Analysis of an Adaptive Switching Point for LTE TDD by Dynamic System-Level Simulations

Abstract

This paper introduces an LTE system level simulator and presents investigations based on simulation results of this simulator as well as comparison of different aspects like scheduling algorithm, system load or other relevant parameter changes. In the TDD mode of LTE, duplexing is implemented via sharing the time domain between uplink and downlink users. This is done by ten different switching configurations, which offer varying capacity distributions between downlink and uplink, from a downlink-heavy configuration with 90% of the capacity in downlink direction to uplink heavy configurations with 60% uplink. The available bandwidth can be utilized perfectly if the link configuration is adjusted appropriately to traffic emergence. This paper investigates the performance gain when selecting a configuration appropriate to the traffic compared to usage of a static configuration equally distributed capacity. In case of different configurations, additional interference can occur in neighbored cells due to distinct communication direction at the same time. This paper is supposed to clarify the differences between these scenarios and quantify the gains and losses when the switching point between uplink and downlink is variable.