Diversity gain is the increase in signal-to-interference ratio due to some
diversity scheme
In telecommunications, a diversity scheme refers to a method for improving the reliability of a message signal by using two or more communication channels with different characteristics. Diversity is mainly used in radio communication and is a c ...
, or how much the transmission power can be reduced when a diversity scheme is introduced, without a performance loss. Diversity gain is usually expressed in
decibels
The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a power or root-power quantity on a logarithmic scale. Two signals whose levels differ by one decibel have a ...
, and sometimes as a power ratio. An example is
soft handoff gain. For
selection combining N signals are received, and the strongest signal is selected. When the N signals are independent and
Rayleigh distributed, the expected diversity gain has been shown to be
, expressed as a power ratio.
[D.G. Brennan, "Linear diversity combining techniques," Proc. IRE, vol.47, no.1, pp.1075–1102, June 1959]
See also
*
Array gain
In array antenna systems, array gain is the measure of the improvement in signal-to-noise ratio (SNR) achieved by the array. It is calculated as the SNR of the array output signal divided by the SNR of the array input signal. Intuitively, the a ...
*
Diversity combining Diversity combining is the technique applied to combine the multiple received signals of a diversity reception device into a single improved signal.
Various techniques
Various diversity combining techniques can be distinguished:
* Equal-gain com ...
References
Radio resource management
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