Sensing-Based Dynamic Spectrum Sharing in Integrated Wireless Sensor and Cognitive Satellite Terrestrial Networks

Area of Science:

• Wireless Communication
• Satellite Networks
• Spectrum Management

Background:

• Increasing demand and spectrum scarcity in space networks necessitate efficient solutions.
• Cognitive satellite terrestrial networks offer a promising approach for hybrid wireless systems.
• Resource allocation is critical for meeting high transmit capacity demands in satellite networks.

Purpose of the Study:

• To propose a sensing-based dynamic spectrum sharing scheme for cognitive satellite users.
• To maximize ergodic capacity for satellite users while maintaining acceptable interference levels for terrestrial users.
• To address spectrum scarcity in cognitive satellite terrestrial networks.

Main Methods:

• A cognitive satellite user monitors terrestrial channels via a wireless sensor network.
• Transmit power is dynamically adjusted based on real-time channel sensing results.
• The optimization problem is solved using the Lagrange duality method under perfect and imperfect sensing conditions.

Main Results:

• The proposed scheme increases channel capacity by over 20% compared to opportunistic spectrum access in perfect sensing scenarios.
• Optimal sensing time for maximum ergodic capacity was found to be 2.34 ms in imperfect sensing.
• Satellite users access channels with constrained power when terrestrial users are busy, and allocate power for enhanced capacity when idle.

Conclusions:

• The sensing-based dynamic spectrum sharing scheme effectively maximizes cognitive satellite user capacity.
• This approach balances satellite capacity enhancement with the protection of primary terrestrial users.
• The findings are crucial for developing efficient hybrid wireless networks facing spectrum scarcity.