Related Experiment Video
Updated: May 25, 2026

07:45
Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
Real-time Nyquist pulse generation beyond 100 Gbit/s and its relation to OFDM
R Schmogrow1, M Winter, M Meyer
1Institute of Photonics and Quantum Electronics, Karlsruhe Institute of Technology, Karlsruhe, Germany. rene.schmogrow@kit.edu
Optics Express
|January 26, 2012
Summary
Nyquist sinc-pulse shaping achieves near-theoretical spectral efficiency. This study compares it with optical orthogonal frequency division multiplexing, demonstrating real-time 100 Gbit/s+ data transmission using Nyquist pulses.
Area of Science:
- Optical Communications
- Signal Processing
- Information Theory
Background:
- Nyquist sinc-pulse shaping offers high spectral efficiency, approaching theoretical limits.
- Optical orthogonal frequency division multiplexing (O-OFDM) is a key technology in modern optical networks.
Purpose of the Study:
- To compare Nyquist pulse shaping with O-OFDM regarding spectral efficiency and peak-to-average power ratio (PAPR).
- To demonstrate the feasibility of real-time, high-speed data transmission using Nyquist pulse-shaped modulation formats.
Main Methods:
- Comparative analysis of spectral efficiency and PAPR for Nyquist pulse shaping and O-OFDM.
- Implementation of algorithms for encoding Nyquist pulse-shaped modulation formats.
- Real-time transmission testing at speeds exceeding 100 Gbit/s.
Main Results:
- Nyquist pulse shaping demonstrates spectral efficiencies comparable to the theoretical maximum.
- The study validates the real-time encoding of Nyquist pulse-shaped modulation formats at speeds beyond 100 Gbit/s on a single wavelength.
- Proper reception techniques for Nyquist pulses are discussed.
Conclusions:
- Nyquist pulse shaping is a viable technique for achieving ultra-high spectral efficiency in optical communications.
- The demonstrated real-time capabilities pave the way for next-generation high-speed optical networks.
- Effective reception strategies are crucial for the successful deployment of Nyquist pulse-shaped systems.
Related Concept Videos
Sampling Theorem
In signal processing, the analysis of continuous-time signals, denoted as x(t), often involves sampling techniques to convert these signals into discrete-time signals. This process is essential for digital representation and manipulation. A critical component in sampling is the train of impulses, characterized by the sampling interval and the sampling frequency. The relationship between these parameters and the original signal's properties dictates the success of the sampling process.
Upsampling
Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
Aliasing
Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original signal...
Bandpass Sampling
In signal processing, bandpass sampling is an effective technique for sampling signals that have most of their energy concentrated within a narrow frequency band. This type of signal is known as a bandpass signal. The key principle of bandpass sampling involves sampling the signal at a rate that is greater than twice the signal's bandwidth to prevent aliasing.
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2. The spectrum...
A bandpass signal has a spectrum with a lower frequency limit, denoted as ω1, and an upper frequency limit, denoted as ω2. The spectrum...
Propagation Speed of Electromagnetic Waves
Electromagnetic waves are consistent with Ampere's law. Assuming there is no conduction current Ampere's law is given as:
Sampling Continuous Time Signal
In signal processing, a continuous-time signal can be sampled using an impulse-train sampling technique, followed by the zero-order hold method. Impulse-train sampling involves the use of a periodic impulse train, which consists of a series of delta functions spaced at regular intervals determined by the sampling period. When a continuous-time signal is multiplied by this impulse train, it generates impulses with amplitudes corresponding to the signal's values at the sampling points.
In the...
In the...
