Fading depth evaluation in mobile communications - from GSM to future mobile broadband systems

A technique for fading depth characterisation in wideband mobile communications systems is described. The approach, based on the eigenvalue decomposition technique, allows deriving the cumulative distribution functions of the received power for Rayleigh and Ricean fading channels. Application examples for different systems, namely GSM, UMTS, HIPERLAN and MBS, working within different environments, as proposed by standard-setting bodies, are shown in detail, and the results are discussed, giving a general insight into the fading depth behaviour. In the considered environments, the fading depth experienced by GSM is between 9.4 and 18.4 dB. The fading depth observed by UMTS is below the one for GSM by 2.1 to 10.3 dB. Regarding HIPERLAN, the observed fading depth is 2.6 to 4.9 dB below the one for UMTS. MBS experiences fading depths that are usually below 9.7 dB (a worst case of 10.6 dB is observed in City Streets under NLoS). Since the observed fading depth depends on the system and environment characteristics, different fading margins should be considered for each system and working environment.