tailieunhanh - Báo cáo hóa học: " Research Article Performance Analysis of Ad Hoc Dispersed Spectrum Cognitive Radio Networks over Fading Channels"

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 Ad Hoc Dispersed Spectrum Cognitive Radio Networks over Fading Channels | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2011 Article ID 849105 10 pages doi 2011 849105 Research Article Performance Analysis of Ad Hoc Dispersed Spectrum Cognitive Radio Networks over Fading Channels Khalid A. Qaraqe 1 Hasari Celebi 1 Muneer Mohammad 2 and Sabit Ekin2 1 Department of Electrical and Computer Engineering Texas A M University at Qatar Education City Doha 23874 Qatar 2 Department of Electrical and Computer Engineering Texas A M University College Station TX 77843 USA Correspondence should be addressed to Hasari Celebi Received 1 September 2010 Revised 6 December 2010 Accepted 19 January 2011 Academic Editor George Karagiannidis Copyright 2011 Khalid A. Qaraqe 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. Cognitive radio systems can utilize dispersed spectrum and thus such approach is known as dispersed spectrum cognitive radio systems. In this paper we first provide the performance analysis of such systems over fading channels. We derive the average symbol error probability of dispersed spectrum cognitive radio systems for two cases where the channel for each frequency diversity band experiences independent and dependent Nakagami-m fading. In addition the derivation is extended to include the effects of modulation type and order by considering M-ary phase-shift keying M-PSK and M-ary quadrature amplitude modulation M-QAM schemes. We then consider the deployment of such cognitive radio systems in an ad hoc fashion. We consider an ad hoc dispersed spectrum cognitive radio network where the nodes are assumed to be distributed in three dimension 3D . We derive the effective transport capacity considering a cubic grid distribution. Numerical results are presented to verify the theoretical .