Combined adaptive Cooperative with Cross-Layer design under imperfect feedback

In this paper, a Cooperative Cross-Layer (CCL) scheme based on the adaptive cooperative system is proposed to improve the system performance, which is scheduled through combining multilevel adaptive modulation (AM) at the physical layer with truncated automatic repeat request (ARQ) protocol at the data link layer. The transmitter receives the feedback of the modulation mode and ARQ from the receiver. This paper derives the closed-form expressions of the spectral efficiency and outage probability for the CCL. It shows by simulation that the CCL system has better performance than the original adaptive cooperative system. Under outdated feedback, we also analyze the impact of the retransmission number, delay-time and the number of cooperative users on the performance of the CCL system.