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Showing papers on "Filter (video) published in 2005"


Journal ArticleDOI
TL;DR: The transmit filters are based on similar optimizations as the respective receive filters with an additional constraint for the transmit power and has similar convergence properties as the receive Wiener filter, i.e., it converges to the matched filter and the zero-forcing filter for low and high signal-to-noise ratio, respectively.
Abstract: We examine and compare the different types of linear transmit processing for multiple input, multiple output systems, where we assume that the receive filter is independent of the transmit filter contrary to the joint optimization of transmit and receive filters. We can identify three filter types similar to receive processing: the transmit matched filter, the transmit zero-forcing filter, and the transmit Wiener filter. We show that the transmit filters are based on similar optimizations as the respective receive filters with an additional constraint for the transmit power. Moreover, the transmit Wiener filter has similar convergence properties as the receive Wiener filter, i.e., it converges to the matched filter and the zero-forcing filter for low and high signal-to-noise ratio, respectively. We give closed-form solutions for all transmit filters and present the fundamental result that their mean-square errors are equal to the errors of the respective receive filters, if the information symbols and the additive noise are uncorrelated. However, our simulations reveal that the bit-error ratio results of the transmit filters differ from the results for the respective receive filters.

792 citations


Proceedings ArticleDOI
18 Apr 2005
TL;DR: Adapt techniques to reduce the number of particles in a Rao-Blackwellized particle filter for learning grid maps are presented and an approach to selectively carry out re-sampling operations which seriously reduces the problem of particle depletion is presented.
Abstract: Recently Rao-Blackwellized particle filters have been introduced as effective means to solve the simultaneous localization and mapping (SLAM) problem. This approach uses a particle filter in which each particle carries an individual map of the environment. Accordingly, a key question is how to reduce the number of particles. In this paper we present adaptive techniques to reduce the number of particles in a Rao-Blackwellized particle filter for learning grid maps. We propose an approach to compute an accurate proposal distribution taking into account not only the movement of the robot but also the most recent observation. This drastically decrease the uncertainty about the robot's pose in the prediction step of the filter. Furthermore, we present an approach to selectively carry out re-sampling operations which seriously reduces the problem of particle depletion. Experimental results carried out with mobile robots in large-scale indoor as well as in outdoor environments illustrate the advantages of our methods over previous approaches.

763 citations


Patent
27 Jan 2005
TL;DR: In this article, a method and system for programming the digital filter compensation coefficients of a digitally controlled switched mode power supply within a distributed power system is provided, which includes a plurality of point-of-load (POL) regulators each comprising at least one power switch adapted to convey power to a load and a digital controller adapted to control operation of the power switch responsive to a feedback measurement.
Abstract: A method and system is provided for programming the digital filter compensation coefficients of a digitally controlled switched mode power supply within a distributed power system. The distributed power system comprises a plurality of point-of-load (POL) regulators each comprising at least one power switch adapted to convey power to a load and a digital controller adapted to control operation of the power switch responsive to a feedback measurement. The digital controller further comprises a digital filter having a transfer function defined by plural filter coefficients. A serial data bus operatively connects each of the plurality of POL regulators. A system controller is connected to the serial data bus and is adapted to communicate digital data to the plurality of POL regulators via the serial data bus. The digital data includes programming data for programming the plural filter coefficients. The system controller further comprises a user interface adapted to receive the programming data therefrom.

525 citations


Journal ArticleDOI
TL;DR: Although base flow separation algorithms in the WHAT system cannot consider reservoir release and snowmelt that can affect stream hydrographs, the Web based WHAT system provides an efficient tool for hydrologic model calibration and validation and demonstrates how remote, distributed resources can be shared through the Internet using Web programming.
Abstract: The separation of the base flow component from a varying streamflow hydrograph is called “hydrograph analysis.” In this study, two digital filter based separation modules, the BFLOW and Eckhardt filters, were incorporated into the Web based Hydrograph Analysis Tool (WHAT) system. A statistical component was also developed to provide fundamental information for flow frequency analysis and time series analysis. The Web Geographic Information System (GIS) version of the WHAT system accesses and uses U.S. Geological Survey (USGS) daily streamflow data from the USGS web server. The results from the Eckhardt filter method were compared with the results from the BFLOW filter method that was previously validated, since measured base flow data were not available for this study. Following validation, the two digital filter methods in the WHAT system were run for 50 Indiana gaging stations. The Nash-Sutcliffe coefficient values comparing the results of the two digital filter methods were over 0.91 for all 50 gaging stations, suggesting the filtered base flow using the Eckhardt filter method will typically match measured base flow. Manual separation of base flow from streamflow can lead to inconsistency in the results, while the WHAT system provides consistent results in less than a minute. Although base flow separation algorithms in the WHAT system cannot consider reservoir release and snowmelt that can affect stream hydrographs, the Web based WHAT system provides an efficient tool for hydrologic model calibration and validation. The base flow information from the WHAT system can also play an important role for sustainable ground water and surface water exploitation, including irrigation and industrial uses, and estimation of pollutant loading from both base flow and direct runoff. Thus, best management practices can be appropriately applied to reduce and intercept pollutant leaching if base flow contributes significant amounts of pollutants to the stream. This Web GIS based system also demonstrates how remote, distributed resources can be shared through the Internet using Web programming.

414 citations


Journal ArticleDOI
TL;DR: In this paper, the authors presented a rigorous design of microstrip bandpass filters with a dual-passband response in parallel-coupled and vertical-stacked configurations, where the second resonant frequency can be tuned over a wide range by adjusting its structure parameters.
Abstract: This paper presents a rigorous design of microstrip bandpass filters with a dual-passband response in parallel-coupled and vertical-stacked configurations. Based on resonance characteristics of a stepped impedance resonator (SIR), the second resonant frequency can be tuned over a wide range by adjusting its structure parameters. Emphasis is placed on filter synthesis for simultaneously matching in-band response and singly loaded Q by using tapped input/output couplings for the two designated passbands. Fractional bandwidth design graphs are used to determine proper geometric parameters of each coupled stage when filter specification is given. Realizable fractional bandwidths of the two passbands for a coupled SIR structure are clearly depicted in fractional bandwidth design graphs. Several experimental filters are fabricated and measured to demonstrate the design.

324 citations


Patent
22 Aug 2005
TL;DR: Everting filter devices as mentioned in this paper are a family of intra-vascular filters that can be used to filter thrombus, emboli, and plaque fragments from blood vessels, and they have a large proximal opening.
Abstract: Everting filter devices and methods for using the devices, including using the devices as intra-vascular filters to filter thrombus, emboli, and plaque fragments from blood vessels. The filter devices include a filter body nominally tubular in shape and having a large proximal opening. The filter body can extend from a proximal first end region distally over the non-everted exterior surface of the filter, further extending distally to a distal-most region, then converging inwardly and extending proximally toward the filter second end region, forming a distal everted cavity. The degree of eversion of the filter can be controlled by varying the distance between the filter first end region near the proximal opening and the closed second end region. Bringing the filter first and second end regions closer together can bring filter material previously on the non-everted filter exterior to occupy the distal-most region.

308 citations


Proceedings ArticleDOI
12 Dec 2005
TL;DR: In this article, two different non-linear complementary filters are proposed: Direct complementary filter and Passive nonlinear complementary filter, which evolve explicity on the special orthogonal group SO(3) and can be expressed in quaternion form for easy implementation.
Abstract: This paper considers the problem of obtaining high quality attitude extraction and gyros bias estimation from typical low cost intertial measurement units for applications in control of unmanned aerial vehiccles. Two different non-linear complementary filters are proposed: Direct complementary filter and Passive non-linear complementary filter. Both filters evolve explicity on the special orthogonal group SO(3) and can be expressed in quaternion form for easy implementation. An extension to the passive ocmplementary filter is proposed to provide adaptive gyro bias estimation.

290 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented a state-of-the-art RF microelectromechanical systems wideband miniature tunable filter designed for 6.5-10 GHz frequency range.
Abstract: This paper presents a state-of-the-art RF microelectromechanical systems wide-band miniature tunable filter designed for 6.5-10-GHz frequency range. The differential filter, fabricated on a glass substrate using digital capacitor banks and microstrip lines, results in a tuning range of 44% with very fine resolution, and return loss better than 16 dB for the whole tuning range. The relative bandwidth of the filter is 5.1 /spl plusmn/ 0.4% over the tuning range and the size of the filter is 5 mm /spl times/ 4 mm. The insertion loss is 4.1 and 5.6 dB at 9.8 and 6.5 GHz, respectively, for a 1-k/spl Omega//sq fabricated bias line. The simulations show that, for a bias line with 10-k/spl Omega//sq resistance or more, the insertion loss improves to 3 dB at 9.8 GHz and 4 dB at 6.5 GHz. The measured IIP/sub 3/ level is > 45 dBm for /spl Delta/f > 500 kHz, and the filter can handle 250 mW of RF power for hot and cold switching.

236 citations


Journal ArticleDOI
TL;DR: The objective is to build a set of filters that are capable of responding stronger to features present in vehicles than to nonvehicles, therefore improving class discrimination and unifies filter design with filter selection by integrating genetic algorithms (GAs) with an incremental clustering approach.
Abstract: Robust and reliable vehicle detection from images acquired by a moving vehicle is an important problem with numerous applications including driver assistance systems and self-guided vehicles. Our focus in this paper is on improving the performance of on-road vehicle detection by employing a set of Gabor filters specifically optimized for the task of vehicle detection. This is essentially a kind of feature selection, a critical issue when designing any pattern classification system. Specifically, we propose a systematic and general evolutionary Gabor filter optimization (EGFO) approach for optimizing the parameters of a set of Gabor filters in the context of vehicle detection. The objective is to build a set of filters that are capable of responding stronger to features present in vehicles than to nonvehicles, therefore improving class discrimination. The EGFO approach unifies filter design with filter selection by integrating genetic algorithms (GAs) with an incremental clustering approach. Filter design is performed using GAs, a global optimization approach that encodes the Gabor filter parameters in a chromosome and uses genetic operators to optimize them. Filter selection is performed by grouping filters having similar characteristics in the parameter space using an incremental clustering approach. This step eliminates redundant filters, yielding a more compact optimized set of filters. The resulting filters have been evaluated using an application-oriented fitness criterion based on support vector machines. We have tested the proposed framework on real data collected in Dearborn, MI, in summer and fall 2001, using Ford's proprietary low-light camera.

235 citations


Journal ArticleDOI
24 Oct 2005
TL;DR: In this paper, the authors proposed a novel approach to adapt a conventional direct power control (DPC) for high-power applications, where a third-order LCL filter is frequently required.
Abstract: This paper proposes a novel approach to adapt a conventional direct power control (DPC) for high-power applications, where a third-order LCL filter is frequently required. The LCL filter can cause a strong resonance and requires additional effort for system control. The application of a DPC for the control of a three-phase voltage source inverter that is connected to the grid through an filter has not yet been considered. The addition of an active damping strategy, together with a harmonic rejection control loop, to the conventional DPC is proposed and analyzed in this paper. The steady-state, as well as the dynamic performance of the proposed system, is verified with simulation results and experimental measurements.

222 citations


01 Jan 2005
TL;DR: Huang's data-driven technique of empirical mode decomposition is given a filter bank interpretation from two complementary perspectives and a stochastic approach shows the spontaneous emergence of an equivalent dyadic filter bank structure when EMD is applied to the versatile class of fractional Gaussian noise processes.
Abstract: Huang’s data-driven technique of empirical mode decomposition (EMD) is given a filter bank interpretation from two complementary perspectives. First, a stochastic approach operating in the frequency domain shows the spontaneous emergence of an equivalent dyadic filter bank structure when EMD is applied to the versatile class of fractional Gaussian noise processes. Second, a similar structure is observed when EMD is operated in the time domain on a deterministic pulse. A detailed statistical analysis of the observed behavior is carried out involving extensive numerical simulations that suggest a number of applications. New EMD-based approaches are used to estimate the scaling exponents in the case of self-similar processes, to perform a fully data-driven spectral analysis, and to denoise-detrend signals that contain noise.

Journal ArticleDOI
TL;DR: In this paper, a coplanar-waveguide filter was proposed for the 12-18 GHz frequency range, with a tuning range of 40% with very fine resolution, and return loss better than 10 dB for the whole tuning range.
Abstract: This paper presents a state-of-the-art RF microelectromechanical systems (MEMS) wide-band tunable filter designed for the 12-18-GHz frequency range The coplanar-waveguide filter, fabricated on a glass substrate using loaded resonators with RF MEMS capacitive switches, results in a tuning range of 40% with very fine resolution, and return loss better than 10 dB for the whole tuning range The relative bandwidth of the filter is 57/spl plusmn/04% over the tuning range and the size of the filter is 8 mm/spl times/4 mm The insertion loss is 55 and 82 dB at 178 and 122 GHz, respectively, for a 2-k/spl Omega//sq bias line The loss improves to 45 and 68 dB at 178 and 122 GHz, respectively, if the bias line resistance is increased to 20 k/spl Omega//sq The measured IIP/sub 3/ level is >37 dBm for /spl Delta/f>200 kHz To our knowledge, this is the widest band planar tunable filter to date

Proceedings ArticleDOI
13 Mar 2005
TL;DR: Distributed crossproducing of field labels (DCFL) is introduced, a novel combination of new and existing packet classification techniques that leverages key observations of the structure of real filter sets and takes advantage of the capabilities of modern hardware technology.
Abstract: A wide variety of packet classification algorithms and devices exist in the research literature and commercial market. The existing solutions exploit various design tradeoffs to provide high search rates, power and space efficiency, fast incremental updates, and the ability to scale to large numbers of filters. There remains a need for techniques that achieve a favorable balance among these tradeoffs and scale to support classification on additional fields beyond the standard 5-tuple. We introduce distributed crossproducing of field labels (DCFL), a novel combination of new and existing packet classification techniques that leverages key observations of the structure of real filter sets and takes advantage of the capabilities of modern hardware technology. Using a collection of real and synthetic filter sets, we provide analyses of DCFL performance and resource requirements on filter sets of various sizes and compositions. An optimized implementation of DCFL can provide over 100 million searches per second and storage for over 200 thousand filters in a current generation FPGA or ASIC without the need for external memory devices.

Journal ArticleDOI
01 Jul 2005
TL;DR: This work proposes a novel, fully autonomous method for pulling a matte using multiple synchronized video streams that share a point of view but differ in their plane of focus, and solves the fully dynamic video matting problem without user assistance.
Abstract: Video matting is the process of pulling a high-quality alpha matte and foreground from a video sequence. Current techniques require either a known background (e.g., a blue screen) or extensive user interaction (e.g., to specify known foreground and background elements). The matting problem is generally under-constrained, since not enough information has been collected at capture time. We propose a novel, fully autonomous method for pulling a matte using multiple synchronized video streams that share a point of view but differ in their plane of focus. The solution is obtained by directly minimizing the error in filter-based image formation equations, which are over-constrained by our rich data stream. Our system solves the fully dynamic video matting problem without user assistance: both the foreground and background may be high frequency and have dynamic content, the foreground may resemble the background, and the scene is lit by natural (as opposed to polarized or collimated) illumination.

Journal ArticleDOI
M Zhong1, H Ye1, Peng Shi1, G Wang1
08 Jul 2005
TL;DR: In this article, the robust fault detection problem for a class of discrete-time linear Markovian jump systems with an unknown input is formulated as an H∞-filtering problem, in which the filter matrices are dependent on the system mode.
Abstract: The paper deals with the robust fault detection problem for a class of discrete-time linear Markovian jump systems with an unknown input. By using a general observer-based fault detection filter as residual generator, the robust fault detection filter design is formulated as an H∞-filtering problem, in which the filter matrices are dependent on the system mode, i.e. the residual generator is a Markovian jump linear system as well. The main objective is to make the error between residual and fault (or, more generally, weighted fault) as small as possible. A sufficient condition to solve this problem is established in terms of the feasibility of certain linear matrix inequalities (LMI), which can be solved with the aid of Matlab LMI Toolbox. A numerical example is given to illustrate the effectiveness of the proposed techniques.

Journal ArticleDOI
01 May 2005
TL;DR: The proposed RegionScout, a family of simple filter mechanisms that dynamically detect most non-shared regions, is presented and is used to avoid broadcasts for non- shared regions thus reducing bandwidth and snoop induced tag lookups thus reducing energy.
Abstract: It has been shown that many requests miss in all remote nodes in shared memory multiprocessors. We are motivated by the observation that this behavior extends to much coarser grain areas of memory. We define a region to be a continuous, aligned memory area whose size is a power of two and observe that many requests find that no other node caches a block in the same region even for regions as large as 16K bytes. We propose RegionScout, a family of simple filter mechanisms that dynamically detect most non-shared regions. A node with a RegionScout filter can determine in advance that a request will miss in all remote nodes. RegionScout filters are implemented as a layered extension over existing snoop-based coherence systems. They require no changes to existing coherence protocols or caches and impose no constraints on what can be cached simultaneously. Their operation is completely transparent to software and the operating system. RegionScout filters require little additional storage and a single additional global signal. These characteristics are made possible by utilizing imprecise information about the regions cached in each node. Since they rely on dynamically collected information RegionScout filters can adapt to changing sharing patterns. We present two applications of RegionScout: In the first RegionScout is used to avoid broadcasts for non-shared regions thus reducing bandwidth. In the second RegionScout is used to avoid snoop induced tag lookups thus reducing energy.

Journal ArticleDOI
TL;DR: In this article, a compact wideband high-rejection microstrip bandstop filter (BSF) was proposed, which combines two traditional BSFs: open-stub filter and spurline filter.
Abstract: A compact wideband high-rejection microstrip bandstop filter (BSF) is presented This filter combines two traditional BSFs: open-stub filter and spurline filter Due to the inherently compact characteristics of the spurline, the proposed filter shows a better rejection performance than open-stub BSF without increasing the circuit size From 37 to 54 GHz, the proposed BSF has a rejection of better than 20 dB and the maximum rejection level of 61 dB Application of this BSF to suppress the second harmonic of an open-loop ring bandpass filter is also investigated with a 40-dB suppression improvement achieved

Proceedings ArticleDOI
13 Mar 2005
TL;DR: This work presents ClassBench, a suite of tools for benchmarking packet classification algorithms and devices, and seeks to eliminate the significant access barriers to realistic test vectors for researchers and initiate a broader discussion to guide the refinement of the tools and codification of a formal benchmarking methodology.
Abstract: Packet classification is an enabling technology for next generation network services and often the primary bottleneck in high-performance routers. The performance and capacity of many algorithms and classification devices, including TCAMs, depend upon properties of the filter set and query patterns. Despite the pressing need, no standard filter sets or performance evaluation tools are publicly available. In response to this problem, we present ClassBench, a suite of tools for benchmarking packet classification algorithms and devices. ClassBench includes a filter set generator that produces synthetic filter sets that accurately model the characteristics of real filter sets. Along with varying the size of the filter sets, we provide high-level control over the composition of the filters in the resulting filter set. The tool suite also includes a trace generator that produces a sequence of packet headers to exercise packet classification algorithms with respect to a given filter set. Along with specifying the relative size of the trace, we provide a simple mechanism for controlling locality of reference. While we have already found ClassBench to be very useful in our own research, we seek to eliminate the significant access barriers to realistic test vectors for researchers und initiate a broader discussion to guide the refinement of the tools and codification of a formal benchmarking methodology.

Journal ArticleDOI
24 Oct 2005
TL;DR: In this paper, the authors proposed to use a controlled excitation in measuring the grid impedance, since this one influences also the resonance frequency, and validated both by simulations and experimental results.
Abstract: Inverters adopted in distributed power generation, active filter, and uninterruptible power supply are often connected to the grid through an inductance-capacitor-inductance (LCL) filter. The impedance of the LCL filter has a typical frequency characteristic with a resonance peak. Hence, the LCL filter has to be damped in order to avoid instability. However, the resonance of the LCL filter can be also excited in a controlled way in order to individuate the resonance frequency in the spectrum (using for example the fast Fourier transform). This paper proposes to use a controlled excitation in measuring the grid impedance, since this one influences also the resonance frequency. This paper will address some possible limits, some solutions, and some implementation issues (e.g., how to obtain a controlled resonance in the filter without damaging the system) in order to use the resonant peak for grid impedance detection. The analysis is validated both by simulations and experimental results.

Patent
07 Apr 2005
TL;DR: In this article, a method and system for detecting and predicting air filter condition for an air handling system operates by determining a system resistance to air flow, which is utilized to determine a detection statistic indicative of current filter condition and to predict remaining life of the air filter.
Abstract: A method and system for detecting and predicting air filter condition for an air handling system operates by determining a system resistance to air flow. The system resistance is utilized to determine a detection statistic indicative of current filter condition and to predict remaining life of the air filter. The system resistance is determined using models that approximate the expected operation of the air handling system. The approximation is then compared to actual values to obtain a difference. Once the difference between the approximated value exceeds a threshold value, an alarm is initiated that is indicative of system resistance. The remaining air filter life is then determined by using historically gathered data, or by using a known degradation rate of the air filter. Once the remaining life of the air filter is estimated, replacement can be scheduled that would coincide with other maintenance.

Journal ArticleDOI
TL;DR: A novel constraint-based motion editing technique that works as a filter that sequentially scans the input motion to produce a stream of output motion frames at a stable interactive rate, based on the per-frame Kalman filter framework.
Abstract: This article presents a novel constraint-based motion editing technique. On the basis of animator-specified kinematic and dynamic constraints, the method converts a given captured or animated motion to a physically plausible motion. In contrast to previous methods using spacetime optimization, we cast the motion editing problem as a constrained state estimation problem, based on the per-frame Kalman filter framework. The method works as a filter that sequentially scans the input motion to produce a stream of output motion frames at a stable interactive rate. Animators can tune several filter parameters to adjust to different motions, turn the constraints on or off based on their contributions to the final result, or provide a rough sketch (kinematic hint) as an effective way of producing the desired motion. Experiments on various systems show that the technique processes the motions of a human with 54 degrees of freedom, at about 150 fps when only kinematic constraints are applied, and at about 10 fps when both kinematic and dynamic constraints are applied. Experiments on various types of motion show that the proposed method produces remarkably realistic animations.

Journal ArticleDOI
TL;DR: In this paper, the insertion voltage gains were derived for EMI filter with arbitrary levels of source and load impedances, based on the S-parameters model, and experiments were carried out to verify this approach.
Abstract: In this paper, the electromagnetic interference (EMI) filter is first characterized using Scattering parameters (S-parameters). Based on this S-parameters model, the insertion voltage gains are derived for EMI filter with arbitrary levels of source and load impedances. Experiments are carried out to verify this approach. Based on the network theory, S-parameters are then utilized to extract the parasitic couplings in both one-stage and two-stage EMI filters. EMI filter models are constructed. Experiments finally verify the proposed methods. The approaches are very useful for the prediction of EMI filter performance, and for the design and optimization of EMI filters.

Proceedings ArticleDOI
05 Dec 2005
TL;DR: A bearing only 3D SLAM algorithm which has the same complexity and optimality as the usual extended Kalman filter used in classical SLAM, and results with an indoor robot and an airship are presented.
Abstract: This article presents a bearing only 3D SLAM algorithm which has the same complexity and optimality as the usual extended Kalman filter used in classical SLAM. We especially focus on the landmark initialization process, which relies on visual point features tracked in the sequence of acquired images: a probabilistic approach to estimate their parameters is presented. This induces a particular structure of the filter architecture, in which are memorized a set of past robot poses. Simulations are made to compare the influence of some parameters required by our approach, and results with an indoor robot and an airship are presented.

Journal ArticleDOI
TL;DR: A high-performance and memory-efficient pipeline architecture which performs the one-level two-dimensional (2-D) discrete wavelet transform (DWT) in the 5/3 and 9/7 filters by cascading the three key components.
Abstract: In this paper, we propose a high-performance and memory-efficient pipeline architecture which performs the one-level two-dimensional (2-D) discrete wavelet transform (DWT) in the 5/3 and 9/7 filters. In general, the internal memory size of 2-D architecture highly depends on the pipeline registers of one-dimensional (1-D) DWT. Based on the lifting-based DWT algorithm, the primitive data path is modified and an efficient pipeline architecture is derived to shorten the data path. Accordingly, under the same arithmetic resources, the 1-D DWT pipeline architecture can operate at a higher processing speed (up to 200 MHz in 0.25-/spl mu/m technology) than other pipelined architectures with direct implementation. The proposed 2-D DWT architecture is composed of two 1-D processors (column and row processors). Based on the modified algorithm, the row processor can partially execute each row-wise transform with only two column-processed data. Thus, the pipeline registers of 1-D architecture do not fully turn into the internal memory of 2-D DWT. For an N/spl times/M image, only 3.5N internal memory is required for the 5/3 filter, and 5.5N is required for the 9/7 filter to perform the one-level 2-D DWT decomposition with the critical path of one multiplier delay (i.e., N and M indicate the height and width of an image). The pipeline data path is regular and practicable. Finally, the proposed architecture implements the 5/3 and 9/7 filters by cascading the three key components.

Journal ArticleDOI
TL;DR: The possibility of combining different rugate filter designs to attain more complex responses is demonstrated by the achievement of a multi-stop-band filter.
Abstract: We report an experimental study of porous silicon-based rugate filters. We performed filter apodization, following a half-apodization approach, which successfully attenuated the sidelobes at both sides of the photonic stop band. We achieved successful reduction of interference ripples through the insertion of index-matching layers on the first and last interfaces. An apodized dielectric mirror and a rugate filter are compared: Appreciable differences in the harmonic presence and stop-band performance were observed and are commented on. Bandwidth control when index contrast is modified is also demonstrated. Finally, the possibility of combining different rugate filter designs to attain more complex responses is demonstrated by the achievement of a multi-stop-band filter. Numerical calculations for design optimization and comparison with experimental data are reported too.

Journal ArticleDOI
07 Nov 2005
TL;DR: In this article, the authors present new ideas for the design and implementation of microwave filters with single and dual stopbands, which can be realized with waveguide, coaxial, dielectric resonators, or in a planar technology.
Abstract: This paper presents new ideas for the design and implementation of microwave filters with single and dual stopbands. They can be realized with waveguide, coaxial, dielectric resonators, or in a planar technology. The new methods represent an advance over present methods in that the resonators are direct coupled, thus avoiding the need for transmission line phase lengths between resonator stubs that tend to degrade performance due to their dispersion and are difficult to adjust during tuning. Three bandstop (BS) configurations are presented. The first will accommodate even or odd characteristics and also asymmetric responses, although some negative or diagonal cross-couplings will be needed. The second resembles the cul-de-sac configuration for bandpass filters and needs no diagonal or negative couplings even for asymmetric characteristics. The third is an application of the cul-de-sac synthesis technique to dual-band bandstop (DBBS) filters. All these BS designs are very similar to regular bandpass filters in their design and realization. The design of a DBBS filter is presented and compared with an equivalent bandpass filter to demonstrate its advantages. Finally, the simulated and measured results of a fourth-degree BS filter design in the novel cul-de-sac configuration are presented.

Journal ArticleDOI
TL;DR: In this paper, the authors reviewed the recent developments of piezoelectric thin-film resonator filters in the world, including their development for mobile communication applications, and described the feature and history of the PLS resonators.
Abstract: The bulk acoustic wave filter composed of piezoelectric thin film resonators has many features superior to those of other small filters such as a surface acoustic wave (SAW) filter and a ceramic filter. As it has no fine structure in its electrode design, it has a high Q factor that leads to low-loss and sharp-cut off characteristics and a high power durability particularly in the high-frequency range. Furthermore, it has the potentiality of integrated devices on a Si substrate. In this paper, we review the recent developments of piezoelectric thin film resonator filters in the world, including our development for mobile communication applications. After describing the feature and history of the piezoelectric thin film resonator filters, our technologies are introduced in focusing on the resonator structures, the piezoelectric thin film and electrode film materials, the cavity structures, the filter structure and its design rules and characteristics, comparing with SAW filters. The competition and coexistence between the piezoelectric thin film resonator filters and the SAW filters are also described. In this paper, we describe the development of a piezoelectric thin film resonator from the standpoint of researchers who have a long experience of SAW filter development.

Proceedings ArticleDOI
01 Jan 2005
TL;DR: In this article, two types of suspended stripline ultra-wideband bandpass filters are described, one based on a standard lumped element (L-C) filter concept including transmission zeroes to improve the upper passband slope, and another consisting of the combination of a low-pass and a high-pass filter.
Abstract: Two types of suspended stripline ultra-wideband bandpass filters are described, one based on a standard lumped element (L-C) filter concept including transmission zeroes to improve the upper passband slope, and a second one consisting of the combination of a low-pass and a high-pass filter.

Proceedings ArticleDOI
15 Aug 2005
TL;DR: Simulation and experimental results are shown to compare the performance of the sigma-point filter with a standard EKF approach, which shows faster convergence from inaccurate initial conditions in position/attitude estimation problems.
Abstract: A sigma-point Kalman filter is derived for integrating GPS measurements with inertial measurements from gyros and accelerometers to determine both the position and the attitude of a moving vehicle. Sigma-point filters use a carefully selected set of sample points to more accurately map the probability distribution than the linearization of the standard extended Kalman filter (KKF), leading to faster convergence from inaccurate initial conditions in position/attitude estimation problems. The filter formulation is based on standard inertial navigation equations. The global attitude parameterization is given by a quaternion, while a generalized three-dimensional attitude representation is used to define the local attitude error. A multiplicative quaternion-error approach is used to guarantee that quaternion normalization is maintained in the filter. Simulation and experimental results are shown to compare the performance of the sigma-point filter with a standard EKF approach.

Proceedings ArticleDOI
04 Apr 2005
TL;DR: The REPLICA (relocation per online configuration alteration) filter is developed, which is capable of performing the necessary bitstream manipulations during the regular download process and enables the integration of dynamic systems that can be adapted to changing demands during runtime.
Abstract: The feature of partial reconfiguration provided by currently available field programmable gate arrays (FPGAs) makes it possible to change hardware modules while others keep working. The combination of this feature and the high gate capacity enables the integration of dynamic systems that can be adapted to changing demands during runtime. Placing the dynamically changing modules along a horizontal communication infrastructure does not only provide communication facilities it also enables the relocation of pre-synthesized modules by bitstream manipulations. The exact placement of an incoming module is determined according to the current resource allocation, which results in an online placement problem. In order to prevent any extra configuration overhead for the relocation process, we developed the REPLICA (relocation per online configuration alteration) filter, which is capable of performing the necessary bitstream manipulations during the regular download process. The filter architecture, a configuration manager and an evaluation example are presented in this paper.