A low-complexity CFO compensation scheme for uplink interleaved OFDMA

In this paper, a improved low-complexity scheme is presented to compensate the multiple carrier frequency offsets (CFOs) in the uplink of interleaved orthogonal frequency division multiple access (OFDMA) systems. Based on the assumption that multiple CFOs is modeled as Gaussian variables [11][12], all the users are divided into two different sets, defined as large CFO users set (LCUS) and small CFO users set (SCUS) in the proposed scheme. Then, a joint CFO compensation algorithm for both LCUS and SCUS is proposed to make a better tradeoff between computational complexity and system performance. Simulation results show that the proposed scheme achieves a comparable system performance in terms of bit error rate compared to Zero-forcing (ZF) scheme and parallel interference cancellation (PIC) scheme whereas its computational complexity is much lower than the two conventional schemes.