Design And Implementation Of The Radio Monitoring System

With the rapid development of wireless communication services, efficient use of spectrum resources has become a common concern. People can get information through different media in our daily life in order to determine their own actions. Radio is widely used as its many advantages among all media of human information transmission, such as the flexible and convenient use, less restrictions, openness, and so on. The government department needs to monitor those activities endangering the society for people's orderly life, such as illegal electromagnetic radiation, which can damage the mass media and spread harmful information to achieve unfair commercial purposes. Clearly, it is necessary that the radio management committee carry on management to these illegal electromagnetic radiations.The rapid growth of both number and variety in wireless communication and satellite communication technology presents unprecedented challenges to the radio frequency spectrum technology. We cannot always know the location and appearance time of the interested signals, and these signals may have a very short duration and low power, so there may be many signals with different frequency, duration and bandwidth prevent us from identifying the interested signal. The radio monitoring system in future needs a great high frequency search speed and resolution, because the faster the system monitoring the broadband spectrum, the more probability that we may see the relatively short duration signal. A high-resolution system can find our interested signal close to the location of other large-signals, or discover low-level signals near the location of the noise floor. Therefore, a modern monitoring system needs to have a higher speed and resolution to find the hidden signals or those with a relatively short duration. A receiver can generate tens of thousands of data per second, but only a few is interesting. Thus, the system needs to provide some reliable tools to screen out the data collected, and obtain information from the seldom key transferring data. This system is used to manage the local and remote radio monitoring equipment, collect the local and remote monitoring data, and provide analytical processing tools. Then it can present a visual management platform to the users. The system monitors the sound signal and the ITU parameters of emission signals, such as frequency, bandwidth, field strength, and modulation mode, make identification of the emission signal and statistics on the degree of frequency utilization and channel occupancy. At the same time, it can achieve a more rational and effective use of the frequency resources through analysis of the signal utilization situation. Through analysis and identification of the received illegal signals, the system can further test the location of interference source, eliminate the interference, and investigate illegal radio stations and non-approved radio communication systems to ensure the business security of the communication system.This article refers the related technology of radio monitoring as the main object of study, and makes a thorough study on some key technologies of them. Firstly, the monitoring and measurement of modulation signal, mainly including the measurement of modulated signals, demodulation of the modulation signal, and the automatic recognition of signal modulation mode. Secondly, we make a further analysis and processing on the received signal of digital zero IF receiver, and measure the received signal to realize a further monitoring or identifying on the interested signal. Finally, realizing the test on the radiation sources, and monitoring the recorded signal in real time.