  This letter provides closed-form expressions for the outage probability, the
average level crossing rate (LCR) and the average fade duration (AFD) of a dual
diversity selection combining (SC) system exposed to the combined influence of
the cochannel interference (CCI) and the thermal noise (AWGN) in Nakagami
fading channel. The branch selection is based on the desired signal power SC
algorithm with all input signals assumed to be independent, while the powers of
the desired signals in all diversity branches are mutually equal but distinct
from the power of the interference signals. The analytical results reduce to
known solutions in the cases of an interference-limited system in Rayleigh
fading and an AWGN-limited system in Nakagami fading. The average LCR is
determined by an original approach that does not require explicit knowledge of
the joint PDF of the envelope and its time derivative, which also paves the way
for similar analysis of other diversity systems.
