Analysis of Channel Access Delay for Unlicensed LTE Systems

摘要

D295 long term evolution (LTE) in unlicensed spectrum is a promising method to cope with the radically increasing requirement of data traffic. However, whether the unlicensed LTE (LTE-U) can provide transmissions comparatively at higher data rates depends on its channel access delay characteristic. In this paper, we focus on the LTE-U system's channel access delay distribution to study the potential for it to run and support the delay-sensitive traffic. We first develop a unified analytical model to analyze the coexistence of LTE-U system and Wi-Fi system, and then derive the close-form expression of the channel access delay under the condition of LTE-U system coexistence with Wi-Fi system. By Lattice-Poisson inversion algorithm we obtain the numerical results of the distribution of LTE-U's channel access delay and the analytical results match the simulated results demonstrating the accurate prediction of the distribution of channel access delay for LTE-U system by the proposed analytical model.