The ionospheric delay is one of the largest sources of error that affects the Global Positioning System (GPS) positioning accuracy. By combining simultaneous measurements of signals at two different frequencies the effect can be minimized due to the depressive nature of the ionosphere. But it remains a problem for single-frequency GPS receiver users. GPS signal propagation speed in the ionosphere is characterized by its refractive index. The phase and group refractive indexes are derived to calculate the ionosphere effect on the GPS signal measurement. Several electron density models such as Bent and IRI are available for the study of electron density profiles at different altitudes of the ionosphere. Klobuchar model is the only model available for estimating the ionospheric time delay for single frequency GPS users. The Klobuchar model is a simple-computational model with an ideal description for the ionosphere’s average behavior. In dual frequency receivers, ionosphere delay can be estimated precisely by taking the advantage of the depressive nature of the GPS frequencies. In this paper Total Electron Content (TEC) values are presented for a typical day using phase and code measurements of a dual frequency GPS receiver located at Hyderabad, India and using the Klobuchar model also. The results are analyzed and presented.

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This paper presents simple and reliable method for the detection of QRS complexes (cardiac beat) in single lead Electrocardiograms (ECG) using Support Vector Machine (SVM). Two different preprocessing techniques are applied for the generation of features. First involves digital filtering to remove base line wander and power line interference while the second involves entropy criterion for feature generation. SVM is used as a classifier to classify QRS and non-QRS regions. The results of the validation of the method on the standard CSE ECG database are also presented. Detection rate of 99.79 % is achieved. The percentage of false positive and false negative is 0.86 % and 0.21 % respectively. The proposed method functions reliably even under the condition of poor signal quality of the ECG. The detection rate depends strongly on the quality of training, data representation and the mathematical basis of the classifier.

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Information about location of a mobile phone can be very useful in tacking issues like limitations of frequency spectrum and co-channel interference which has always presented challenges in proper functioning of a mobile communication system. This paper presents simulation results of two mobile location-tracking techniques in terms of accuracy. The techniques considered are represented in terms of mathematical equations which give information about location of mobile station (MS) in terms of x and y coordinates. A modification in one of the equations is also suggested which is verified through simulation, regarding its accuracy in determining the location of a mobile station can be increased.

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This paper presents a new methodology to re-use test-benches in FPGA/ASIC testing. The state-of-the art methodology uses hardware/software co-design. A platform is developed which combines the advantages of simulation & Automatic Test Equipment (ATE) using Re-configurable Devices (RD) like FPGAs to verify the functionality of ASICs and RDs. The proposed testing environment consists of the FPGA based re-configurable hardware and set of software tools to interface between a simulator and hardware environment. It is a standalone tool i.e. Independent of any CAD development environment and runs from any PC with windows operating system. It takes in a test bench in Value Change Dump (VCD) format (1) and converts it to a set of test patterns, compatible with hardware. Software tool includes VCD to IOC (Input-Output Conflagration), Signal replication and methodology of generating test patters. The test bench created by the designer is reused to create VCD file. The same is input as a test pattern for the Device Under Test (DUT) through ASIC Tester (AT). In the developed AT, VCD formats are modified, rather de-optimized in memory usage for hardware design simplicity and acceleration. The results obtained from DUT are compared with the simulation results obtained while designing RTL of the ASIC/FPGA for further fault analysis if any.

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A new block-based normalized least mean square (NLMS) algorithm with set-membership filtering (SMF) criteria is proposed for symbol rate decision feedback equalization. This block-based simplification of NLMS algorithm with the principle of SMF provides substantial reduction in filter weight updating operations as well as less bit error rate while keeping the convergence speed almost same as the existing algorithms for the same purpose. It is shown in the results that the introduced algorithm yields better performance in presence of co-channel interference and also offers significant reduction in certain implementational operations due to its structural simplicity.

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The detection of neural spike activity is a technical challenge that needs to be studied for examining many types of brain functions, This paper presents some aspects of fast non-linear association measures, based on the work of Cramer (V) and Sakoda’s adjusted Pearson’s C, (C�). The features of these new measures like the V measure and Sakoda’s measure are manifested when applied to bio-signals like Electroencephalographic (EEG) signals. A comparative study with other well-known association measures of EEG signals is presented. Based on the analysis of the experimental results it can be concluded that Sakoda’s adjusted Person’s measure produces better results than other measures. The following results are also verified (1) Chi-Squared (X2) value which is approximately equal to 2N times the Mutual information (M1) and (2). The value of the Information Transmission coefficient Txy without and with V yielded approximately the same result. This proposal aims at optimizing the resources such as time and memory storage by reducing the number of electrodes.

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In this paper, we have proposed an analytical model that computes the blocking probability and the channel utilization for a given load on the optical networks with wavelength conversion at the nodes. The computation has been carried out for fixed routing with uniform traffic distribution (UTD). When any link on a route blocks a call, the dropped call reduces the offered load on all other links involved in the route. The overall blocking probability of the network is estimated using Erlang fixed point approximation with the reduced load on the links. The expression has been validated by comparing the results with that of simulation for a number of standard networks including 14 node NSFNET, 20 node ARPANET and 20 node INDIANET, We show that the analytical method performs well in the desired range of blocking probabilities and is applicable to any network topology.

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A feedback configuration is presented for canonical realization of an arbitrary IIR transfer function H(z) = P(z) / Q(z) with M = P(z) < N = Q(z), which does not appear to have been discussed in the literature. It consists of an IIR transfer function F(z) of degree R in the forward path, where M < R > N, and an FIR transfer function G(z) AND G(z) can be realized by an any structure including lattice, if applicable. Application of this method is shown to solve the problem of canonical lattice realization of any IIR transfer function H(z) = P(z) / Q(z) in which M < N and the constant terms in P(z) is absent.

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In this paper the performance of an Integrated Services (IntServ) Satellite network, loaded with two QoS traffic classes, Controlled Load traffic classes, Controlled Load Services (CLS) and Guaranteed Services (GS), has been shown. The GS Burst Loss Percentage (BLP) has examined and the behavior of the system loaded with both classes of service has been analyzed. A novel management of CLS has been considered in order to analyze the system behavior with different percentages of GS and CLS traffic in terms of burst loss. We have studied the Call Admission Control (CAC) phase for CLS in the satellite network. Different simulations have been performed varying some network parameters and we have analyzed the CLS bandwidth levels declared in satellite admission phase. Furthermore, a regression analysis on simulation results is carried out in order to obtain an expression for the average GS BLP as a function of the traffic load and CLS peak values.

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This note presents some simple alternative solutions to the cases requiring modification of the procedure given in [1] for canonic lattice realization of a arbitrary transfer functions.

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