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: Comparison between Coherent and Noncoherent Receivers for UWB Communications | EURASIP Journal on Applied Signal Processing 2005 3 359-368 2005 Hindawi Publishing Corporation Comparison between Coherent and Noncoherent Receivers for UWB Communications Giuseppe Durisi Istituto Superiore Mario Boella 10138 Torino Italy Email durisi@ Sergio Benedetto Center for Multimedia Radio Communications CERCOM Politecnico di Torino 10129 Torino Italy Email benedetto@ Received 1 October 2003 Revised 1 March 2004 We present a comparison between coherent and noncoherent UWB receivers under a realistic propagation environment that takes into account also the effect of path-dependent pulse distortion. As far as coherent receivers are concerned both maximal ratio combining MRC and equal gain combining EGC techniques are analyzed considering a limited number of estimated paths. Furthermore two classical noncoherent schemes a differential detector and a transmitted-reference receiver together with two iterative solutions recently proposed in the literature are considered. Finally we extend the multisymbol approach to the UWB case and we propose a decision-feedback receiver that reduces the complexity of the previous strategy thus still maintaining good performance. While traditional noncoherent receivers exhibit performance loss if compared to coherent detectors the iterative and the decision-feedback ones are able to guarantee error probability close to the one obtained employing an ideal RAKE without requiring channel estimation in the presence of static indoor channel and limited multiuser interference. Keywords and phrases ultra-wideband communications noncoherent detection multisymbol differential detection. 1. INTRODUCTION Ultra-wideband UWB systems are based on the transmission of subnanosecond pulses typically obtained by directly driving an antenna with short electrical pulses. According to the FCC regulation of February 2002 signals belonging to this category are required to possess a -10 dB bandwidth which exceeds 500 MHz or 20 of its .
