Digital intermediate frequency module used for satellite television signal monitoring system

Abstract

A digital intermediate frequency module used for a satellite television signal monitoring system is characterized by being composed of a digital down converter, a digital detector and an abnormal alarm, wherein the digital down converter, the digital detector and the abnormal alarm are sequentially connected, each part is completed in an FPGA XC5VSX95T-1FF136 of the Xilinx, the digital down converter is used for inputting ADC sampling data, center frequency of digital signals is positioned within an intermediate frequency band after being sampled, signal frequency spectrums are transmitted to a base band through an NCO after being input into the digital down converter, and then the data rate of the digital signals is reduced through a sampling filter circuit. Two routes of base band signals I(n) and Q(n) processed by the digital down converter are input into the digital detector. The digital detector is composed of an envelope detection circuit, a video filter circuit and a video detector circuit, wherein the envelope detection circuit, the video filter circuit and the video detector circuit are sequentially connected, and detection signals processed by the digital detector is input into the abnormal alarm for monitoring and alarm of abnormal satellite television signals on one hand, and are displayed through an interface input upper host on the other hand.

Description

technical field [0001] The invention relates to a digital intermediate frequency module used in a satellite TV signal monitoring system capable of completing full-band signal monitoring and finding abnormal alarms. technical background [0002] In recent years, satellite radio and television technology has developed rapidly in satellite TV services, mobile satellite services, Internet access, private networks, military communications and other fields due to its "ubiquitous" and "direct-to-user" characteristics. The number, frequency band and communication capacity keep growing. Satellite radio and television signals are transmitted in satellite communication links, which are easily affected by changes in meteorology, astronomy and geography. At the same time, they may also be interfered by signals from other communication equipment or artificially. For example, hostile forces illegally occupy Interstitial behavior of broadcast television signal frequency bands. On the othe...

AI Technical Summary

Problems solved by technology

The traditional sweep frequency spectrum analysis circuit adopts a superheterodyne structure. Although it has a high measurement dynamic range, it can only measure the amplitude spectrum of the signal within the sweep frequency range, and lacks the ability to measure the phase information of the signal.

At the same time, the traditional sweep frequency spectrum analysis method is realized by scanning the local oscillator signal, which is a non-real-time method, and the measured signal can only be a periodic stable signal. Signal lacks measurement capability

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