A Comprehensive Analysis of the Achievable Channel Capacity in $\mathcal{F}$ Composite Fading Channels

The F composite fading model was recently proposed as an accurate and tractable statistical model for the characterization of the composite fading conditions encountered in realistic wireless communication scenarios. In the present contribution, we capitalize on the distinct properties of this composite model to derive an analytical framework and then to evaluate the achievable channel capacity over F composite fading channels under different channel state information (CSI) assumptions. To this end, we first consider that the CSI is known only at the receiver, for which we derive novel analytic expressions for the channel capacity under optimum rate adaptation as well as for the corresponding effective capacity. Then, by considering that the CSI is known both at the transmitter and at the receiver, we derive novel analytic expressions for the channel capacity under optimum power and rate adaptation, channel inversion with fixed rate and truncated channel inversion with fixed rate. The derived analytic expressions for the considered scenarios are provided in closed-form and benefit from being tractable both analytically and numerically. This enables the derivation of simple bounds as well as approximate and asymptotic expressions, which are shown to be useful as they provide meaningful insights on the effect of fading conditions and/or latency on the overall system performance.