An effective capacity based approach to multi-channel low-latency wireless communications

IEEE In this paper, we study the effective capacity and quality of service (QoS) exponent for low-latency communications through multiple channels under fading. We consider both the cases that the instantaneous channel state information (CSI) and statistical CSI are available at a transmitter that may have sporadic traffics. In particular, when a fixed transmission rate is chosen by the transmitter with statistical CSI, we derive an upper-bound on the (packet) error probability, which can be used not only to guarantee a certain reliability, but also to derive a lower-bound on the QoS exponent for short-packet transmissions under fading. Simulation results with short-length codes are obtained and compared with the derived bounds on the error probability and QoS exponent, which show that the derived bounds are reasonably tight to be used to guarantee reliability (in terms of the error probability) as well as latency (in terms of the QoS exponent).