Radio Signal Propagation Model Recognition Basing On WM Operator

With the development of society, Communications needs is increasingly urgent. Channel characteristics have a serious impact on the performance of mobile communication systems. Wireless channel model research has been paid attention to by people. The mobile communication network planning based on accurate propagation model, The reasonable propagation is correlated to the mobile network cell planning. With the rapid development of mobile communication networks, the mobile network operators have an increasing emphasis on communication model and the matching degree of the local environment. Mobile wireless communication environment is complex, big difference, through the actual model tests, we can get a nice propagation model based on radio propagation characteristics. This characteristic for a multi-service 3G system is particularly important.In this paper, given the radio signal propagation model, and based on the credibility theory, mainly discusses the following four aspects:â‘ Analyze radio signal characteristics and radio signal attenuation rule. And review timing characteristics, spectral characteristics, propagation characteristics, modulation characteristics of radio signal. In addition, introduce radio signal channel characteristics and signal transmission in the air caused by the decay; multi-path effects and the Doppler effect will cause a number of signal overlay at the receiving terminal, so that signal attenuation caused by rapid changes in signal amplitude;â‘¡Discusses the types of radio signal propagation model and the relationship between the various models, and analyze the Cost-231 Hata model and COST231-Walfish-Ikegami model. Current wireless signal transmission in the air empirical model derived from Okumura-Hata model. Cost-231 Hata model is Okumura-Hata model does not fully apply the requirements of the modern radio communication, under the premise was amended to conform to the needs of modern radio communications. COST231-Walfish-Ikegami model is the European Science and Technology Research Council (EURO-COST) in Walfish-Bertoni urban environment based on the measurement results obtained correction factor model of urban radio signal propagation;â‘¢Discusses the definition and nature of the mathematical expectation, variance and the weighted average operator (WM operator), propsed the new identification method under the mathematical background of radio signal propagation model.First, divided a given region into several small sector-wide, reaching from the "rough" to "fine" and given the possible spread of model test area based on the experience of experts; Second, give simulation calculation of each small sector according to the propagation model, using field testing equipment test the actual field strength in each region, and then calculate difference value between the experimental field strength and the actual field strength.At last, given the mathematical expression based on the relevant mathematical knowledge;â‘£According to the vicinity of West China University of radio signal propagation characteristics, through specific experimental verification of the proposed method is feasible.The results obtained have practical work guide.