  Both the first-order signal statistics (e.g. the outage probability) and the
second-order signal statistics (e.g. the average level crossing rate, LCR, and
the average fade duration, AFD) are important design criteria and performance
measures for the wireless communication systems, including the equal gain
combining (EGC) systems in presence of the cochannel interference (CCI).
Although the analytical expressions for the outage probability of the coherent
EGC systems exposed to CCI and various fading channels are already known, the
respective ones for the average LCR and the AFD are not available in the
literature. This paper presents such analytical expressions for the Rayleigh
fading channel, which are obtained by utilizing a novel analytical approach
that does not require the explicit expression for the joint PDF of the
instantaneous output signal-to-interference ratio (SIR) and its time
derivative. Applying the characteristic function method and the Beaulieu
series, we determined the average LCR and the AFD at the output of an
interference-limited EGC system with an arbitrary diversity order and an
arbitrary number of cochannel interferers in forms of an infinite integral and
an infinite series. For the dual diversity case, the respective expressions are
derived in closed forms in terms of the gamma and the beta functions.
