论文部分内容阅读
HFC网络结构的出现为CATV网络的双向通信提供了实现基础.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.在对噪声漏斗效应进行定量分析的基础上,导出了同轴电缆网络上行信道用户终端输出载噪比、工作电平(输出信号功率)、上行放大器个数、用户数与所选调制技术接收门限信噪比之间的约束关系,为上行信道调制技术的选择提供了依据
The emergence of HFC network structure provides the foundation for the bidirectional communication of CATV network.However, the noise funnel effect existing in the uplink channel of coaxial cable network in HFC network limits the choice of uplink channel modulation technology.After quantitative analysis of noise funnel effect Based on this, the constraint relationship between the output carrier-to-noise ratio, the working level (output signal power), the number of upstream amplifiers, the number of users and the SNR of the receiving threshold of the selected modulation technique is derived for the uplink channel user equipment in the coaxial cable network. It provides the basis for the choice of uplink channel modulation technology