Cross-Layer Optimization of Adaptive Modulation and Coding Preserving Packet Average Delay Time

In this paper we introduce a novel cross layer design between MAC and physical layers. Our novel design is based on controlling the adaptive modulation and coding (AMC) transmission mode at the physical layer according to the queue length of finite buffer at the data link layer and each transmission mode of AMC. The aim is optimizing system performance over a wireless link, preserving the important quality of service (QoS) parameter, packet average delay time. Analytical expressions such as packet drop probability, channel packet error rate, packet loss rate and packet average delay time are derived both analytically and through simulations according to the system and channel parameters. Using these expressions, a constrained optimization problem is solved numerically to maximize the overall system throughput, preserving packet average delay time.