Showing papers on "Bessel filter published in 2019"

Wavelet Denoising of High-Bandwidth Nanopore and Ion-Channel Signals.

Abstract: Recent work has pushed the noise-limited bandwidths of solid-state nanopore conductance recordings to more than 5 MHz and of ion channel conductance recordings to more than 500 kHz through the use of integrated complementary metal-oxide-semiconductor (CMOS) integrated circuits. Despite the spectral spread of the pulse-like signals that characterize these recordings when a sinusoidal basis is employed, Bessel filters are commonly used to denoise these signals to acceptable signal-to-noise ratios (SNRs) at the cost of losing many of the faster temporal features. Here, we report improvements to the SNR that can be achieved using wavelet denoising instead of Bessel filtering. When combined with state-of-the-art high-bandwidth CMOS recording instrumentation, we can reduce baseline noise levels by over a factor of 4 compared to a 2.5 MHz Bessel filter while retaining transient properties in the signal comparable to this filter bandwidth. Similarly, for ion-channel recordings, we achieve a temporal response bett...

Performance of grey-coded IQM-based optical modulation formats on high-speed long-haul optical communication link

Abstract: In this article the performance of grey-coded advanced optical modulation formats is evaluated on a single-channel high-speed long-haul optical communication link and are compared to the respective differential-coded modulation formats. Polarisation division multiplexed optical in-phase quadrature modulator (IQM) structure and homodyne detection scheme are used to realise 100 Gbps quadrature phase-shift keying (QPSK), 120 Gbps 16-ary quadrature amplitude modulation (16-QAM), 360 Gbps 32-QAM and 480 Gbps 64-QAM modulation formats. Advanced digital signal processing unit with various pre-processing and recovery stages such as direct current blocking, normalisation, low-pass Bessel filter, resampling, quadrature imbalance compensation, chromatic dispersion compensation, non-linear compensation, timing recovery, adaptive equalisation, down-sampling, frequency offset estimation, and carrier phase estimation is used at the receiving end to compensate for signal impairments during propagation. Maximum transmission distances of 7200, 1050, 560, and 360 km have been achieved at an acceptable bit error rate for QPSK, 16-QAM, 32-QAM, and 64-QAM, respectively. The grey-coded systems outperformed the differential-coded systems regarding optical signal-to-noise ratio requirement, receiver sensitivity, and transmission distance.

An algorithm for the rapid numerical evaluation of Bessel functions of real orders and arguments

Abstract: We describe a method for the rapid numerical evaluation of the Bessel functions of the first and second kinds of nonnegative real orders and positive arguments. Our algorithm makes use of the well-known observation that although the Bessel functions themselves are expensive to represent via piecewise polynomial expansions, the logarithms of certain solutions of Bessel’s equation are not. We exploit this observation by numerically precomputing the logarithms of carefully chosen Bessel functions and representing them with piecewise bivariate Chebyshev expansions. Our scheme is able to evaluate Bessel functions of orders between 0 and 1,000,000,000 at essentially any positive real argument. In that regime, it is competitive with existing methods for the rapid evaluation of Bessel functions and has at least three advantages over them. First, our approach is quite general and can be readily applied to many other special functions which satisfy second order ordinary differential equations. Second, by calculating the logarithms of the Bessel functions rather than the Bessel functions themselves, we avoid many issues which arise from numerical overflow and underflow. Third, in the oscillatory regime, our algorithm calculates the values of a nonoscillatory phase function for Bessel’s differential equation and its derivative. These quantities are useful for computing the zeros of Bessel functions, as well as for rapidly applying the Fourier-Bessel transform. The results of extensive numerical experiments demonstrating the efficacy of our algorithm are presented. A Fortran package which includes our code for evaluating the Bessel functions is publicly available.

Optimization of out-of-band emission using kaiser-bessel filter for UFMC in 5G cellular communications

Abstract: Across the world, we are currently witnessing the deployments of 4G LTE-Advanced and the 5G research is reaching its peak point. The 5G research mainly concentrates on addressing some of the existing OFDM based LTE problems along with use of non-contiguous fragmented spectrum. Universal Filtered Multi Carrier (UFMC) has been considered as one of the candidate waveform for the 5G communications because it provides robustness against the Inter Symbol Interference (ISI), and Inter Carrier Interference (ICI) and is suitable for low latency scenarios. In this paper, a novel approach is proposed to use Kaiser-Bessel filter based pulse shaping instead of standard Dolph-Chebyshev filter for UFMC based waveform to reduce the spectral leakage into nearby sub-bands. In this paper, UFMC system is simulated using MATLAB software, a comparative study for Dolph-Chebyshev and Kaiser-Bessel filters are performed and the results are also presented in terms of power spectrum density (PSD) analysis, Complementary Cumulative Distribution Function (CCDF) analysis, and Adjacent Channel Power Ratio (ACPR) analysis. The simulated results show a better power spectral density and lower sidebands for UFMC (Kaiser Based window), when compared with UFMC (Dolph-Chebyshev) and conventional OFDM.

Selecting the Fastest Settling-Time Filter in PDM-based DACs used for Dynamic Calibration Applications

Abstract: PDM-based DACs are often used in dynamic calibration applications, largely on account of their low cost. An extremely important performance measure in calibration DACs is the settling time. In such DACs, Butterworth filter realizations are widely used because they provide maximum pass-band flatness. In this paper, a study is performed to select the filter type and order that yields the lowest possible settling time with an acceptable area and power efficient design. It will be shown that the use of a 3rd order Bessel or Gaussian filter provides a system that settles quicker than others employing Butterworth. A 3rd order Bessel filter is realized using the Sallen-Key topology with the TSMC 65nm CMOS process to design a 10-bit DAC, used as a design example. The proposed design provides around 25% lower settling time compared to other design architectures in the literature that use Butterworth filters with almost the same power consumption and area occupancy. Similar results are also obtained for 8, 9, 11 and 12-bits of DAC resolution.

Modeling Packet Losses in Communication Networks

Abstract: An approach to constructing discrete models of packet losses suitable for a wide variety of communication network applications is studied. It is based on estimating parameters of probabilistic automata described via so-called pseudo-Markov chains. The new technique is applied both to approximating a discrete time analog process at the output of known channel models and to the experimental data stream. Comparison of models is performed by computing probabilities of more than m losses out of n transmitted packets (P (≥ m, n)). It is shown that for the Rician fading channel with exponential correlation and correlation determined by a Bessel filter, the obtained rank-two and rank-three discrete modes, respectively, provide high accuracy coincidence of P (≥ m, n) performances. The rank-three discrete model computed on the experimental data stream obtained from the LTE network provides significantly better approximation of P (≥ m, n) performance than that obtained by the Baum-Welch algorithm.

G m -C Fractional Bessel Filter Of Order ( $1+\alpha$ )

Abstract: The paper discusses the design and circuit realization of a low-pass fractional Bessel filter of order ( $1+\alpha$ ) using the inverse-follow-the-leader-feedback (IFLF) structure. The transfer function of the Bessel filter is verified for correctness using MATLAB software. The circuit realization of Bessel filter using voltage controlled current source (VCCS) behavioral model of $G_{m}$ -block is validated using Cadence software. The flexibility to adjust the cut-off frequency for different values of $\alpha$ has been verified. The group delay and step response plots for different values of $\alpha$ are presented.

Mach-Zehnder-modulator-based odd sideband suppression ROF system

Abstract: The invention discloses a Mach-Zehnder-modulator-based odd sideband suppression ROF system comprising a wavelength division multiplexing demultiplexer, a wavelength division multiplexer, a single-modefiber, an erbium-doped fiber amplifier, and a first filter processing module and a second filter processing module. The first filter processing module includes a first Bessel filter, a first opticalcoherent DP PSK receiver, a first general digital signal processor, a first determiner, a first PSK sequence decoder and a first parallel-to-serial converter; and the second filter processing module includes a second Bessel filter, a second optical coherent DP PSK receiver, a second general digital signal processor, a second determiner, a second PSK sequence decoder and a second parallel-to-serialconverter.

Electrocardiogram collecting platform

Abstract: The invention belongs to the field of medical instruments, and discloses an electrocardiogram collecting platform. The platform is provided with an input module, and the input module and a preamplifier module are connected by conducting wires; an internal integrated instrument of the preamplifier module is used for amplifying circuit, and the preamplifier module and a main amplifier module are connected by conducting wires; the main amplifier module and a filter network module are connected by conducting wires; the filter network module has a high-pass filter circuit and a low-pass filter circuit, and the low-pass filter circuit uses a second-order Bessel filter circuit; the filter network module is connected to an ECG imaging module by conducting wires; the ECG imaging module is connectedto an image recognition module by conducting wires; and the image recognition module is connected to a display module. The platform can collect the user's electrocardiogram, diagnoses the electrocardiogram image by recognition, displays the diagnosis result intuitively on the display module, has strong practicability and is convenient for the user to understanding self condition without a doctor.

DAQ Golden Rules in the Anti-Aliasing Bessel Filter vs. Potentially Lost Events in the Surface Detectors in Cosmic Rays Experiments

Abstract: The paper discusses the consequence of a standard approach (known as “Golden Rules”) to data acquisition for any surface detector of the cosmic rays experiments. When digitizing the analog signal, the spectrum is usually cut-off according to the Nyquist theorem. The cut-off frequency is set on a half of the sampling frequency. This approach allows avoiding aliasing effects. Nevertheless, if the signals, which we expect to detect, are very short with fast attenuated tails the anti-aliasing filter may dramatically reduce their amplitudes which in consequence may violate the standard trigger conditions. We analyzed large numbers of ADC traces detected by the prototype Front-End Board (FEB) based on the CycloneV FPGA 5CEFA9F31I7. The prototype FEB was not equipped with the anti-aliasing filter. We compared the original traces with filtered off-line in MATLAB. We see that a non-negligible number of events may be lost if the anti-aliasing hardware filter is implemented on the FEB.

Comparative Study About the Effect of Order on Different Analog filters and Adaptive Filters(RLS Algorithm) using MATLAB

Abstract: Filters mainly represent a niche in processing a signal. Analog and digital sections have their own pros and cons. The paper gives an overview of the effect, that the order of the filter imposes on the response of the analogue filters such as: Butterworth, Chebyshev, Elliptic(Cauer)and Bessel filter. The paper also includes the experimental analysis of the noise cancellation using adaptive filters. The implemented example is used to obtain the effect of, the order of the Recursive least square algorithm used for filtering, and the results are demonstrated in frequency domain.