Telecom Techniques Guide


Effect of Antenna Gain and Diversity Gain in GSM RF

Gain is most important thing in wireless communication and if its passive then it will be very useful here I write about antenna gain and diversity gain definition and its effect.

Antenna Gains

Mobile Station Antenna

  • Portable mobile phones antennas have typically gain of 0 to 1 dBd.
  • Car mounted antenna has a typical gain of 1 to 3 dBd.

Base Station Antenna

  • Omni directional antennas typically have a gain of 0-9dBd.
  • Directional antennas typically have a gain of 9 to 14 dBd.

Antenna Gain in GSM

Diversity Gain

  • Diversity is used on the uplink to overcome deep fades due to multipath by combining multiple uncorrelated signals.
  • Diversity antenna systems are used mostly at the BTS on the uplink.
  • Diversity antenna system can be realised by physically separating two receive antenna in space or by using polarization diversity.
  • Diversity gain should be considered in Link Budget Analysis whenever it is used.
  • Typically a gain of 3dB is considered whenever diversity is used in the Uplink calculation.