On the analysis of effective capacity over generalized fading channels

Quality of service (QoS) guarantees play a significant role in next-generation wireless networks and the concept of effective capacity is proposed to characterize the maximum arrival rate that a time-varying fading channel can support under a delay-QoS constraint. However, the probability density function (PDF)-based analysis of effective capacity over generalized fading channels suffers from mathematical intractability in some situations of interest. In this paper, an approach based on the moment generating function (MGF) is introduced, which is suitable to deduce the closed-form expression for effective capacity computation. We start with the general case of adaptation transmission policy under the assumption of channel side information (CSI) only at the receiver, and then extend it to other adaptation policies. In addition, we derive unified and concise expressions of effective capacity by means of Fox's H function, which can be easily calculated, accommodating a wide variety of fading scenarios. Finally, the formulas of effective capacity are verified by numerical and simulation results.