Digital Line Coding Simulated in Python: NRZ, Manchester, AMI & PSD Analysis
In this video, we dive deep into digital communication by simulating six standard line codes from scratch using Python (NumPy & SciPy). Instead of relying on built-in communications toolboxes, we manually encode Unipolar NRZ, Polar NRZ, Polar RZ, Manchester, Differential Manchester, and Alternate Mark Inversion (AMI) to truly understand how they work under the hood.
We analyze the critical engineering trade-offs of each code by looking at their physical waveforms, estimating their Power Spectral Density (PSD) using Welch's method, tracking their DC baseline wander via the Running Digital Sum (RDS), and stress-testing their self-clocking capabilities with a long-run sequence of identical bits.
Topics Covered:
Building manual Python line encoders without toolboxes
Visualizing transition logic for NRZ, RZ, Manchester, and AMI
Frequency domain analysis and bandwidth requirements (PSD)
Understanding DC wander and bounded running digital sums
Self-clocking vs. clock loss during long runs of identical bits
Resources & Code:
💻 Get the full Python code and README on GitHub: https://github.com/Rakesh-2211/Digital-lin...
Libraries Used:
numpy for signal generation and math
matplotlib.pyplot for visualization
scipy.signal for Welch's method (PSD estimation)
#DigitalCommunications #LineCoding #PythonSimulation #SignalProcessing #Engineering #ManchesterEncoding #Telecommunications #DataTransmission