Low-Cost Sensor Based on SDR Platforms for TETRA Signals Monitoring

Area of Science:

• Electrical Engineering
• Signal Processing
• Wireless Communication

Background:

• Terrestrial Truncked Radio (TETRA) systems are crucial for public safety and professional mobile radio communications.
• Accurate monitoring of TETRA electromagnetic fields is essential for network performance and interference analysis.
• Existing monitoring solutions can be costly and lack flexibility for diverse deployment scenarios.

Purpose of the Study:

• To design and implement a cost-effective electromagnetic field monitoring sensor for TETRA signals.
• To leverage low-cost Software Defined Radio (SDR) platforms for enhanced measurement capabilities.
• To develop both fixed and mobile sensor variants for versatile field applications.

Main Methods:

• Utilized Software Defined Radio (SDR) platforms with varying analog-digital converter resolutions.
• Integrated Global Positioning System (GPS) modules for location-based measurements.
• Developed hardware control modules, including fixed (laptop) and mobile (Raspberry Pi) versions.
• Tested and validated sensor performance in terms of acquisition bandwidth, dynamic range, and frequency resolution.

Main Results:

• Achieved an instantaneous acquisition bandwidth of 5.12 MHz.
• Demonstrated a dynamic range for input signal levels from -100 dBm to -30 dBm.
• Obtained a frequency resolution of 2.5 kHz.
• Validated portability and flexibility for outdoor use.
• Confirmed correct operation of the mobile version at speeds up to 120 km/h.

Conclusions:

• The developed sensor offers a low-cost, high-performance solution for TETRA electromagnetic field monitoring.
• The mobile variant provides accurate, real-time data acquisition in dynamic environments.
• The system's flexibility and affordability make it suitable for widespread deployment and research.