Various binary and non-binary modulation techniques, in conjunction with appropriate detection techniques, are compared in terms of their spectral efficiencies and signal-to-noise ratio requirements, assuming amplified spontaneous emission is the dominant noise source. These include (a) pulse-amplitude modulation with direct detection, (b) differential phase-shift keying with interferometric de...

This report presents a brief overview of the GMSK modulation scheme. 1 What is GMSK ? GMSK stands for Gaussian Minimum Shift Keying. This is a modulation scheme in which the phase of the carrier is instantaneously varied by the \modulating" signal (i.e. the information to transmit). GMSK diiers from MSK (Minimum Shift Keying) in that a Gaussian Filter of an appropriate bandwidth (deened by the ...

We describe a relatively simple derivation of the bit-error probability for a lightwave communications system using an amplitude-shift-keying (ASK) pulse modulation format and employing optical amplifiers such that amplified spontaneous emission noise dominates all other noise sources. This noise may be either polarized in the same direction as the signal or it may be unpolarized. Mathematicall...

We evaluate the isospin breaking corrections to the scattering amplitude πK → πK at threshold in the framework of chiral perturbation theory. This channel is of particular interest for the strong 2S− 2P energy level shift in pion–kaon bound states. While a prediction of this level shift is hampered by a large uncertainty in the isoscalar scattering length, we find only a moderate uncertainty of...

We show that the shift in the transition temperature of the dilute homogeneous Bose gas is nonanalytic in the scattering amplitude a. The first correction beyond the positive linear shift in a is negative and of order a(2)lna. This nonuniversal nonanalytic structure indicates how the discrepancies between numerical calculations at finite a can be reconciled with calculations of the limit a-->0,...

This paper presents two low-power sensor read-out circuit schemes for implantable biosensor applications. The proposed work presents the design of ASK and FSK schemes in bulk CMOS technology. Either scheme consists of a data generator block and modulator block. The first version of the circuit is designed in a 0.35μm CMOS process and it can generate an amplitude-shift-keying (ASK) signal while ...

Hundreds of millions multiple choice exams are given every year in the United States. Form filling shift errors, where a single absent-minded mismarking displaces a long run of correct answers, can substantially reduce scores and invalidate the results of the exam. In this paper, we study the prevalence, impact and detectability of shift errors by analyzing over 100,000 Scholastic Amplitude Tes...

This paper presents an efficient method to analyze the aquifer response to periodic forcing. A complex transformation is used to change the time-dependent linear aquifer model into an equivalent time-independent problem of a complex function (referred to as the ‘‘complex amplitude’’ hereafter). The magnitude of the complex amplitude represents the amplitude of the sinusoidal fluctuation of the ...

This effort focuses on the comparison of On Off Keying (OOK) to incoherent 4-ary Amplitude Shift Keying (ASK). We show that a 0.4 bits/s/Hz improvement in spectral efficiency is obtained by utilising 4-ary ASK. We determined the filter steepness required to achieve this maximum obtainable spectral efficiency. The comparison of OOK and 4-ary ASK in terms of dispersion tolerance for Non-Return-to...

In 1976, Hughes and Thompson introduced the idea of steering the maximum response of a linear array by amplitude weighting the output signals of the elements, thus eliminating the need for time delays or phase-shift networks. Currently that amplitude-steered array concept is being extended to a broadband two-dimensional array that can be used for real-time three-dimensional imaging. In shifting...