On the capacity of dual diversity combining schemes on correlated Rayleigh fading channels with unequal branch gains

In this paper, we investigate the effect of fade correlation and the level of imbalance in the mean signal strength on the capacity of Rayleigh fading channels with dual antenna receive diversity. We consider maximal ratio combining (MRC), equal gain combining (EGC) and selection combining (SC) diversity schemes and derive expressions for the average and the outage capacities of the channel. For the case of MRC and SC schemes we obtain closed-form expressions for the average and the outage capacities, whereas efficient Gauss-Hermite quadrature rule-based expressions are provided for ECG diversity. Numerical results are provided to illustrate the capacity degradation due to channel correlation and unbalanced diversity branches.