This paper presents simple closed-form expressions for the ergodic channel capacity of SIMO (single-input and multiple output) wireless systems operating in a Nakagami fading channel. As the performance of SIMO channel is closely related to the diversity combining techniques, we present close form expressions for the capacity of maximal ratio combining (MRC), equal gain combining (EGC) and selection combining (SC) diversity systems for Nakagami fading channels. Also for the first time in international literature, the ergodic capacity of a SIMO system in a Nakagami fading channel with none diversity combining technique applied, is derived. Finally numerical results are presented for illustration.