Performance of coherent receivers with hybrid selection/equal-gain combining in Nakagami-m fading

The symbol error rates of several linear M-ary modulations are derived for a coherent receiver employing hybrid selection/equal-gain combining (SC/EGC), in a Nakagami-m fading channel. The L-branch receiver selects the two diversity branches with the strongest signals, and then performs equal-gain combining on these signals. Closed-form expressions are obtained for the symbol error rates and the outage probability for integer values of the Nakagami-m fading parameter.