Statistical modeling of RMS-delay spread under multipath fading conditions in local areas

Two statistical models for the parameter of local root mean square (RMS) delay spread taking into account multipath fading characteristics of the received paths' amplitudes are presented. The models have been developed under the assumption that only two "paths" exist in the radio channel. A rather specialized definition for the term "path" is used, which is explained in the introduction. The aim is the description of RMS delay spread when the transceiver moves in a local area and experiences multipath fading. For this reason, the amplitudes of the two paths have been assumed to follow both the Rayleigh distribution at the first model and the Rayleigh and Rice distributions, respectively, at the second model. The time difference between the arrival of the two paths has been assumed to follow the uniform distribution for both models. In order to examine the validity of the models, measurements have been conducted and experimental results have been compared with the theoretical ones. Moreover, measurements from the literature have been obtained for additional confirmation of the models.