One of the most important problems of reliable communications in shallow water channels is intersymbol interference (ISI) which is due to scattering from surface and reflecting from bottom. Using adaptive equalizers i...
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One of the most important problems of reliable communications in shallow water channels is intersymbol interference (ISI) which is due to scattering from surface and reflecting from bottom. Using adaptive equalizers in receiver is one of the best suggested ways for overcoming this problem. In this paper, we apply the family of selective regressor affine projection algorithms (SR-APA) and the family of selective partial update APA (SPU-APA) which have low computational complexity that is one of the important factors that influences adaptive equalizer performance. We apply experimental data from Strait of Hormuz for examining the efficiency of the proposed methods over shallow water channel. We observe that the values of the steady-state mean square error (MSE) of SR-APA and SPU-APA decrease by 5.8 (dB) and 5.5 (dB), respectively, in comparison with least mean square (LMS) algorithm. Also the families of SPU-APA and SR-APA have better convergence speed than LMS type algorithm.
STEPPING MOTORS ARE USED IN numerous applications because of their low manufacturing cost and simple open-loop position control capabilities. It is well known that their energy efficiency is low, although the actual e...
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STEPPING MOTORS ARE USED IN numerous applications because of their low manufacturing cost and simple open-loop position control capabilities. It is well known that their energy efficiency is low, although the actual efficiency values are generally not available. Moreover, the bulk of the stepping motors are driven in a non-optimal way, e.g., in an open loop with a maximum current to avoid step loss and, thus, with low efficiency. In this article, the impact of the control algorithm on the efficiency of the motor is analyzed, measured, and discussed. The basic open-loop full-, half-, and microstepping algorithms are considered together with a more advanced vector control algorithm. For each algorithm, the torque/current optimization is discussed.
An algorithm for adaptive pulse signal shaping is proposed for the tag response signal with large fluctuations of radio frequency identification (RFID) tag test systems, which has not been addressed in the literature ...
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An algorithm for adaptive pulse signal shaping is proposed for the tag response signal with large fluctuations of radio frequency identification (RFID) tag test systems, which has not been addressed in the literature for the scenario. To verify the proposed algorithm, an experimental platform implemented with a field programmable gate array (FPGA) is set up based on National Instruments. The experimental results show that the algorithm is sufficient for correcting the RFID tag response pulse signal even for the signal with severe signal distortion.
A novel wide-pipeline low-density parity-check (LDPC) decoder approach for the worldwide interoperability for microwave access (WiMAX) standard (802.16e) is proposed for execution on field-programmable gate arrays (FP...
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A novel wide-pipeline low-density parity-check (LDPC) decoder approach for the worldwide interoperability for microwave access (WiMAX) standard (802.16e) is proposed for execution on field-programmable gate arrays (FPGAs), using a high-level synthesis tool to reduce the development effort and design validation time that generates a wide-pipeline architecture. Optimised open computing language (OpenCL)-based kernels are developed and the integration of distinct configurations of single instruction multiple data and compute units to increase the level of parallelism are analysed. The decoding throughput surpasses the minimal requirements of 75 Mbit/s, a key figure of merit that ranks the design with other very large-scale integration-based approaches. Furthermore, extra precision is deployed with 8-bit fixed-point arithmetic, delivering superior bit error rate performance and lower error floor regions.
A wireless indoor positioning system using white LED lights is proposed. The time difference of arrival technique is employed and the phase differences between the received signals are determined to develop a position...
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A wireless indoor positioning system using white LED lights is proposed. The time difference of arrival technique is employed and the phase differences between the received signals are determined to develop a positioning algorithm which can estimate the receiver location with a mean localisation error as low as 1 mm in a room of dimensions 5 x 5 x 3 m. Through simulations, it is identified that the optimum receiver height where localisation error gets minimised is between 2.5 and 3 m from the ceiling which corresponds well with the typical dimensions of a room.
In this study, a new normalised adaline-based control algorithm is proposed to control voltage source converter (VSC) used for voltage control and harmonics mitigation of two-winding asymmetric single-phase self excit...
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In this study, a new normalised adaline-based control algorithm is proposed to control voltage source converter (VSC) used for voltage control and harmonics mitigation of two-winding asymmetric single-phase self excited induction generator (SEIG) feeding fluctuating linear and non-linear loads. The proposed control algorithm is implemented on a digital signal processor (DSP). In the proposed SEIG system, a two-winding asymmetric single-phase SEIG is driven by a speed governor controlled diesel/biogas engine. The VSC is used for adjustable fundamental reactive current compensation of a two-winding single-phase SEIG for voltage control, and harmonics elimination of variety of loads. An insulated gate bipolar transistor-based two-leg VSC is connected at the point of common coupling. The proposed new control algorithm has many distinct advantages such as fast response which is highly desirable for fluctuating loads and fast convergence at all frequency components. The mathematical formulation of the proposed control algorithm is given and recorded test results of the SEIG system are presented to demonstrate the voltage control, harmonics mitigation and fast response of the algorithm. The proposed controller of single-phase SEIG system is designed, developed and implemented on a DSP to validate the claims. A MATLAB simulation model of SEIG system with proposed controller is also developed and simulated results are presented along with the test results to validate the model developed.
Motivation: New sequencing technologies generate larger amount of short reads data at decreasing cost. De novo sequence assembly is the problem of combining these reads back to the original genome sequence, without re...
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Motivation: New sequencing technologies generate larger amount of short reads data at decreasing cost. De novo sequence assembly is the problem of combining these reads back to the original genome sequence, without relying on a reference genome. This presents algorithmic and computational challenges, especially for long and repetitive genome sequences. Most existing approaches to the assembly problem operate in the framework of de Bruijn graphs. Yet, a number of recent works use the paradigm of string graph, using a variety of methods for storing and processing suffixes and prefixes, like suffix arrays, the Burrows-Wheeler transform or the FM index. Our work is motivated by a search for new approaches to constructing the string graph, using alternative yet simple data structures and algorithmic concepts. Results: We introduce a novel hash-based method for constructing the string graph. We use incremental hashing, and specifically a modification of the Karp-Rabin fingerprint, and Bloom filters. Using these probabilistic methods might create false-positive and false-negative edges during the algorithm's execution, but these are all detected and corrected. The advantages of the proposed approach over existing methods are its simplicity and the incorporation of established probabilistic techniques in the context of de novo genome sequencing. Our preliminary implementation is favorably comparable with the first string graph construction of Simpson and Durbin (2010) (but not with subsequent improvements). Further research and optimizations will hopefully enable the algorithm to be incorporated, with noticeable performance improvement, in state-of-the-art string graph-based assemblers.
To focus synthetic aperture radar data suffering from phase errors, a novel autofocus algorithm is presented. The algorithm uses the coordinate descent technique to estimate the phase errors for maximum sharpness auto...
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To focus synthetic aperture radar data suffering from phase errors, a novel autofocus algorithm is presented. The algorithm uses the coordinate descent technique to estimate the phase errors for maximum sharpness autofocus, where analytical-form expressions are easy to find for the optimal estimates on a per-parameter basis. Experimental results show the validity of the proposed algorithm.
Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand m...
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Wind-blown sand movement often occurs in a very complicated desert environment where sand dunes and ripples are the basic forms. However, most current studies on the theoretic and numerical models of wind-blown sand movement only consider ideal conditions such as steady wind velocity, flat sand surface, etc. In fact, the windward slope gradient plays a great role in the lift-off and sand particle saltation. In this paper, we propose a numerical model for the coupling effect between wind flow and saltating sand particles to simulate wind-blown sand movement over the slope surface and use the SIMPLE algorithm to calculate wind flow and simulate sands transport by tracking sand particle trajectories. We furthermore compare the result of numerical simulation with wind tunnel experiments. These results prove that sand particles have obvious effect on wind flow, especially that over the leeward slope. This study is a preliminary study on windblown sand movement in a complex terrain, and is of significance in the control of dust storms and land desertification.
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