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 Interference Mitigation Technique for Coexistence of Pulse-Based UWB and OFDM | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 285683 11 pages doi 2008 285683 Research Article Interference Mitigation Technique for Coexistence of Pulse-Based UWB and OFDM Kohei Ohno and Tetsushi Ikegami Department of Electronics and Communications Meiji University 1-1-1 Higashimita Tama-ku Kawasaki Kanagawa 214-8571 Japan Correspondence should be addressed to Kohei Ohno koh@ Received 31 May 2007 Revised 16 December 2007 Accepted 4 February 2008 Recommended by Ryuji Kohno Ultra-wideband UWB is a useful radio technique for sharing frequency bands between radio systems. It uses very short pulses to spread spectrum. However there is a potential for interference between systems using the same frequency bands at close range. In some regulatory systems interference detection and avoidance DAA techniques are required to prevent interference with existing radio systems. In this paper the effect of interference on orthogonal frequency division multiplexing OFDM signals from pulsebased UWB is discussed and an interference mitigation technique is proposed. This technique focuses on the pulse repetition cycle of UWB. The pulse repetition interval is set the same or half the period of the OFDM symbol excluding the guard interval to mitigate interference. These proposals are also made for direct sequence DS -UWB. Bit error rate BER performance is illustrated through both simulation and theoretical approximations. Copyright 2008 K. Ohno and T. Ikegami. 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 Spectrum sharing technologies are attractive since there is a real lack of frequency bands for radio systems. Cognitive radio is one approach to coexisting radio systems. Ultra-wideband UWB is also able to share .
