Title :
Pilot-Aided IQ Imbalance Compensation for OFDM Systems Operating Over Doubly Selective Channels
Author :
He, Lanlan ; Ma, Shaodan ; Wu, Yik-Chung ; Zhou, Yiqing ; Ng, Tung-Sang ; Poor, H. Vincent
Author_Institution :
Dept. of Electr. & Electron. Eng., Univ. of Hong Kong, Hong Kong, China
fDate :
5/1/2011 12:00:00 AM
Abstract :
In this paper, pilot-aided in-phase and quadrature-phase (IQ) imbalance compensation for orthogonal frequency division multiplexing (OFDM) systems operating over doubly selective channels is addressed. Based on a reformulated system model and the least squares (LS) criterion, a joint IQ imbalance and channel estimation method is developed, and the corresponding compensation scheme is also proposed. Moreover, to further enhance the compensation performance, an iterative compensation algorithm is derived via an expectation-maximization (EM) algorithm. Simulation results show that the iterative compensation algorithm initialized by the proposed LS compensation scheme converges in a few iterations and its performance after convergence is close to the ideal case with perfect IQ imbalance and channel state information.
Keywords :
OFDM modulation; channel estimation; expectation-maximisation algorithm; intercarrier interference; least squares approximations; EM algorithm; LS criterion; OFDM system; channel estimation method; channel state information; double selective channel; expectation-maximization algorithm; iterative compensation algorithm; least square criterion; orthogonal frequency division multiplexing system; pilot-aided IQ imbalance compensation; pilot-aided in-phase and quadrature-phase imbalance compensation; Channel estimation; Joints; Noise; OFDM; Radio transmitters; Receivers; Time domain analysis; Channel estimation; doubly selective channel (DSC); in-phase and quadrature-phase (IQ) imbalance; intercarrier interference (ICI); orthogonal frequency division multiplexing (OFDM);
Journal_Title :
Signal Processing, IEEE Transactions on
DOI :
10.1109/TSP.2011.2112649
