The Research And Implementation Of Electromagnetic Compatibility In Radio Spectrum Management

With the development of radio communication, many newtechnologies and new operations mushroomed.　 At the same time,it becomes more and more difficult　 to manage the resource offrequency spectrum with the highly increase of all kinds of stationwhich change the electromagnetism into more complicated.Specially, after China has joined in WTO and the transformationof government's function, the corresponding demand and standardof management become more and more important. Obviously, thetraditional ways and experiences, which were used to manage,examine, approve frequency resources and search the source ofdisturbance passively, are not fit for the new situation. So, theevident development trend of radio communication is to researchand develop a compatible electromagnetism system with scientificand automatic measures, which can be used in management ofcomplicated frequency spectrum. The most purpose of analysis of compatibleelectromagnetism is to assign radio frequency optimally, decreasethe mutual interference between stations and increase utilizationefficiency of frequency spectrum through selecting reasonablepropagation model of electromagnetism and taking advantage ofcomputer system to perform heavily prediction and analysis ofradio field intensity, analysis of cover region, analysis ofdisturbance, assignment of frequency, harmonization of frequencyand station and so on, which are based on the database to be madefrom resources of frequency spectrum and all kinds of stations andthree-dimensional geographic information system. This system ofcompatible electromagnetism of frequency spectrum has someimportant functions listed as follows: (1) Analysis disturbance of the same or adjacent frequencies (2) Analysis of performance of radio link (including microwave link) (3) Analysis of intermodulation (4) Automatic selection of frequency(auxiliary assignment of frequency) (5) Prediction of region of radio field intensity (6) Harmonization of frequency border (7) Analysis and design the system of microwave and satellite earth station. (8) Generate photographs This paper realizes the function of harmonization analysis ofthe system of microwave and satellite earth station. The concretework includes: (1) Based on the propagation model of radio wave,computing the absorption loss of atmosphere of microwavecommunication system and its fading, simulating the receivingvoltage and realizing the computation of disturbance andharmonization between microwave station and earth station. (2) Getting the harmonic range of satellite earth station andshowing it with photographs when assumed that the diffusionpropagation model of disturbance signal was under great circle orraindrop, realizing harmonization of disturbance of microwavelink. (3) Building a system and presented a corresponding method - IV-to detect electromagnetism environment. Analyzed the cause oferror and presented a method to decrease error. These were provedby some experiments. (4) According to the principle of F-D, using relativefrequency utility factor, presented a more simple method to realizea measurable analysis of the use of frequency and made ascientific reference for using and planning frequency.