The Research Of Communication Twist Single Ended Testing By TDR

In the field of telecommunicate cable testing, if twists topology can begot in center office, it can cost down much on maintaining sealed twists.Furthermore, it`ll be possible to estimate the speed of ADSL run on twists, ifthe topology is got. But now, it has been possible to get the topology justthrough single ended testing by Time domain reflectometry.To enlarge the effective testing range, this article will discuss a newarithmetic and a hardware structure to process the TDR signal. Andfurthermore, it will extend the ADSL speed estimation function based on theTDR testing. About TDR arithmetic, to separate an effective TDR signalfrom the original signal, we experiment many arithmetic and finally decideto use comparing method. To get the topology more exactly, we optimize thearithmetic of distance according to the TDR theory and the characteristic oftwists system. About the hardware, we design it to get an undistorted TDRsignal in effective arrange. And it will also accord the standard ofTelecommunicate nets. About the arithmetic of ADSL speed estimation, wewill use the topology which get by TDR testing to figure out the FR of twists,and finish the noise power spectrum test on the TDR hardware. And then wecan finally figure out the ADSL speed estimation by DMT arithmeticthrough FR and noise power spectrum.Finally, through this article, we can get a TDR test system which can:extend the longest test range through2km in past to3.5km on0.4cm twists,and to4km on0.5twists; get more precise data of topology in5%error; themean square error of the test results in repeatedly testing is lower than0.001;extend the ADSL speed estimation...