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Wireless sensor networks (WSNs) have potential military, industrial, biomedical, environmental, and residential applications. However, implementing sensor networks and realizing their potential faces various challenges. Sensors nodes should be small in size, ultra-low-power, and WSNs should be comprised of large quantities of sensor nodes [1][2]. These challenges emphasize the need for low-cost and eco-friendly substrates suitable for mass production of wireless sensor nodes. Organic substrates is one of the leading solutions to realize ultra-low cost and eco-friendly sensor networks [3]. This paper presents the first IEEE 802.14.4 and ZigBee complaint wireless sensor node on organic substrates. The wireless node is a System-on-Package (SoP) solution operating at 2.4GHz with a printed Planar Inverted-F Antenna (PIFA) on organic substrates using inkjet printing technology. A prototype is realized on FR-4 substrate and used to compare traditional manufacturing techniques with an inkjet-printing solution on paper, which is promising in the large scale manufacturing of ultra-low-cost eco-friendly “green” wireless sensor networks. [ABSTRACT FROM PUBLISHER]

In this paper, a novel Coplanar Wire-Patch (CWP) antenna for 2.5 GHz applications is presented. This antenna has been fabricated using inkjet-printing technology on a flexible, low-cost paper substrate using a simple, fast and cheap process compared to the photolithography technology. The design characteristics of the antenna are verified and the experimental measurements are successfully compared to the simulated ones. [ABSTRACT FROM PUBLISHER]

Ultra-wideband (UWB) has become the promising wireless technology in commercial applications such as short-range high-data-rate wireless communication, high-resolution imaging, and high-accuracy radar. The antenna is one of the key designs in UWB wireless systems. This paper starts with a brief introduction of particular design challenges of UWB antennas, followed by state-of-the-art solutions. Next, the miniaturization technologies for UWB antennas are addressed. Planar designs are highlighted due to their unique merits and wide adoption in practical applications. A newly developed technique to achieve the less-ground-plane-effect performance of UWB antennas, one of the most challenging issues in small antenna designs, is addressed. A design is exemplified to elaborate the mechanism of the method. Based on this concept, an antenna with further reduced size is designed to fit wireless USB dongles. Furthermore, an innovative compact diversity UWB antenna shows the advantage of the ground-plane-independence of small antennas in diversity applications. In the end, the trends of UWB antenna R&D are discussed, correlated with applications and market demands. [ABSTRACT FROM PUBLISHER]

Data Centers face considerable challenges in seamless propagation of telemetry data and executing control functions for performing various management functions. These functions are related to power capping, cooling, reliability, predictability, survivability, and adaptability control. In a conventional approach, distributed sense-data in a server node is collected through wired management interconnects and LAN. We present an alternative approach for this unique data center environment using wireless sensor network to improve data-collection efficiency and real-time delivery. We survey 2-tier sense data collection methodology using narrow-channel wireless interconnects for server management and RACK-level wireless sensor network for data center management. [ABSTRACT FROM PUBLISHER]

Automatic Braille reading systems have been developed and they are put in the Braille library. However, the system is larger scale and it is difficult to carry everywhere. In this paper we introduce a portable Braille reading system, which consists of sensing unit and processing unit. The sensing unit consisits of three plate springs and strain gages. This unit detects convex points of Braille, and the processing unit converts it to corresponding letters. In order to scan the Braille by the plate spring appropriately, a sensor holder of suitable shape is required. This paper considers a shape of the plate spring holder. Four basic shape of sensor holder are compared by electrpmyogram (EMG) and contact pressure of fingers. [ABSTRACT FROM PUBLISHER]

The paper describes a project to determine and model a performance baseline for a satellite communication system concept. It is expected to improve communication capabilities while maintaining low operational cost using a newly proposed antenna system. The system will consist of a large, stationary spherical reflector fed by multiple, steerable feeds. The size of the reflector will improve signal gain and resolvability of individual signals. This paper will use a derivation of far field solutions for spherical shaped current sources. These solutions will be used to look at the interaction between current distributions on the reflector and the resulting EM field distributions. This will allow for estimation of the beam quality of the system as a function of the reflector geometry, and feed illumination. Other methods may be applied as needed to determine the feed systems. This may include ray-tracing code for reflector based systems, and numerical simulations for phased array systems. [ABSTRACT FROM PUBLISHER]

In this paper we introduce a mathematical model in the framework of long term evolution (LTE) to solve the problem of coverage and capacity optimization by employing multi-level random Taguchi's Method. The optimization process runs in a centralized manner with no human intervention required and interacts with environment situation automatically. Under the mathematical model which combines coverage and capacity optimization by a coefficient factor, conventional Taguchi's Method transcends traditional trial-and-error approach in convergence speed and simple implementation, to offer even more search capacity, Gaussian shrink coefficient and random optimization offset are applied to the level-to-tilts mapping function. Antenna tilt is an effective interference reduction technique, which has been adopted as the tuning parameter. The simulation results turn out to be better than traditional Taguchi's Method and trial-and-error approach. The system model presented and evaluated also gives an insight to the mathematical model especially the trade-off between coverage and capacity in homogeneous scenario. [ABSTRACT FROM PUBLISHER]

World is seeing a rapid growth in mobile communication and along with it is becoming difficult to maintain secrecy. There are device developments going on to mitigate this problem. The paper proposes a Mobile detection device which can be used as a metal detector to detect cell phones from the range of few centimeters to few feet's depending upon the Cell phones transmission strength and other parameters. Moreover there is high probability of secret leakages of defense meeting and big gangs use technological means to target high value item or for terrorist activities. This paper presents and proposes a mobile jammer that provides service denial for high security zones and is also used by the high profile person while travelling to avoid technological techniques of tracking. [ABSTRACT FROM PUBLISHER]

Coverage optimisation is an important self-organising capability that operators would like to have in LTE networks. This paper applies a Reinforcement Learning (RL) based Sparse Sampling algorithm for the self-optimisation of coverage through antenna tilting. This algorithm is better than supervised learning and Q-learning based algorithms as it has the ability to adapt to network environments without prior knowledge, handle large state spaces, perform self-healing and potentially focus on multiple coverage problems. [ABSTRACT FROM PUBLISHER]

A novel inkjet-printed electromagnetic bandgapbacked (EBG) RFID tag has been designed and tested for wearable and metal mount applications. An array of split-ring resonators and a dipole antenna matched to an RFID chip at 915 MHz were designed and inkjet printed on paper substrate. Measurements of the tag in free space show that the required reader's minimum transmit power for successful tag reading decreases by 6 dB compared to the case without EBG, while for on-body and on-metal measurements, the read range increases by nearly a factor of 2. It has to be noted that the proposed RFID tag is flexible since it can be easily fabricated by inkjet printing nano- silver particles on paper or platic substrates. It can find numerous applications ranging from wearable antennas and bio-monitoring to transportation and logiitics for mass shipping. [ABSTRACT FROM PUBLISHER]

Full Paper — This paper deals with the proposition of a methodology for the design of reconfigurable antennas. First a basic review of reconfigurable antennas will illustrate the lack of a general method of design. Then the paper will discuss about the limitations of existing design methods and the way to overcome them. The restriction to MEMS switches on planar antennas is introduced. Finally some preliminary works are shown. [ABSTRACT FROM PUBLISHER]

In this paper, we consider a cooperative jammer to improve secrecy of the wireless transmission in a cellular downlink network. The private message intended for a single user should be kept from the remainder of the users who are regarded as internal eavesdroppers. To improve the secrecy of the intended user, we propose an employment of a helper with multiple antennas and design its optimal transmit beamforming vector. Specifically, the helper node generates the artificial interference to the internal eavesdroppers and so enhances the security by increasing the ambiguity at the eavesdroppers. Based on a framework of power gain region in [1], we optimize the transmission strategy for the helper which maximizes the secrecy capacity of the intended user. The analytical and simulation results show that the proposed scheme enhances the secrecy capacity. In addition, all users whose secrecy rates are zero with no helper's cooperation can achieve the positive secrecy rate by the proposed scheme. [ABSTRACT FROM PUBLISHER]

In the past decade entrepreneurship has become a fast growing field of study with contributions from several disciplines including psychology, sociology, strategic management, or economics. This paper reviews engineering literature and shows that by number of publications entrepreneurship is a relevant field of study for engineering (management), but it is scattered among multiple journals and lacks visibility and the conceptual integrity of a scholarly discipline and body of knowledge. The paper puts forward that engineering is well positioned to make an original contribution to entrepreneurship as engineers and entrepreneurs both are seen as “creators”. Engineering can contribute a systems perspective to understanding the entrepreneurial phenomenon and can offer a well-developed formal and mathematical apparatus to further the understanding of complex non-linear and dynamic processes in the creation of new ventures. The engineering code of ethics provides a broader basis to understand entrepreneurial motivations including utilitarian and esthetic values than a one-dimensional economic profit maximization assumption alone. The paper discusses elements of a research road map to develop this view. [ABSTRACT FROM PUBLISHER]

As the overexposure of personnel aboard ships to electromagnetic fields must be prevented, the protection against the hazards of non-ionizing radiation from antennas fed by high-powered transmitters is important. Such a protection is usually realized by organizational methods based on radiation protection areas on deck. Various standards and guidelines are enforced to ensure safe levels of radiation. The evaluation of radiation levels on deck around the RF-antennas is based on the magnitude of the electromagnetic field as criterion. This paper presents results of a new numerical code and compares them with results of common software as well as to measured data. In regard to the confidential nature of some data, the paper presents all results in a normalized form. The aim of this paper is the presentation of the used methods and not the presentation of exact numerally results. [ABSTRACT FROM PUBLISHER]

Space Shift Keying (SSK) is a novel low-complexity digital modulation technique for multiple antenna wireless systems. In SSK, blocks of data are encoded in the index of a specific transmit antenna of the antenna array, which is switched on for data transmission while all the other antennas radiate no power. Recent results have shown that SSK can outperform, with low computational complexity, conventional modulation schemes when many antennas at the transmitter are available. Unfortunately, this makes SSK a useful candidate for transmission technology only in the downlink of cellular networks. In this paper, by exploiting the concept of virtual antenna arrays, we propose a novel relay-aided scheme to make SSK useful in the uplink of cellular networks. The specific contributions of this paper are as follows: i) the optimal decoder which takes into account decoding errors at the relays is developed; and ii) the performance in terms of Average-Bit-Error-Probability (ABEP), and the energy gain in terms of Relative-Average-Energy-Reduction (RAER) per bit is studied. Via Monte-Carlo simulations, it is shown that the proposed optimal decoder outperforms the conventional decoder for SSK, which does not account for decoding errors at the relays. [ABSTRACT FROM PUBLISHER]

This paper investigates a weighted gain combining cooperative spectrum sensing (W-CSS), which has the potential to achieve increased diversity gain and enhance detection performance. In previous works of W-CSS, weight is set based on estimated primary user (PU) signal power. However, their woks did not present an analysis of the detection performance of W-CSS. In this paper, we analyzed the statistics of the estimator and derived the detection probability of the W-CSS under time-invariant case. We also evaluated the proposed W-CSS under time-variant Rayleigh fading by computer simulations. We introduced an asymptotic nature of the P-CSS, i.e. the detection probability of the proposed W-CSS under time-variant Rayleigh fading asymptotically approaches the detection probability under time-invariant case as the number of antennas is increased. [ABSTRACT FROM PUBLISHER]

In this paper, we consider K-user multiple input and multiple output (MIMO) Y channel where each user is equipped with M antennas and the relay N antennas. A scheme that each user exchanges d pairs of messages with each of the other users simultaneously via an intermediate relay is proposed. It is accomplished by utilizing signal space alignment for network coding and interference nulling beam forming combined with receiving antenna selection technique. By using multiple antennas at both ends of wireless links, more diversity gain can be obtained if d is small, while more degrees of freedom (DOF) can be achieved if d becomes larger. The feasibility conditions and the achievable DOF are verified at last. [ABSTRACT FROM PUBLISHER]

This paper focuses in the construction of a new near-field antenna measurement facility in Electromagnetic Research Department of Supelec dedicated to pulsed antennas characterization. The planar near-field measurement data are exploited through near-field to near-field or near-field to far-field transformation algorithms to determine the antenna radiation pattern in the different spatial areas. The measurement system is described and the results of the experimental validation of the developed algorithms are depicted. [ABSTRACT FROM PUBLISHER]

Full Paper — This paper deals with the design of an electrically small antenna embedded on a fire fighter's equipment. A miniature printed parasitic Planar Inverted-F Antenna (PIFA) has been developed in order to respect allotted volume and operating bandwidth. The antenna consists of a two bended PIFA antennas with a single feed. The parasitic IFA is linked to the fed one by a metallic strip in order to enhance the impedance matching bandwidth. Good matching and radiation properties have been measured and compatibility with fire fighter's equipment has been validated. [ABSTRACT FROM PUBLISHER]

For the sake of the increase of energy consumption, the emission of carbide can't be negligible. In this paper, we propose a mathematical model which adjusts the radius of base station, to figure out the problem of energy saving, while the quality of services such as the traffic volume of each base station and the service area should be satisfied. For the model, we use ant colony algorithm as a practical method to solve this problem. By using this mechanism, we can achieve the purpose of energy saving, when the traffic in a service area is low. [ABSTRACT FROM PUBLISHER]

This paper presents the simulation results of thermal emission from a corn canopy. The corn stalks are modeled using the quasi-periodic approach. The wave attenuation through the corn leaves modeled as elliptical disks is taken into account in the simulations. The computed brightness temperature that depends on the azimuthal look angle shows the attenuation effects due to the leaves in addition to the coherence effects due to the periodic structure of the stalks. [ABSTRACT FROM PUBLISHER]

This paper presents a method for reducing a bumblebee noise generated by a GSM technology in a smartphone. Global smartphone penetration has been very swift and 2nd generation, 3rd generation and 4th generation communication technology are commercially used in the world. The 2nd generation wireless telephone technology is based on two standards, depending on the type of multiplexing used the Global System for Mobile Communication (GSM) and Code-Division Multiple Access (CDMA). In particular, the GSM technology has a market share of almost more than 79% in the world. GSM technology uses a channel access method that combines frequency division multiple access (FDMA) and time division multiple access (TDMA). There are four commercial frequency bands. GSM technology has a burst structure by a TDMA method. And hence, the GSM technology has a disadvantage; radiation noise is generated from an antenna propagation signal of the smartphone, and consequently, the voice quality of the smartphone is degraded. This noise is commonly known as bumblebee noise, buzz noise or TDMA noise. There have been several studies to reduce the noise since a release of GSM technology in a commercial market. Those studies mainly focused on designing infinite impulse response (IIR) notch filters by the signal processing technology or on data burst transmission schemes. The first method needs more million instructions per second (MIPS) for operation, and hence, current consumption increases accordingly. The latter method requires a change in the protocol standard of the GSM; hence, its feasibility is low. This paper presents hardware filters designed to reduce the bumblebee noise in smartphones, especially the bumblebee noise in the headset mode during calls. The bumblebee noise is easily generated in the headset mode of smartphones during calls because the headset is necessarily connected to the smartphone. This paper verified that, on an average the bumblebee noise was reduced up to 14dBm by experiments. [ABSTRACT FROM PUBLISHER]

Multi-user MIMO is an important technique to utilize the spatial degree of freedom brought by multiple antennas at the transmitter. To be employed in the downlink of practical systems, some sub-optimal algorithms have to be developed to handle the user selection and precoding with limited feedback on channel state information and reasonable computational complexity at a base station. In this paper we evaluate the performance of a specific multi-user scheduling algorithm, which selects users one by one with greedy search and results in a scheduled user set with adaptive size. The performance is compared with traditional two-user scheduling algorithm in single-cell, and we also show the performance of Coordinated Multi-Point transmission with the layer adaptive algorithm by applying it to users from multiple cells. The system level simulation is based on 3GPP LTE-A framework, and the evaluation can be used as guidance for concrete scheduler design. [ABSTRACT FROM PUBLISHER]

The production of energy by alternative environmentally friendly means that are not dependent on rechargeable pollutant batteries and regular maintenance is proposed as a promising way of powering autonomous low-consumption electronic systems. This paper presents a laboratory practice using a radio frequency (RF) energy harvesting circuit. Students learn to design and characterize a basic patch antenna, understand the process of tuning RF signals, and check operation of the system. It also considers several possible extensions and modifications that helped students enrich their knowledge of potential RF energy harvesting applications. Finally, the paper describes the feedback received from students after implementation of this laboratory practice in three academic years. [ABSTRACT FROM PUBLISHER]

The ability to detect instantaneous speed is crucial for several applications. Moving objects such as vehicles and robots need to detect their speeds on a regular basis. Current systems measure speed using radars and speedometers which base the detection of the speed on the Doppler frequency shift phenomenon. Furthermore, Global Positioning Systems (GPS) do not usually work inside closed structures. In this paper, we present a cheap alternative to measure speed using RFID passive tags. The system is based on a RFID reader that reads tags installed within its reading range. The reader can be fixed or moving. Several configurations are tested to determine the best spacing of the tags as well as the possible benefit of using an extra antenna to detect speed. Moreover, calculations will be based on three different selection criteria of the time instances. [ABSTRACT FROM PUBLISHER]

It is well known that Multiple-Input Multiple-Output (MIMO) system provides both spatial and diversity gains by using multiple antennas at both mobile and base stations. However, the mobile station cannot effort multiple antennas due to small and limited dimension. Therefore, the MIMO technique cannot be successfully operated. In this light, the cooperative MIMO technique enables a mobile user with single antenna to realize a virtual multiple antennas by using the antennas of neighboring users. As a result, the mobile user can experience the full benefits of MIMO system. In literatures, the cooperative MIMO technique using Space-Time Block Codes (STBC) is created by the relay capability of neighbor users. However, the devices of all users have the same potential to detect symbols. Therefore, this paper proposes the STBC scheme by changing the symbol order from source to relay in order to be easily performed as MIMO at the destination. The simulation results reveal that it is possible to obtain a better error performance as well as a higher channel capacity by using the proposed scheme for mobile cellular networks. [ABSTRACT FROM PUBLISHER]

We consider the minimization of the energy per bit (or, equivalently, the maximization of the energy efficiency) in a multiple-input single-output (MISO) broadcast channel with rate balancing constraints, i.e., in a multiuser system where certain fixed ratios between the rates of the various users have to be kept. This paper deals with the practically relevant case where the transmit strategy is restricted to simple linear filtering without time-sharing, i.e., sophisticated coding schemes such as dirty paper coding (DPC) are not allowed. Even though the arising optimization problem is non-convex, it can be solved with reasonable complexity in a globally optimal manner using the algorithm proposed in this paper. This globally optimal solution enables us to study the impact of rate balancing constraints on the energy efficiency of a vector broadcast channel in numerical simulations. [ABSTRACT FROM PUBLISHER]

In recent years Finite Difference Time Domain (FDTD) method [1] is widely used for printed antenna analysis. Because a complicated-shaped model is easily analyzable by using FDTD method. However, it is well known that quite small cell is required when an extremely accurate result is needed for analyzing impedance characteristics of antennas on dielectric substrate. The improving calculation accuracy method has been proposed for straight shape printed antenna [2]. In the method, quasi-static field was used to improve calculation accuracy. In this paper, we expand the quasi-static approximation to bent antennas including loop antenna and we will demonstrate improvement of calculation accuracy. [ABSTRACT FROM PUBLISHER]

Scintillation is the rapid signal fluctuations of amplitude and phase of a radiowave which can cause signal loss in the transmission path with time. Other propagation factors that contribute to the signal fluctuations must be omitted before using the raw data for scintillation studies. Scintillation occurs continuously whether it is under clear sky condition or raining. Therefore, during raining event, the scintillation data will be accompanied by the signal level attenuation caused by the rain. Hence, attention must be given when analyzing scintillation data during raining event. This paper presents the data analysis of the tropospheric scintillation for earth to satellite link at Ku-band. Eight months (May 2011 till December 2011) data were collected and were analyzed to see the effect of tropospheric scintillation during morning, midday, evening and midnight. In this paper, the scintillation data were analyzed during clear sky condition. Any spurious signals caused by other propagation factors were eliminated accordingly. The experimental data were collected using 2.4 m dish antenna through MEASAT 3 at 10.982 GHz. The elevation angle of the dish antenna is stationed at 77.5°. The findings show that scintillation amplitude during midday is highest if compared to morning, evening and midnight. During midnight, the scintillation amplitudes drop significantly. [ABSTRACT FROM PUBLISHER]

Coordinated Multipoint (CoMP) has been proposed as a promising way to enhance cell-edge performance in terms of throughput and coverage. Significant performance gain can be achieved in LTE-A through base station (eNB) coordination by exchanging information such as user data, channel state information (CSI) and scheduling decision. Multiple antennas technique (e.g., MIMO) on the other hand exploits antenna diversity which allows multiple simultaneous transmissions to a group of active users to enhance network performance. Therefore, user selection is important in maximizing system performance. Besides, system resources (e.g., power, bandwidth, transmission rate) in MIMO system must be managed efficiently. Optimal resource utilization should be used without performance compromise. In this paper we propose a joint approach of MIMO user selection strategy and optimal water filling (WF) power allocation in CoMP (JP) transmission. Simulation study shows that our proposed approach outperformed traditional CoMP with and without water filling power allocation. [ABSTRACT FROM PUBLISHER]

This paper focuses on capacity in cooperative base stations MIMO in a realistic MIMO channel measurement. Two widely separated base stations have been assumed in this work and measurement has been done simultaneously from both base stations to four users. The effect of beamforming on capacity in different scenarios in this novel measurement setup has been investigated. The results shows great increase in capacity after cooperation consideration and optimization applied. [ABSTRACT FROM PUBLISHER]

A fresh and creative passive UHF RFID tag, which can be referred to as "Chip-ID tag", has been proposed in this paper. The fully integrated Chip-ID tag, fabricated on the same substrate of the identified SOC, can be used for the SOC chip information identification, such as the chip manufacturer, function and series number identification, etc. The Chip-ID tag without OCA can be implemented as small as a PAD. OCA can be embedded in the periphery of the identified SOC chip or outside the ring of bonding pad. In order to guarantee the maximum power transmission between the reader antenna and the OCA tag, theoretical and experimental analysis between reader antenna and Chip-ID tag have been presented for verifying the feasibility of the proposed Chip-ID tag in this work. Finally, a Chip-ID tag with 4 mm × 4 mm single-turn square loop OCA, including the identified SOC chip, is successfully designed and taped out in 0.18-um CMOS technology. Measurement results demonstrate that the Chip-ID tag can be powered up and then transmit a unique Chip-ID data to the single-turn loop reader antenna with diameter of 1 cm by 110 KHz full-ASK clock signals modulation in complete contact circumstances, when reader transmit −9dBm RF input power at 915 MHz band. The maximum reading range of 1.3 cm can be achieved with 20dBm RF input power by the reader generated. It is worth emphasizing that, within all published papers, this paper is the first time to put forward a self-contained, CMOS-only Chip-ID tag for the SOC chip information identification. [ABSTRACT FROM PUBLISHER]

In this paper, the Pareto optimum of the max-min beamforming problem with general power constraints is discussed. Conditions without a balanced signal to interference plus noise ratio are identified and based on the discussions an improved direct and iterative solution of the max-min beamforming problem is proposed. Numerical results show the performance gain of the presented solution compared to a classical bisection based approach. The presented solution is able to jointly find the optimized beamforming weights and an assignment of base stations (BSs) to users based on the optimization of the beam-formers if a cooperative multipoint transmission is feasible. In the case of long-term channel state information at the BSs, a diversity gain can be achieved. [ABSTRACT FROM PUBLISHER]

In this paper the optimal design for maximum sidelobe level (SLL) reduction of three-ring concentric circular antenna array (CCAA) is determined using a novel Particle Swarm Optimization (PSO) technique namely Craziness based Particle Swarm Optimization (CRPSO). Standard PSO is also adopted for the comparative optimization. The present text assumes non-uniformly excited and non-uniform inter-element spacing array with a design goal of maximizing SLL reduction using the above two evolutionary optimization techniques. Among all the designs, the three-ring structure containing (N1=4, N2=6, N3=8) elements proves to be the optimal design owing to the highest SLL reduction achieved by each technique. CRPSO yields grand minimum SLL (−32.22 dB) for the above optimal set. [ABSTRACT FROM PUBLISHER]

This paper discusses about the lateral wave phenomenon encountered when an antenna or scatter is close to dielectric interface. Although such wave mechanism has been known for its existence in theory and observed in measured data. Most GPR operators are not familiar with the behavior and effects of lateral waves related to ground GPR surveys. The oneway propagation loss (in power) of lateral waves is independent of soils and follows behavior of 1/ ρ4 (ρ: lateral distance to the source). This is greater loss compared to air and ground waves which are spherical waves. However, over a large lateral distance, the amplitude of lateral waves near ground surface eventually exceeds that of ground wave. The latter suffers from exponential decay in lossy soils. This phenomenon makes lateral waves interesting for forward-looking GPR but also potentially introduce surface clutter in GPR survey data. This paper will discuss properties of lateral waves via 3D simulations. Possible applications of lateral waves in forward-looking GPR configuration in homogeneous and layered ground will also be discussed. [ABSTRACT FROM PUBLISHER]

High-speed and energy-efficient wireless communication using the 60GHz band is attracting attention, and recent works have realized a highly integrated CMOS transceiver (TRX) [1–2]. This paper presents a fully integrated chipset for short-range/one-to-one wireless communication. The chipset is composed of 2 chips, an RF chip with in-package antenna and a BB chip including PHY/MAC layer. The chipset achieves 2.62Gb/s PHY data rate and 2.07Gb/s MAC throughput. The MAC is designed to have a high efficiency feature due to short interval DATA/Acknowledgement (ACK) frame exchange. It is realized by fast transmitter (TX)/receiver (RX) switching. Achieved energy consumption of 651pJ/bit is the lowest value in the compared TRXs that include a MAC layer. [ABSTRACT FROM PUBLISHER]

An architecture concept for multi-antenna mass market GNSS receivers is presented. The architecture is composed of a central processing unit and attached coprocessors to solve the conflict between continuously increasing computational complexity of receiver algorithms and the demand for maximal receiver mobility (i.e. hardware featuring low cost and low energy consumption). To optimize navigation performance and robustness the presented receiver processing relies on the collected data in space, time, and frequency domain. Multi-antenna algorithms, e.g. interferer suppression, direction of arrival estimation, and tracking are briefly described. The basic hardware building blocks (coprocessors) required to efficiently realize these algorithms are introduced. Examples for the dimensioning of internal word length and block parameters are presented and first coprocessor implementations are shown. To reduce the costs of the overall receiver, synergistic effects should be exploited and the coprocessors should be used in a time multiplexed manner, where possible. Therefore, a first simple scheduling for the coprocessor access is shown. Finally, a platform for a real-time prototype realization of the presented architecture concept, on a state-of-the-art FPGA development board, is introduced. This paper proves that high performance multi-antenna GNSS receivers featuring interferer suppression as well as advanced signal processing and analysis can be realized using state-of-the-art FPGAs and thus shows a first step towards a mass market multi-antenna GNSS receiver. [ABSTRACT FROM PUBLISHER]

This paper introduces new monitors for the detection of orbit ephemeris faults affecting differential carrier phase measurements in a shipboard aircraft landing application. Two shipboard monitors are first designed. While they provide high detection performance against two targeted fault types, they are ineffective against the other types of orbit ephemeris faults. In response, to protect the user against the entire threat space, a new airborne receiver autonomous integrity monitoring (RAIM) algorithm is developed. This ‘unified’ RAIM approach (URAIM) exploits both differential RAIM (which is most efficient at airship separation distances larger than 5 nmi) and relative RAIM (which, in contrast, performs better as the aircraft approaches the ship). Performance evaluations demonstrate URAIM'm potential to detect all types of orbit ephemeris faults using a single, unified residual-based RAIM method. [ABSTRACT FROM PUBLISHER]

The use of beamforming antennas has received significant attention over the last decade. We consider beamforming applied to dynamic operations such as networked UAV hubs which interconnect with users on the ground. The key problem involves scheduling these communications with users serviced by different beam patterns. This paper develops a linear program to optimally allocate time to beams for client specific traffic for such an application in order to maximize client throughput. It also incorporates l1 norm regularization to help allocate time for non-linear factors such as beam-switching while still maintaining optimality. Furthermore this paper implements delay constraints and verifies the program's performance. A shortest path first approach is presented that optimally schedules the order of the beam switches such that inter-switch delay, and associated protocol specific overhead, is minimized. We show how we implement, and then test, a multi-UAV scenario where the separate UAVs service their respective users while being interconnected in an ad hoc network. Finally, we present a working prototype implementation incorporating this work. [ABSTRACT FROM PUBLISHER]

In this paper, we investigate the application of superposition coding to multi-group multiuser two-way relay channel. A novel scheme combining network coding and superposition coding is proposed. In the two-phase communication scenario considered, single-antenna users of each group wish to exchange information with their corresponding partners with the assistance of the relay node (RN) which is equipped with multiple antennas. Decode-and-forward (DF) strategy is employed by RN. Network coding is used to handle intra-group interference while superposition coding is deployed to cope with inter-group interference. We make explicit analysis of ergodic sum rate and outage probability which are chosen as the metrics to evaluate the performance of the proposed scheme. Space-time coding (STC) adopted by the multi-antenna RN enables the users to achieve spatial diversity gain. It shows that the proposed scheme outperforms other existing comparable approaches in terms of sum rate and outage probability. Simulation results are provided to verify our analysis and demonstrate the performance of the proposed scheme. [ABSTRACT FROM PUBLISHER]

During last year's MILCOM event (MILCOM 2011), McLain et al [1] presented a paper that provided a comprehensive comparison of Ku, commercial Ka and military Ka-band efficiencies against a number of parameters; including terminal size, regulatory restrictions, and performance in the presence of rain. This comparison showed that each band has its strengths and weaknesses, depending on the application for which it is being used (aeronautical, maritime, land based), terminal size, and operational environment (mobile and fixed). This paper provides an expanded comparison of Ku and Ka-band, focusing on operational aspects and other key considerations; including coverage resilience, operational flexibility, regulatory impacts and potential regulatory changes that would improve commercial Ka-band performance, as well as the use of hybrid (multi-band) systems to further improve performance when operating in adverse weather conditions. [ABSTRACT FROM PUBLISHER]

Methods of waveguided measurements of the interference of multiple wireless transmissions are well known. In this paper a new method is shown using a well defined line-guided procedure to measure the interference between several wireless transmission systems in the same frequency range. The setup is based on wired connections in order to produce a repeatable RF channel between the DUT's. Complex structures such as anechoic chambers are not necessary for this setup. It is possible to simulate the individual free-field-loss between each antenna as well as the signal propagation time between the wireless devices. Variations of the setup can be easily made in order to test the performance of the DUTs under various wireless channel conditions. [ABSTRACT FROM PUBLISHER]

Data throughput demands of fourth generation telecommunication systems have acted as a stimulus for a paradigm shift of the cell tower structure. This paradigm shift has included the implementation of the fiber-to-the-antenna (FTTA) architecture. FTTA architecture implementation has enabled lower power requirements, distributed antenna sites and a smaller base station footprint when compared to conventional tower sites. This paper will review the changes in cell tower architecture being implemented to meet fourth generation network operating performance criteria and examine the steps that need to be taken to protect cell tower components from lightning and other surge and transient effects. [ABSTRACT FROM PUBLISHER]

This paper presents modeling results from National Institute for Occupational Safety and Health (NIOSH) research into through-the-earth (TTE) communications technology for underground coal mines. Research focuses on the factors controlling the propagation and coupling of radio signals between transmit and receive antennas separated by earth or coal. Most TTE sytems use single or multiturn loops of conductor for the transmit antenna. We compare the magnetic field distribution predicted from analytical formulas to the predictions of a method of moments computational electromagnetic (CEM) code. The predictions are compared in free space, in a homogeneous earth, and with the effect of the presence of the surface of the earth. The evaluations are done with the transmit loop buried in the earth and with the loop above the surface. The analytic results are shown to agree reasonablly well with the more detailed CEM predictions for the situations considered, reducing the need for expensive and complicated CEM codes in analyzing simple TTE configurations. The predictive methods are applied to TTE measurements made in 94 different coal mines by the Bureau of Mines in the 1970s and the implications for the apparent conductivity of the earth are discussed. [ABSTRACT FROM PUBLISHER]

This paper focuses on the design of embroidered textile antenna, where a fractal technology is used to integrate. Modern telecommunication systems require an antenna with low cost of fabrication and low profile features. This has initiated antenna research in various directions and one of them is wearable textile antenna. A wearable antenna is meant to be a part of clothing used for communication purposes. Fractal technology allowed us to design miniature antennas and integrate multiple telecommunication services into a single device. This study focuses on the investigation of embroidered Sierpinski carpet textile antenna's design using different fabrics suitable for wearable application. The substrate of this antenna is made of from two different low cost textile materials. Radiating element and ground plane are made of conductive threads. The performance of these two antennas that operated at 2.45 GHz such as return loss, bandwidth, VSWR and impedance are extensively investigated and carried out. All results have been demonstrated using simulation and measurement. From this study, it is found that both antennas from denim and felt fabrics can be used for wireless application. Besides, these antennas also still operate in bending condition. The result shows these antennas suitable for wearable application. However, the antenna that used denim textile shows the best performance compared to the antenna with felt fabrics. [ABSTRACT FROM PUBLISHER]

Compressive sensing (CS) for urban operations and through-the-wall radar imaging has been shown to be successful in fast data acquisition and moving target localizations. However, the research work in this area thus far has assumed prior effective wall removal, allowing proper detection of indoor targets. In this paper, we show that wall removal techniques, operating with full data volume and applying backprojection imaging methods, can be equally effective under reduced data volume and within the sparse signal reconstruction framework. Specifically, we demonstrate that the spatial filtering and the singular value decomposition based approaches, which, respectively, exploit the spatial invariance and the strength of the EM wall return, for suppression of the wall reflections, can be employed using few measurements, thus allowing CS to be applied to data with higher target-to-wall-clutter ratio. [ABSTRACT FROM PUBLISHER]

This paper presents two fast and computationally efficient interferometric algorithms that allow high accuracy, unambiguous angle-of-arrival (AOA) estimates to be obtained using physically large wideband antennas that are suitable for electronic surveillance. The performance of the algorithms are compared against conventional interferometric techniques using simulations and are also verified experimentally. [ABSTRACT FROM PUBLISHER]

1 This paper describes a method for detecting and tracking multiple moving targets using a multistatic narrowband radar sensor array. We show that the appropriate model for the sensor array measurements is non-linear and the statistics are non-Gaussian. We use this model in conjunction with a Bayesian estimation algorithm which constructs a probability density on the number of targets and their states. The density is approximated using a novel hybrid discrete grid/particle filter. We evaluate the performance on a set of experimental data from a 6-channel array to detect and track two targets that cross, make sharp turns, and move nearly cross-radially to some pairs for a significant portion of the collect. [ABSTRACT FROM PUBLISHER]

Inkjet-printed conductors with large areas and increased layer thickness may cause challenges with the materials applied. The possibly required increased sintering energy can r esult in exceedin g the h eat toler an ce of the substrate and cracks in the conductor surface can be formed. The advantages of inkjet print technology can be applied to reduce these challenges by limiting the ink usage by varying the conductor thickness locally or even removing the parts of material from the layout. In this paper, large-area RF applications are studied in terms of varying conductive ink usage and sintering profile. An antenna type with high current density areas is used as a demonstrator of an application requiring larger uniform printed area. The paper shows the advantages of limited local printing on additional layers compared to printing full layers. Two different sintering profiles are applied to differently printed antenna versions fabricated for 868 MHz and 2.4 GHz frequencies. It is shown, that with less sintering energy, the antennas with only local additions perform better than antennas with fully printed antennas with more ink. With longer sintering process time, the local antenna and the fully printed antenna behave equally in terms of total efficiency. [ABSTRACT FROM PUBLISHER]

In order to counteract antenna impedance mismatch due to interaction with environment, one solution is to use a tuner between the front end module and the antenna. In this paper, a 4G antenna tuner integrated in STMicroelectronics 130 nm CMOS SOI technology and operating between 2500 MHz and 2690 MHz is described. Thanks to high power CMOS SOI Digitally Tunable Capacitances (DTCs), the proposed tuner is able to match to 50 Ω an antenna presenting a VSWR degraded up to 5:1. Minimal input reflection coefficient of −10 dB is reached and promising insertion losses are obtained (minimal losses of 3.5 dB for an antenna with initial VSWR of 5:1). [ABSTRACT FROM PUBLISHER]