Random Process Analysis of Digital Baseband Line Codes

This repository models digital baseband communication line codes as stochastic random processes. It simulates large ensembles of waveforms and verifies core statistical properties including expected value, wide-sense stationarity (WSS), ergodicity, and power spectral density (PSD).

Repository Structure

Digital_comm_Transceiver/
├── Project's Document.pdf         # Final project report
├── Report.rar                     # Original report archive
├── src/                           # MATLAB source code
│   ├── digital_comm.m             # Main simulation script
│   ├── digital_comm.asv           # MATLAB auto-save backup
│   └── ExportFigures.m            # Figure export utility
├── figures/                       # Generated plots and report figures
└── docs/                          # Supplementary documentation
    ├── report.pdf                 # Compiled LaTeX report
    └── bibliography.bib           # BibTeX reference list

Signaling Schemes

The simulation analyzes three primary line-coding schemes:

• Unipolar Non-Return-to-Zero (NRZ): Binary 0 maps to 0 V, binary 1 maps to +A V. Uses a full-width rectangular pulse.
• Polar NRZ: Binary 0 maps to -A V, binary 1 maps to +A V. Uses a full-width rectangular pulse.
• Polar Return-to-Zero (RZ): Binary 0 maps to -A V, binary 1 maps to +A V. The pulse returns to zero halfway through the bit period.

Configuration

The simulation behavior is controlled by a parameter block at the top of src/digital_comm.m. Key parameters include:

Parameter	Value	Description
N_bits	100	Number of bits per realization
N_realizations	500	Total number of generated waveforms
Pw	0.07 s	Pulse width of a single bit
Ts	0.01 s	Time sample duration (Fs = 100 Hz)
L	7	Samples per symbol period
A	4 V	Signal amplitude
N_fft	1024	FFT size for high-resolution PSD

How To Run

1. Open src/digital_comm.m in MATLAB.
2. Modify the configuration parameters as needed.
3. Run the script. All plots are generated and saved automatically to the figures/ directory.

Output Figures

The figures/ directory contains the following plots for each signaling scheme:

• PSD (Theoretical): Power spectral density computed analytically.
• Realization samples: Example waveforms from the ensemble.
• Stationarity check: Comparison of ensemble statistics over time.
• Time autocorrelation: Autocorrelation for a single realization.
• Time mean per realization: Time-averaged mean plotted across all realizations.

The compiled report (Project's Document.pdf) provides the full theoretical background, methodology, and analysis of results.

Authors

• Youssif991
• youssefteam18-boop
• naderhany12
• minawaeltanagho
• AbdelrhmanAtta