tailieunhanh - Báo cáo hóa học: " Principles and Limitations of Ultra-Wideband FM Communications Systems"

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: Principles and Limitations of Ultra-Wideband FM Communications Systems | EURASIP Journal on Applied Signal Processing 2005 3 382-396 2005 Hindawi Publishing Corporation Principles and Limitations of Ultra-Wideband FM Communications Systems John F. M. Gerrits Centre Suisse d Electronique et de Microtechnique SA Jaquet-Droz 1 CH-2007 Neuchatel Switzerland Email Michiel H. L. Kouwenhoven National Semiconductor BV Amplifier Design Europe Delftech Park 19 2628 XJ Delft The Netherlands Email Paul R. van der Meer Electronics Research Laboratory DIMES Faculty of Electrical Engineering Mathematics and Computer Science EEMCS Delft University of Technology Mekelweg 4 2628 CD Delft The Netherlands Email p. r. vandermeer@ John R. Farserotu Centre Suisse d Electronique et de Microtechnique SA Jaquet-Droz 1 CH-2007 Neuchâtel Switzerland Email John R. Long Electronics Research Laboratory DIMES Faculty of Electrical Engineering Mathematics and Computer Science EEMCS Delft University of Technology Mekelweg 4 2628 CD Delft The Netherlands Email j. Received 10 October 2003 Revised 7 March 2004 This paper presents a novel UWB communications system using double FM a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low 1-10 kbps and medium 100-1000 kbps bit rate and short-range WPAN systems. A wideband delay-line FM demodulator that is not preceded by any limiting amplifier constitutes the key component of the UWBFM receiver. This unusual approach permits multiple users to share the same RF bandwidth. Multipath however may limit the useful subcarrier bandwidth to one octave. This paper addresses the performance with AWGN and multipath the resistance to narrowband interference as well as the simultaneous detection of multiple FM signals at the same carrier frequency. SPICE