Digital transmission systems are required to introduce new services of CATV such as PPV and VOD. In this paper we describe the development of 64QAM transmission equipment . It has 30Mbps transmission capability with 6MHz bandwidth. We experiment hybrid optical transmission with a 64QAM signal and 60 VSB-AM signals of conventional CATV systems. We get sufficient 64QAM BER performance. We also measure phase noise of recovered IF carrier and estimate its effect on the QAM transmission performance.
