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Báo cáo hóa học: "Research Article Implementation of a Smart Antenna Base Station for Mobile WiMAX Based on OFDMA"

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 Implementation of a Smart Antenna Base Station for Mobile WiMAX Based on OFDMA | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2009 Article ID 950674 9 pages doi 10.1155 2009 950674 Research Article Implementation of a Smart Antenna Base Station for Mobile WiMAX Based on OFDMA Seungheon Hyeon Changhoon Lee Chang-eui Shin and Seungwon Choi Department of Electronics and Computer Engineering Hanyang University 17 Haengdang-Dong Seongdong-Gu Seoul 133-791 South Korea Correspondence should be addressed to Seungwon Choi choi@dsplab.hanyang.ac.kr Received 1 August 2008 Revised 7 January 2009 Accepted 12 February 2009 Recommended by Alister G. Burr We present an implementation of a mobile-WiMAX m-WiMAX base station BS that supports smart antenna SA functionality. To implement the m-WiMAX SA BS we must address a number of key issues in baseband signal processing related to symboltiming acquisition the beamforming scheme and accurate calibration. We propose appropriate solutions and implement an m-WiMAX SA BS accordingly. Experimental tests were performed to verify the validity of the solutions. Results showed a 3.5-time 5.5 dB link-budget enhancement on the uplink compared to a single antenna system. In addition the experimental results were consistent with the results of the computer simulation. Copyright 2009 Seungheon Hyeon 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 Modern mobile communication requires not only a high data rate transmission but also a relatively fast mobility. The mobile WiMAX m-WiMAX based on orthogonal frequency division multiple access OFDMA is believed to be a solution that addresses both of these requirements 1 . Moreover the application of smart antenna SA technologies to OFDMA is regarded as a key solution for increasing the data rates and the mobility of fourth generation 4G wireless .