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 Neural Network MLSE Receiver Based on Natural Gradient Descent: Application to Satellite Communications Mohamed Ibnkahla | EURASIP Journal on Applied Signal Processing 2004 16 2580-2591 2004 Hindawi Publishing Corporation A Neural Network MLSE Receiver Based on Natural Gradient Descent Application to Satellite Communications Mohamed Ibnkahla Electrical and Computer Engineering Department Queen s University Kingston Ontario Canada K7L 3N6 Email Jun Yuan Electrical and Computer Engineering Department Queen s University Kingston Ontario Canada K7L 3N6 Email steveyuan@ Received 30 August 2003 Revised 12 February 2004 The paper proposes a maximum likelihood sequence estimator MLSE receiver for satellite communications. The satellite channel model is composed of a nonlinear traveling wave tube TWT amplifier followed by a multipath propagation channel. The receiver is composed of a neural network channel estimator NNCE and a Viterbi detector. The natural gradient NG descent is used for training. Computer simulations show that the performance of our receiver is close to the ideal MLSE receiver in which the channel is perfectly known. Keywords and phrases neural networks satellite communications high-power amplifiers. 1. INTRODUCTION The satellite communications field is getting an enormous attention in the wake of third generation 3-G and future fourth generation 4-G mobile communication systems challenges 1 2 . Currently when the telecommunications industries are planning to deploy the 3-G system worldwide and researchers are coming up with tons of new ideas for the next-generation wireless systems a load of challenges are yet to be fulfilled. These include high data rate transmissions multimedia communications seamless global roaming quality of service QoS management high user capacity integration and compatibility between 4-G components and so forth. To meet these challenges presently researchers are focusing their attention in the satellite domain by considering it an integrated part of the so-called information superhighway 2 3 4 5 . As a .
