Performance analysis of system with selection combining over correlated Weibull fading channels in the presence of cochannel interference

Selection diversity based on the signal to interference ratio (SIR) is a very efficient technique that reduces fading and channel interference influence. In this paper, system performances of selection combining and correlated Weibull channels are analyzed. Fading between the diversity branches and between interferers is correlated and Weibull distributed. Very useful closed-form expressions are obtained for the output SIR's probability density function (PDF) and cumulative distribution function which is main contribution of this paper. Outage probability, the average output SIR, and the average error probability for coherent, noncoherent modulation are derived. Numerical results presented in this paper point out the effects of fading severity and correlation on the system performances.     

An Approach to the Triple Branch Selection Diversity Analysis Over Correlated α-μ Fading Channels in the Presence of CCI

In this paper, an approach to derivation of the joint trivariate ??-?? probability density function (pdf) and cumulative distribution function (cdf) expressions will be presented. Capitalizing on this, closed-form expressions for the cdf and pdf at the output of triple branch selective combiner (SC) in the presence of correlated co-channel interference (CCI) will be determined. The main contribution of this paper is generality of our model, since the expressions accommodate arbitrary correlation structures. General results, from this paper, could be reduced to the specific ones for various fading models and types of correlation. Important performance measures like outage probability (Pout) and average output signal-to-interference ratio (SIR) will also be determined and graphically illustrated for various values of existing parameters.     

BPSK and QPSK non‐linear satellite communication system performance in the presence of cochannel interference

Taking the uplink and downlink cochannel interference and noise into account, the analytical expressions are derived for determining the bit error probability in detecting a binary phase‐shift‐keying (BPSK) and a quaternary phase‐shift‐keying (QPSK) Gray coded signal, transmitted over a satellite system exhibiting amplitude modulation‐to‐amplitude modulation (AM/AM) conversion effects and amplitude modulation‐to‐phase modulation (AM/PM) conversion effects. On the basis on the derived theoretic formulae, using real‐life system parameters, numerical results are obtained and presented. We point out the explicit comparisons of satellite communication system performance obtained when a satellite transponder amplifier is modelled by a hard‐limiter and those obtained when both AM/AM and AM/PM non‐linearities of the satellite transponder amplifier are taken into consideration. Copyright © 2003 John Wiley & Sons, Ltd.     

PAD: A New Interactive Knowledge-Based Analog Design Approach

This paper presents a new Procedural Analog Design tool called PAD. It is a chart-based design environment dedicated to the design of analog circuits aiming to optimize design and quality by finding good tradeoffs. This interactive tool allows step-by-step design of analog cells by using guidelines for each analog topology. Its interactive interface enables instantaneous visualization of design tradeoffs. At each step, the user modifies interactively one subset of design parameters and observes the effect on other circuit parameters. At the end, an optimized design is ready for simulation (verification and fine-tuning). The present version of PAD covers the design of basic analog structures (one transistor or groups of transistors) and the procedural design of transconductance amplifiers (OTAs) and different operational amplifier topologies. The basic analog structures calculator embedded in PAD uses the complete set of equations of the EKV MOS model, which links the equations for weak and strong inversion in a continuous way [1, 2]. Furthermore, PAD provides a layout generator for matched substructures such as current mirrors, cascode stages and differential pairs.Danica Stefanovic was born in 1976. She received the B.S. and M.S. degrees in electrical engineering from the University of Nis (Serbia and Montenegro) in 2000 and 2003 respectively. In 2001/2002 she was a scholarship holder of Swiss Confederation working with Electronic Laboratories, Swiss Federal Institute of Technology (EPFL), on a research project in the domain of analog circuits design techniques and their translation into specific CAD tool. She is currently working towards Ph.D. degree at the Swiss Federal Institute of Technology (EPFL). Her research interests include low power, low voltage analog design methodologies and optimisation techniques.Maher Kayal was born in 1959. He received the M.S. and Ph.D. degrees in electrical engineering from the Swiss Federal Institute of Technology (EPFL, Switzerland) in 1983 and 1989 respectively.In 1990, he had a Research Associate in the Swiss Federal Institute of Technology. From 1999 he became a professor in the Electronics Laboratories of this institute. He has published many scientific papers and contributed in three books dedicated to mixed-mode CMOS design. His current research interests include: mixed-mode circuit design, sensors, signal processing and CAD tools for analog design and layout automation. He received in 1990 the Swiss Ascom award for the best work in telecommunication fields and in 1997 the best ASIC award at the European Design and Test Conference ED&TC.Marc Pastre was born in 1977. He received the M.S. degree in computer science at EPFL (Swiss Federal Institute of Technology) in 2000. He is currently working towards his Ph.D. at the Electronics Laboratories LEG (EPFL). His research interests include mixed circuits, ADCs/DACs, sensor frontends and CAD tools.     

Experimentally friendly geometrical criteria for entanglement

A simple geometrical criterion gives experimentally friendly sufficient conditions for entanglement. Its generalization gives a necessary and sufficient condition. It is linked with a family of entanglement identifiers, which is strictly richer than the family of entanglement witnesses.     

Performance of optical heterodyne PSK systems with Costas loop inmultichannel environment for nonlinear second-order PLL model

Using the nonlinear second-order phase-locked loop (PLL) model the performance of the heterodyne coherent optical phase shift keying (PSK) systems with Costas loop in multichannel environment is considered in this paper for the first time. The shot noise of the corresponding photodiodes and adjacent channel interferences are described through the signal-to-noise ratio (SNR) in the loop bandwidth, while the laser phase noise is described through the normalized frequency fluctuations instead of the phase ones. The theory and results presented in this paper can be applied when analyzing and optimizing the performance in the region where the linear PLL model is not enough good     

Fluorescent Isoindole Crosslink (FlICk) Chemistry: A Rapid,User‐friendly Stapling Reaction

The stabilization of peptide secondary structure via stapling is a ubiquitous goal for creating new probes, imaging agents, and drugs. Inspired by indole‐derived crosslinks found in natural peptide toxins, we employed ortho‐phthalaldehydes to create isoindole staples, thus transforming inactive linear and monocyclic precursors into bioactive monocyclic and bicyclic products. Mild, metal‐free conditions give an array of macrocyclic α‐melanocyte‐stimulating hormone (α‐MSH) derivatives, of which several isoindole‐stapled α‐MSH analogues (K_i≈1 nm ) are found to be as potent as α‐MSH. Analogously, late‐stage intra‐annular isoindole stapling furnished a bicyclic peptide mimic of α‐amanitin that is cytotoxic to CHO cells (IC₅₀=70 μm ). Given its user‐friendliness, we have termed this approach FlICk (fluorescent isoindole crosslink) chemistry.     

Performance Analysis of Interference-Limited Mobile-to-Mobile κ–μ Fading Channel

Wireless Personal Communications - In this paper, a wireless cooperative network, with two sections, operating over multipath mobile-to-mobile interference-limited fading channel is considered. The...     

Effect of noisy carrier reference signal and interference on performance of MSK receiver

This paper considers the coherent detection of minimum shift keying signal and a degradation in error rate performance from ideal due to an interference and a phase discrepancy between the carrier of the received signal and the carrier of the receiver. The error rate is calculated for the simple receiver model with integrate‐and‐dump circuits. The reference carrier signal unsteadiness is presented by the probability density function of the first order non‐linear PLL phase error, while the uncertainty due to an interference is involved in the system model with a random phase of cosine signal that accompanied the useful signal. Copyright © 2004 John Wiley & Sons, Ltd.     

Signal Propagation in Multi‐Layer DNAzyme Cascades Using Structured Chimeric Substrates

Signal propagation through enzyme cascades is a critical component of information processing in cellular systems. Although such systems have potential as biomolecular computing tools, rational design of synthetic protein networks remains infeasible. DNA strands with catalytic activity (DNAzymes) are an attractive alternative, enabling rational cascade design through predictable base‐pair hybridization principles. Multi‐layered DNAzyme signaling and logic cascades are now reported. Signaling between DNAzymes was achieved using a structured chimeric substrate (SCS) that releases a downstream activator after cleavage by an upstream DNAzyme. The SCS can be activated by various upstream DNAzymes, can be coupled to DNA strand‐displacement devices, and is highly resistant to interference from background DNA. This work enables the rational design of synthetic DNAzyme regulatory networks, with potential applications in biomolecular computing, biodetection, and autonomous theranostics.