摘　要:根据HFC网络上行信道的特性,建立了信道模型 分析了上行信道中存在的各种噪声对QPSK

调制技术的影响。结果表明在C /N (传输信道载噪比)较低的情况下,采用QPSK调制方式,可以提高系

统的抗干扰能力。

关键词: QPSK 光纤同轴电缆混合网 上行信道 噪声-Abstract: HFC network in accordance with the characteristics of the uplink channel, the establishment of a channel model　an analysis of the various uplink channel noise on the impact of QPSK modulation. The results show that the C/N (transmission channel carrier-to-noise ratio) lower, the use of QPSK modulation, can improve the system of anti-interference ability. Keywords: QPSK　hybrid fiber coaxial cable network　uplink channel　noise