Short-term variations of the mobile channel and the GSM signal

Measurements of complex impulse responses and transmission of pan-European mobile telephone system GSM timeslots have been carried out in different environments. The short-term variations of the mobile channel have been simulated on computer for comparison. Power, time and phase gradients put demands on the receiver. The variations of these parameters are discussed in theoretical, numerical, and experimental terms. The experimentally obtained values of power gradients are on the order 10 dB between two frames at the 1% level, while the variation from one timeslot to the next is on the order 3 dB at normal speeds of about 50 km/h. Theoretically obtained values show considerably higher variations. The distributions of time-jitter as a function of different environments are also given.<>