We present here a simple technique for parametrization of popular biorthogonal wavelet filter banks (BWFBs) having vanishing moments (VMs) of arbitrary multiplicity. Given a prime wavelet filter with VMs of arbitrary multiplicity, after formulating it as a trigonometric polynomial depending on two free parameters, we prove the existence of its dual filter based on the theory of Diophantine equation. The dual filter permits perfect reconstruction (PR) and also has VMs of arbitrary multiplicity. We then give the complete construction of two-parameter families of 17/11 and 10/18 BWFBs, from which any linear-phase 17/11 and 10/18 BWFB possessing desired features could be derived with ease by adjusting the free parameters. In particular, two previously unpublished BWFBs for embedded image coding are constructed, both have optimum coding gains and rational coef ficients. Extensive experiments show that our new BWFBs exhibit performance equal to Winger's W-17/11 and Villasenor's V-10/18 (superior to CDF-9/7 by Cohen et al. and Villasenor's V-6/10) for image compression, and yet require slightly lower computational costs.

In this paper, we address the problem of the rotation-invariant texture analysis. For this purpose, we first present a modified version of the discrete Radon transform whose performance, including accuracy and processing time, is significantly better than the conventional transform in direction estimation and categorization of textural images. We then utilize this transform with a rotated version of Gabor filters to propose a new scheme for texture classification. Experimental results on a set of images from the Brodatz album indicate that the proposed scheme outperforms previous works.

An effective way to boost power gain without noise figure degradation in a cascode low noise amplifier (LNA) is demonstrated at 4 GHz using 0.35 µm SiGe HBT technology. This approach maintains the same current consumption because a low-pass π-type LC matching network is inserted in the inter-stage of a conventional cascode LNA. 5 dB gain enhancement with no noise figure degradation at 4 GHz is observed in the SiGe HBT LNA with inter-stage matching.

A Non-Uniform Discrete Multitone (DMT) transceiver employing an octave spaced quadrature mirror filter (QMF) bank, can be used to overcome the problem of channel noise enhancement in the zero-forcing (ZF) equalization technique. In this letter, performance of the Non-Uniform DMT system is analyzed. A study of the crosstalk between sub-channels due to non-ideal filter banks is also presented. Crosstalk analysis is based upon the bit error rate (BER) performance versus the QMF order in a standadard ADSL channel. Performance comparison of the Non-Uniform DMT transceiver and a conventional DMT system is given, and it is shown that the Non-Uniform DMT transceiver displays slight improvement over the conventional DMT system for the filters of higher order.

We propose and demonstrate wavelength-selectable filters available for 32 WDM channels using a micro-mechanically movable mechanism with miniaturized voice-coil motors (VCMs). A simple straight geometry with a staggered configuration is used to densely pack 32 in/out moving elements into a small space of 452411 mm. The elements are precisely arranged along a collimated beam between fiber facets to provide flat-top passbands centered at ITU-T grids while maintaining small total insertion losses of less than 2.5 dB for all elements. The driving condition of the VCMs is also optimized for quick dynamic response with typical settling time of less than 10 ms. A repetition test 106 repetitions per element showed good wavelength reproducibility to an accuracy of below 0.1 nm, indicating the switches are feasible for practical system equipped with reconfigurable functionality for the next generation of optical networks.

This paper presents a method for synthesizing a coherent 1-input 3-output optical delay-line circuit with N stages that is composed of 2(N + 1) directional couplers, N optical delay-lines, 2(N + 1) phase shifters and one external phase shifter with phase value φc . The path difference is equal to the delay time difference Δτ. Synthesis algorithm is based on the division of the transfer matrix into basic component transfer matrices and factorization is completed by repeated size-reduction. A set of recursion equations are also defined to obtain the unknown circuit parameters. In the developed method, it is shown that (13) optical delay-line circuit has the same transmission characteristics as finite impulse response (FIR) digital filters with complex expansion coefficients. Band-pass flat group delay type filter is considered as an example in this paper. It is also confirmed that developed (13) optical delay-line circuit can realize 100% power transmittance.

We report on a channel drop filter with a mode gap in the propagating mode of a photonic crystal slab that was fabricated on silicon on an insulator wafer. The results, simulated with the 3-dimensional finite-difference time-domain and plane-wave methods, demonstrated that an index-guiding mode for the line defect waveguide of a photonic crystal slab has a band gap at wave vector k = 0.5 for a mainly TM-like light-wave. The mode gap works as a distributed Bragg grating reflector that propagates the light-wave through the line defect waveguide, and can be used as an optical filter. The filter bandwidth was varied from 1-8 nm with an r/a (r: hole radius, a: lattice constant) variation around the wavelength range of 1550-1600 nm. We fabricated a Bragg reflector with a photonic crystal line-defect waveguide and Si-channel waveguides and by measuring the transmittance spectrum found that the Bragg reflector caused abrupt dips in transmittance. These experimental results are consistent with the results of the theoretical analysis described above. Utilizing the Bragg reflector, we fabricated channel dropping filters with photonic crystal slabs connected between channel waveguides and demonstrated their transmittance characteristics. They were highly drop efficient, with a flat-top drop-out spectrum at a wavelength of 1.56 µm and a drop bandwidth of 5.8 nm. Results showed that an optical add-drop multiplexer with a 2-D photonic crystal will be available for application in WDM devices for photonic networks and for LSIs in the near future.

In this paper, we study and analyze the computational complexity of deblocking filter in H.264/AVC baseline decoder based on SimpleScalar/ARM simulator. The simulation result shows that the memory reference, content activity check operations, and filter operations are known to be very time consuming in the decoder of this new video coding standard. In order to improve overall system performance, we propose a novel processing order with efficient VLSI architecture which simultaneously processes the horizontal filtering of vertical edge and vertical filtering of horizontal edge. As a result, the memory performance of the proposed architecture is improved by four times when compared to the software implementation. Moreover, the system performance of our design significantly outperforms the previous proposals.

This paper describes a method of free iris and focus image generation based on transformation integrating multiple differently focused images. First, we assume that objects are defocused by a geometrical blurring model. And we combine acquired images on certain imaging planes and spatial information of objects by using a convolution of a three-dimensional blur. Then, based on spatial frequency analysis of the blur, we design three-dimensional filters that generate free iris and focus images from the acquired images. The method enables us to generate not only an all-in-focus image corresponding to an ideal pin-hole iris but also various images, which would be acquired with virtual irises whose sizes are different from the original one. In order to generate a certain image by using multiple differently focused images, especially very many images, conventional methods usually analyze focused regions of each acquired image independently and construct a depth map. Then, based on the map, the regions are merged into a desired image with some effects. However, generally, it is so difficult to conduct such depth estimation robustly in all regions that these methods cannot prevent merged results from including visible artifacts, which decrease the quality of generated images awfully. In this paper, we propose a method of generating desired images directly and robustly from very many differently focused images without depth estimation. Simulations of image generation are performed utilizing synthetic images to study how certain parameters of the blur and the filter affect the quality of generated images. We also introduce pre-processing that corrects the size of acquired images and a simple method for estimating the parameter of the three-dimensional blur. Finally, we show experimental results of free iris and focus image generation from real images.

Using a pair of matched square-root-raised-cosine (SRRC) filters in the transmitter and the receiver in a band-limited digital communication system can theoretically achieve zero inter-symbol interference (ISI). In reality, the ISI cannot be zero when both SRRC filters are approximately implemented because of some numerical precision problems in the design phase as well as in the implementation phase. In this paper, the author proposes an iterative method to design the coefficients of SRRC FIR filters. The required ISI of the system can be specified such that both ISI and frequency domain specifications are monitored in the design phase. Since the ISI can be specified beforehand, the tradeoff between performance and the filter length becomes possible in the proposed design algorithm.

This paper analyzes the steady-state properties of a CORDIC-based adaptive ARMA lattice filter. In our previous study, the convergence properties of the filter in the non-steady state were clarified; however, its behavior in the steady state was not discussed. Therefore, we develop a distinct analysis technique based on a Markov chain in order to investigate the steady-state properties of the filter. By using the proposed technique, the relationship between step size and coefficient estimation error is revealed.

This paper proposes a new microstrip stepped-impedance resonator (SIR) used for bandpass filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends of the resonator with loaded triangular and rectangular microstrips is described. The design concept is demonstrated by two filter examples including four-resonator parallel-coupled Chebyshev bandpass and compact four-resonator cross-coupled elliptic-type filters. These filters are not only compact size due to the slow-wave effect, but also have a wider upper stopband resulting from the resonator bandstop characteristic. The filter designs are described in details. The simulated and experimental results are demonstrated and discussed.

A new receiver structure that combines the constant modulus algorithm (CMA) and the Kalman filter (KF) is investigated to exploit the advantages of both algorithms; simple implementation of blind algorithms, and excellent tracking ability, respectively. The proposed scheme achieves faster convergence and adaptability to the channel variation, which is verified through comparative simulations in doubly-selective (time- and frequency-selective) fading channels.

This paper proposes a Miller capacitor which has a wide input signal range. By discharging the charge of the capacitor connected between the input and output terminals of an amplifier before the output voltage of the amplifier exceeds its maximum range, the amplifier always operates in the active region and the Miller operation can be guaranteed. Thus a large value capacitor with a wide dynamic operation range can be realized using a small value capacitor. The Miller capacitor proposed in this paper is applied to a loop filter of phase locked loop (PLL) circuit that requires a large value capacitor to realize a low cutoff frequency. SPICE simulation of the PLL circuit using the Miller capacitor confirms the operation of the Miller capacitor and shows good performances that are similar to those obtained using a passive capacitor of a large value.

This letter presents an efficient multichannel low-IF reception scheme that improves digital communication quality in the sense of BER performance. Created by simply adding cosine rolloff filters to the conventional multichannel receiver, the proposed receiver achieves much higher accuracy than the conventional one.

This paper overviews the history of a class of varactor tuned bandpass filters. Since the miniaturization as well as the high performance of the tunable bandpass filters is required for the next generation mobile communication systems, the discussion is focused on the various planar type tunable filters including active configurations. Brief design concepts of various tunable filter configurations as well as their characteristics are discussed.

This letter presents an efficient Signed-Power-of-Two (SPT) term allocation for filter coefficients in order to improve the BER characteristics of digital communication systems. The performance of the present allocation is evaluated by BER characteristics through digital modulation simulations and FPGA-based digital implementation.

The Evolutionary Electronics refers to the design method of electronic circuits with the help of Evolutionary Algorithms. Over the years huge experience has been accumulated and tremendous results have been achieved in this field. Two obvious tendencies are prevailing in the area over designers to improve the performance of Evolutionary Algorithms. First of all, as with any solution-search-algorithm, the designers try to reduce the potential solution space in order to reach the optimum solution faster, putting some constrains onto search algorithm as well as onto potential solutions. At the same time, the second tendency of unconstraining the Evolutionary Algorithms in its search gives unpredictable breakthroughs in results. Enabling the evolution to optimize with more experimental parameters devoted to drive the evolution and adjusted previously manually, is one of an example where such kind of unconstraining takes place. The evolution with the maximum freedom of search can be addressed as unconstrained evolution. The unconstrained evolution has already been applied in the past towards the design of digital circuits, and extraordinary results have been obtained, including generation of circuits with smaller number of electronic components. Recently, the similar method has been introduced by authors of this paper towards the design of analogue circuits. The new algorithm has produced promising results in terms of quality of the circuits evolved and evolutionary resources required. It differed from constrained method by its simplicity and represented one of the first attempts to apply Evolutionary Strategy towards the analogue circuit design. In this paper both conventional constrained evolution and newly developed unconstrained evolution in analogue domain are compared in detail on the example of "LC" low-pass filter design. The unconstrained evolution demonstrates the superior behaviour over the constrained one and exceeds by quality of results the best filter evolved previously by 240%. The experimental results are presented along with detailed analysis. Also, the obtained results are compared in details with low-pass filters designed previously.

A novel structure of bandpass filter using NRD guide E-plane resonators is proposed. The NRD guide E-plane resonator is constructed by inserting metal foils in the E-plane of NRD guide. Simulation, fabrication and handling of the filter are very easy because each resonator is separated by simple metal foils. Chebyshev response bandpass filters are designed based on the theory of direct-coupled resonator filters and fabricated at 60 GHz. Simulated and measured filter performances agreed well with the design specifications. Insertion losses of the fabricated filters were found to be around 0.3 dB for 3-pole filter and 0.5 dB for 5-pole bandpass filter, respectively.

A novel wideband bandpass filter with improved stopband characteristics is presented in this paper. Dual-mode square ring resonator is used in the proposed filter. New formulas based on the even- and odd-mode analysis are derived to facilitate the design of transmission zeros of the square ring resonator. A short-circuited stub and a piece of aperture-enhanced parallel-coupled lines are introduced to the input and output of the resonator to lower the passband return loss and widen the stopband of the filter significantly. The filter has a 50% fractional bandwidth, is compact in configuration, and shows remarkably improved performance compared with previously reported filters of the same kind. The measured filtering response shows a good agreement with the simulated result.