Performance analysis for M-ary orthogonal FSK with hybrid selection/equal-gain combining over Nakagami fading channels

In this paper, we consider a diversity system with M-ary orthogonal FSK and hybrid selection/equal-gain combining (HS/EGC) which combines, per the EGC rule, the L_c strongest diversity branches out of the L available ones. We assume independent Nakagami fading on the diversity branches with unequal fading parameters and unequal signal-to-noise ratios (SNRs) and derive different closed-form expressions for the average symbol error probability (SEP). The closed-form expressions are in canonical form as a weighted sum of elementary closed-form expressions, which are the closed-form expressions for a diversity system with EGC in various Nakagami fading environments.