Method to determine effective number of diversity branches

The diversity gain is the measure of performance of a diversity system. In a diversity implementation, system constraints often result in the branches being correlated and having unequal average SNR levels. Evaluating the diversity gain then becomes difficult because of the statistical nature of the metrics. A method is presented here for diversity evaluation which can be used as an aid for design. It comprises calculating the equivalent number of uncorrelated branches with equal average SNRs, for a system with correlated, unequal average SNR branches. The technique uses eigen decomposition of the correlation matrix estimate and a calculation of diversity gain using maximum ratio combining with unequal average SNRs