Feasibility Analysis of Dynamic Adjustment of TDD Configurations in Macro-Femto Heterogeneous LTE Networks

Abstract

The dynamic adaptation of TDD configurations to traffic conditions at low power base stations (femtocells and picocells) in heterogeneous LTE networks can be used to optimize the system performance. For instance, a significant performance improvement can be achieved in DL and UL packet throughputs. However, in practical multi-cell deployments the TDD configuration adaptation may result in opposite transmission directions in the neighboring cells and thus cause new types of inter-cell interference such as BS-BS and UE-UE. These interference types are often called DL-UL cross interference and may significantly deteriorate the overall system performance. For this reason all homogeneous Macro cell TDD deployments typically operate synchronously (i.e. use same TDD configurations). However the recent advances in the field of heterogeneous networks have reopened the dynamic TDD problem since low power small cells are rather isolated from each other and thus can be considered as candidates for dynamic TDD adaptation. In this paper we provide a feasibility analysis of dynamic TDD configuration adjustment in application to Macro-Femto LTE TDD networks.