THE PRINCIPLES OF THE CONSTRUCTION OF AN URBAN MULTIPATH RADIO-CHANNEL SIMULATOR

It is well known [1, 2] that an urban radio channel has pronounced mul tipath properties, which gives rise to deep frequency-selected fading of the transmitted signals. The distortions that occur under such fadi ng conditions degrades the data transmission quality in various commun ications systems. Fading has a particularly strong effect on the opera tion of broadband digital cellular mobile and personal radio-communica tions systems, which are receiving considerable attention at the prese nt time. Multipath propagation of radio waves can be countered by usin g diversity reception, special antifading forms of modulation, adaptiv e equalizers and noise-immune coding. In practice, these methods can b e used separately or in different combinations. To investigate the fea tures of their operation, the choice of nomenclature and the optimizat ion of the parameters of the devices which combat multipath propagatio n, devices are necessary that simulate the actual processes occurring in an urban multipath channel under laboratory conditions. In this pap er we estimate the potential possibilities of the most universal softw are and hardware methods of simulating an urban multipath channel and we determine the basic principles of the construction of a simulator.