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: Letter to the Editor Correction to “Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System” | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2010 Article ID 126230 1 page doi 2010 126230 Letter to the Editor Correction to Optimally Joint Subcarrier Matching and Power Allocation in OFDM Multihop System Lijie Wang Yong Xi and Jibo Wei National University of Defense Technology Changsha 410071 China Correspondence should be addressed to Lijie Wang lilywaiig_gao@ Received 22 June 2010 Accepted 1 August 2010 Copyright 2010 Lijie Wang 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. In the above paper 1 the author gives that dRtot k dxk is always greater than 0 as 15 in 1 . However dRtot k dxk should be dRtot k Py P21 dxk B 4In2 2xkP1 Ptot P1 2 Ptot H Xk 2P1 H2 xk ơ2 H xk 2 P1 H xk Ơ2 H xk 2 Ptot P1 H xk B 4In2 2xkP1 Ptot P1 Ơ2 Ptot H xk 2P1 h2 x2 h2 xk ơ2 H xk Py Ơ2 H xk Ptot P1 1 References 1 W. Wang S. Yan and S. Yang Optimally joint subcarrier matching and power allocation in OFDM multihop system EURASIP Journal on Advances in Signal Processing vol. 2008 Article ID 241378 8 pages 2008. where Ptot Py 0. It is observed that the denominators of 1 and 15 in 1 are the same and positive whereas the numerators are different. From 1 it cannot be assured that dRtot k dxk is always greater than 0 for example when Pl - Ptot dRtot k dxk 0. Therefore the total channel capacity is not always monotonically increasing function of xk for the given power allocation and 16 and 17 in 1 cannot be obtained. Meanwhile the extended proposition in 1 Section 4 does not .
