FROM ELECTROMAGNETICS TO SYSTEM PERFORMANCE - A NEW METHOD FOR THE ERROR-RATE PREDICTION OF ATMOSPHERIC COMMUNICATIONS LINKS

An original and general method is proposed to predict the impact of el ectromagnetic effects due to the environment on the error performance of microwave communications systems. The method is based on the concep t of a process-oriented model which consists of a simplified represent ation of the physical phenomenon responsible for transmission impairme nts and simulates its influence on the signals received by any given c ommunications link. The method yields a thorough characterization of t he system impairments in both the time domain, by calculating the fluc tuations of the received signal during the evolution of the physical p rocess, and the frequency domain, by inferring the communication chann el transfer function from the frequency dependence of the received wav eform. In addition, by introducing the simulated channel transfer func tion as a filter in a communications system simulation software, the m ethod evaluates the degradation induced on system performances. Three applications as different as scintillation due to turbulence in clouds , depolarization by rain and ice crystals, and interference in the pre sence of diffraction on obstacles demonstrate the ability of the metho d to deal with actual radio-communications system impairments.