tailieunhanh - Báo cáo hóa học: "Research Article OV-CDMA System: Concept and Implementation"

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 OV-CDMA System: Concept and Implementation | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 460628 9 pages doi 2008 460628 Research Article OV-CDMA System Concept and Implementation Elie Inaty and Rafic Ayoubi Department of Computer Engineering Faculty of Engineering University ofBalamand P. O. Box 100 Deir El-Balamand El-Koura Lebanon Correspondence should be addressed to Elie Inaty Received 7 September 2007 Revised 5 December 2007 Accepted 25 January 2008 Recommended by Stefan Kaiser A new method is proposed to achieve a multirate overlapped code division multiple access system OV-CDMA based on a novel code overlapping procedure. The signal-to-interference ratio SIR performance has been investigated for such system. A channel model that allows multirate overlapped transmission is presented based on which a closed form solution for the SIR has been derived. In addition a simple yet very efficient block diagram of the transmitter and the receiver architecture has been proposed for such a system. Based on the proposed block diagram the encoder-decoder has been implemented using an FPGA. Numerical results show that the newly proposed OV-CDMA scheme outperforms the classical variable processing gain fast frequency hopping CDMA VPG-FFH-CDMA for different system scenarios. Finally real-time measurements have been successfully obtained using a hardware prototype utilizing the simple Xilinx Spartan IIE XC2S200E FPGA. Copyright 2008 E. Inaty and R. Ayoubi. 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 During the past few years there has been a growing interest in the development of broadband wireless communication networks for multimedia applications. The communication services in such networks can be high- and low-speed data video and many