Energy Efficient Cognitive Spectrum Sharing Scheme Based on Inter-Cell Fairness for Integrated Satellite-Terrestrial Communication Systems

Integrated satellite-terrestrial network combines both advantages of satellite and the terrestrial network and it can achieve all-day seamless coverage and broad coverage areas. Cognitive satellite spectrum sharing scheme increases spectrum utilization significantly, but it can cause satellite network and terrestrial network intensive co-frequency interference. However, the exclusion zone makes the signal to interference and noise ratio (SINR) of the satellite-terrestrial link increase significantly and the performance of throughput, energy efficiency (EE) and inter-cell fairness have not been improved. Therefore, continuous optimization of inter-cell fairness and energy efficiency will improve the Quality of Experience (QoE). Thus, we investigate an integrated satellite terrestrial spectrum sharing scheme based on cognitive frequency band isolation, where both inter-cell fairness and user density are considered. Moreover, integrated satellite terrestrial network overlapping coverage framework is firstly proposed, where the optimization of EE or SINR can be flexibly adapt to integrate satellite-terrestrial network. Furthermore, a joint soft frequency reuse strategy can achieve maximum throughput. Finally, the numerical results show that the performance of EE, SINR, throughput and the inter- cell fairness of proposed scheme are superior to the traditional integrated satellite-terrestrial spectrum sharing scheme.