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In recent years model and Digital Pre-Distortion dimension reduction has been widely researched. The oper- ations involved when running DPD are often far less than those needed during the training of the DPD coefficients. The proposed partitioned Least Squares (LS) adaptation allows a selected subset of DPD coefficients to be updated while the remaining coefficients are held constant. This technique allows a more adaptive training procedure, improved interpretability of the important DPD coefficient’s during training and the ability to partition the DPD function into specific groups. The Frisch-Waugh-Lovell (FWL) theorem is exploited to partition the coefficients of a DPD basis function trained using LS regression. The proposed methodology was experimentally validated with a Generalized Memory Polynomial (GMP) DPD function, used to linearize a 5W power amplifier (PA) driven by a 40MHz 5G-NR signal.

Efficient and linear power amplifiers (PA) are an essential part of forthcoming 5G wireless systems. Outphasing class-E PAs offer high power efficiency and an option for higher efficiency cellular networks. However, they employ signal component separators, which split the signal into two paths. In order to efficiently recombine the signal, nonlinear power combiners are used. This paper proposes a novel phase-only predistortion technique for outphasing class-E PAs. The predistortion coefficients can be extracted based on AMAM characteristics of the output signal and an analytical model of an outphasing Class E PA. The suggested technique has been validated by simulation of an outphasing power amplifier in ADS Ptolemy software. It is shown that applying this technique to a 16QAM OFDM modulated signal with 20 MHz bandwidth improves error vector magnitude (EVM) from 10.39% to 2.43% compared to the signal without predistortion.

In this paper, a nonlinear autoregressive with exogenous inputs (NARX) digital pre-distortion scheme to linearize power amplifiers is proposed. The proposed NARX digital pre-distortion gives better accuracy and spectral leakage suppression compared with other commonly used Volterra-based techniques. The stability criterion of the NARX digital pre-distortion is derived from the frequency domain analysis. Simulation is carried out with a 20MHz single carrier long-term evolution signal and two-carrier long-term evolution signal and instantaneous to average ratio of 6.2dB at 0.01% complementary cumulative distribution function (CCDF). The results ofsimulation analysisshow aslightimprovementin adjacent channelleakageratio performance with 30% reduction in the number of floating point operations compared with conventional predistortion techniques.

In this paper, we demonstrate a nonlinear autoregressive with exogenous input (NARX) DPD technique which is more compact, less computationally intensive and less susceptible to errors caused by noise in the PA output compared to an equivalent memory polynomial based DPD. Experimental validation is performed with a 20 MHz LTE signal for a GaN Doherty power amplifier.

Next generation wireless communication systems such as high throughput satellites and fifth generation mobile communications have promised a step increase in the rate at which data can be transmitted. This would ideally require bespoke modulator designs for the ground stations with wide bandwidths employing expensive high throughput data converters. The next generation communications hardware also need to be backward compatible with legacy systems of lower bandwidths till they are rendered obsolete. In this paper we demonstrate a scheme to generate a wide bandwidth modulated baseband signal with multiple modulators of narrower bandwidths in a satellite communications ground station.

In this paper, a nonlinear autoregressive with exogenous inputs (NARX) digital pre‐distortion scheme to linearize power amplifiers is proposed. The proposed NARX digital pre‐distortion gives better accuracy and spectral leakage suppression compared with other commonly used Volterra‐based techniques. The stability criterion of the NARX digital pre‐distortion is derived from the frequency domain analysis. Simulation is carried out with a 20 MHz single carrier long‐term evolution signal and two‐carrier long‐term evolution signal and instantaneous to average ratio of 6.2 dB at 0.01% complementary cumulative distribution function (CCDF). The results of simulation analysis show a slight improvement in adjacent channel leakage ratio performance with 30% reduction in the number of floating point operations compared with conventional pre‐distortion techniques.

Multi standard channelization for base stations is a big application of Generalised Discrete Fourier Transform Modulated Filter Banks (GDFT-FB) in digital communications. For technologies such as Software-Defined Radio (SDR) and Cognitive Radio (CR), non uniform channelizers must be used if frequency bands are shared by different standards. However, GDFT-FB based non-uniform channelizers can suffer from high filter orders when applied to wideband input signals. In this paper various combinations of GDFT-FB with the Frequency Response Masking (FRM) technique are proposed and evaluated for both uniform and non uniform channelization applications. Results show that the proposed techniques achieve savings in both the number of filter coefficients and the number of operations per input sample.

In this short paper, we introduce ROUTE-TO-PA project, funded by European Union under the Horizon 2020 program, whose aim is to improve the transparency of Public Administration, by allowing citizens to make better use of Open Data, through collaboration and personalization.

In an Frequency-Division Duplexing (FDD) transceiver, a high power transmitted signal can leak into the RX chain due to limited isolation of a duplexer. Such signal is known as TX leakage and can seriously affect the performance of the receiver. A transmitter leakage canceller structure is proposed in this paper in order to improve isolation between the transmitter and receiver. The simulations show the proposed structure increases the isolation of a Surface Acoustic Wave (SAW) duplexer by more than 25 dB in 20 MHz bandwidth

This paper presents a method for reducing the number of weights in a time series behavioral model for a power amplifier. The least-absolute shrinkage and selection operator (Lasso) algorithm is used to reduce the kernel size, preserving the important kernels, while eliminating the less important kernels. The algorithm is evaluated on a behavioral model for a class AB amplifier, the algorithm reduces the number of weights by greater than 70% without degrading model performance by a significant amount.

This paper presents a high precision wide band switched delay line with fine tuning capability and low insertion loss. The circuit is designed to operate in the frequency range from 1 GHz to 5 GHz and tuned using MEMS switches targeting a minimum delay step of 7 ps. The delay line uses a single layer of a high permittivity substrate ("r =10), and the MEMS devices are interconnected using conventional coplanar waveguide technology (CPW). The circuit was designed and simulated using CST Microwave Studio. The simulated group delay shows a small deviation from the linear phase of less than 1o over a wide bandwidth compared to the performance of SAW and ceramic filters [1]. The simulation results shows an insertion loss and a return loss of better than 1 dB and 20 dB respectively.

This work preliminarily introduces an up to date measurement-driven examination of the spatial characteristics of network resource usage. The data set used is from a large nationwide 3G cellular network comprised of several thousand base stations. Firstly, we discuss our data set and how it can be appropriately used. Next, we examine the spatial correlation between base stations in terms of radio resource usage. We find significant spatial correlation, particularly for proximate base stations. We also examine the causality structure in the network using Granger causality and explore a metric for the identification of key indicator base stations. These indicator base stations act as hubs in the wider network and provide additional information about the future states of their neighbors. Finally, we conclude with a brief discussion of how we wish to build on this work.

A novel low-rate identication method for high power ampliers with memory-effect is presented. It is demonstrated that the required bandwidth of the feedback signal is not required to be greater than twice the signal modulation bandwidth, but is instead determined by the number of feedback samples and the degree of freedom of coefcients in the behavioral model. As the experimental measurements and extracted power amplier model show, this method can achieve a much better NMSE accuracy of modeling power amplier with nonlinear memory-effects compared with previously published approaches

A modular testbed for use in developing software defined radio is documented in this paper. The testbed is focused on the 2.4 GHz ISM band but may be used at other frequencies. An RF transceiver with variable transmit/receive frequencies and bandwidths is provided. It provides the capability to support many modulation schemes and standards such as GSM, UMTS< IEEE 802.11b and parts of the IEEE802.16 standards. It performs the RF functions of the radio, with the other PHY and MAC layer functions such as equalisation and error-coding being performed by a host computer. It communicates with the host computer system through a USB2 interface allowing data rates of up-to 60Mbytes a second. An API is used for communications with the host computer system allowing for modulation/demodulation and coding/decoding in software on the host system and reconfiguration of the radio system

In this paper a new stable high order Digital Phase Lock Loop (DPLL) design technique is proposed. This technique uses linear theory to design the DPLL. The stability of the DPLL is guaranteed by placing a restriction on the system gain. This stability boundary is found by transforming the system transfer function to the Z-domain and plotting the root locus of the LPLL for values of gain where all the system poles lie inside the unit circle. The max value of gain where all the poles lie inside the unit circle is the stability boundary. It is shown that the stability boundary of the LPLL is comparable to the stability boundary of the DPLL. Finally where the above Bessel filter system produces slow lock, gear shifting of the DPLL components is considered. This allows the DPLL to start off with a wide loop bandwidth and switch to the narrow bandwidth once the system has locked.

This article presents a method for design of cross-coupled LC oscillators using open-loop technique and large signal scattering matrix parameters (S-parameters) in place of well known and established negative resistance approach. Thanks to the open-loop methodology, the main circuit parameters such as loaded quality factor, steady-state oscillation amplitude and signal frequency under large signal regime can be extracted without, often tedious and time consuming, transient simulations. The most important aspect of the proposed method is its ability to provide relatively simple and intuitive representation of a cross-coupled oscillator under changing bias conditions, with 10% accuracy in comparison to analysis in time domain. The presented methodology is not technology specific, however CMOS was chosen due to its availability, relative low cost and popularity of circuit implementation. The article shows two low power, sub-1 V voltage controlled oscillator prototypes, one operating in class-B, the other one in class-C, designed using the described method and operating under the reduced power supply requirements yet retaining a state of the art Figure of Merit (FoM) of various VCO reported in the literature.

Mobile phone networks were traditionally voice and SMS messaging networks which made them easy to quantify and model. More recently with the advent of broadband data connections and smart phones, mobile phone networks are being used for a wide range of purposes using ever more bandwidth. This paper utilises data provided by an Irish operator to provide an initial perspective on the current uses of mobile phone networks as a within Ireland. This work serves as a precursor to the development of a quantitative model of existing behaviour which in turn will help predict future requirements.

The paper presents a method for design of LC cross-coupled oscillators based on open-loop technique and its practical application leading to a high frequency CMOS oscillator prototype. Thanks to the proposed approach, main circuit parameters as loaded quality factor (responsible for phase noise performance of LC oscillator) and steady-state oscillation amplitude can be extracted, without the necessity of time consuming transient simulations. The presented method is not technology specific and allows fast calculations under changing bias conditions. The proposed 130 nm CMOS prototype operates 10 GHz from 0.5 V power supply achieving SSB phase noise of -113 dBc/Hz at 1 MHz offset from the carrier. Low power consumption of 1.09 mW RMS, has been obtained by biasing the oscillator devices to operate in class-B i.e. VGS =Vth.

This work utilises data from an Irish mobile phone network to provide a preliminary, but novel, analysis of the interurban communication network between twenty five of the largest cities and towns in Ireland. An intuitive technique is applied to a mobile phone operator’s call detail records to identify the actual subscriber population of different urban areas with various penetration rates. Weighted communication links are generated between the urban centres based on spatial and temporal metrics of distance, and are examined for different times of the day and for different days of the week. These communication links are compared to the output of a standard gravity model in order to ascertain the latter’s ability to accurately represent Ireland’s interurban communication network. The results obtained are presented and discussed within.

non-peer-reviewed The objective of this thesis is to explore theatrical space and the cultural relationship of materials as they are experienced by people in rural Ireland. The method involved the investigation of five handball alleys in Co.Mayo, the identification of materials and the location of the sources of those materials. The results found that one of these handball alleys was part of an urban arrangement of theatrical spaces. The alley was no longer in use, in a state of disrepair and the materiality experience was lost due to the ivy covering the walls. I propose for this project a reuse of the site as a theatre with poetry with an associated playwright hostel, using this to explore a nomenological approach to design through the relationship of old and new materials with reference to past and present culture. TOC: Introduction / Primer projects in Shannon and Hamburg / Chapter One - Theatrical Space / -Theatre in everyday life / -Three Theatre Experiences / Chapter Two - Material / -Physicality of materials / -Sense of Place / Chapter Three - Investigation / -Learning From Alleys / -Advanced Construction / Conclusion - Final Presentation / Bibliography

In this paper we present the design of a low power VCO with reduced variations in VCO gain (KVCO) and subband spacing resolution (fres). The proposed VCO is designed using a 90nm CMOS process to cover a tuning range of 23%. Variations in KVCO and fres are reduced by factors of 6 and 17 respectively over a conventional sub-banded VCO, designed using the same process, to meet the same tuning range. This makes the proposed VCO more suited to stable PLL operation with its reduced KVCO requirements resulting in an improvement in phase noise performance over the conventional VCO by 2 dB. Due to the reduced loading on the VCO tank achieved by the presented design, power consumption is kept extremely low at 850 μW from a 1 V supply

Mismatches within the charge pump (CP) deteriorate the spectral perfor- mance of the CP-PLL output signal resulting in a static phase offset. Classical analog approaches to reducing this offset consume large silicon area and increase gate leak- age mismatch. For ultra-deep-submicron (UDSM) technologies where gate leakage in- creases dramatically, reduction of static phase offset through digital calibration becomes more favorable. This paper presents a novel technique which digitally calibrates static phase offset down to < 10 ps for a PLL operating at 4.8 GHz, designed using a 1V 90nm CMOS process. Calibration is completed in only 2 steps, making the proposed technique suitable for systems requiring frequent switching such as frequency hopping systems commonly used in today’s wireless communication systems.

This work utilises data from a mobile phone network to observe the com- munication and movement patterns of the Irish population between specic locations. A novel technique is applied to mobile phone network billing data to estimate the distri- bution of the phone network population across the country at key times, namely home times and work times. From these population distributions, sets of weighted trans- portation and communications links between locations are generated. These networks are analysed using indicators commonly employed in network theory such as cluster- ing coecients and betweenness centrality. Furthermore, the ability to generate such weighted links when phone network data is unavailable is investigated.

This paper presents a DC-11GHz CMOS low noise amplifier (LNA) for software-defined radio (SDR). The broadband performance is extended to cover the spectrum from near DC to 11GHz by adopting extra inductors with modified resistive feedback, folded current reuse topology. Bandwidth extension is proposed by inserting pole splitting, interstage and LC ladder inductors. A source follower jointly acts as the buffer stage for broadband output matching and feed-forward path for gain enhancement as well as noise cancellation. Simulation shows power gain of 11 ±4dB and the NF ranging from 1.8 to 3dB in 0.4-11GHz band. The LNA achieves an average IIP3 of -10dBm while consumes only 5.3mW. The proposed broadband LNA is designed in 0.18-µm CMOS process from 1.5V supply.

An optimal resource control mechanism for a multiprocessor, multi-radio node architecture is proposed. To achieve our objective, a constrained semi-Markov decision problem is formulated, which not only provides optimal resource control but also meets quality of service demands imposed by application. For each sensed event, the desired energy efficiency and performance tradeoff is achieved by the optimal stochastic policy, which selects an appropriate set of processors and radios. The proposed solution is assessed using the reported energy consumption measurements for the existing platforms. Performance evaluation results point towards the importance of proper pairing of processor and radio in achieving the energy efficiency and performance tradeoff. The proposed solution can also be employed for hand held devices equipped with multiple processors and radios.

A dual Pyroelectric InfraRed (PIR) sensor node is used for human activity monitoring by using simple data processing techniques. We first point out the limitations of existing approaches, employing PIR sensors, for activity monitoring. We study the spectral characteristics of the sensor data for the cases of varying distance between the sensor and moving object as well as the speed of the object under observation. The sampled data from two PIR sensors, is first processed individually to determine the activity window size, which is then fed to a simple algorithm to determine direction of motion.We also claim that human count can be obtained for special scenarios. Preliminary results of our experimentation show the effectiveness of the simple algorithm proposed and give us an avenue for estimating more involved parameters used for speed and localization.

Techniques for observing the flow of people are creating new means for observing the dynamics between people and the environments they pass through. This ubiquitous connectivity can be observed and interpreted in real-time, through mobile device activity patterns. Recent research into urban analysis through the use of mobile device usage statistics has presented a need for the collection of this data independently from mobile network operators. In this paper we demonstrate that by extracting cumulative received signal strength indication (RSSI) for overall mobile device transmissions, such information can be obtained independently from network operators. We present preliminary results and suggest future applications for which this collection method may be used.

TErrestrial Trunked Radio (TETRA) offers capabilities equivalent to the second generation of mobile phones with voice and limited data capabilities. TETRA needs to evolve to satisfy increasing user demand for new services and facilities as well as gleaning the benefits of new technology. An initial enhancement (TETRA Enhanced Data Service, TEDS) has been agreed. The enhanced TETRA services allows for more flexibility in the communication modes used, so as to provide adaptability in applications. We propose that it is possible to deploy Software Defined Radio (SDR) technologies into the basestation to economically provide this level of flexibility and to further extend the capability of TETRA services by deploying a WiMAX channel into the proposed TETRA tuning range. Thus delivering true broadband data service while simultaneously supporting the original and enhanced TETRA services.

This paper presents a hardware platform for antenna array calibration research in tower top electronics. The platform has eight phase and amplitude controlled transmit channels and a novel antenna coupler array structure which provides nonradiative calibration capability. The phase and amplitude of each channel can be varied between 0 and 360° and over 25dB respectively under full software control. The platform has been used to test and develop array calibration routines which achieve amplitude variances of less than 1dB and phase variances of less than 5° measured between eight channels at the antenna connections.

A multi-sensor, multi-modal sensor node for human and vehicle activity monitoring is designed and developed. As a first step to achieve our objective, we have used a dual pyroelectric IR (PIR) sensor system for human activity monitoring. The sampled data from two PIR sensors, under laboratory conditions, is first processed individually to determine the event window size, which is then fed to simple algorithms to determine direction and potentially measure speed of passing humans. We also show that human count can be obtained for some special scenarios. Preliminary results of our experimentation show the effectiveness of the simple algorithms proposed.

Recent research into urban analysis through the use of mobile device usage statistics has presented a need for the collection of this data independently from mobile network operators. In this paper we propose that cumulative received signal strength indications (RSSI) for overall mobile device transmissions in an area may provide such independent information. A process for the detection of high density areas within the RSSI temporal data set will be demonstrated. Finally, future applications for this collection method are discussed and we highlight its potential to complement traditional metric analysis techniques, for the representation of intensity of urban and local activities and their evolution through time and space.

This paper presents a low-power coherent receiver for UWB pulsed Radar for motion detection. Due to accuracy of the radar motion detection, coherent detection scheme is adopted in the receiver. To relax the stringent requirement of timing synchronization, sliding correlation detection is proposed. The clocking step which determines detection resolution is determined by 2ns which is half of a pulse width or equivalent to 30cm. Receiver is designed in 0.13-μm CMOS process from 1.5 V supply. The pulse center frequency is 4GHz. The receiver includes a high voltage gain L3A, a analog correlator, a sampling comparator and a Flip Flop. The wholereceiver excluding an L3A consumes 0.9 mA of DC current and 10pJ/pulse.

The task of determining low noise amplifier (LNA) high-frequency performance in functional testing is as challenging as designing the circuit itself due to the difficulties associated with bringing high frequency signals offchip. One possible strategy for circumventing these difficulties is to inferentially estimate the high frequency performance measures from measurements taken at lower, more accessible, frequencies. This paper investigates the effectiveness of this strategy for classifying the high frequency gain of the amplifier, a key LNA performance parameter. An indirect Multilayer Perceptron (MLP) and direct support vector machine (SVM) classification strategy are considered. Extensive Monte-Carlo simulations show promising results with both methods, with the indirect MLP classifiers marginally outperforming SVMs.

This article presents a low-power, high-linearity cascodetype low noise amplifier (LNA) with 36 dB of variable gain for the WIDE Code Division Multiple Access systems. By enhancing the substrate resistance of a common gate transistor along with adopting multiple-gate technique, the linearity is significantly improved. Shunt-current steering is adopted for smooth gain control. Step gain mode is used to further increase the gain control range. The main common source transistor is disabled in attenuation mode, saving unwanted power consumption. Measurements show maximum gain of 12.3 dB with S11 of 19.5 dB, and S22 of 14 dB. The total gain control range is 36 dB. NF is measured as 2 dB and two-tone test shows 9.1 dBm of IIP3. Implemented in 0.13-m CMOS technology, the LNA consumes only 1.6 mA at maximum gain mode and only 0.2 mA in attenuation mode from 1.2 V supply. Its die size is 0.3 mm2. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1385–1388, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop. 24320

Radio technology has advanced tremendously over the past century with increased capacities and addressing a disparate range of applications. However, from an external perspective, the design philosophies behind radio architectures and wireless standards remain rooted in the methodologies of the 1930’s. In this paper, we propose that this conservative approach has served the communication system engineer well for the past century, but it is now constraining the development of future communication devices and networks that are based on software defined radio technology. The scope for evolutionary improvement on the existing architectures is becoming limited, and it is now appropriate to reconsider our basic assumptions in order to determine whether a radically different approach may yield significant benefits in terms of system performance, cost, mobility, and functionality.

This paper proposes a rigorous stability criterion for an arbitrary order digital phase locked loop (DPLL), with a charge pump phase frequency detector (CP-PFD) component. Stability boundaries for such systems are determined using piecewise linear methods to model the nonlinear nature of the CP-PFD component block. The model calculates the control voltage, after a predetermined number of input reference signal sampling periods, to a small initial voltage offset. This paper, in particular, takes an in-depth look at the second order system. The second order stability boundaries, as defined by the proposed technique, are compared to that of existing linear theory stability boundaries, and display a significant improvement. The applicability of the proposed technique to higher order systems, using a numerically iterative solution, is presented. Finally the proposed methodology is used to determine the stability boundary of a third order system and thus the component values for a stable system. Using these component values the response of the DPLL to an initial control voltage offset is simulated using a circuit level simulation. Index Terms—High Order, Phase Locked Loop, Piecewise Linear, Stability.

Digital signal processing (DSP) techniques are being incorporated in the design of modern power amplifiers (PA) and as the speed of DSP advances it is envisioned that DSP will develop to a point where algorithms will provide signals at RF particularly for switching amplifiers. The digital transmitter has many potential benefits such as the absence of aging or tuning problems, reconfigurability, programmability as well as ease of integration and testing. In this paper a new class S RF power amplifier architecture is proposed for use in high frequency transmitters and is not restricted by the requirement for the square wave modulator to have a sampling rate of 4 times the carrier frequency.

Building a new Software Defined Radio (SDR) system requires multidisciplinary research covering the engineering disciplines of communication systems, radio frequency, digital and analog hardware, software and digital signal processing. This paper focuses on the efforts at the low-level software development, such as device drivers, embedded source code at firmware-space and Application- Programming Interfaces (APIs) at user-space. In the early stages of constructing a SDR platform, design decisions are made regarding the interface between the SDR hardware and the PC. These decisions are of great importance and will determine the complexity of the low-level software development, its interoperability with third-party tools for waveform development and its efficiency in terms of bandwidth and configurability. This position paper reviews the experiences in using a USB interface between the PC and the SDR platform and the corresponding impact in the software development stage.

This paper presents the impact that gain, offset and timing mismatch in time-interleaved analog-to-digital converter (TIADC) have on digital receiver systems. An analysis of the mismatch errors shows the dependency of the different errors from the spectrum of the input signal. A discrete-time TIADC model is derived allowing to simulate the mismatch effects of the individual ADCs. Finally, simulations results present the performance degradation that can be expected by the usage of non-ideal analog-to-digital converters (ADC) sampling alternately the inphase and quadrature signals in a direct conversion receiver architecture when random data is processed.

In recent years there has been a move to increase the data capabilities of TErrestrial Trunked Radio (TETRA) so as to provide secure broadband data capabilities. An initial enhancement (TETRA Enhanced Data Service, TEDS) has been agreed but there is a need to access additional spectrum. An investigation was carried out by European Telecommunications Standards Institute (ETSI) has concluded that a single standardised frequency band cannot be agreed and the concept of a tuning range for enhanced TETRA services can be deployed is gaining acceptance. In addition to needing flexibility in frequency, the enhanced TETRA services allows for more flexibility in the communication modes used so as to provide adaptability in applications. We propose that it is possible to deploy Software Defined Radio (SDR) technologies into the basestation to economically provide this level of flexibility, and to further extend the capability of TETRA services by deploying a WiMAX channel into the proposed TETRA tuning range and deliver true broadband data service while simultaneously support the original and enhanced TETRA services.

This paper describes a sharp-rejection technique in designing active-RC LPF for MB-OFDM UWB applications. Sharp rejection is attributed to the combination of different AC characteristic of three Biquads in series. A simple operational amplifier (Op-amp) is adopted to ensure high frequency and high linear performance for the designed filter. The cutoff frequency is 264MHz, with 13dB rejection at 290MHz and about 50dB at twice bandwith. the LPF is designed in 0.13um IBM CMOS process with pass-band ripple of less that 1dB, IIP3 is 23dBm while cnsuming 8.4mA from 1.5V supply.

Software Defined Radio efforts are focused in both software and hardware areas. Nowadays software products are designed to allow newer and better software radio products for a quick reconfiguration and adaptation to new challenges. With the proliferation of reconfigurable radio software, having a complete SDR system has never been as approachable/accessible. This paper focused on the integration and testing efforts of a RF front-end with the existing reconfigurable radio software called IRIS [1] (Implementing Radio in Software) developed by CTVR (Centre for Telecommunications Value-Chain Research). Several papers were presented at SDR’07 Forum in Denver (CO) [2][3] regarding this RF front-end and its lowlevel software elements. The RF front-end consists of four hardware elements, namely a radio transmitter, a radio receiver, a baseband interface and a PC to perform signal processing and configuration. Additionally, there is a substantial software element to configure the hardware and to receive/transmit data via a USB 2.0 interface. The IRIS system is a component framework for building radio systems, which integrates a great variety of signal processing components. In order to integrate our RF front-end with IRIS two new IRIS components were written in C++: one for transmitting and another for receiving. This integration was possible thanks to the high quality of both software elements: IRIS and the RF front-end software elements (USB driver, embedded code and additional API libraries). High quality measured in terms of reusable, maintainable, modifiable and extendible. The full paper version will include a demonstration of the complete SDR system: IRIS and RF front-end working together. This demonstration consists of building two radios in IRIS, one for transmission and another for reception of an image file using DBPSK modulation. This radio makes use of the two new IRIS components that communicate with our RF front-end. Integrations with other software systems for building radios are planned for the near future, such as OSSIE system by Virginia Tech. All this work will lead us to a better understanding about these systems, which will help us to face the challenge of building an improved one.

This document presents the design and implementation of a low cost reconfigurable radio transceiver platform. The platform will be used as a research tool in the investigation of software defined radio techniques. The hardware presented is an evolution of work presented at the 2006 RIA colloquium. The platform consists of four hardware elements, namely a radio transmitter, a radio receiver, a baseband interface and a PC to perform signal processing and configuration. Data and control communication is performed via a USB 2.0 interface between the transceiver and a laptop PC. The platform development included a substantial software element to configure the hardware and to receive and transmit data between the PC and the transceiver. The technical choices, design and realization of the prototype are discussed.

Software defined radio (SDR) technologies have been long promoted for use in the professional mobile radio (PMR) application domain, as typified by the TETRA standard. The need to retain and enhance compatibility with a proliferation of legacy systems provided the incentive, and the typically very narrowband nature of these communications schemes made SDR appear feasible. In practice the evolution of these standards has moved faster than the development of viable SDR implementations. In recent years, use of PMR radio systems has expanded beyond voice to include data. There is now increasing demand for high speed data access to support applications such as the transmission of highresolution images (eg maps for emergency services), and video clips. This has resulted in an evolution in the TETRA standard, from the original voiceonly service, to an enhanced data version (TEDS) and finally to a proposed new approach which implements a WiMAX subchannel within the TETRA band. This paper will analyse the effect that this evolution in the standards will have on any potential SDR implementation.

Video imagery can be acquired from aerial, terrestrial and marine based platforms and has been exploited for a range of remote sensing applications over the past two decades. Examples include coastal surveys using aerial video, routecorridor infrastructures surveys using vehicle mounted video cameras, aerial surveys over forestry and agriculture, underwater habitat mapping and disaster management. Many of these video systems are based on interlaced, television standards such as North America’s NTSC and European SECAM and PAL television systems that are then recorded using various video formats. This technology has recently being employed as a front-line, remote sensing technology for damage assessment post-disaster. This paper traces the development of spatial video as a remote sensing tool from the early 1980s to the present day. The background to a new spatial-video research initiative based at National University of Ireland, Maynooth, (NUIM) is described. New improvements are proposed and include; low-cost encoders, easy to use software decoders, timing issues and interoperability. These developments will enable specialists and non-specialists collect, process and integrate these datasets within minimal support. This integrated approach will enable decision makers to access relevant remotely sensed datasets quickly and so, carry out rapid damage assessment during and post-disaster.

In the wireless sector maintenance costs form a large part of the total network operating cost. This paper presents a proactive maintenance scheme for wireless systems which is aimed at reducing the high operational costs encountered in the wireless industry by decreasing maintenance costs and system downtime. An on-line monitoring system is used to identify performance degradation, as well as its possible sources via symbol frequency distribution analysis. It ensures that maintenance occurs only when necessary and not at routine intervals. Keywords — RF Hardware, Fault Detection, Fault Diagnosi

This paper presents an performance evaluation of GNU Radio and OSSIE, two open source Software Defined Radio (SDR) architectures. The two architectures were compared by running implementations of a BPSK waveform utilising a software loopback channel on each. The upper bound full duplex throughput was found to be around 700kbps in both cases, though OSSIE was slightly faster than GNU Radio. CPU and memory loads did not differ significantly.

This paper proposes a rigorous stability criterion for the 2nd order digital phase locked loop (DPLL),with a charge pump phase frequency detector (CP-PFD) component. The Stability boundary is determined using piecewise linear methods to model the non-linear nature of the CP-PFD component block. It calculates the control voltage, after a predetermined number of input reference signal sampling periods, to a small initial voltage offset. Using this piecewise linear model an exact closed form stability criterion is proposed for the second order system. The 2nd order stability boundaries, as defined by the proposed technique, are compared to that of existing linear theory stability boundaries, and display a significant improvement.

Integrated circuit design is entering an era of truly nanoscale transistors with minimum device geometries now at 32nm and soon to be at 25nm. While actual transistor and logic gate sizes are many times the minimum lengths possible, logic elements are becoming increasingly small and more closely packed together. There is now an increasing possibility of getting coupling errors where nearby logic gates and wires can induce an erroneous response in a logic gate. This has been a significant problem in memory systems for many years where techniques to test for this fault mechanism are well developed. In logic test, there are few methodologies or technologies for detecting this new category of errors.