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 Performance Analysis of SNR-Based Scheduling Policies in Asymmetric Broadcast Ergodic | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 163826 6 pages doi 2009 163826 Research Article Performance Analysis of SNR-Based Scheduling Policies in Asymmetric Broadcast Ergodic Fading Channel Jesus Perez Jesus Ibanez Javier Via EURASIP Member and Ignacio Santamaria EURASIP Member Department of Communications Engineering University of Cantabria Avda. de los Castros s n 39005 Santander Spain Correspondence should be addressed to Jesus Perez jperez@ Received 1 July 2008 Accepted 26 January 2009 Recommended by Kwang-Cheng Chen We analyze the performance of SNR-based scheduling algorithms in broadcast ergodic fading channels where multiuser selection diversity is exploited. At each channel state the user with the highest weighted signal-to-noise ratio is selected to be transmitted. The use of weights associated to the users allows us to control the degree of fairness among users and to arrange them according to a prescribed quality of service. These weights parametrize the scheduling algorithms so each set of weights corresponds to a specific scheduling algorithm. Assuming Rayleigh fading broadcast channel we derive a closed-form expression for the achievable user s rates as a function of the scheduling algorithm the channel fading statistics of each user and the transmit power. With the help of this expression we solve some interesting inverse problems. For example for a given arbitrary channel statistics we obtain the optimum scheduling algorithm to achieve a prescribed set of users rates with minimum transmit power. Copyright 2009 Jesus Perez 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 It is well known that the capacity region of broadcast ergodic fading channels is achieved by .
