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: A Network of Kalman Filters for MAI and ISI Compensation in a Non-Gaussian Environment Bessem Sayadi | EURASIP Journal on Applied Signal Processing 2005 5 635-648 2005 Hindawi Publishing Corporation A Network of Kalman Filters for MAI and ISI Compensation in a Non-Gaussian Environment Bessem Sayadi Laboratoire des Signaux et Systemes LSS Supelec CNRS Plateau de Moulon 3 rue Joliot Curie 91192 Gif-sur-Yvette Cedex France Email sayadi@ Sylvie Marcos Laboratoire des Signaux et Systemes LSS Supelec CNRS Plateau de Moulon 3 rue Joliot Curie 91192 Gif-sur-Yvette Cedex France Email marcos@ Received 4 September 2003 Revised 30 November 2004 This paper develops a new multiuser detector based on a network of kalman filters NKF dealing with multiple-access interference MAI intersymbol interference ISI and an impulsive observation noise. The two proposed schemes are based on the modeling of the DS-CDMA system by a discrete-time linear system that has non-Gaussian state and measurement noises. By approximating the non-Gaussian densities of the noises by a weighted sum of Gaussian terms and under the common MMSE estimation criterion we first derive an NKF detector. This version is further optimized by introducing a feedback exploiting the ISI interference structure. The resulting scheme is an NKF detector based on a likelihood ratio test LRT . Monte-Carlo simulations have shown that the NKF and the NKF based on LRT detectors significantly improve the efficiency and the performance of the classical Kalman algorithm. Keywords and phrases multiuser detection Kalman filtering Gaussian sum approximation impulsive noise likelihood ratio test. 1. INTRODUCTION Direct-sequence code-division multiple access DS-CDMA is emerging as a popular multiple-access technology for personal cellular and satellite communication services 1 2 3 for its large capacity that results from several advantages 4 such as soft handoffs a high-frequency reuse factor and the efficient use of the voice activity. However in the case of a multipath transmission channel the signals received
