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: Direct Position Determination of Multiple Radio Signals | EURASIP Journal on Applied Signal Processing 2005 1 37-49 2005 Hindawi Publishing Corporation Direct Position Determination of Multiple Radio Signals Anthony J. Weiss Department of Electrical Engineering-Systems Tel Aviv University Tel Aviv 69978 Israel Email ajw@ Alon Amar Department of Electrical Engineering-Systems Tel Aviv University Tel Aviv 69978 Israel Email amar@ Received 25 December 2003 Revised 8 June 2004 The most common methods for position determination of radio signal emitters such as communications or radar transmitters are based on measuring a specified parameter such as angle of arrival AOA or time of arrival TOA of the signal. The measured parameters are then used to estimate the transmitter s location. Since the measurements are done at each base station independently without using the constraint that the AOA TOA estimates at different base stations should correspond to the same transmitter s location this is a suboptimal location determination technique. Further if the number of array elements at each base station is M and the signal waveforms are unknown the number of cochannel simultaneous transmitters that can be localized by AOA is limited to M - 1. Also most AOA algorithms fail when the sources are not well angularly separated. We propose a technique that uses exactly the same data as the common AOA methods but the position determination is direct. The proposed method can handle more than M - 1 cochannel simultaneous signals. Although there are many stray parameters only a two-dimensional search is required for a planar geometry. The technique provides a natural solution to the measurements sources association problem that is encountered in AOA-based location systems. In addition to new algorithms we provide analytical performance analysis Cramer-Rao bounds and Monte Carlo simulations. We demonstrate that the proposed approach frequently outperforms the traditional AOA methods for unknown as well as known signal .
