A Time-domain Technique for Fading Depth Characterisation Inwideband Mobile Communications Systems

A time-domain technique for fading depth characterisation in wideband Rayleigh and Ricean environments is proposed. New expressions for the probability functions of the received power, which apply to both Line-of-Sight and Non-Line-of-Sight cases, are derived. The fading depth for continuous and discrete channel models is evaluated as a function of the Rice factor, and the product between the system bandwidth and the rms delay spread of the propagation channel. Application examples for UMTS working in different environments are shown, and the results are discussed, giving a general insight into the fading depth behaviour. The fading depth observed by UMTS within different environments ranges from less than 4.3 to 12.5 dB, which is significantly lower than the ones for GSM, thus, different fading margins must be considered. Moreover, UMTS is less sensitive to the existence of Line-of-Sight than GSM.