A low-cost blind estimation of I/Q imbalance in OFDM systems in the presence of CFO

The estimation of carrier frequency offset (CFO) and in-phase and quadrature-phase (I/Q) imbalance is an important issue in the study of the orthogonal frequency division multiplexing (OFDM) systems. In our recent work [6], we have proposed a blind algorithm for the estimation of CFO in the absence of I/Q imbalance. In this paper, a blind algorithm is introduced for the estimation of I/Q parameter in the presence of CFO. The proposed method does not need to know the channel and CFO value. Moreover a closed form formula for the I/Q parameter is derived and thus the algorithm has low complexity. Simulation results show that the proposed method performs very well. Combining the proposed method and our method in [6], we can solve the joint estimation problem of I/Q and CFO.

[1]  Marc Moeneclaey,et al.  BER sensitivity of OFDM systems to carrier frequency offset and Wiener phase noise , 1995, IEEE Trans. Commun..

[2]  Yonghong Zeng,et al.  Robust subspace blind channel estimation for cyclic prefixed MIMO ODFM systems: algorithm, identifiability and performance analysis , 2008, IEEE Journal on Selected Areas in Communications.

[3]  Mikko Valkama,et al.  Blind Moment Estimation Techniques for I/Q Imbalance Compensation in Quadrature Receivers , 2006, 2006 IEEE 17th International Symposium on Personal, Indoor and Mobile Radio Communications.

[4]  Tao Liu,et al.  Blind estimation of carrier frequency offset, I/Q imbalance and DC offset for OFDM systems , 2012, EURASIP J. Adv. Signal Process..

[5]  V.K.-P. Ma,et al.  Analysis of IQ imbalance on initial frequency offset estimation in direct down-conversion receivers , 2001, 2001 IEEE Third Workshop on Signal Processing Advances in Wireless Communications (SPAWC'01). Workshop Proceedings (Cat. No.01EX471).

[6]  Navin Kumar,et al.  Design and development of non data aided estimation algorithm for carrier frequency-offset and I/Q imbalancing in OFDM-based systems , 2013, 2013 Tenth International Conference on Wireless and Optical Communications Networks (WOCN).

[7]  Mikko Valkama,et al.  Advanced methods for I/Q imbalance compensation in communication receivers , 2001, IEEE Trans. Signal Process..

[8]  See-May Phoong,et al.  A low-complexity blind CFO estimation for OFDM systems , 2014, 2014 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP).

[9]  Xingbo Hu,et al.  Blind joint estimation of carrier frequency offset and I/Q imbalance in OFDM systems , 2015, Signal Process..