There are many natural factors in the radio propagation channels influence small scale fading. Some of the common factors of influencing the small scale fading include:
Multi-path propagation
Due to the reflecting objects and scatters in the channels creates a changing environment which will reduce the signals power in amplitude, phase, and time. Including different multi-path components and amplitude of random phase cause the variation of the signals.
Speed of the mobile.
Between the mobile and base station the relative motion results the random frequency modulation due to the Doppler's shift. Whether Doppler shift will be positive or negative it's depending on the mobile receiver is moving towards or away form base station.
Speed of surrounding objects.
Objects are in the range of radio channels are in motion; if the objects in the area moves at a higher rate than the mobile, the small fading effects will be dominate.
The transmission bandwidth of the signal.
The bandwidth of the transmitted radio signal is greater than the bandwidth of multi-path channel, that causing receiving signal distorted. The bandwidth of channel can be quantified by the coherence of bandwidth.
Multi-path propagation
Due to the reflecting objects and scatters in the channels creates a changing environment which will reduce the signals power in amplitude, phase, and time. Including different multi-path components and amplitude of random phase cause the variation of the signals.
Speed of the mobile.
Between the mobile and base station the relative motion results the random frequency modulation due to the Doppler's shift. Whether Doppler shift will be positive or negative it's depending on the mobile receiver is moving towards or away form base station.
Speed of surrounding objects.
Objects are in the range of radio channels are in motion; if the objects in the area moves at a higher rate than the mobile, the small fading effects will be dominate.
The transmission bandwidth of the signal.
The bandwidth of the transmitted radio signal is greater than the bandwidth of multi-path channel, that causing receiving signal distorted. The bandwidth of channel can be quantified by the coherence of bandwidth.
