Influence to QAM of CATV in Long Distance Using Raman Amplifier

Performance improvement of 64-QAM transmission in long distance digital cable television(CATV) network using Raman amplifier is presented.The mutual influence of analog channel and digital channel in digital CATV network is emphasized.It indicates that the non-linear distortion of analog channel will influence the bit error rate of QAM seriously, such as CSO, CTB and so on.And the bit error rate will be improved by applying Raman amplifier.