Cross-Layer Framework for Capacity Analysis in Multiuser Ultra-Dense Networks with Cell DTx

摘要

Cell discontinuous transmission (Cell DTx) is a key technology to mitigate inter-cell interference (ICI) in ultra-dense networks (UDNs). The aim of this work is to understand the impact of Cell DTx on physical- layer sum rates of SBSs and link-layer quality-of-service (QoS) performance in multiuser UDNs. In this work, we develop a cross-layer framework for capacity analysis in multiuser UDNs with Cell DTx. In particular, we first extend the traditional one-dimensional effective capacity model to a new multidimensional effective capacity model to derive the sum rate and the effective capacity. Moreover, we propose a new iterative bisection search algorithm that is capable of approximating QoS performance. The convergence of this new algorithm to a unique QoS exponent vector is later proved. Finally, we apply this framework to the round-robin and the max-C/I scheduling policies. Simulation results show that our framework is accurate in approximating 1) queue length distribution, 2) delay distribution and 3) sum rates under the above two scheduling policies, and further show that with the Cell DTx, systems have approximately 30％ higher sum rate and 35％ smaller average delay than those in full-buffer scenarios.