Many times when we talk on mobile there are distortion in conversation (some unwanted noise) speciall in urban areas even the mobile network operator are trying there best to overcome these problems but still there are distortion due to fading.
What is Fading?
Fading is rapid fluctuation of signal over a short period of time. In technical words ” Fading is caused by the interference between two or more version of the transmitted signal which arrive at reciever at slightly diffrent time.these waves are called multipath waves combined at reciever antenna.
Main causes of Fading:
1. Height of mobile antennas are well below the height of surrounding structure .
2. Even when line of sight(LOS or direct path) exist fading still occure due to reflection from ground and surrounding structure.
*Rapid changes in signal strength over small travel distance or time interval.
* Random frequency Modulation due to varying Doppler shift on different multipath signal.
*Time dispersion caused by multipath delays.