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: Research Article Wideband Impulse Modulation and Receiver Algorithms for Multiuser Power Line Communications | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2007 Article ID 96747 14 pages doi 2007 96747 Research Article Wideband Impulse Modulation and Receiver Algorithms for Multiuser Power Line Communications Andrea M. Tonello Dipartimento diIngegneria Elettrica Gestionale eMeccanica DIEGM Universita di Udine Via delle Scienze208 33100 Udine Italy Received 8 November 2006 Accepted 23 March 2007 Recommended by Moises Vidal Ribeiro We consider a bit-interleaved coded wideband impulse-modulated system for power line communications. Impulse modulation is combined with direct-sequence code-division multiple access DS-CDMA to obtain a form of orthogonal modulation and to multiplex the users. We focus on the receiver signal processing algorithms and derive a maximum likelihood frequency-domain detector that takes into account the presence of impulse noise as well as the intercode interference ICI and the multiple-access interference MAI that are generated by the frequency-selective power line channel. To reduce complexity we propose several simplified frequency-domain receiver algorithms with different complexity and performance. We address the problem of the practical estimation of the channel frequency response as well as the estimation of the correlation of the ICI-MAI-plus-noise that is needed in the detection metric. To improve the estimators performance a simple hard feedback from the channel decoder is also used. Simulation results show that the scheme provides robust performance as a result of spreading the symbol energy both in frequency through the wideband pulse and in time through the spreading code and the bit-interleaved convolutional code . Copyright 2007 Andrea M. Tonello. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION The design of .
