Bounds on outage probabilities for diversity receptions over arbitrarily correlated Rician channels

Existing work on exact outage probabilities of diversity receptions over arbitrarily correlated Rician channels involves intractable integrals. Although asymptotic analysis provides closed-form approximation and can be highly accurate at large signal-to-noise ratio, it is not known at what signal-to-noise ratio will the exact outage probability converge to the asymptotic result. In this paper, we propose a new approach to derive the asymptotic outage probability of maximal ratio combining, selection combining and equal gain combining over arbitrarily correlated Rician channels. The new asymptotic analysis is more straightforward than the previous approach, and results in an interesting geometrical explanation for the asymptotic outage probabilities. More importantly, asymptotically tight outage probability bounds of the three most popular linear diversity receptions are also derived for the arbitrarily correlated Rician channels. Using these bounds, we can show at what signal-to-noise ratio the asymptotic results are accurate without resorting to computer simulations.