1. Background 1. With the development and application of radio technology, the electromagnetic environment is becoming more and more complex, and the base stations of mobile companies are often interfered by various radio signals. 2. With the development of mobile communication technology, the increase in the complexity of equipment and the mining of communication capabilities (such as the mining of spectrum potential, the saturation of mobile company base station channels, etc.), RF resources are becoming more and more saturated, and the base station's tolerance for interference Low, which means that it is more and more susceptible to interference and cause deterioration of indicators. It is urgent to find and eliminate interference and purify the communication electromagnetic environment. Second, the technical solution interference is essentially an illegal signal that appears in the frequency band of the useful signal and is strong enough to affect the operation of the useful signal. In principle, the so-called interference search is to use the spectrum analyzer or receiver to display the characteristics of the spectrum status in a certain frequency band, scan the upstream or downstream frequency band of the GSM signal, and analyze the obtained signal spectrum. Because the GSM signal except the C0 carrier , Are frequency-hopping signals, then the signal strength in the band is large, it is not on the C0 carrier frequency point and always exists, and the frequency does not change is the interference signal. The location of interference is to use the directivity of the directional antenna to locate the location of the interference source. Due to the many types of radio interference (currently the main sources of interference are: illegal repeaters, communication blockers, Unicom's CDMA downlink signal tail, small microwave signals, etc.), plus the mobile company's base stations are mostly in downtown areas with complex electromagnetic environments Or the top of a tall building. Therefore, at present, there is no simple and easy solution for the search of interference by various instrument companies. The general and effective method is to complete the spectrum scanning + directional antenna. The steps are as follows: 1. Perform a spectrum scan of the GSM upstream and downstream frequency bands to determine the frequency range of the interference signal. 2. Use the directivity of the directional antenna to determine the direction of the interference signal. 3. Cross-locate at the commanding height of the interference signal direction and adjacent buildings to determine the interference signal building. 4. In the interference building, the location of the interference source is further determined by observing the signal strength. From the above steps, it can be seen that the measurement of interference is basically determined by manual analysis and experience accumulation, which is a time-consuming and labor-intensive process. Some interferences, such as communication blockers, radio work equipment and TV tuner, are also intermittent The characteristics are more difficult to discover and lock, and it often takes several days of patient and meticulous work to discover. Therefore, the performance, efficiency, and portability of the instrument are very important, and it is determined whether interference can be found quickly and conveniently.
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