Performance Analysis of a Low-Complexity CFO Compensation Scheme for OFDMA Uplink

Chao-Yuan HSU  Wen-Rong WU  

IEICE TRANSACTIONS on Communications   Vol.E92-B   No.3   pp.954-963
Publication Date: 2009/03/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E92.B.954
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Wireless Communication Technologies
orthogonal frequency-division multiple access (OFDMA),  carrier frequency offset (CFO),  intercarrier interference (ICI),  

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Similar to orthogonal frequency-division multiplexing (OFDM) systems, orthogonal frequency-division multiple access (OFDMA) is vulnerable to carrier frequency offset (CFO). Since the CFO of each user is different, CFO compensation in OFDMA uplink is much more involved than that in OFDM systems. It has been shown that the zero-forcing (ZF) compensation method is a simple yet effective remedy; however, it requires the inversion of a large matrix and the computational complexity can be very high. Recently, we have developed a low-complexity iterative method to alleviate this problem. In this paper, we consider the theoretical aspect of the algorithm. We specifically analyze the output signal-to-interference-plus-noise-ratio (SINR) of the algorithm. Two approaches are used for the analysis; one is simple but approximated, and the other is complicated but exact. The convergence problem is also discussed. In addition to the analysis, we propose a pre-compensation (PC) method enhancing the performance of the algorithm. Simulations show that our analysis is accurate and the PC method is effective.