Low Complexity Channel Estimation Method of MIMO-OFDM for LTE Downlink

In this paper channel estimation method of long Term Evolution (LTE) system is addressed. For pilot aided channel estimation of OFDM system mainly includes coarse channel estimation and interpolation to reconstruct the channel impulse response. To keep better performance of channel estimation in OFDM system, the optimum linear minimum mean squared error (LMMSE) generally is addressed for interpolation procedure. We present poly-phase filter architecture and method to implement interpolation process of channel estimation to reduce the complexity of LMMSE estimator. Meanwhile, we also fully utilize the symmetry of coefficient matrix to further reduce the complexity of the traditional poly-phase filter of channel estimation. Algorithm deductions show that the complexity of proposed method greatly reduced with the same performance of LMMSE estimator in realistic scenarios.