A test method for interference of onu to catv TV channel

Abstract

A test method for the interference of an ONU (Optical Network Unit) to CATV (Community Antenna Television) channels includes the following steps: (1) building a digital TV interference test system including a GEPON (Gigabit Ethernet Passive Optical Network) OLT (Optical Line Terminal), an optical fiber splitter, a multi-channel digital signal source, an optical transmitter and a spectrum analyzer;(2) testing the spectrums of real interference signals in different scenes in the system by setting optical input under different conditions, generating different signal spectrograms, and analyzing the level intensity and frequency point of interference signals generated by an ONU module, the distribution of interference signals and the devices generating interference sources; (3) analyzing whichCATV channels are interfered according to the spectrums generated under different conditions after the interference signals pass through a CATV module; and (4) verifying the specific influence of theinterference signals on TV signals through a CATV multi-channel digital signal source, finding out the interference path of the ONU to the CATV module, and confirming a solution to the interference based on the spectrograms. The test of the interference of an ONU module to the TV channels of a CATV module in an ONU+CATV two-in-one terminal is realized. The interference intensity can be tested, and the interference path of the ONU to the CATV module can be found out.

Description

technical field [0001] The invention relates to the field of ONU testing, in particular to a testing method for ONU interference with CATV television channels. Background technique [0002] The interference of ONU to CATV mainly refers to the mutual interference caused by the integration of ONU and CATV optical receiver on a PCB board. This integrated device is designed to meet the needs of broadcasting and television operators for broadband access and FTTH fiber-to-the-home An ONU product that integrates a two-in-one CATV optical receiver. This product realizes the passive optical network terminal product that integrates broadband and CATV services. This product is aimed at the broadband access market based on EPON technology and integrates Gigabit Ethernet switching. technology, WDM technology and HFC optical receiving technology, to provide users with a complete broadband, CATV single-fiber multi-service access solution based on EPON technology. [0003] In the GEPON pas...

AI Technical Summary

Problems solved by technology

[0004] The ONU+CATV two-in-one ONU product reduces the PCB area and improves the integration level, but at the same time, the ONU module and the CATV module are integrated on the same PCB, which cannot avoid the space radiation interference caused by the close proximity of the modules; The closed loop of the closed loop, the common ground formed by the power supply loop, the control signal wiring between the modules, etc., there may be conduction interference, crosstalk, etc. formed by power supply ripple, power supply impedance coupling and common ground impedance coupling; how these interferences are tested, the strength How much is it, will it cause interference to the TV image, and which TV channels will be interfered, so a test method and system are needed for simple and quick measurement of this interference

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