نتایج جستجو برای: quatrature amplitude modulation

تعداد نتایج: 234755  

Journal: :IEICE Transactions 2009
Tetsuya Kawanishi Takahide Sakamoto Akito Chiba

We present recent progress of high-speed Mach-Zehnder modulator technologies for advanced modulation formats. Multi-level quadrature amplitude modulation signal can be synthesized by using parallel Mach-Zehnder modulators. We can generate complicated multi-level optical signals from binary data streams, where binary modulated signals are vectorially summed in optical circuits. Frequency respons...

2013
Zhengping Wang Yuekun Wang Shuai Sun

For actively modulated In-line Sagnac interferential all optic fiber current transformers (AOFCTs), the accuracies are directly affected by the amplitude of the modulation signal. In order to deeply undertand the function of the modulator, a theoretical model of modulation effect to AOFCTs is built up in this paper. The effect of the amplitude of the modulation signal to the output intensity of...

Journal: :International Journal of Applied Mechanics and Engineering 2021

Abstract The investigation of thermal modulation on double-diffusive stationary convection in the presence an applied magnetic field and internal heating is carried out. A weakly nonlinear stability analysis has been performed using finite-amplitude Ginzburg-Landau model. This finite amplitude obtained at third order system. study considers three different forms temperature modulations. OPM-out...

2010
Refael Z. Whyte Andrew D. Payne Adrian A. Dorrington Michael J. Cree

Time-of-flight range imaging cameras operate by illuminating a scene with amplitude modulated light and measuring the phase shift of the modulation envelope between the emitted and reflected light. Object distance can then be calculated from this phase measurement. This approach does not work in multiple camera environments as the measured phase is corrupted by the illumination from other camer...

1992
Julius O. Smith Perry R. Cook

A digital sinusoidal oscillator derived from digital waveguide theory is described which has good properties for VLSI implementation. Its main features are no wavetable and a computational complexity of only one multiply per sample when amplitude and frequency are constant. Three additions are required per sample. A piecewise exponential amplitude envelope is available for the cost of a second ...

2013
Majed Omar Al-Dwairi

This paper evaluate the multilevel modulation for different techniques such as amplitude shift keying (M-ASK), MASK, differential phase shift keying (M-ASK-Bipolar), Quaternary Amplitude Shift Keying (QASK) and Quaternary Polarization-ASK (QPol-ASK) at a total bit rate of 107Gbps. The aim is to find a costeffective very high speed transport solution. Numerical investigation was performed using ...

2009
Marijan HERCEG Tomislav MATIĆ Tomislav ŠVEDEK

This paper analyzes the performance of the hybrid Amplitude Shape Modulation (h-ASM) scheme for the time-hopping ultra-wideband (TH-UWB) communication systems in the single and multi-user environment. h-ASM is the combination of Pulse Amplitude Modulation (PAM) and Pulse Shape Modulation (PSM) based on modified Hermite pulses (MHP). This scheme is suitable for high rate data transmission applic...

2000
Sae-Young Chung Hui-Ling Lou

Bandwidth efficient modulation schemes using Reed-Solomon (RS) codes are proposed for Hybrid In-Band-On-Channel (IBOC) systems that broadcast digital audio signals simultaneously with analog Amplitude Modulation (AM) programs in the AM band. Since both the power and bandwidth allocated for digital audio transmission are limited in this application, the system cannot afford to add enough redunda...

2013
A. Sangeetha I. Srinivasa Rao

AbstractLong haul transmission links evolve with the advent of new multiplexing and modulation schemes. We propose a new approach of dispersion compensated coherent optical orthogonal frequency division multiplexing scheme which is combined with quadrature amplitude modulation to double the data rate and spectral efficiency as transmitted in an optical OFDM system. Quadrature amplitude modulati...

Journal: :The Journal of the Acoustical Society of America 2005
Alexandra Stein Stephan D Ewert Lutz Wiegrebe

Recent temporal models of pitch and amplitude modulation perception converge on a relatively realistic implementation of cochlear processing followed by a temporal analysis of periodicity. However, for modulation perception, a modulation filterbank is applied whereas for pitch perception, autocorrelation is applied. Considering the large overlap in pitch and modulation perception, this is not p...

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