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 Tower-Top Antenna Array Calibration Scheme for Next Generation Networks | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID41941 12 pages doi 2007 41941 Research Article Tower-Top Antenna Array Calibration Scheme for Next Generation Networks Justine McCormack Tim Cooper and Ronan Farrell Centre for Telecommunications Value-Chain Research Institute of Microelectronics and Wireless Systems National University of Ireland Kildare Ireland Received 1 November 2006 Accepted 31 July 2007 Recommended by A. Alexiou Recently there has been increased interest in moving the RF electronics in basestations from the bottom of the tower to the top yielding improved power efficiencies and reductions in infrastructural costs. Tower-top systems have faced resistance in the past due to such issues as increased weight size and poor potential reliability. However modern advances in reducing the size and complexity of RF subsystems have made the tower-top model more viable. Tower-top relocation however faces many significant engineering challenges. Two such challenges are the calibration of the tower-top array and ensuring adequate reliability. We present a tower-top smart antenna calibration scheme designed for high-reliability tower-top operation. Our calibration scheme is based upon an array of coupled reference elements which sense the array s output. We outline the theoretical limits of the accuracy of this calibration using simple feedback-based calibration algorithms and present their predicted performance based on initial prototyping of a precision coupler circuit for a 2 X 2 array. As the basis for future study a more sophisticated algorithm for array calibration is also presented whose performance improves with array size. Copyright 2007 Justine McCormack 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. .
