Interconnecting networks with optimized service provisioning

Telecommunication Systems - A recent trend of peering at geo-diversified Internet exchange points (IXPs) has empowered decades-old proposal of inter-networking and opened up new avenues of business...     

Sustainable Green Fog Computing for Smart Agriculture

Wireless Personal Communications - Medical Body Area Networks or MBANs are gaining popularity in healthcare circles because of the convenience they provide to patients and caregivers and assist in...     

Current mode biquadratic filter realizations employing operational amplifiers

New circuit configurations for realizing current mode biquadratic filter sections using operational amplifiers are presented. Each circuit uses a single operational amplifier and seven passive elements at most. The merits and demerits of the proposed realizations are discussed.     

Fast motion estimation for surveillance video compression

In this article, novel approaches to perform efficient motion estimation specific to surveillance video compression are proposed. These includes (i) selective (ii) tracker-based and (iii) multi-frame-based motion estimation. In selective approach, motion vector search is performed for only those frames that contain some motion activity. In another approach, contrary to performing motion estimation on the encoder side, motion vectors are calculated using information of a surveillance video tracker. This approach is quicker but for some scenarios it degrades the visual perception of the video compared with selective approach. In an effort to speed up multi-frame motion estimation, we propose a fast multiple reference frames-based motion estimation technique for surveillance videos. Experimental evaluation shows that significant reduction in computational complexity can be achieved by applying the proposed strategies.     

A noise constrained least mean fourth (NCLMF) adaptive algorithm

The learning speed of an adaptive algorithm can be improved by properly constraining the cost function of the adaptive algorithm. In this work, a noise-constrained least mean fourth (NCLMF) adaptive algorithm is proposed. The NCLMF algorithm is obtained by constraining the cost function of the standard LMF algorithm to the fourth-order moment of the additive noise. The NCLMF algorithm can be seen as a variable step-size LMF algorithm. The main aim of this work is to derive the NCLMF adaptive algorithm, analyze its convergence behavior, and assess its performance in different noise environments. Furthermore, the analysis of the proposed NCLMF algorithm is carried out using the concept of energy conservation. Finally, a number of simulation results are carried out to corroborate the theoretical findings, and as expected, improved performance is obtained through the use of this technique over the traditional LMF algorithm.     

Configurable FFT Processor Using Dynamically Reconfigurable Resource Arrays

This paper presents results of using a Coarse Grain Reconfigurable Architecture called DRRA (Dynamically Reconfigurable Resource Array) for FFT implementations varying in order and degree of parallelism using radix-2 decimation in time (DIT). The DRRA fabric is extended with memory architecture to be able to deal with data-sets much larger than what can be accommodated in the register files of DRRA. The proposed implementation scheme is generic in terms of the number of FFT point, the size of memory and the size of register file in DRRA. Two implementations (DRRA-1 and DRRA-2) have been synthesized in 65 nm technology and energy/delay numbers measured with post-layout annotated gate level simulations. The results are compared to other Coarse Grain Reconfigurable Architectures (CGRAs), and dedicated FFT processors for 1024 and 2048 point FFT. For 1024 point FFT, in terms of FFT operations per unit energy, DRRA-1 and DRRA-2 outperforms all CGRA by at least 2× and is worse than ASIC by 3.45×. However, in terms of energy-delay product DRRA-2 outperforms CGRAs by at least 1.66× and dedicated FFT processors by at least 10.9×. For 2048-point FFT, DRRA-1 and DRRA-2 are 10× better for energy efficiency and 94.84 better for energy-delay product. However, radix-2 implementation is worse by 9.64× and 255× in terms of energy efficiency and energy-delay product when compared against a radix-2⁴ implementation.

     

Interface state densities, low frequency noise and electron mobility in surface channel In0.53Ga0.47As n-MOSFETs with a ZrO2 gate dielectric

This paper reports on an investigation of interface state densities, low frequency noise and electron mobility in surface channel In_0.53Ga_0.47As n-MOSFETs with a ZrO₂ gate dielectric. Interface state density values of D_it ∼ 5 × 10¹² cm⁻² eV⁻¹ were extracted using sub-threshold slope analysis and charge pumping technique. The same order of magnitude of trap density was found from low frequency noise measurements. A peak effective electron mobility of 1200 cm²/Vs has been achieved. For these surface channel In_0.53Ga_0.47As n-MOSFETs, it was found that η parameter, an empirical parameter used to calculate the effective electric field, was ∼0.55, and is to be comparable to the standard value found in Si device.     

A 550-MSample/s 8-Tap FIR digital filter for magnetic recordingread channels

An area-efficient low-power and low-latency 550-MSample/s FIR filter for magnetic recording read channel applications is presented. A parallel direct type II architecture operates on real-time deinterleaved (even and odd) input data samples and employs a fast low-area multiplier based on selection of radix-8 premultiplied coefficients in conjunction with one-hot encoded bus leading to a very compact layout and reduced power dissipation. The chip has been fabricated using a 0.18-μm L-effective CMOS technology and is currently being used in commercial applications     

Application of local error method to SSSF simulation of vector propagation in dispersion compensated optical links

A local error method based on an analytical scheme previously developed for the scalar optical fiber channel is applied to the second-order symmetrized split-step Fourier simulation of polarization multiplexed signal propagation through dispersion compensated optical fiber links. It is found that the global simulation accuracy for the vector propagation can be satisfied using the local error bound from a scalar propagation model for the same global error over a large range of simulation accuracy, chromatic dispersion, and differential group delay. Furthermore, carefully designed numerical simulations are used to show that similar local simulation error are obtained for vector simulations and that the similar local error leads to higher computational efficiency compared to other prevalent step-size selection schemes. The scaling of the global simulation error with respect to the number of optical fiber spans is demonstrated, and global error control for multi-span simulations is proposed. Combining the local error and global error control, the developed simulation scheme can significantly speed up the time-consuming simulations in coherent optical fiber communication system analysis and design.