются по точности, частотной полосе и по времени вычисления. Модели сравниваются между собой и с методом конечных элементов. Приведенные данные о полосе согласования по коэффициенту отражения позволяют сделать вывод, что наибольший интерес представляют исследования диаграммы направленности в границах этой полосы, от 1 до 15 ka. Предлагаемые модели вполне описывают изменение диаграммы направленности в E-плоскости во всей полосе согласования антенны и открывают новые возможности для оптимизации нерегулярного СШП TEM рупора по характеристикам диаграммы направленности.

A compact, circular UWB fractal antenna with triple reconfigurable notch rejection bands is proposed. It rejects the crowded frequency bands WiMAX, WLAN and X band interferences produced in UWB communication systems. The proposed fractal structure consists of a basic circular patch with circular fractal iterations. By employing this new structure of fractals, the overall size of antenna is reduced 53% to 21x25 mm, in comparison with traditional circular monopole antenna. The implemented antenna operates at 3.1-10 GHz. Re-configurability is realized by designing slots and split ring resonators in desired frequencies with the attached PIN diodes. WLAN band rejection was realized by creating a pair of optimized L-shaped slots in the ground plane. By etching a split ring resonator and a U-shaped slot, X and WiMAX bands were also rejected. Furthermore, by attaching diodes to aforementioned slots and designating the diodes on/off, different bands can be included or rejected. In time domain, the antenna properties are evaluated by a figure of merit called fidelity factor. Finally, the antenna properties are measured in anechoic chamber and the results agrees with simulation findings.

A printed monopole in its planar and vertical configuration has been designed, fabricated and analyzed for microwave applications on low cost FR4 substrate material of thickness, h = 1.56 mm and relative permittivity, εr = 4.3. The designed planar monopole has been simulated and experimented to find its frequency response with coplanar waveguide feed to exhibit dual band characteristics with-10 dB reflection loss bandwidth of 45.078 % (i.e. 1.5:1 between 1.334 and 2.109 GHz) and 114.92 % (i.e. 3.7: 1 between 3.99 and 14.77 GHz). The vertical monopole using the same patch has also been simulated and experimented and-10 dB reflection loss bandwidth of 173.67% (14.2:1 between 0.925 and 13.125 GHz) has been obtained. The antenna finds many applications in microwave bands.

Several microstrip log-periodic antennas are introduced having square Koch, triangular Koch, tree and Giuseppe Peano fractals applied to the edges of their branches with substrate integrated waveguide feed system. The proposed antennas are designed for end-fire radiation and ultra-wideband (UWB) operation (3.1–10.6 GHz), which achieve a fidelity factor of better than 0.9 due to the low variation of their phase centres. These antennas are effectively miniaturised and are suitable for impulse radio-UWB and medical imaging. To prevent interference with commercial bands of 5.8 and 8.3 GHz, two spiral slots are cut on the patch. Their frequency and time-domain operations and also miniaturisation are compared with those in the available literature. A prototype model of an end-fire log-periodic microstrip antenna with the Giuseppe Peano fractal applied to the edges of truncated rhombic branches is fabricated and measured to evaluate and demonstrate its stated properties and specifications.

- by Mehdi Karimi Mehr and +1
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- Antennas, Microstrip Antennas, Antennas & Radio Wave Propagation, Microstrip Antennas and Arrays
- by Yasser Fadhel and +1
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- Electronic Engineering, Telecommunications Engineering, Antennas & Radio Wave Propagation, Wireless Communications

A compact printed antenna is described that exhibits adequate transient performance for ultrawideband (UWB) applications and it is further adequate for polarization diversity schemes. The antenna is based on an original combination of two crossed exponentially tapered slots plus a star-shaped slot to produce a stable radiation pattern with very stable polarization over the 3.1–10.6 GHz FCC assigned band. Results are confirmed with measurements. Figures of merit like output pulse fidelity and time window containing 90% of the transmitted energy are analyzed over the entire solid angle and showed to remain quite stable, in line with envisaged UWB system requirements. Compact dual-antenna arrangements are also analyzed in view of potential use for UWB multiple-input–multiple-output implementations.

A small-size CPW-feed multi-band planar monopole antenna is presented. A Swallow-Shaped-Patch (SSP) that covers the Ultra-Wideband (UWB) frequency range is used in the proposed design. To create a multi-band antenna, several narrow pentagon slots, acting as resonance paths, can be integrated with the SSP antenna. Triple-band antennas are simulated and good results are obtained, while showing a very sharp band-rejection performance at 3.92 GHz, 5.34 GHz and 5.88 GHz, respectively. The antennas have omnidirectional and stable radiation patterns across all the relevant bands. Moreover, a prototype of the triple-band antenna is fabricated and measurement results are compared with simulation results.

In this article, a dual-band WLAN/ultrawideband (UWB) printed wide slot microstrip-fed antenna is presented for multi-input multi-output (MIMO)/diversity applications. The proposed antenna consists of a U-shaped patch, a T-shaped monopole path, and a pentagonal wide slot in the ground plane. The antenna is designed to cover both the WLAN (2.4-2.485 GHz) and UWB (3.1-10.6 GHz) ranges, with value of S 11 below À10 dB. The antenna is constructed on a FR4 substrate with overall dimensions of 28 Â 28 Â 1 mm 3. It is shown that the proposed dual-band antenna is suitable for diversity polarization applications. The simulation results show that the different configurations of the antenna in the MIMO/diversity have good S-parameters over the operating frequency bands. The simulation and measured results of the proposed dual-band antenna as well as that of the MIMO/diversity antenna configuration agree well. V C 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:461-465, 2013; View this article online at wileyonlinelibrary.com.

This paper investigates the performance of high rate IEEE 802.15.4 UWB PHY schemes. Evaluation takes place over office, residential and outdoor IEEE channel models via Monte-Carlo simulation. Special attention is given to the highest rate (27.24 Mbps) scheme that suffers from intersymbol interference (ISI) over NLOS outdoor and residential channels. Optimum bit-to-symbol mapping (OBM), ISI cancellation and MLSE techniques are proposed and evaluated in conjunction with RAKE reception. Significant gains are attained with the proposed enhancements while keeping complexity low. On the other hand, the coverage range of high rate schemes is estimated for a given BEP. It is deduced that 27.24 Mbps and 6.81 Mbps schemes are well applicable to all LOS channels. However, the maximum allowable transmission power deteriorates range in NLOS cases. Overall, high rate schemes are shown to deserve more attention in the context of high rate sensor applications.

- by Athanasios Vasileiadis and +1
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- UWB communication, Bit error probability, IEEE 802.15.4, MRC
- by Borhanuddin Mohd Ali
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- Wireless networks, UWB communication

In Cognitive radio (CR) applications Ultra-wideband (UWB) impulse radio (IR) signals can be designed such as they can co-exist with licensed primary users. The pulse shape should be adjusted such that the power spectral characteristics not only meet the Federal Communications Commission (FCC) constrains, but also mitigate multiple narrow-band interference at the locations of existing primary users. In this paper, the Parks-McClellan (PM) Algorithm and the Eigen Value Decomposition (EVD) approach for UWB impulse radio waveform shaping are considered. The power spectral density (PSD) and the bit-error-rate (BER) performance of the two methods are compared in the presence of single and double narrow-band interference (NBI). The interference rejection capabilities of the two methods are evaluated and compared for different interference and additive noise levels. In particular, the simulations consider the coexistence of practical IEEE 802.15.4a UWB systems with both IEEE 802.11 wireless LAN systems operating at 5.2 GHz and radio location services operating at 8.5 GHz.

Current image coding systems use wavelet transform, which decompose the image into different levels, where the coefficients in each sub band are uncorrelated from coefficients of other sub bands. As a result the coefficients in each sub band can be quantized independently of coefficients in other sub bands with no significant loss in performance. But the coefficient in each sub band requires different amount of bit resources to obtain best coding performance. This results in different quantizer with each sub band having its own bit rate. This gives an issue to bit allocation under image processing. Hence sub band coding can be used for achieving high bit rate. Embedded zerotree wavelet (EZW) encoder is designed to use wavelet transform. EZW coding exploits the multi-resolution properties of the wavelet transform to give a computationally simple algorithm with better performance. A performance analysis of image compression system for various formats of image is considered with EZW based on different wavelets.
The main purpose of this paper is to investigate the impact of different wavelets on image compression using EZW. The effect of the level of wavelet decomposition on compression efficiency is analyzed. The Haar, Dauhechies 4 and bio-orthogonal wavelets are used. The compression simulations are done on few modalities of images. The qualitative and quantitative results of these simulations are presented.

- by Vikas Goyal
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- UWB communication

─ In this paper, a new compact planar antenna is proposed for UWB (Ultra-wideband) operations. The proposed antenna has a low profile structure, consisting of a radiating patch, notched ground plane, and a novel arc-shaped strip connected between the microstrip feed line and the radiating patch. By using the proposed structure, broadband antenna with good impedance matching is obtained. Measured results show that the antenna can achieve a bandwidth of 96.22%. The proposed antenna is optimized in order to satisfy the required band with a good radiation pattern. The fabricated antenna has a compact size of 16 u 20 u 1.6 mm 3. These features demonstrate that the proposed antenna is a suitable candidate for UWB applications, due to its simple configuration, compactness, and low fabrication costs. Index Terms ─ Broadband antenna, planar antenna, ultra-wideband antenna.

For location-based applications, wireless systems in an indoor environment often operate under non-line-of-sight (NLOS)conditions that may cause ranging errors. A promising technology for location-aware sensor networks is an Ultra-wide bandwidth (UWB) transmission due to its robust operation in harsh environments, fine delay resolution, and power efficiency. However, the existence of walls and other obstacles causes a notable challenge in terms of localization, as they can result in positively biased distance estimates. A non-line-of-sight (NLOS) identification and mitigation technique created for UWB technology. A distance mitigation method is proposed using online line-of-sight (LOS) and NLOS identification by Fuzzy logic control decision. The result of the proposed method shows 99 % of the accuracy of the proposed NLOS identification method and less than 20 cm of the measured distance error.

- by Abbas Sabbar Ghali Al Baidhani
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- Indoor Positioning, UWB communication

Ultra wide band (UWB) wireless transmission has received notable and considerable attention in the field of next generation location-aware wireless sensor networks (WSNs). This trend is due to the large bandwidth of UWB signals contributing many advantages for positioning, communication, and radar applications: penetration through obstacles, accurate position estimation, high-speed data transmission, and a low-cost, low power transceiver. Commercially available UWB radio modules were evaluated. Such modules have the ability to very precisely measure time of arrival of RF signals, range, or localization. The physical layers specify the received signal strength indicator utilized in the localization technique. We estimated and compared the distance of a walking human with the reference distance in different environments, indoor LOS and hard-NLOS utilizing one of these commercial modules. This report also introduces the identification and mitigation of NLOS channels. The results were highly acceptable for indoor localization because the module attained ranging accuracy in a hard-NLOS environment below one meter.

- by Abbas Sabbar Ghali Al Baidhani
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- Indoor Positioning, UWB communication

During the health crisis, construction companies are under tremendous pressure to adopt innovative techniques for employee management to meet the health and safety demands and reinstate productivity, starting from managing attendance and monitoring performance. The construction industry can implement more equipment's and robots to address worker safety while maintaining a safe distance, thus reducing the labor force. This intern results in man-machine interaction conflicts and accidents due to the failure of machines or components that needs addressing. Most workplace accidents in South Korea occur in the construction industry, and 60% of them are due to falls from heights. The aging population in South Korea makes the construction industry more prone to mental fatigue, resulting in such accidents. Thus, this study aims to integrate systems of Health and Safety with Performance using pose estimation techniques. Using deep learning techniques, IIOT (Industrial Internet of Things), ICT with wireless access points, and wearable devices such as smart bands, shoes, and helmets aids to monitor workers' Performance, Health, and safety in indoor conditions or after structural frame completion. Combining previous warning alert systems with pose estimation and monitoring will alert workers on unsafe and uncomfortable poses and improve productivity significantly. A future version of this system could use LoRa to extend to outdoor environments.

As a radically distinct wireless communication approach compared to traditional narrow band systems, ULTRA-WIDE BAND (UWB) technology has been applied in various sectors and is gaining in popularity, but there appears to be a lack of systematic summary of the potential of this technology. To provide insights into UWB technology for the uninitiated reader, this paper explores the state-of-the-art research and development of UWB applications in many sectors including the construction industry without concerning the technological details. First this paper presents the key concepts related to UWB technology and a brief history of UWB. Then it summarizes the UWB's technical features which enable its popularity in industry. Finally, application examples of UWB technology in many sectors, including construction, are presented to analyze and highlight the impact on the industry performance. In the near future UWB technology is expected to become a very important component and have far-...

This paper describes a novel wideband CMOS differential four-quadrant analog multiplier which is part of a integrated correlator aiming for application in Ultra-Wideband II. MULTIPLIER DESIGN

- by Ivan Cai
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- UWB communication

Este artigo apresenta o estudo de alguns pulsos Ultra-wideband (UWB) para aplicação em transmissões eletromagnéticas aplicadas a radar de impulso, discutindo os benefícios na utilização do pulso Gaussiano de quinta ordem de derivação em contraste ao uso de outros pulsos eletromagnéticos, sendo eles: Sinc, Quadrado, Gaussiano e as suas sete primeiras ordens de derivação. Este estudo levou em consideração o formato do pulso no domínio do tempo, a assinatura espectral do pulso e o grau de complexidade do circuito necessário para sintetizar o pulso. O pulso Gaussiano de quinta ordem de derivação foi escolhido pois apresenta uma ótima relação de eficiência espectral versus a complexidade moderada do circuito necessário para sua sintetização, além de não possuir a componente DC (corrente contínua ou frequência zero), que em termos de radiação, é menos eficiente que a componente AC (corrente alternada).

- by Alexandre M De Oliveira
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- Radar, UWB communication, Gaussian Pulse

SAR calculation for UWB textile antenna is reported in this paper. This paper presents simulation results of the antenna performance at the conditions of free space and placement at a distance from a portion of a human body. A summary of measurement results of the return loss of the antenna is also included. The simulated S11 parameter shows that the antenna operates within the range 2.25 GHz and 12.19. The measured return loss has shown that the antenna can operate 3.04 GHz-10.3 GHz giving a bandwidth of 108%. The performance antenna near to a human body has been simulated and examined. The SAR 10 g has been evaluated using a four-layer body model.

Este trabalho apresenta a parametrização da estrutura de uma antena UWB TEM Horn Exponencial miniaturizada e seu efeito no casamento de impedância e diretividade. Também propõe-se um microstrip balun que alimenta a antena com o objetivo de melhorar o balanceamento e perda de retorno para baixas frequências; a antena e o microstrip balun foram simulados até obter um modelo final de alto desempenho que posteriormente foi fabricado. A antena cumpre as normas estabelecidos pela FCC e ETSI para a tecnologia de banda ultra larga. Baseando-se nestas características a antena proposta pode ser utilizada em aplicações de radar UWB e comunicação para longas distancias devido ao alto ganho obtido.

- by Bernard Uguen
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- Radio Channel Modelling, UWB communication

In this paper, a novel approach of miniature tri-band microstrip bandpass filter is design for the application of GSM(1.8GHz),WiMAX(3.4GHz) and UWB(6.5-8.1GHz) using Asymmetric SIRs and DGS to achieved the basic characteristic of microstrip filter such as low insertion loss, high selectivity, wider range of bandwidth, low group delay. The novel filter is design intentionally selecting the impedance ration(R) and length of the microstrip of the asymmetric SIRs and DGS is used to improve the coupling strength of the desired band. The measurement entities of the novel filter for GSM (1.8GHz), WiMAX (3.4GHz), and UWB (6.5-8.1GHz) are insertion losses (S 21) are-0.07dB/-0.21dB/-0.12dB,and return losses (S 11) are-31dB/15dB/30dB respectively. The response of the filter was simulated using An soft HFSS Simulator.

- by International Journal of Microwave Engineering (JMICRO) journal and +1
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- German Sign Language (DGS), IEEE 802.16 (WiMAX), UWB communication, Wimax

this paper examines the performance of Minimum-Mean-Square-Error (MMSE) adaptive algorithm as a reception algorithm for the 6th derivative Ultra-wideband (UWB) Gaussian pulse shape signals compared to the performance of conventional Ultra-Wideband (UWB) Rake receiver with different number of Rake fingers. MMSE adaptive algorithm is more efficient and powerful because of its ability and features of adaptation to the substantial changes in the UWB multipath wireless communication channel model proposed by the IEEE 802.15.3a working group based on modified (S-V) channel model because it is the most realistic and practical channel model due to the nature of multipath wireless environment. The paper demonstrates the performance of two commonly used transmission schemes in UWB communications which are Direct-Sequence (DS-UWB) and Time-Hopping (TH-UWB) to compare between their performances over the previously mentioned UWB multipath channel model using also two reception techniques which are the UWB Rake receiver (with different number of Rake fingers) and the MMSE adaptive algorithm receiver to show the latter efficiency due to its distinctive adaptability. Moreover, the performance comparison between the two reception techniques presented in this paper is assumed to be performed in the presence of both; narrowband interference coming from other networks (e.g. IEEE 802.11a WLAN), and also the presence of Multiple-Access-Interference (MAI) coming from other UWB users in the proximity of the desired UWB user.

A novel technique to add an extra Bluetooth band and dual notch bands simultaneously to a compact ultrawideband (UWB) printed slot antenna is proposed. The UWB slot antenna, covering 3.1-11 GHz, is in the shape of an octagon and is fed by a rectangular patch with a beveled bottom edge. To create an extra band outside the UWB frequency range, centered at the 2.4-GHz Bluetooth band, a quarter-wavelength stub is attached to the high concentrated current area in the ground plane. Two notch bands, centered at 3.5-GHz WiMAX and 5.8-GHz WLAN, are also created by placing two stubs similar to that of the extra band. The proposed antenna has a compact size (23 28 mm 2), almost stable radiation pattern, and reflection coefficient of lower than 10 dB across the entire passband. A prototype of the proposed antenna is fabricated, and the measured results are shown to be in good agreement with the simulated results. Index Terms-Multiband, notch bands, printed slot antenna, ultrawideband (UWB).

- by Sajad Mohammad-Ali-Nezhad
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- Antennas, Bluetooth, UWB communication, Uwb

For high data rate ultra wideband communication system, performance comparison of Rake, MMSE and Rake-MMSE receivers is attempted in this paper. Further a detail study on Rake-MMSE time domain equalizers is carried out taking into account all the important parameters such as the effect of the number of Rake fingers and equalizer taps on the error rate performance. This receiver combats inter-symbol interference by taking advantages of both the Rake and equalizer structure. The bit error rate performances are investigated using MATLAB simulation on IEEE 802.15.3a defined UWB channel models. Simulation results show that the bit error rate probability of Rake-MMSE receiver is much better than Rake receiver and MMSE equalizer. Study on non-line of sight indoor channel models illustrates that bit error rate performance of Rake-MMSE (both LE and DFE) improves for CM3 model with smaller spread compared to CM4 channel model. It is indicated that for a MMSE equalizer operating at low to medium SNR values, the number of Rake fingers is the dominant factor to improve system performance, while at high SNR values the number of equalizer taps plays a more significant role in reducing the error rate.

Ultra wideband (UWB) radio for communication has several challenges. From the physical layer perspective, a
signaling technique should be optimally designed to work in synergy with the underneath hardware to achieve
maximum performance. In this paper, we propose a variant of pulse position modulation (PPM) for physical layer
signaling, which can achieve raw bitrate in excess of 150 Mbps on a low complexity in-house developed impulse
radio UWB platform. The signaling system is optimized to maximize bitrate under practical constraints of low
complexity hardware and regulatory bodies. We propose a detector and derive its theoretical performance bounds
and compare the performance in simulation in terms of symbol error rates (SER). Modifications to the signaling, which
can increase the range by 4 times with a slight increase in hardware complexity, is proposed. Detectors for this
modification and a comparative study of the performance of the proposed UWB physical layer signaling schemes in
terms of symbol error rates are discussed.

- by Vijaya Yajnanarayana
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- UWB communication

This paper presents the implementation ofan Impulse Radio Ultra Wide Band (IR-UWB) communication system based on Orthogonal Amplitude Modulation (OAM) on the FPGA board (Field ProgrammableGate Array). The Orthogonal Amplitude Modulationis a new modulation technique that provides a highdata rate transmission, using the orthogonal waveforms named MGF (ModifiedGegenbaeur Function).In this work, the FPGA card and the converters DAC(Digital-to-Analog Converter) and ADC (Analog to Digital Converter) are considered to perform the implementation. The system is running in the simulation field andin the real system on the hardware equipment.The obtained results show that the implementation ofUWB-OAM system on FPGA board is running well andprovide a high-real time computations system.

This paper reports an overview of UWB jeans antenna and evaluates the safety limits by indicating the computed Specific Absorption Rate (SAR). Simple geometry of the design was aimed in order to fabricate the antenna with minimum errors. The proposed design is a rectangular patch placed on 32 × 34 mm2 jeans substrate with partial ground. Simulated and measured S11 parameter for the antenna at free space is reported in this paper. Simulated radiation patterns are also presented in this paper. The performance of the antenna has then been examined in close proximity to a developed model of human arm. Evaluation of SAR has included calculating 10-g SAR when the antenna placed at 5, 10, 15 and 20 mm far from the phantom.

The design and analysis of a new ultra wideband microstrip antenna for optimum performance that satisfied a large bandwidth starting from 3.9GHz to 22.5GHz is introduced . The UWB antenna is capable of operating over an UWB as allocated by the Federal Communications Commission (FCC) with good radiation properties over the entire frequency range. The techniques of enhancing the bandwidth of microstrip UWB antenna were utilized to enhance the performance of the designed antenna. The effect of shifting feed line from the center of patch to the edges was studied in addition to the effect of changing the length of the ground plane. The antenna was designed and simulated using High Frequency Structure Simulator HFSS software packages..

This paper presents a 3D-RT simulator which allows indoor radio wave propagation modeling for multi-standard systems, including UWB. It focuses on the issue of simulation of deterministic radio channel with realistic antenna behavior. Vector Spherical Harmonics (VSH) expansion of antenna radiation vector function is used to have efficient data access, good compression factor, and fast waveform reconstruction.

A new compact planar notched ultrawideband (UWB) antenna is designed for wireless communication application. The proposed antenna has a compact size of 0.182 × 0.228 × 0.018 where is the wavelength of the lowest operating frequency. The antenna is comprised of rectangular radiating patch, ground plane, and an arc-shaped strip in between radiating patch and feed line. By introducing a new Tuning Fork-shaped notch in the radiating plane, a stopband is obtained. The antenna is tested and measured. The measured result indicated that fabricated antenna has achieved a wide bandwidth of 4.33-13.8 GHz (at −10 dB return loss) with a rejection frequency band of 5.28-6.97 GHz (WiMAX, WLAN, and C-band). The effects of the parameters of the antenna are discussed. The experiment results demonstrate that the proposed antenna can well meet the requirement for the UWB communication in spite of its compactness and small size.

This paper presents an introductory yet comprehensive study of the combined signal and geometrical properties of Indoor Positioning Systems (IPSs) based on ultra-wideband (UWB) technology. These IPSs consist of a network of more than three transmitting anchors and a (tagged) single receiving object to be localised. The specific algorithm used in this paper is the Time Difference of Arrival (TDoA) with round-robin scheduling. The analysis is structured in a systematic manner in order to lay the foundations for the optimal number, location and orientation of anchors aiming for maximum precision, and also for maximum size of the working area with a desired prescribed precision.

- by Bernard Uguen
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- Radio Channel Modelling, Communication System, UWB communication, Impulse Radio

In this article, an integrated broadband planar monopole antenna with extra frequency bands is presented. The proposed antenna consists of a simple square shaped planar. The center part of the plate can be removed with negligible effect on reflection coefficient. To improve the impedance matching of the planar antenna, the lower corner of the antenna is removed. Also, the higher cut-off frequency is enhanced by an additional strip at the top corner of the plate. By inserting additional strips in the path of the notched part of the plate, integrated broadband antenna with extra bands can be attained which leads to dual- and triple-band antenna. The additional bands cover 1.71–1.88 (DCS) and 2.4–2.48 (WLAN). Simulation and measurement results of the proposed antenna agree well and show good performance for multiband behavior.

- by Ali Foudazi
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- Antennas, Microstrip Antennas, Antennas & Radio Wave Propagation, Microwave
- by Xiaodai Dong
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- UWB communication

Nowadays, population growth and expansion into geologically unstable areas is raising hydrogeological risk in Europe. In addition, an increase of landslide events is expected in the future due to climate change and the ever increasing exploitation of underground resources is bound to augment subsidence rates and areas. Thus, there is a clear need for tools able to reduce such risks. Continuous and reliable field monitoring, possibly associated with early warning systems, are essential tools for hazard assessment and ground instability risk management (Intrieri et al., 2012). Within this framework, “Wi-GIM: Wireless sensor network for ground instability monitoring” project, a LIFE+ European project (LIFE12 ENV/IT/001033) was born. Its aim is the implementation of a low-cost, accurate and flexible wireless sensor network for ground deformation monitoring by means of an innovative integration of two radio technologies: 1) the LB technology used for the acquisition of the 3D coordinates of the sensor position with an error radius with meter magnitude; 2) the CWR, able to decrease the error radius down to centimeter magnitude. The working principle of Wi-GIM is to create a mesh of slave nodes whose position is triangulated during time by master nodes, which measure and transmit these data that can then be used to obtain 3D displacement maps. We expect that Wi-GIM can work either in conjunction with traditional monitoring systems or substituting them in areas where the available resources are scarce, giving the local authorities and Civil Protection a useful tool for understanding landslide dynamics and for furnishing early warnings. In order to demonstrate the applicability of Wi-GIM to such landslides and subsidence alike, two case studies have been carefully selected: Roncovetro landslide (Emilia Romagna, Italy) and Sallent (Catalunya, Spain).

- by Emanuele Intrieri
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- Engineering, Slope Stability, Environmental Monitoring, Landslides

UWB communication system is a new technique with high performance that has low power consumption and used in wireless communications for ultra-data rates. In this paper, the image transfer techniques using MIMO-UWB system with multiple description coding (MDC) format over AWGN and fading channels are proposed. The proposed methods ensure that in the packet loss scenario due to channel errors, images with acceptable quality without need of retransition can be reconstructed. Also, the performance of the single description coding and MDC method are studied. The simulation results show that the performance of the proposed method is promising.

- by Mohsen Ashourian and +1
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- UWB communication, Image Transmission, Multi-User MIMO Communication

The Multi-Carrier Code Division Multiple Access (MC-CDMA) is becoming a very significant downlink multiple access technique for high-rate data transmission in the fourth generation wireless communication systems. By means of efficient resource allocation higher data rate i.e. throughput can be achieved. This paper evaluates the performance of group (subchannel) allocation criteria employed in downlink transmission, which results in throughput maximization. Proposed algorithm gives the modified technique of sub channel allocation in the downlink transmission of MC-CDMA systems. Simulation are carried out for all the three combining schemes, results shows that for the given power and BER proposed algorithm comparatively gives far better results .

- by Honggang Zhang
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- Wireless Systems, Cognitive Radio Networks, Cognitive radio, Standardization