tailieunhanh - Báo cáo hóa học: " Research Article Direct Conversion EHM Transceivers Design for Millimeter-Wave Wireless Applications"

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 Direct Conversion EHM Transceivers Design for Millimeter-Wave Wireless Applications | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 32807 9 pages doi 2007 32807 Research Article Direct Conversion EHM Transceivers Design for Millimeter-Wave Wireless Applications Abbas Mohammadi 1 Farnaz Shayegh 2 Abdolali Abdipour 1 and Rashid Mirzavand1 1 Microwave and Wireless Communication Research Labratory Electrical Engineering Department Amirkabir University of Technology Polytechnic Tehran 1587-4413 Iran 2 Electrical and Computer Engineering Department Concordia University Montreal QC Canada H4G2W1 Received 29 March 2006 Revised 14 November 2006 Accepted 15 November 2006 Recommended by Kiyoshi Hamaguchi A direct conversion modulator-demodulator with even harmonic mixers for fixed wireless applications is presented. The circuits consist of even harmonic mixers EHMs realized with antiparallel diode pairs APDPs . A communication link is set up to examine the overall performance of proposed modulator-demodulator. The transmission of 16-QAM signal with 110 Mbps data rate over fixed wireless link has been examined. We also evaluate the different levels of I Q imbalances and DC offsets and use signal space concepts to analyze the bit error rate BER of the proposed transceiver using M-ary QAM schemes. The results show that this structure can be efficiently used for fixed wireless applications in Ka band. Copyright 2007 Abbas Mohammadi 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 Local multipoint distribution system LMDS is a broadband wireless point-to-multipoint communication system operating above 20 GHz and provide high-data-rate voice TV and internet services. It is desirable to increase the spectral efficiency or the transmission capacity of LMDS services by using sophisticated amplitude and phase .