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This paper addresses the problem of battery life in ambulatory systems for monitoring biomedical signals in the mobile healthcare environment. Specifically, the paper examines the potential power savings that may be obtained using the recently-introduced Bluetooth Low Energy (BLE) specification, where wireless signal transmission is used between a wearable sensor, and a Body Area Network (BAN) hub...
The paper reports some initial findings in the area of analysis and characterisation of fast switching lasers, specifically Sampled Grating Distributed Bragg Reflector (SG-DBR) lasers. The ability to track the phase of a laser in the moments immediately following a switching event is an important building block in the development of an efficient Optical Burst Switching (OBS) network. In this paper...
This paper aims to discuss the underlying issues with the use of accelerometers sensors within mobile devices to support gait analysis. Standalone accelerometer provides quantitative measurements of acceleration. In recent research within healthcare informatics, accelerometers have been utilised in applications such as activity recognition. However issues such as sampling rates and missing values...
Passive radiometry is a health-safe alternative to other imaging techniques conceived to be used on human beings for security or medical purposes. In this paper we discuss the advantages and show the results of a feasibility study of a W-Band radiometer onto a single chip in standard CMOS technology.
We present a driver circuit that can modulate a VCSEL with a 56Gb/s (28Gbaud/s) 4-level pulse-amplitude-modulated (PAM-4) signal. High power efficiency is achieved using a common-source driver topology that only draws the modulation current corresponding to the PAM-4 symbol being transmitted. A Gray encoder based on MOS Current-Mode Logic (MCML) gates is included on chip, as well as programmable PAM-4...
We present a variable gain amplifier with novel fast feedforward dc-offset compensation intended for use in an optical linear burst-mode receiver. The amplifier was implemented in a 0.25μm SiGe BiCMOS technology. Its gain can be varied from 0dB till 20dB while maintaining a bandwidth of at least 12GHz, peaking of the frequency response is less than 0.5dB and group delay variation less than 5ps (from...
Orthogonal Frequency Division Multiplexing (OFDM) technology, mainly due to its high data rates and effectiveness in combating frequency selective fading channels has been extensively used in wireless (and wired) communication systems. Digital Audio and Video broadcasting, ADSL and VDSL broadband access, and Wireless LAN systems using the IEEE 802.11a, g, n, and HIPERLAN/2 standards are only a few...
Multi-path propagation introduces challenges for UWB ranging due to a large number of multi-path components and relatively long excess delays compared to the transmitted pulse duration. This paper focuses on experimental analysis for various transmit-powers, IEEE 802.15.4a UWB based ranging problem under multi-path environment. A two-step leading path detection technique is presented that robustly...
The holy grail of tracking people indoors is being able to locate them when they are not carrying any wireless tracking devices. The aim is to be able to track people just through their physical body interfering with a standard wireless network that would be in most peoples home. The human body contains about 70% water which attenuates the wireless signal reacting as an absorber. The changes in the...
It is difficult to remove subjectivity from assessment, especially when the assessed material is highly subjective by nature. While one assessor deems work to be of high quality, a second may view it as poor. Moreover, although two assessors may agree that the work is of satisfactory quality, they may nevertheless proceed to grade it significantly different, based on their interpretation of what is...
Digital Delta-Sigma Modulators (DDSMs) are widely used in fractional-N frequency synthesizers. Much design effort is typically expended to smooth and shape the DDSM's output spectrum. This good work can be undone by nonlinearities in the phase-locked loop (PLL) which cause the noise floor resulting from the DDSM to rise, thereby degrading the inband phase noise performance of the system. This paper...
This paper presents a realised prototype of fully integrated CMOS LC-PLL frequency synthesizer. The circuit delivers a wide range of clock signals between 12 MHz and 5800 MHz, with average long term jitter of only 4 ps. The primary application of the presented circuit includes high speed series data transmission links. Low power consumption of the complete synthesizer (including bias circuitry), in...
The system implements a pre-distortion algorithm for a non-linear PA by placing a pseudo static forward model of a PA in the feedback path of a Sigma Delta Modulator. Performing the predistortion in this way reduces the computation overhead incurred in calculating pre-distorter weights for a given power amplifier. In this paper a Cartesian LUT is used to represent the PA model, allowing the system...
Automatic recognition of emotion from speech has many potential applications, from the design of more user friendly human-machine interfaces to the improvement of speech recognition for natural speech. As this is a relatively young field there remains uncertainty in the literature over the best classifier architectures and feature sets for emotion classification. In this work we explore the classification...
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...
We present a Mean Shift algorithm for fitting shape models. This algorithm maximises a posterior density function where the likelihood is defined as the Euclidean distance between two Gaussian mixture density functions, one modelling the observations while the other corresponds to the shape model. We explore the role of the covariance matrix in the Gaussian kernel for encoding the shape of the model...
This paper reports a system-level study of a 60-GHz wireless system for uncompressed high-definition video communications. The study is addressed to explore the implementation of 60-GHz transceivers in nano-scale CMOS technology. A model of the high data rate physical layer based on the specification released by the consortium WirelessHD has been implemented in MATLAB and the system simulations of...
This paper discusses ongoing research being carried out on an autonomic wireless sensor node technology. We investigate two potential research approaches for systematically identifying unknown sensors, and develop three techniques which utilise the sensor identification information to enable the sensor node system to adaptively reconfigure itself to accommodate the newly connected sensor. The paper...
We consider the process of object detection, recognition and classification in digital optical images of human breast cells with the aim of differentiating between normal and abnormal (cancerous) cells. The work is based on research into the development of a breast cancer screening system that can be used by cytologists to differentiate between benign and malignant types using images that are typical...
In this paper we propose a new 4-moduli Residue Number System (RNS) {2k, 2n − 1, 2n−1 − 1, 2n+1 − 1} and its respective reverse converter. The new moduli set is characterized by a very efficient way of utilizing the underlying representation's capacity coming from its two aspects. First, by not including conjugate moduli our set covers the dynamic range of the representation much better than the systems...
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