Related Experiment Video
Updated: Jul 16, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Performance of polar coded probabilistic shaped PAM8 with systematic interleaver and identically distributed pilot in
Abstract:
In this paper, for the first time to the best of our knowledge, we investigate the experiment of polar coded probabilistic shaped 8-ary pulse amplitude modulation (PS-PAM8) in weak turbulence. A systematic interleaver (SIL) is proposed to improve the polar code performance for PS-PAM8, compatible with the 5 G channel coding standard. Considering the effects of turbulence and shaped constellations, the pilot with identical distributions as the transmitted data is used for dynamic channel estimation to avoid demodulation failure. Moreover, the application of hybrid equalization with nonlinear and linear equalizers effectively reduces the receiver sensitivity. In 25 GBd transmission over a 4 m free-space link, the transmission performance of polar coded PAM8 schemes with SIL is better than that of the low-density parity check code by 1.0 dB, and the power budget is further saved by 0.72∼0.83 dB after linear equalization. Meanwhile, the shaping gains of polar coded PS-PAM8 with SIL and hybrid equalization are up to 2.0 dB at 1.5 bits/channel use. In addition, different weak turbulence conditions can be generated inside a chamber, and the observed channel fading is consistent with the log-normal model. The results show that the proposed polar coded PS scheme can improve the Q-factor by 0.49∼1.74 dB in different turbulence conditions.
Related Concept Videos
Turbulent Flow
Propagation of Uncertainty from Systematic Error
Propagation of Uncertainty from Random Error
Steady, Laminar Flow Between Parallel Plates
Pilot and Numeric Relaying
Pole and System Stability
Simple poles are unique roots of the denominator polynomial. Each simple pole corresponds to a distinct solution to the system's characteristic equation, typically resulting in exponential decay terms in the system's...

