Achievable rates for uplink communications in LTE-advanced networks with decode-and-forward relays

This paper studies the cooperative transmission scheme and the achievable rate for uplink communications in an LTE-Advanced cellular network with Type II in-band decode-and-forward relay stations. The physical layer uplink transmission is based on single carrier frequency division multiple access (SC-FDMA) with frequency-domain equalization (FDE). Unlike orthogonal frequency division multiple access (OFDMA) where the users achievable rate is the summation of the rates on all allocated subcarriers, achievable rate of SC-FDMA system has a more complex expression because the subcarriers are transmitted sequentially rather than in parallel. With the joint superposition coding for cooperative relaying, we derive the expressions of the achievable rate for both zero-forcing (ZF) equalization and minimum mean square error (MMSE) equalization. Numerical results are given to verify the derived uplink achievable rates.