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Wireless Broadband and Ultra Wideband Communications, 2007. AusWireless 2007. The 2nd International Conference on

Date 27-30 Aug. 2007

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  • The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications - Cover

    Page(s): c1
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  • The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications-Title

    Page(s): i - iii
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  • The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications-Copyright

    Page(s): iv
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  • The 2nd International Conference on Wireless Broadband and Ultra Wideband Communications - TOC

    Page(s): v
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  • Welcome from the Conference Chairman

    Page(s): vi
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  • General Organising Committee

    Page(s): vii
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  • Technical Program Committee

    Page(s): viii
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  • List of reviewers

    Page(s): ix
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  • A Residual and Sampling Frequency Offset Estimation Scheme for Multiband OFDM

    Page(s): 1
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (352 KB) |  | HTML iconHTML  

    In this paper, a residual frequency offset (RFO) and sampling frequency offset (SFO) estimator is proposed for ultra- wideband multi-band orthogonal frequency division multiplexing (UWB MB-OFDM) systems. The proposed scheme uses a time-domain spreaded data samples which is provided in MB-OFDM system. To demonstrate the efficiency of the proposed RFO and SFO estimator, comparisons are made with other existing estimator. View full abstract»

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  • Selective Detection for MIMO-OFDM Transmission

    Page(s): 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (135 KB) |  | HTML iconHTML  

    We present a novel technique for the detection of spatially multiplexed transmitted symbols in uncoded multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. The method, termed selective detection, observes errors caused by a simple zero- forcing (ZF) on different OFDM sub-carriers, and selectively performs list sphere detection (LSD) on sub-carriers with larger errors. Compared with the full-complexity LSD, the proposed algorithms could significantly reduce the receiver complexity at a small signal-to-noise ratio (SNR) loss. For example, simulation results for a MIMO-OFDM system using four transmitters and four receivers with 16 quadrature amplitude modulation (16-QAM) show that 93% of SNR gain that can be achieved by the use of LSD over ZF can be realised if only 33% of sub-carriers are intelligently selected for LSD. View full abstract»

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  • Performance Improvement of the Combined AMC-MIMO Systems with MCS Level Selection Technique

    Page(s): 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (579 KB) |  | HTML iconHTML  

    In this paper, we propose and observe a system that adopts independent MCS (modulation and coding scheme) level for each layer in the combined AMC-V- BLAST (adaptive modulation and coding-vertical- bell-lab layered space-time) system. Also, comparing with the combined system using common MCS level, the proposed system applied to Independent MCS level shows how much throughput performance is improved. As a result of simulation, Independent MCS level case adapts modulation and coding scheme for maximum throughput to each channel condition in separate layer, resulting in improved throughput compared to common MCS level case. Especially, the results show that the combined AMC-V-BLAST system with Independent MCS level achieves a gain of 700 kbps in 7~9 dB SNR (signal-to-noise ratio) range. View full abstract»

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  • Performance Analysis of Adaptive Modulation System with Optimal Turbo Coded V-BLAST Technique corresponding to each MIMO

    Page(s): 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB) |  | HTML iconHTML  

    In this paper, we propose and analyze an adaptive modulation system with optimal turbo coded V- BLAST (vertical-bell-lab layered space-time) technique that adopts the extrinsic information from MAP (maximum a posteriori) decoder with iterative decoding as a priori probability in two decoding procedures of V-BLAST scheme; the ordering and the slicing. Also, we consider and compare The adaptive modulation system using conventional turbo coded V-BLAST technique that is simply combined V-BLAST scheme with turbo coding scheme and that is decoded by the ML(maximum likelihood) decoding algorithm. In addition, we apply MIMO (multiple input multiple output) schemes to the systems for more performance improvement. The result indicates that the proposed systems achieve a better throughput performance than the conventional systems in the whole SNR range. And in terms of the throughput performance, the suggested system is close proximity to the conventional system using the ML decoding algorithm. In addition, the simulation result shows that the maximum throughput improvement in each MIMO scheme is respectively about 350 kbps, 460 kbps, and 740 kbps. It is suggested that the effect of the proposed decoding algorithm accordingly gets higher as the number of system antenna increases. View full abstract»

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  • A Low Power Programmable CMOS Circuit for Generating Modulated Pulses for UWB Applications

    Page(s): 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (507 KB) |  | HTML iconHTML  

    This paper describes the use of a digital to analog converter (DAC) based circuit structure for generating modulated Gaussian pulses for low (3.1 to 5 GHz) and high (6 to 10.6 GHz) UWB bands. The voltage references in DAC circuit are obtained by piecewise constant approximation of the pulses. Experimental results with HSPICE using a 0.18 mum CMOS technology with 1.8 V power supply are given for modulated Gaussian pulses with 4 and 8 GHz center frequencies, which resemble 4 and 6 order derivative of the Gaussian pulse. The power consumptions are, respectively, 0.82 mW and 1.26 mW for the main circuit in low and high UWB bands. Since the circuit structure is simple, both the power consumption and the area are relatively much lower than the existing pulse generators. Also, generating sub-nanosecond signals for high UWB band is due to simplicity of the circuit, which otherwise would require a CMOS technology with finer feature size. View full abstract»

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  • UWB Acquisition at Symbol Sampling Rate Using Reference Aided Match Filter and Adaptive Post Detection Integration

    Page(s): 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (298 KB) |  | HTML iconHTML  

    Short pulse, multi-path, intersymbol interference, and high sampling rate in UWB communications pose more challenges in system synchronization. This paper proposes an acquisition structure to synchronize the system at symbol rate sampling. The reference aided match filter is used at the front end to match the incoming data with the pilot codes. An adaptive post detection integration helps to suppress ISI and provides an easy threshold set-up. A bit iteration search assists in reducing acquisition time. Simulation results show a promising acquisition scheme for UWB communication systems at symbol sampling rate. View full abstract»

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  • A TR-UWB Receiver using Correlation in Frequency Domain

    Page(s): 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (254 KB) |  | HTML iconHTML  

    This paper presents a new TR-UWB receiver using correlation in the frequency domain. Correlation is performed on the real and imaginary frequency-components of UWB pulses, respectively and correlation results are combined to enhance the output SNR. Analytical and numerical derivations are presented. View full abstract»

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  • A Simple Estimation of the Optimum Load Resistance in a UWB System

    Page(s): 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (406 KB) |  | HTML iconHTML  

    The parameter energy link loss between the source of the transmitter and the load of the receiver is used to evaluate the performance of a ultrawideband (UWB) radio system. The rigorous calculation of the link loss in a UWB system is a complicated task. However, for the special cases of two similar small antennas (dipoles and loops) a simple approximate analytical estimation of this parameter can be obtained. These expressions are derived assuming that the antennas are excited by Gauss-Hermite pulses (GHP). For the first three modes (n = 0, 1, 2) simple formulas for the optimum load resistance are derived. View full abstract»

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  • UWB Multipath Simulator based on TEM Horn Antenna

    Page(s): 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (273 KB) |  | HTML iconHTML  

    Most of the existing UWB models are extensions of narrowband models. These models suffer from limitations because UWB multipath propagation is frequency and antenna dependent. In this paper, a directional simulator based on TEM horn antenna is developed. This simulator illustrates the spatial impact on the received multipath profiles. Several deterministic scenarios are simulated to examine the antenna impact on receiver design and positioning accuracy. View full abstract»

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  • Socio-inspired Design Models for Software Systems Infrastructure

    Page(s): 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (174 KB) |  | HTML iconHTML  

    This paper outlines our charitable model, the technical challenges that drove the concept behind this model and the rationale behind its design. Social models such as the benefactor/beneficiary model of multi-agent distributed storage middlewarecan be successfully applied to many areas as a means of automating a wide variety of resource distribution challenges in both traditional and future distributed systems. An environment populated with many redundant components can benefit from a charitable entity, allowing wasted resources to be efficiently distributed to the network on a voluntary manner. View full abstract»

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  • Interactive Protection System for Operator Training Simulator Using New Wavelet Techniques

    Page(s): 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (293 KB) |  | HTML iconHTML  

    An increase in complexity of relays and power systems makes the relay settings and the process of coordination quite difficult. The changes of operating conditions in power systems also adversely affect the installed relays. There is a strong requirement to avoid protection relay maloperation and to ensure continuing optimal relay coordination and operation. It is rather difficult to determine which of the protective relays will operate as specified or whether the coordination of the relays is maintained due to complexity of the system. This paper introduces a reliable and secure interactive framework system for investigation, calculation of relay settings and relay coordination using wavelet based techniques. The interactive system allows an engineer in the control room to assign the location, the type of fault and the relay data set pattern; then the operating time of the protective devices is generated. The system framework introduces a dynamic, interactive transient of the relay models for the power system. View full abstract»

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  • Service Criticality Based Scheduling for IEEE 802.16 WirelessMAN

    Page(s): 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (323 KB) |  | HTML iconHTML  

    IEEE 802.16 WirelessMAN (WiMax) has emerged as broadband wireless access (BWA) solution for fixed and mobile communication requirements in the metro area. While the 802.16 standard throws adequate light on aspects of bandwidth-request and subsequent grants as well as supported service types, it however does not discuss service scheduling. In this paper, we propose a new scheduling algorithm, referred as service criticality (SC) based scheduling scheme. The SC scheme offers fairness, efficiency and low-latency scheduling and facilitates QoS guarantees. SC is based on a dual of buffer occupancies at nodes and allowable latencies for a particular service. We compare SC scheme with round-robin and max-min fair scheduling schemes under different system loads. We observe that while round robin and max-min scheme does not guarantee QoS support at high loads, the SC scheme facilitates efficient scheduling even at heavy loads. Simulation based study is reported that considers a multitude of services using realistic physical and MAC layer models. Delay and blocking results are investigated. The SC concept shows betterment over conventional max-min scheme as well as round robin. View full abstract»

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  • Using Spectral Analysis to Extract Frequency Components from Electroencephalography: Application for Fatigue Countermeasure in Train Drivers

    Page(s): 13
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (306 KB) |  | HTML iconHTML  

    Train accidents can have a massive impact towards the surrounding area as well as the general community. Most train accidents can be attributed to fatigue, and hence, development of fatigue countermeasure devices that can warn drivers of fatigue status and prevent accidents can greatly benefit train drivers, passengers, society and general community. Electroencephalography (EEG) has been proven to be one of the most reliable indicators of fatigue. This study investigated the change of brain activity during fatigue-instigating monotonous driving session, by extracting the four frequency components (delta, theta, alpha, and beta) using FFT spectral analysis at different brain sites (frontal, central, temporal, parietal, and occipital). Results identified some statistically significant differences between early and later stages of driving in delta, theta and beta activities at different brain sites. The results of the current study may be used for future development of fatigue countermeasure by targeting specific frequency component and brain sites. View full abstract»

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  • Analogy of Promising Wireless Technologies on Different Frequencies: Bluetooth, WiFi, and WiMAX

    Page(s): 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (235 KB) |  | HTML iconHTML  

    The explosive growth of the Internet over the last decade has led to an increasing demand for high-speed, ubiquitous Internet access. Broadband wireless technologies are increasingly gaining popularity by the successful global deployment of the wireless personal area networks (Bluetooth-IEEE 802.15.1), wireless local area networks (WiFi- IEEE 802.lln), and wireless metropolitan area networks (WiMAX- IEEE 802.16). New ICT and e-Learning strategies and advances in wireless standards and technologies- particularly in the areas of Bluetooth, WiFi (wireless fidelity), WiMAX (worldwide interoperability for microwave access) and mobile computing can help to bridge the digital divide in education and research. Using open broadband Wireless technologies and implementing mobile computing architectures, one can overcome the challenges of ground, infrastructure, and finance to increase access; deploy broadband quickly and cost-effectively to areas currently not served; and extend the benefits of digital revolution to previously unreachable populations. These technologies aim to provide low-cost, high-performance Wireless access to residential and business applications. As technology evolves to address portable and mobile applications, the required features and performance of the system will increase. Evolution toward the phase called "full mobility" provides incremental support for low latency, low packet loss and real-time handoff of subscriber terminals operating at high speeds. This paper presents the analogy of promising wireless technologies on different frequencies: Bluetooth, WiFi, and WiMAX. This paper is organised into four parts: part I describes the functionality and usage of Bluetooth in the wireless personal area networks, part II presents the WiFi- IEEE 802.1 In strategies for users considering higher-bandwidth alternatives to existing wireless personal area networks, part III discusses how the WiMAX is used as a current standard for Wireless data transmission tec- hnology, which is optimized to deliver high, bursty data rates to mobile subscribers, and to support real-time multimedia and Voice over IP (VoIP) applications, and part-TV explores how these emerging Wireless technologies differ from one another. View full abstract»

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  • Pre-Coordination Mechanism for Fast Handover in WiMAX Networks

    Page(s): 15
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB) |  | HTML iconHTML  

    The most challenging research issue of investigating broadband wireless access (BWA) technologies is how to support mobility in WiMAX networks smoothly and seamlessly. It is essential that providing continuous services of multimedia streaming data when a mobile subscriber station (MSS) is across a boundary of a serving area to another one. Although the IEEE 802.16e standard is proposed to tackle this difficult problem, the disruption time (DT) of handover is still too long to overcome the maximum delay time of real-time services. To deal with this problem, this paper proposes a pre-coordination mechanism (PCM) for supporting fast handover in WiMAX networks. This goal is achieved by measuring the distance between the BS and the MSS and predicting the time of handover occurs, and thus pre-allocating available resources for handover usages. Simulation results show that the enhanced DT of handover can achieve approximately to 11 milliseconds. The proposed mechanism is fully compatible with the IEEE 802.16e standard. View full abstract»

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  • Methodology and initial analysis results for development of non-invasive and hybrid driver drowsiness detection systems

    Page(s): 16
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (298 KB) |  | HTML iconHTML  

    Application of piezofilm movement sensors integrated into the car seat, seat belt and steering wheel was proposed for development of a non-invasive and hybrid systems for detecting driver drowsiness. A car simulator study was designed to collect physiological data for validation of this technology. Methodology for analysis of physiological data, independent assessment of driver drowsiness and development of drowsiness detection algorithm by means of sequential fitting and selection of regression models is presented. Statistical analysis shows that during the episodes of transitions to dangerous levels of drowsiness movement variations recorded by the seat sensors are decreasing. This finding indicates that the piezofilm movement sensors could be used as noninvasive devices for detecting the level of drowsiness on their own or in combination with other physiological signals. View full abstract»

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  • New Higher Order Rotation Spreading Matrix for BSOFDM

    Page(s): 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (393 KB) |  | HTML iconHTML  

    Previously a new matrix called the rotation spreading matrix was proposed for block spread OFDM which had advantages over other well known spreading matrices such as the Hadamard in frequency selective channels such the UWB channels. Then a new paper discussed a method to expand this Rotation spreading matrix into higher order allowing the system BSOFDM to achieve higher order matrices which still showed excellent orthogonal properties which can be used in these frequency selective channels. This work is continued on the rotation spreading matrix and this paper presents another method to expand the rotation spreading matrix based on complete complementary sets of sequences which the authors have shown to have excellent properties in higher order matrices. This paper discusses the new method and presents a comparison between the two mentioned methods. View full abstract»

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