Improving the capacity of cooperative SC-FDMA systems with frequency domain equalization

In this paper, we present power optimization and sub-carrier pairing strategies to maximize the capacity of a dualhop amplify-and-forward cooperative single carrier frequency division multiple access (SC-FDMA) system. We solve the power allocation problem for frequency domain equalizer schemes based on minimum mean square error (MMSE) and zero forcing (ZF) criterion. We prove the optimality of ordered sub-carrier pairing (OSP) and reverse OSP (ROSP) methods for MMSE and ZF equalizers, respectively. We show that joint power allocation and sub-carrier pairing significantly improves the system capacity.