Performance analysis of cooperative communications from MAC layer perspectives

In recent years, cooperative communication has been proposed as a new communication paradigm that incorporates a relay node to assist the direct point-to-point transmission. By exploiting the cooperative diversity, different types of techniques have been proposed to improve the transmission reliability from the physical layer perspective, e.g. the cooperative automatic repeat request. However, owing to the longer transmission time resulting from the cooperative schemes, there is no guarantee to enhance the network throughput in view of the medium access control (MAC) performance. In this paper, the system throughput of the cooperative communication is evaluated by exploiting the proposed analytical model based on the IEEE 802.11 MAC protocol. Both the relay-based and the original direct communications are considered in the analytical studies. Simulations are conducted to further validate the effectiveness of the proposed model. In terms of the network throughput, whether to adopt the cooperative schemes depends on the tradeoff between the cooperative transmission delay and the channel condition of the direct communication.