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 Crosstalk Channel Estimation via Standardized Two-Port Measurement | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 916865 14 pages doi 2008 916865 Research Article Crosstalk Channel Estimation via Standardized Two-Port Measurements Fredrik Lindqvist 1 Neiva Lindqvist 2 Boris Dortschy 3 Per idling 1 Per Ola Borjesson 1 Klas Ericson 3 and Evaldo Pelaes2 1 Department of Electrical and Information Technology Lund University 221 00 Lund Sweden 2 Signal Processing Laboratory LaPS Federal University of Para 66075-110 Belem PA Brazil 3 Ericsson Research Broadband Technologies Ericsson AB 16480 Stockholm Sweden Correspondence should be addressed to Fredrik Lindqvist Received 21 September 2008 Accepted 19 December 2008 Recommended by Jonathon Chambers The emerging multiuser transmission techniques for enabling higher data rates in the copper-access network relies upon accurate knowledge of the twisted-pair cables. In particular the square-magnitude of the crosstalk channels between the transmission lines are of interest for crosstalk-mitigation techniques. Acquiring such information normally requires dedicated apparatus since crosstalk-channel measurement is not included in the current digital subscriber line DSL standards. We address this problem by presenting a standard-compliant estimator for the square-magnitude of the frequency-dependent crosstalk channels that uses only functionality existing in today s standards. The proposed estimator is evaluated by laboratory experiments with standard-compliant DSL modems and real copper access network cables. The estimation results are compared with both reference measurements and with a widely used crosstalk model. The results indicate that the proposed estimator obtains an estimate of the square-magnitude of the crosstalk channels with a mean deviation from the reference measurement less than 3 dB for most frequencies. Copyright 2008 Fredrik Lindqvist et al. This is an open access article distributed .
