Patent ID: 6691262
Filing Date: 2004-02-10
Classification: H04B,H04L

Abstract:
A method for evaluating a quality of a cable line which transmits a digital modulation signal in a bidirectional manner, comprising the steps of:extracting a noise signal of an upstream line of the cable line from one connection point of a head end of the cable line to be evaluated and a connection point between a tap-off and the cable line to be evaluated; generating a pseudo random signal; modulating a carrier signal having a predetermined frequency by means of said pseudo random signal, and then, outputting the modulated signal as a test carrier; generating an output signal by adding the noise signal of said upstream line and said test carrier; outputting the output signal; selectively receiving a signal having a predetermined frequency from said output signal, and demodulating the selectively received signal; and comparing said demodulated signal with said pseudo random signal in bits, and then measuring a bit error rate.