Orthogonal frequency-division multiplexing (OFDM) baseband signals may be modeled by complex Gaussian processes with Rayleigh envelope distribution and uniform phase distribution, if the number of carriers is sufficiently large. The output correlation function of instantaneous nonlinear amplifiers and the signal-to-distortion ratio can be derived and expressed in an easy way. As a consequence, ...

An all-optical UWB pulses generation and modulation scheme using cross phase modulation (XPM) effect of semiconductor optical amplifier (SOA) and DWDM-based multi-channel frequency discrimination is proposed and demonstrated, which has potential application in multiuser UWB-Over-Fiber communication systems. When a Gaussian pulse light and a wavelength-tunable CW probe light are together injecte...

Trends in modern communication systems place high demands on low power consumption, high speed transmission and anti-interference characteristics. Therefore impulse radio ultra–wideband (IR-UWB) [1] radio systems have recently gained increased popularity. Since IR-UWB symbols are transmitted with short pulses (< 2 ns), in IR-UWB systems, energy has been spread over the frequency bands of up to ...

This work represents the synthesis of the 211 pulse sequence for the study of electron spin-echo envelope modulation ~ESEEM! with the technique of spin-echo correlated spectroscopy ~SECSY!, which has previously been used to study nuclear modulation by two-dimensional Fourier transform ESR methods. This example of ‘‘pulse adjustable’’ spectroscopy, wherein the pulse width and pulse amplitude of ...

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...

UWB impulse radios (UWB-IR) have attracted increasing interest due to their potential to propose high user capacity with low-complexity and low-power transceivers (Win & Sholtz, 2000). It is approved by the Federal Communications Commission’s (FCC) Report in which the UWB spectral mask is released and published in February 2002. Most of these benefits initiate from the distinctive characteristi...