Performance of MRC satellite diversity receivers over correlated lognormal and gamma fading channels

Multi-satellite or orbital diversity is an effective technique to reduce the large fading margins in satellite communications under fading conditions. Transmitted signals from multiple angularly-spaced satellites are combined at the terminal station which is equipped with multiple antennas or a single multiple-input (multiple satellite feed - MSF) antenna. Typical signal processing techniques used for diversity combining of the multiple satellite signals are selection combining (SC) and maximal ratio combining (MRC). The subject of this paper is to present physical statistical models for the signal-to-noise ratio distribution as well as a closed-form mathematical expression for the outage probability of dual-satellite orbital diversity with MRC operating under correlated log-normal or gamma fading conditions.