The automatic generation of dynamic or complex audio signals has a wide range of applications, from sound effects design to virtual instrument implementation. Techniques for the creation of content in these domains typically involve searching though large input spaces in order to find combinations that produce interesting results. These input spaces can be viewed as all the possible input signa...

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. ABSTRACT Biological signal transduction networks are commonly viewed as circuits that pass-along information-in the process amplifying, enhancing sensitivity, or performing other signal-processing tasks-to transcriptional and other components. Here, we report on a " reverse-cau...

We demonstrate an ultra-low light level optical modulator using a tapered nano fiber embedded in a hot rubidium vapor. The control and signal beams are co-propagating but orthogonally polarized, leading to a degenerate V-system involving coherent superpositions of Zeeman sublevels. The modulation is due primarily to the quantum Zeno effect for the signal beam induced by the control beam. For a ...

Abstract Pulse-Position Modulation (PPM) is a modulation method that only makes every pulse in the carrier sequence change with time but without changing shape and amplitude of signal. In this paper, PPM system designed. Firstly, an appropriate mathematical model established to represent transmission, signal After that, we write code add white Gaussian noise channel. Then transmission process s...

The current project dealing with communication system through adoption of the particular digital modulation by using solid state components as a semiconductor device, phase- Shift keying (PSK) signal that has been adopted combined coding phase modulation. To increase coded signal's minimum free distance an objective work, (Channel Coding) is preferred approach to enhance noise ratio (SNR) perfo...

Quadrature Amplitude Modulation is widely used modulation format in software defined radios. The major problem in QAM scheme is the recovery of a quality signal at the receiving end. The purpose of the adaptive equalizer is to remove the intersymbol interference caused by the amplitude and phase distortions of the channel. In this paper CrossCoupled Passband Adaptive Equalizer has been used for...

The majority of the existing data hiding schemes are based on the direct-sequence (DS) modulation where a low-power random sequence is embedded into the original cover signal to represent hidden information. In this paper, we investigate linear and nonlinear modulation approaches in digital data hiding. One typical DS modulation algorithm is explored and its optimal oblivious detector is derive...

Biological signal transduction networks are commonly viewed as circuits that pass along information--in the process amplifying signals, enhancing sensitivity, or performing other signal-processing tasks--to transcriptional and other components. Here, we report on a "reverse-causality" phenomenon, which we call load-induced modulation. Through a combination of analytical and experimental tools, ...

We first investigate the probe transmission signal (PTS) and the four wave mixing band gap signal (FWM BGS) modulated simultaneously by the relative phase and the nonlinear phase shift in the photonic band gap (PBG) structure. The switch between the absorption enhancement of PTS and the transmission enhancement of PTS with the help of changing the relative phase and the nonlinear phase shift is...

Microelectronic devices that contain biological components are typically used to interrogate biology rather than control biological function. Patterned assemblies of proteins and cells have, however, been used for in vitro metabolic engineering, where coordinated biochemical pathways allow cell metabolism to be characterized and potentially controlled on a chip. Such devices form part of techno...