The combined effect of imperfect magnitude and phase of fading estimates in maximal ratio combining (MRC) is analysed. Theoretical error rate bounds are derived under small estimate errors. These bounds are tested ove...
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The combined effect of imperfect magnitude and phase of fading estimates in maximal ratio combining (MRC) is analysed. Theoretical error rate bounds are derived under small estimate errors. These bounds are tested over Rayleigh and Nakagami-m fading channels with binary phase shift keying (BPSK) modulation, and verified using computer simulation. Numerical results quantify the sensitivity of MRC to errors in fading estimates. It is numerically demonstrated that for BPSK, MRC is more sensitive to errors in phase estimates than to errors in magnitude estimates.
Circuits and knots in the digraph model of a manufacturing system are the rudimentary causes of deadlocks. The order of circuits is closely related to impending deadlocks - a type of deadlock that is difficult to dete...
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Circuits and knots in the digraph model of a manufacturing system are the rudimentary causes of deadlocks. The order of circuits is closely related to impending deadlocks - a type of deadlock that is difficult to detect. A new deadlock avoidance algorithm that dynamically evaluates the order of circuits is presented. The algorithm is highly permissive since the order evaluation captures more parts flow dynamics, especially when there exist multiple knots in the digraph model. It also runs in polynomial time once the set of circuits of the digraph is given. Simulation results are provided to illustrate the application of the algorithm.
Microwave brightness temperatures are obtained from the SeaWinds scatterometer on the QuikSCAT satellite. These QuikSCAT Radiometer (QRad) measurements are used to infer instantaneous oceanic rain rates using a statis...
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Microwave brightness temperatures are obtained from the SeaWinds scatterometer on the QuikSCAT satellite. These QuikSCAT Radiometer (QRad) measurements are used to infer instantaneous oceanic rain rates using a statistical retrieval algorithm that is based upon collocated TMI measurements. QRad instantaneous rain rate measurements have been binned in 0.5 hour local time windows onto a 0.5° × 0.5° ocean grid. Also, an average rain rate product is produced, where QRad instantaneous rain rates have been averaged for five-day intervals (pentads) in the 0.5 hour local time windows. The scientific utility of QRad rain measurements is that they provide increased temporal and spatial sampling, which complements that provided by the TRMM Microwave Imager (TMI) and the Special Sensor Microwave Imagers (SSMI's) on the three DMSP satellites. Examples for the year 2000 are presented with corresponding rain rate measurements derived from TMI and SSMI. The results demonstrate that QRad rain measurements agree well with these independent rain observations.
Three-dimensional circuits built on multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimetre-wave integrated circuits on CMOS (low resistivity) Si wafers. However, the closely...
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Three-dimensional circuits built on multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimetre-wave integrated circuits on CMOS (low resistivity) Si wafers. However, the closely spaced transmission lines are susceptible to high levels of coupling, which degrade circuit performance. In this paper, finite difference time domain (FDTD) analysis and measured characteristics of novel shielding structures that significantly reduce coupling between embedded microstrip lines are presented. A discussion of the elec.ric and magnetic field distributions for the coupled microstrip lines is presented to provide a physical rationale for the presented results.
This paper addresses the problem of robust filtering for uncertain linear signal models affected by time delays in the state. Uncertainty is structured and the model is assumed to lie in a given bounded polyhedral set...
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ISBN:
(纸本)0780379241
This paper addresses the problem of robust filtering for uncertain linear signal models affected by time delays in the state. Uncertainty is structured and the model is assumed to lie in a given bounded polyhedral set. The main innovation is the use of a nonrational filter, that is, a filter that also contains delays in the filter state. Robust filtering performance is evaluated using the H2 or the H∞ norm. The performance conditions are delay independent, and provide convex filtering design problems which are convex optimization problems with linear matrix inequalities constraints.
Various aspects that have been discussed in a report entitled IT Roadmap to a Geospatial Future are reported. The report presents the challenges faced in location-aware computing. It also covers other themes such as g...
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Various aspects that have been discussed in a report entitled IT Roadmap to a Geospatial Future are reported. The report presents the challenges faced in location-aware computing. It also covers other themes such as geospatial databases and data mining, and human interaction with geospatial information. Advances in location-aware computing, in particular, could have important implications not just for how geospatial data are acquired but also for how and with what quality can they be delivered.
An algorithm for computing ray/Bézier patch intersections is described from a hardware design perspective. This algorithm uses patch subdivision and other geometrical techniques to find a given maximum number of ...
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An algorithm for computing ray/Bézier patch intersections is described from a hardware design perspective. This algorithm uses patch subdivision and other geometrical techniques to find a given maximum number of intersection points nearest to the ray origin. A pipeline-based hardware architecture is proposed, the number of pipeline stages required is verified by simulation, and the performance of a load-balanced implementation based on a state-of-the-art digital signal processor is estimated.
In this paper, a novel approach for fabricating low cost capacitive RF MEMS switches using directly photodefinable high dielec.ric constant metal oxides has been developed. In this approach, a radiation sensitive meta...
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In this paper, a novel approach for fabricating low cost capacitive RF MEMS switches using directly photodefinable high dielec.ric constant metal oxides has been developed. In this approach, a radiation sensitive metal-organic precursor is deposited via spin coating and converted patternwise to a high dielec.ric constant metal oxide via ultraviolet exposure. The feasibility of this approach is demonstrated by fabricating bridge-type and cantilever-type switches with a nitride/metal-oxide/nitride dielec.ric film stack. These switches exhibited significantly higher isolation and load capacitances as compared to comparable switches fabricated using a simple silicon nitride dielec.ric.
Nano scale body-tied FinFETs have been firstly fabricated. They have fin top width of 30 nm, fin bottom width of 61 nm, fin height of 99 nm, and gate length of 60 nm. This Omega MOSFET shows excellent transistor chara...
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Nano scale body-tied FinFETs have been firstly fabricated. They have fin top width of 30 nm, fin bottom width of 61 nm, fin height of 99 nm, and gate length of 60 nm. This Omega MOSFET shows excellent transistor characteristics, such as very low subthreshold swing, Drain Induced Barrier Lowering (DIBL) of 24 mV/V, almost no body bias effect, and orders of magnitude lower I SUB/ID than planar type DRAM cell transistors.
Estimation of the number of clusters is an essential processing step for various applications. Existing approaches search for an optimal solution by computing and comparing a validity measure for all feasible configur...
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Estimation of the number of clusters is an essential processing step for various applications. Existing approaches search for an optimal solution by computing and comparing a validity measure for all feasible configurations, and tend to under-estimate the number of clusters incorrectly. In this paper, we propose a fast and robust method to estimate the number of clusters without adopting the exhaustive search. Our sch.me first extracts the relationship of neighboring features, and then uses this information to partition the clusters. The superb performance of the method is verified by the simulation results in determining the number of texture segments in the textured images.
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