Digital Communication Laboratory Codes

This repository contains simulations related to basic digital communication methods and principles. Each folder represents a specific session. Below is a list of sessions along with a brief description of their contents.

Sessions Overview

1. PreLab01
2. PreLab02
3. PreLab03
4. Lab01
5. Lab02
6. Lab03
7. Lab04
8. Lab05
9. Lab06

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PreLab01

• Topics:
  • Working with basic pulse shapes and analyzing their characteristics.
  • Deriving PSK modulation bit error rate (BER) formula and plotting it versus SNR, comparing it with MATLAB’s berawgn function.
  • Examining the effects of channel magnitude ($\alpha$) and phase ($\phi$) on the Symbol Error Rate (SER) of PSK modulation.

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PreLab02

• Topics:
  • Implementing a method to achieve a Gaussian distribution using the Central Limit Theorem (CLT).
  • Implementing digital filtering and comparing results with MATLAB’s built-in filter function.
  • Determining the start of data transmission using correlation and a predefined header.
  • Visualizing the FFT of a single-tone signal and analyzing how various parameters (e.g., sample size, input frequency) affect the FFT output.

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PreLab03

• Topics:
  • Using matrices to calculate the Discrete Fourier Transform (DFT) and signal spectrum.
  • Observing the impact of non-ideal transformations from intermediate-band to baseband.

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Lab01

• Topics:
  • Simulations related to white noise, filtering, baseband signals, and intermediate-band signals.

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Lab02

• Topics:

  • Implementing a transmission simulation. The goal is to send data packets through an ideal channel and detect them.

• Main functions:

  • bitGenerator: Generates bits for transmission.
  • grayMatrixGenerator: Generates Gray code matrix for encoding.
  • pulseModulation: Modulates bits with different pulse shapes (e.g., triangular).
  • symbolDetection: Detects symbols using correlators or matched filters.
  • minDistanceDetector: Detects symbols based on minimum distance.

• Modulation schemes:

  • PAM
  • PSK
  • QAM

Note: FSK modulation (coherent and non-coherent) is implemented in lab05.m.

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Lab03

• Topics:
  • A complete implementation of a communication system, transmitting data with added noise, time delay, and phase offset.
  • Bit Error Rate (BER) vs SNR curves were plotted and compared with MATLAB’s built-in functions.

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Lab04

• Topics:

  • Implementing a simple example to get started with the ADALM-PLUTO (PlutoSDR).
  • Transmitting and receiving data using the PlutoSDR, visualized with MATLAB plots.

• Files:

  • example.m: A basic code for initializing and working with PlutoSDR.
  • lab04.m: Implements the communication system from lab03.m on PlutoSDR.

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Lab05

• Topics:
  • Completion of lab03.m with added Frequency Shift Keying (FSK) modulation and simulation.

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Lab06

• Topics:
  • Hardware implementation of lab05.m using ADALM-PLUTO (PlutoSDR). It builds upon lab04.m with updates for FSK modulation.

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How to Use

1. Clone the repository:

   git clone https://github.com/your-username/digital-communication-lab.git
   cd digital-communication-lab

2. Open MATLAB and navigate to the desired session folder (e.g., PreLab01, Lab01, etc.).

3. Run the MATLAB scripts from the command line or MATLAB editor.

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Contributions

• Salar Safardoust
• Fateme Jalili