An Optimal Stopping Approach to Listen-Before-Talk for Frame Based Equipment in Unlicensed Spectrum

摘要

Listen-before-talk (LBT) is enforced in the regions such as European Union and Japan to harmonize coexistence of cellular and incumbent systems in unlicensed spectrum. In this paper, we study how to exploit LBT strategies for frame based equipment (FBE) in unlicensed spectrum. We consider two optimization problems: Throughput optimal stopping and nominal throughput optimal stopping. We discover that the throughput optimal transmission strategy for FBE in unlicensed spectrum is to transmit whenever the channel is clear. In contrast, we find that the nominal throughput optimal transmission strategy is less aggressive: The FBE does not transmit until it finds that the channel is clear and the channel quality exceeds an optimized threshold.