Research Of Cell Identification On Heterogeneous Network For LTE-A System

In order to meet the challenges of WiMAX, and fulfill the requirements of higher speed data rate services, LTE begins a further evolution of LTE-Advanced. With the increasing demands of high-speed data services and system capacity in the future mobile communication systems, LTE-Advanced system, as a candidate technology for the next generation mobile communication systems, introduces the heterogeneous network as feature, which offers more flexible deployment and effective solution to increase system capacity, improves system throughput as well. Currently domestic and foreign major telecom operators and mobile equipment makers have been invested significant resource on various aspects of this topic. The User Equipment must first do cell identification when wishing to access a LTE cell. As a host of Low Power Nodes is overlaid by a Macro cell and the unbalanced transmitting power exits between different cell layers in the heterogeneous networks, the control channels would suffer more severe interference than in the case of homogeneous networks. This makes cell edge users identifying LPN more difficultly. To resolve the problem cell identification for Hetnet link level simulation platform is developed, and solutions are respectively given in asynchronous scenario and synchronous scenario. The main works of the thesis are summarized as follows:(1) LTE cell identification is deeply researched in this thesis and cell identification for HetNet link level simulation platform is developed in accordance with 3GPP LTE-Advanced contributions and protocols.(2) In asynchronous scenario considering backward compatibility for Release 8/Release 9 terminals as well as minimize physical layer air interface impact, a time domain solution for enhanced Inter-Cell Interference Coordination is given in this thesis, which can efficiently mitigate the strong interference by muting the Macro cell transmission in some of its sub-frames. Through analyzing how the Time Division Multiplexing eICIC techniques assist cell identification when suffering serious interference from the Macro cell, two novel methods of synchronization time offset transmitting are proposed in order to improve cell identification performance. Finally link level simulations are presented on the cell identification performance for legacy Release 8 Release 9 terminals, and the sufferable interference level for cell identification performance in asynchronous scenario is proposed in this thesis.(3) In synchronous scenario a novel method of eICIC is proposed to mitigate the strong interference from Macro cell in synchronizing channel and improve cell identification performance of Low Power Nodes. Through link level simulations on the cell identification performance for legacy Release 8/Release 9 terminals, its feasibility is evaluated and the sufferable interference level for cell identification performance in various conditions is proposed in this thesis.