📡 BPSK Communication System with PRN Code Synchronization

📋 Table of Contents

1. Overview
2. Features
3. Repository Structure
4. How It Works
   • Transmitter
   • Receiver
5. Installation & Usage
6. Performance Considerations
7. Future Improvements
8. License
9. Author

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🌟 Overview

This MATLAB-based project implements a Binary Phase Shift Keying (BPSK) communication system with Pseudo-Random Noise (PRN) code synchronization. The system includes a transmitter and a receiver, allowing for data transmission over an audio channel. It supports multiple PRN codes for synchronization and identification, making it suitable for applications like satellite communication and spread spectrum systems. 🚀

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✨ Features

✅ BPSK Modulation and Demodulation
✅ PRN Code Generation (Gold Codes)
✅ Audio Transmission via soundsc
✅ Cross-Correlation-Based PRN Synchronization
✅ Bit Error Rate (BER) Calculation
✅ Support for Multiple PRN Codes (Simulated Satellites)

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🗂 Repository Structure

BPSK-PRN-Synchronization
├── Transmitter/                # Transmitter code
│   ├── transmitter.m           # MATLAB script for BPSK modulation
│   ├── generateGoldCode.m      # Function to generate PRN codes
│   ├── bpsk_modulate.m         # Function for BPSK modulation
├── Receiver/                   # Receiver code
│   ├── receiver.m              # MATLAB script for BPSK demodulation
│   ├── bpsk_demodulate.m       # Function for BPSK demodulation
│   ├── recorded_signal.wav     # Example recorded signal (optional)
├── README.md                   # Project documentation
└── LICENSE                     # License file

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🛠 How It Works

📤 Transmitter (transmitter.m)

1. Generates random binary data. 🎲
2. Appends a PRN code to the beginning of the data for synchronization. 🔗
3. Modulates the data using BPSK. 📡
4. Broadcasts the signal using soundsc. 🔊

Key Functions:

• bpsk_modulate(data, fc, fs, data_rate): BPSK modulation
• generateGoldCode(length): Generates PRN codes

📥 Receiver (receiver.m)

1. Records the transmitted signal (or loads a pre-recorded signal). 🎤
2. Uses cross-correlation with the PRN code to find the start of the signal. 🔍
3. Extracts and demodulates the BPSK signal to recover the original data. 📟
4. Calculates the bit error rate (BER) to evaluate performance. 📊

Key Functions:

• bpsk_demodulate(signal, fc, fs, data_rate): BPSK demodulation
• PRN Synchronization: Cross-correlation with stored PRN codes
• Bit Error Rate Calculation

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🚀 Installation & Usage

Prerequisites

• MATLAB (Tested on R2023a, but compatible with earlier versions) 🖥️
• A sound card and speakers (for transmission) 🔊
• A microphone (for receiving audio signals) 🎙️

Running the Transmitter

1. Open transmitter.m in MATLAB. 💻
2. Set parameters like fs, fc, data_rate, and prn_length. ⚙️
3. Run the script to generate and broadcast the BPSK-modulated signal. 📡
4. The transmitted signal is saved in transmitted_signal.mat. 💾

Running the Receiver

1. Record the transmitted signal (e.g., using an external microphone or MATLAB's audiorecorder). 🎤
2. Load the recorded .wav file in MATLAB. 📂
3. Run receiver.m to:
   • Identify the correct PRN code using cross-correlation. 🔍
   • Extract and demodulate the BPSK signal. 📟
   • Display the recovered data and compute the BER. 📊

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📊 Performance Considerations

⚠️ Works well for data lengths < 50 bits
⚠️ For data > 50 bits, potential errors up to 50% may occur
✅ Requires improved synchronization and error correction

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🔮 Future Improvements

🚀 Enhancing PRN synchronization robustness
🚀 Implementing error correction (e.g., Hamming codes, Viterbi decoding)
🚀 Expanding to Quadrature Phase Shift Keying (QPSK) for higher data rates
🚀 Improving audio transmission reliability

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📜 License

This project is open-source under the MIT License. Feel free to use, modify, and contribute! 🤝

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👨‍💻 Author

[Saba_abiri]
🔗 GitHub: Saba Abiri

📧 Email: [Saba0abiri@gmail.com]

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💡 If you encounter any issues or have suggestions, feel free to open an issue or contribute to the repository! 🚀