Smart cooperative relay schemes in LTE-advanced system

Cooperative relaying is considered as the most cost-efficient method in 3GPP LTE-Advanced in terms of coverage prolongation and transmission efficiency. In this paper, we analyze the best performing cooperative relaying scheme between the Amplify-- and--Forward (AF) and Decode-and--Forward (DF) schemes for LTE-Advanced systems. The comparison between AF and DF Relay Nodes (RN) is important because both approaches are currently under consideration for 3GPP LTE-Advanced (LTE-A). The performance analysis of these two relay nodes considers the criteria of: (1) Linear equalization techniques such as Zero Forcing (ZF) and Minimum Mean Square Error (MMSE) and (2) Cooperative Diversity using 2x2 Multiple Input and Multiple Output (MIMO) Alamouti scheme also termed as Space Frequency and Block Coding. Simulation results show that the Bit Error Rate (BER) performance of AF RN and DF RN improves in LTE-Advanced system and that DF RN clearly outperforms AF RN.