混合光纤同轴电缆(HFC)系统的前端近年来没有引起人们的充分注意。随着一些高级服务—如通话、数据和互联数字网络技术—通过此系统的实施。人们更加清楚地认识到,需要不断提高调制技术,以在CATV网络上提供高质、可靠的电讯服务。 通过现有的CATV设施传输POTS、数据和其他电讯服务,系统的可靠性主要依赖于坚固的实际传输层(由一个调 The front end of hybrid fiber coaxial cable (HFC) systems has not attracted enough attention in recent years. With some advanced services - such as call, data and Internet digital network technology - through the implementation of this system. There is a greater awareness of the need to continually improve modulation techniques to provide high quality, reliable telecommunications services over the CATV network. The delivery of POTS, data and other telecommunications services through existing CATV facilities relies primarily on the solid real transport layer (consisting of one tone