Analytical Research on Upstream Channel Noise Monitoring

摘要

The Hybrid Fiber Coax (HFC) network of CATV has tremendous advantages as the platform of B-ISDN. In practical application, the upstream channel noise and the special tree-and-branch topology will make it difficult to transmit data. Hence it’s necessary to monitor and analyse the real-time characteristics of the upstream channel noise and bit-error-rate (BER), and understand present and historical situation of noise. In the paper, the cause and characteristics of each kind of noise especially the noise in the upstream channel are studied. Based on this, the formula to calculate the BER of QPSK and 16QAM signal in various environment of upstream channel noise is developed respectively. The imitation of system is made. And the performance comparison between them is given.