Related Experiment Video
Updated: Jul 1, 2026
09:43
Transmission of Multiple Signals through an Optical Fiber Using Wavefront Shaping
Published on: March 20, 2017
Digital non-data-aided symbol synchronization in optical coherent intradyne reception
Sun Hyok Chang1, Hwan Seok Chung, Kwangjoon Kim
1Optical Communications Research Center, Electronics and Telecommunications Research Institute 138 Gajeongno, Yuseong, Daejeon, Korea. shchang@etri.re.kr
Optics Express
|September 17, 2008
Summary
Digital symbol synchronization for optical binary phase shift keying signals was demonstrated. A timing error feedback algorithm ensures stable operation for coherent intradyne reception across a range of symbol rates.
Area of Science:
- Optical Communications
- Digital Signal Processing
Background:
- Accurate symbol synchronization is critical for coherent optical receivers.
- Intradyne reception requires precise timing recovery for optimal performance.
Purpose of the Study:
- To experimentally demonstrate digital symbol synchronization for optical binary phase shift keying (BPSK) signals.
- To propose and validate a timing error feedback algorithm for coherent intradyne reception.
Main Methods:
- Experimental setup for optical BPSK signal transmission.
- Implementation of a digital timing error feedback loop algorithm.
- Testing the feedback loop stability across varying symbol rates (9.7–10.3 GSymbol/s).
Main Results:
- Successful experimental demonstration of digital symbol synchronization.
- Stable operation of the timing error feedback loop achieved.
- Performance evaluated at a 20 GSampling/s rate with a bit error rate of approximately 2x10(-2).
Conclusions:
- The proposed timing error feedback algorithm enables stable digital symbol synchronization for optical BPSK signals.
- The system demonstrates reliable performance in coherent intradyne reception within the tested symbol rate range.
Related Concept Videos
01:10Reconstruction of Signal using Interpolation
Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next sampling...
01:08IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
Identical bonds within a polyatomic group can stretch symmetrically (in-phase) or asymmetrically (out-of-phase). Similar to hydrogen bonding, these vibrations also influence the shape of the IR peak. Generally, asymmetric stretching frequencies are higher than symmetric stretching frequencies. For example, primary amines exhibit two distinct IR peaks between 3300–3500 cm−1 corresponding to the symmetric and asymmetric N-H stretching, while secondary amines exhibit a single stretching vibration...
01:05Doppler Effect - II
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...
01:02¹H NMR: Interpreting Distorted and Overlapping Signals
Spin systems where the difference in chemical shifts of the coupled nuclei is greater than ten times J are called first-order spin systems. These nuclei are weakly coupled, and their chemical shifts and coupling constant can generally be estimated from the well-separated signals in the spectrum.
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
01:12Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
00:56Doppler Effect - I
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...