Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
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: Iterative PDF Estimation-Based Multiuser Diversity Detection and Channel Estimation with Unknown | EURASIP Journal on Applied Signal Processing 2005 6 872-882 2005 Hindawi Publishing Corporation Iterative PDF Estimation-Based Multiuser Diversity Detection and Channel Estimation with Unknown Interference Nenad Veselinovic Centre for Wireless Communications University of Oulu P.O. Box 4500 90014 Oulu Finland Email nenad.veselinovic@ee.oulu.fi Tad Matsumoto Centre for Wireless Communications University of Oulu P.O. Box 4500 90014 Oulu Finland Email tadashi.matsumoto@ee.oulu.fi Markku Juntti Centre for Wireless Communications University of Oulu P.O. Box 4500 90014 Oulu Finland Email markku.juntti@ee.oulu.fi Received 8 October 2003 Revised 14 July 2004 The equivalent diversity order of multiuser detector employing multiple receive antennas and minimum mean squared error MMSE processing for frequency-selective channels is decreased if it aims at suppressing unknown cochannel interference UCCI while detecting multiple users signals. This is an unavoidable consequence of linear processing at the receiver. In this paper we propose a new multiuser signal detection scheme with the aim to preserve the detector s diversity order by taking into account the structure of the UCCI. We use the fact that the structure of the UCCI appears in the probability density function PDF of the UCCI plus noise which can be characterized as multimodal Gaussian. A kernel smoothing PDF estimation-based receiver is derived. The PDF estimation can be based on training symbols only noniterative PDF estimation or on training symbols as well as feedback from the decoder iterative PDF estimation . It is verified through simulations that the proposed receiver significantly outperforms the conventional covariance estimation in channels with low frequency selectivity. The iterative PDF estimation significantly outperforms the noniterative PDF estimation-based receiver with minor training overhead. Keywords and phrases turbo equalization cochannel interference PDF estimation. 1. INTRODUCTION The scarcity