Digital Modulation Techniques in Mobile Communications

The reliability of a data message produced by a GMSKsystem is highly dependent on the following:(1) Receiver thermal noise: this is produced partly by the receiveantenna and mostly by the radio receiver.(2) Channel fading: this is caused by the multipath propagationnature of the radio channel.(3) Band limiting: This is mostly associated with the receiver Iffrequency and phase characteristics(4) DC drifts: may be caused by a number of factors such astemperature variations, asymmetry of the frequency response ofthe receiver, frequency drifts of the receiver local oscillator.