Special Issue Article
Low Complexity CFO Compensation Scheme for SC-FDMA Uplink System
K.Selvaraj1, M.Alice Margaret2 and P.Ganesh Kumar3
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Single Carrier Frequency Division Multiple Access (SC-FDMA) has been adopted for fourth generation (4G) mobile uplink transmission schemes because of its low Peak to Average Power Ratio (PAPR) as compared to that of Orthogonal Frequency-Division Multiple Access (OFDMA).Since SC-FDMA has low PAPR, it is sensitive to Carrier Frequency Offsets (CFOs) similar to that of OFDMA. To minimize and compensate CFO effects on SC-FDMA, the uplink system with Zero- Forcing (ZF) equalization can be used. In this, the method involves is an inverse of an N × N CFO induced intercarrier interference (ICI) matrix, where N denotes the number of subcarriers. When N is large, it will leads to large number computational complexity of the system and the performance of the system will degrade. To overcome this complexity, we propose a low- complexity ZF method and Newton’s method with fast Fourier transforms which is used to solve the matrix inversion problem. This reduces the complexity from O(N3) to O(2N log2N). The proposed compensation scheme can able to improve the system performance.