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 the Delay-Energy Tradeoff in Multiuser Fading Channels | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 198903 14 pages doi 2009 198903 Research Article On the Delay-Energy Tradeoff in Multiuser Fading Channels Prasanna Chaporkar Kimmo Kansanen and Ralf R. Muller Department of Electronics and Telecommunications Norwegian University of Science and Technology 7491 Trondheim Norway Correspondence should be addressed to Kimmo Kansanen Received 16 October 2008 Revised 15 June 2009 Accepted 11 August 2009 Recommended by Michael Gastpar We consider the delay-energy tradeoff on a fading channel with multiuser diversity. For fixed arbitrary rates of the users the total transmitted energy is minimized subject to a delay constraint. To achieve this goal we propose a scheme which schedules a subset of all users simultaneously. The scheduled users are allocated power to guarantee successful separation at the detector by successive decoding. In this way we can benefit from both multiuser diversity and the near-far situation via scheduling and simultaneous transmission respectively. We analytically show that when the number of users goes to infinity the energy required to guarantee the required user rates can be made as small as required at the cost of a higher delay delay-energy tradeoff . We explicitly compute the delay under the proposed scheduling policy and discuss how delay differentiation can be achieved. We extend the results to multiband multiaccess channel. Finally all the results can be generalized in a straightforward fashion to broadcast channel due to the Gaussian multiaccess-broadcast channel duality. Copyright 2009 Prasanna Chaporkar 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. 1. Introduction A comprehensive treatment of multiaccess fading channels .
