Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Propagation Speed of Electromagnetic Waves01:30

Propagation Speed of Electromagnetic Waves

4.4K
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
4.4K
Doppler Effect - I00:56

Doppler Effect - I

4.3K
The Doppler effect and Doppler shift were named after the Austrian physicist and mathematician Christian Johann Doppler in 1842, who conducted experiments with both moving sources and moving observers. Consider an observer standing on a street corner, observing an ambulance with a siren sound passing by at a constant speed. The observer experiences two characteristic changes in the sound of the siren. Initially, the sound increases in loudness as the ambulance approaches and decreases in...
4.3K
Doppler Effect - II01:05

Doppler Effect - II

4.0K
The Doppler effect has several practical, real-world applications. For instance, meteorologists use Doppler radars to interpret weather events based on the Doppler effect. Typically, a transmitter emits radio waves at a specific frequency toward the sky from a weather station. The radio waves bounce off the clouds and precipitation and travel back to the weather station. The radio frequency of the waves reflected back to the station appears to decrease if the clouds or precipitation are moving...
4.0K
Relation of DFT to z-Transform01:20

Relation of DFT to z-Transform

635
The Discrete Fourier Transform (DFT) is a crucial tool for analyzing the frequency content of discrete-time signals. It converts a sequence of N samples from the time domain into its corresponding sequence in the frequency domain, where each sample represents a specific frequency component.
To understand how the DFT works, it's helpful to consider the z-transform, which is a method for representing discrete sequences in the complex frequency domain. The z-transform involves summing the...
635

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

[Changes in health-related quality of life in incipient stroke survivors].

Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition·2015
Same author

Stereoselective synthesis of 1,4-diols by a tandem allylboration-allenylboration sequence.

Organic letters·2015
Same author

The effect of lactic acid bacteria on cocoa bean fermentation.

International journal of food microbiology·2015
Same author

The performance of a combined nitritation-anammox reactor treating anaerobic digestion supernatant under various C/N ratios.

Journal of environmental sciences (China)·2015
Same author

Cytotoxicity profile of novel sterically hindered platinum(II) complexes with (1R,2R)-N(1),N(2)-dibutyl-1,2-diaminocyclohexane.

European journal of medicinal chemistry·2015
Same author

Functional Proteomics Study Reveals SUMOylation of TFII-I is Involved in Liver Cancer Cell Proliferation.

Journal of proteome research·2015
Same journal

Denoising algorithm of Φ-OTDR systems based on adaptive fractional wavelet transform denoising.

Optics express·2026
Same journal

Millisecond photon-to-photon latency and high-speed volumetric projection system for optogenetics.

Optics express·2026
Same journal

Polarization-encoded coaxial structured light for high-precision 3D surface profilometry.

Optics express·2026
Same journal

Discrete freeform optical design based on collaborative optimization of point cloud and local normals.

Optics express·2026
Same journal

Ultrafast ghost imaging with 25 GHz speckle switching and wavelength-division multiplexing.

Optics express·2026
Same journal

Atomic vapor cells fabricated by femtosecond laser welding of standard-optical-quality glass.

Optics express·2026
See all related articles

Related Experiment Video

Updated: Nov 25, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
06:42

Generation and Coherent Control of Pulsed Quantum Frequency Combs

Published on: June 8, 2018

9.4K

DFT-based offset-QAM OFDM for optical communications.

Jian Zhao

    Optics Express
    |February 12, 2014
    PubMed
    Summary
    This summary is machine-generated.

    Offset quadrature-amplitude modulation orthogonal frequency division multiplexing (offset-QAM OFDM) offers significant advantages over conventional systems. This advanced technique minimizes signal distortion and reduces the need for guard intervals, boosting data rates in fiber optic communications.

    More Related Videos

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
    09:43

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

    Published on: March 20, 2017

    10.2K
    Quasi-light Storage for Optical Data Packets
    07:45

    Quasi-light Storage for Optical Data Packets

    Published on: February 6, 2014

    11.1K

    Related Experiment Videos

    Last Updated: Nov 25, 2025

    Generation and Coherent Control of Pulsed Quantum Frequency Combs
    06:42

    Generation and Coherent Control of Pulsed Quantum Frequency Combs

    Published on: June 8, 2018

    9.4K
    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
    09:43

    Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping

    Published on: March 20, 2017

    10.2K
    Quasi-light Storage for Optical Data Packets
    07:45

    Quasi-light Storage for Optical Data Packets

    Published on: February 6, 2014

    11.1K

    Area of Science:

    • Optical Communications
    • Digital Signal Processing
    • High-Speed Data Transmission

    Background:

    • Conventional Orthogonal Frequency Division Multiplexing (OFDM) systems face limitations with signal distortion and require guard intervals (GI) for dispersion compensation.
    • Nyquist FDM (N-FDM) and conventional OFDM (C-OFDM) exhibit performance penalties with certain spectral functions.
    • Efficient pulse shaping is crucial for Discrete Fourier Transform (DFT)-based implementations in high-speed optical systems.

    Purpose of the Study:

    • To experimentally demonstrate and numerically investigate a DFT-based offset-QAM OFDM system.
    • To analyze the performance of offset-QAM OFDM with various spectral functions compared to N-FDM and C-OFDM.
    • To evaluate the guard interval (GI) requirements and pulse-shaping filter design for offset-QAM OFDM.

    Main Methods:

    • Experimental demonstration and numerical investigation of a DFT-based offset-QAM OFDM system.
    • Utilized square-root-raised-cosine and super-Gaussian functions as signal spectra for analysis.
    • Analyzed guard interval length requirements and pulse-shaping filter memory length.

    Main Results:

    • Offset-QAM OFDM exhibited negligible penalty across all investigated spectra, outperforming N-FDM and C-OFDM.
    • Required GI length for offset-QAM OFDM scales with twice the subcarrier spacing, significantly less than C-OFDM.
    • Experimental results showed 38-Gb/s offset-16QAM OFDM supporting 600-km transmission without GI, while C-OFDM required GI length of eight.
    • Numerical simulations indicated 112-Gb/s polarization multiplexed offset-4QAM OFDM achieved a 23% net data rate increase over C-OFDM without GI.
    • Reduced pulse-shaping filter memory length from 60 (N-FDM) to 2 in offset-QAM OFDM.

    Conclusions:

    • Offset-QAM OFDM offers a robust solution for high-speed optical communication systems, minimizing signal penalties.
    • The reduced GI requirement and efficient pulse shaping in offset-QAM OFDM enable higher net data rates and longer transmission distances.
    • DFT-based offset-QAM OFDM presents a significant advancement over conventional and N-FDM schemes for future optical networks.