  In this paper, we investigate the performance of the Viterbi decoding
algorithm with/without Automatic Repeat reQuest (ARQ) over a Rician flat fading
channel with unlimited interleaving. We show that the decay rate of the average
bit error probability with respect to the bit energy to noise ratio is at least
equal to $d_f$ at high bit energy to noise ratio for both cases (with ARQ and
without ARQ), where $d_f$ is the free distance of the convolutional code. The
Yamamoto-Itoh flag helps to reduce the average bit error probability by a
factor of $4^{d_f}$ with a negligible retransmission rate. We also prove an
interesting result that the average bit error probability decays exponentially
fast with respect to the Rician factor for any fixed bit energy per noise
ratio. In addition, the average bit error exponent with respect to the Rician
factor is shown to be $d_f$.
