Advances in Cooperative Single-Carrier FDMA Communications: Beyond LTE-Advanced

In this paper, we focus our attention on the cooperative uplink transmissions of systems beyond the LTE-Advanced initiative. We commence a unified treatment of the principle of single-carrier frequency-division multiple-access (FDMA) and the similarities and dissimilarities, advantages, and weakness of the localized FDMA, the interleaved FDMA, and the orthogonal FDMA systems are compared. Furthermore, the philosophy of both user cooperation and cooperative single-carrier FDMA is reviewed. They are investigated in the context of diverse topologies, transmission modes, resource allocation, and signal processing techniques applied at the relays. Benefits of relaying in LTE-Advanced are also reviewed. Our discussions demonstrate that these advanced techniques optimally exploit the resources in the context of cooperative single-carrier FDMA system, which is a promising enabler for various uplink transmission scenarios.