Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article On Uplink Interference Scenarios in Two-Tier Macro and Femto Co-Existing UMTS Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2010 Article ID 240745 8 pages doi 2010 240745 Research Article On Uplink Interference Scenarios in Two-Tier Macro and Femto Co-Existing UMTS Networks Zhenning Shi 1 Mark C. Reed 2 3 and Ming Zhao2 3 1 Alcatel Lucent-Shanghai Bell China 2NICTA Canberra Research Laboratory Locked Bag 8001 Canberra ACT 2601 Australia 3 The Australian National University Australia Correspondence should be addressed to Mark C. Reed Received 4 September 2009 Revised 30 November 2009 Accepted 2 March 2010 Academic Editor Holger Claussen Copyright 2010 Zhenning Shi et al. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. A two-tier UMTS network is considered where a large number of randomly deployed Wideband Code Division Multiple Access WCDMA femtocells are laid under macrocells where the spectrum is shared. The cochannel interference between the cells may be a potential limiting factor for the system. We study the uplink of this hybrid network and identify the critical scenarios that give rise to substantial interference. The mechanism for generating the interference is analyzed and guidelines for interference mitigation are provided. The impacts of the cross-tier interference especially caused by increased numbers of users and higher data rates are evaluated in the multicell simulation environment in terms of the noise rise at the base stations the cell throughput and the user transmit power consumption. 1. Introduction Recent decades have witnessed an unprecedented growth in the achieved data rate and the quality of service QoS in wireless communications. A coarse breakup on the increased capacity reveals that most cellular throughput improvement comes from better area spectrum efficiency. Mobile .
