Unlicensed Spectra Fusion and Interference Coordination for LTE Systems

Unlicensed spectra fusion technology for LTE holds the promise of alleviating the licensed spectra scarcity and enhancing capacity. It allows LTE to effectively utilize the unlicensed spectra distributed over high frequency bands with significant different propagation characteristics from its licensed spectra. However, the interference caused by other systems over unlicensed spectra, particularly the public unlicensed spectra, is viewed as the most serious challenge. In this paper, aiming to guarantee the feasibility in existing LTE systems, we design a novel unlicensed spectra fusion scheme based on the popular standard TDD-LTE. To mitigate the interference, we develop an interference coordination scheme which is carried out in two stages: screen the available unlicensed channels for every UE, and allocate unlicensed spectra based on Hungarian algorithm. We have conducted extensive simulation study and demonstrate that our proposed scheme can handle interference coordination effectively and enhance throughput significantly.