Optimal resource allocation in LTE-Advanced network using hybrid Cooperative Relaying and network coding

Cooperative relaying (CoR) and network coding (NC) are two promising techniques for improving the performance of next generation LTE-Advanced networks. In this paper, a dynamic resource allocation scheme is proposed in relay-assisted LTE-Advanced networks which consists of three nodes: User Equipment (UE), Base Station or eNodeB (eNB) and an intermediate Relay Station (RS). In such a network, LTE UEs and eNB can choose between different transmission schemes: direct transmission, pure CoR (CoR scheme) using an intermediate relay station, or via the combination of Network Coding and Cooperative Relaying (NC/CoR scheme). We study the achievable rate regions for direct transmission, CoR and NC/CoR and it is noticed that NC/CoR does not always achieve better performance than CoR or direct transmission. Therefore, a hybrid transmission scheme with adaptive resource allocation is proposed to dynamically choose the best transmission scheme among NC/CoR, CoR or direct transmission. The proposed hybrid scheme determines the best transmission strategy and the optimal resource allocation decision at each bidirectional transmission time-frame based on the system channel information as well as the queue length information. The simulation results show that the hybrid algorithm significantly outperforms conventional schemes for both SISO and MIMO systems.