Finally, points out the main problems exists in the HFC network: noise funneling in the re-turn path; control tactics of noise; reflection in the cable.
同时对双向HFC网存在的主要问题：上行通道噪声漏斗效应、各种噪声干扰控制策略、回波反射等进行了说明。
But the existence of noise funneling in the return path of cable network in HFC system restricts the selection of modulation techniques for the return path.
但HFC网络中同轴电缆网络上行信道中存在的噪声漏斗效应限制了上行信道调制技术的选择。
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