The current issue of the IETE Journal of Research (Vol.63, No.3, May–June 2017) contains 15 articles. These articles present on-going research and developments taking place in the broad areas of Communication Engineering and Signal Processing, Electromagnetics, Computer Science and Biomedical Engineering.
The paper on ‘A lightweight trust mechanism and overhead analysis for clustered WSN’ presents a framework of trust model for large scale clustered wireless sensor network for protecting against malicious attacks. A trust metric is given to assign importance levels. A dynamic trust update algorithm for rewarding or penalizing the trust values of each node is presented. The model also reduces computational overheads, and lowers the communication and storage overhead. The performance of the trust model is reported through simulation studies and comparisons with other methods.
The next paper titled ‘A monolithic low noise channelized active band pass filter using GaAs 0.15 μm technology’, presents a structure for monolithic microwave integrated circuit channelized active band pass filter. Three band pass filter structures are used in which the respective output currents are added. A noise cancelling circuit in the 1 – 7 GHz range is used to reduce the noise of the filter for which the noise analysis is presented. The filter layout is given in GaAs 0.15 μm technology for simulation studies. The performance of the filter is reported in the paper.
In the paper ‘A new technique for reduced order modelling of linear time invariant system’, a method for order reduction of linear time invariant systems is given for both SISO and MIMO systems. The method uses modified pole clustering and factor division algorithm to obtain stable reduced order system while preserving the key properties of the original system. Eigen spectrum analysis and the cuckoo search algorithm are used for the denominator and numerator polynomials. Numerical examples are provided to illustrate the method. It is also compared with other methods of order reduction to show the efficacy of the proposed method.
The next paper ‘A novel nanometric parity-preserving reversible carry look-ahead adder’, presents methods for nanometric parity preserving reversible 2-bit carry look- ahead adder. The arithmetic and logic unit (ALU) components in the quantum cellular automata framework is required for realizing the advantages of quantum computing. The given method optimizes on the number of garbage outputs, constant inputs, and quantum costs. Nanometric parity preserving reversible 4-bit carry look-ahead adder is also presented.
The paper titled ‘A novel time-to-digital converter based on low jitter phase-locked loop’, presents a multi-level time-to-digital converter (TDC) for array architectures for measuring photon time-of-flight. A low jitter phase-locked loop is used in realizing the TDC in TSMC 0.35 μm standard CMOS process with 3.3 V supply. The efficacy of the design is presented through simulation studies in terms of time interval error, jitter and other measures and is compared with other methods from the literature.
The following paper on ‘A stream cipher based on spatiotemporal chaos and true random synchronization’, is concerned with encryption algorithms. It presents a chaos-based stream cipher with a method for synchronization. Stream ciphers are required for initialization vectors (IV) for ensuring the same secret key in different key streams but are used only once. Fixed-point representation is used for higher efficiency. The design details, including IV setup and key stream phase are presented. The paper presents the security analysis of the chaotic cipher in terms of randomness, periodicity, entropy, complexity and other measures.
In the paper on ‘A weighted sparse neighbourhood preserving projections for face recognition’, an unsupervised sparse subspace learning approach for face recognition is presented. The method addresses the problem of large dimensionality of data and their projections to lower dimensional space, in an unsupervised manner given its advantages of flexibility and effectiveness. The method uses a weighted sparse representation model to represent the samples. The performance of the method on different image datasets is presented.
The next paper titled ‘An energy-aware routing and filtering node (ERF) selection in CCEF to extend network lifetime in WSN’, gives an energy-aware routing and filtering node selection criteria to extend the lifetime of a network. The criteria of distance to destination and residual energy are considered for forwarding node selection. The paper presents simulation results that show the efficacy of the approach in improving the network lifetime and energy balancing across large number of sensors.
The paper ‘Calibration of high resolution synthetic aperture radar (SAR) image features by ground based experiments’, shows a ground based calibration method for high resolution FMCW SAR image features. The features of images generated by FMCW SAR sensors require calibration for interpretation purposes. Target RCS and speckle properties are derived from single-look and multi-look processing of experimental data to calibrate and process the FMCW SAR images.
The next paper, ‘Investigation on the compression of electrocardiogram signals using dual tree complex wavelet transform’, is concerned with the compression of ECG signals. It examines the dual-tree complex wavelet transform (DT-CWT) and set partitioning in hierarchical tree (SPHIT) coding to compress the data. The compression performance is compared with other methods in the paper.
In the paper ‘Null placement in time modulated linear antenna arrays of dipole element’, an implementation of time modulated linear dipole antenna arrays (TMLDAA) is presented. The null performance of TMLDAA by RF switch is improved using CSO algorithm. The optimized results from CSO algorithm are used in CST-MWS simulation software to derive the performance of the antenna.
The paper titled ‘Optimal and suboptimal estimation of quadratic functionals of the state vector in linear stochastic systems’, deals with the estimation of a quadratic functional of a random signal in dynamic systems described by linear stochastic differential equations. An optimal mean square estimator for arbitrary quadratic functional in linear stochastic systems is presented. The estimation method leads to closed-form estimation procedure. The mean square errors are derived. The method is demonstrated with examples and comparisons are made between optimal and suboptimal estimators.
In the paper ‘Outage probability of EGC receiver over composite fading channels with phase error and co-channel interference’, the derivation of the outage probability of an arbitrary branch equal gain combining receiver with carrier phase error in the presence of co-channel interference in composite generalized gamma and composite generalized K fading environment, is given. The numerical evaluation of the outage probability as function of SIR from the expressions is shown in graphical form.
The next paper ‘Synthesis of reconfigurable antenna array using differential evolution algorithm’, presents the design of a reconfigurable array using differential evolution algorithm. The optimum phase weights are obtained. Discrete amplitudes and discrete phases of 4 and 5 bits respectively are used for the array feed network. Various cost function parameters are considered in obtaining the optimal weights of the array for dual-beam. Simulation results are given to show the efficacy of the given reconfigurable antenna array design method in terms of side lobe levels and null steering performance.
The paper on ‘Systematic design of current-mode multiple-loop feedback filters based on a single CDCTA’, gives a design for current differencing cascaded trans- conductance amplifier (CDCTA). Its circuit realization is presented. The CDCTA is used to design a method for generating current-mode multiple-loop feedback filter. Using the design matrix, several current-mode all-pole low pass filter structures can be synthesized without altering the internal circuit. An example filter design and its Cadence simulation results are presented and compared with theoretical analysis.
Related Research Data
