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.