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Design Of XDSL Subscriber Loop Analyzer

Posted on:2007-02-26Degree:MasterType:Thesis
Country:ChinaCandidate:Z L ZhangFull Text:PDF
GTID:2178360182986221Subject:Instrumentation engineering
Abstract/Summary:PDF Full Text Request
xDSL is a main technology of current broadband accesses. Because of its utilization of existing telephone copper twisted-pair, low-cost and short-term construction, meeting the demands of various subscribers, its development is very rapid. The loop is designed for calling primely, so the transmitting quality and reliability of it can't be comparable with modern telecommunication cable. Before being brought into service, test and optimization of the loop must be taken. At present domestic market demand for subscriber loop test is increasing quickly.xDSL subscriber loop analyzer is widely used for testing and faults locating of all kinds of lines like POTS, broadband and digital subscriber loop, and can be used to evaluate the copper twisted-pair to see if it is qualified for digital transmission, determine the capability of the loop to support xDSL service. The analyzer is an ideal instrument for broadband installation, maintenance, troubleshooting.This paper mainly discusses design technology of xDSL subscriber loop analyzer. First the paper introduces the concept of xDSL, then introduces the key technology and the overall scheme of xDSL subscriber loop analyzer. It explicates design of transmitting circuit, receiving channel circuit, data acquisition circuit and multimeter circuit. It introduces the basic theory of transmission line, deducts transient response expressions of semi-infinitely extended transmission line. It details core algorithm of the instrument including TDR test, frequency response test, digital tracking filter, power spectral density test, load coil detection, DMT test, voltage test, current test, resistance test and capacitance test. It provides measure methods and test results of main technical specifications. Finally, it gives some design experiences. The xDSL subscriber loop analyzer fills the domestic vacancy, and its performance and specifications reach domestic leading level and oversea advanced level of this field.
Keywords/Search Tags:TDR, Frequency Response, Power Spectral Density, Load Coil Detection, DMT Test
PDF Full Text Request
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