Secrecy performance analysis of satellite-terrestrial heterogeneous symbiotic security

In integrated satellite-terrestrial networks, satellite and terrestrial heterogeneous networks employ spectrum sharing technology to enhance system resource utilization. However, this approach results in mutual co-frequency interference between satellite and terrestrial communication links, degrading overall communication performance. The concept of satellite-terrestrial heterogeneous symbiotic secure communication is proposed to convert detrimental interference into a beneficial resource, making the safe transmission of satellite-terrestrial heterogeneous links form a mutually beneficial symbiotic relationship. The need for secure satellite-terrestrial transmission under eavesdropping threats was addressed by theoretically analyzing the secrecy rate and secrecy outage probability of the symbiotic secure communication system. A theoretical lower bound for the secrecy rate was derived, and simulation results validated the theoretical analysis. The findings indicate that the satellite and terrestrial links can be leveraged to achieve secure transmission through reciprocal interference, without the need for additional resource allocation.