Author(s)

Jaymin Bhalani, Dharmendra Chauhan, Y. P. Kosta, A. I. Trivedi

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In this paper, we propose two novel semi-blind channel estimation techniques based on QR decomposition for Rayleigh flat fading Multiple Input Multiple output (MIMO) channel using various pilot symbols. In the first technique, the flat-fading MIMO channel matrix H can be decomposed as an upper triangular matrix R and a unitary rotation matrix Q as H = RQ. The matrix R is estimated blindly from only received data by using orthogonal matrix triangularization based house holder QR decomposition, while the optimum rotation matrix Q is estimated exclusively from pilot based Orthogonal Pilot Maximum Likelihood Estimator (OPML) algorithm. In the second technique, joint semi-blind channel and data estimation is performed using QR decomposition based Least Square (LS) algorithm. Simulations have taken under 4-PSK data modulation scheme for two transmitters and six receiver antennas using various training symbols. Finally, these two new techniques compare with Whitening Rotation (WR) based semi-blind channel estimation technique and results shows that those new techniques achieve very nearby performance with low complexity compare to Whitening rotation based technique. Also first technique with perfect R outperforms Whitening Rotation based technique.

Multiple Input Multiple Output, Orthogonal Pilot ML Estimator, QR Decomposition, Semi Blind Channel Estimation

J. Bhalani, D. Chauhan, Y. Kosta and A. Trivedi, "Novel Semi-blind Channel Estimation Schemes for Rayleigh Flat Fading MIMO Channels," International Journal of Communications, Network and System Sciences, Vol. 4 No. 9, 2011, pp. 578-584. doi: 10.4236/ijcns.2011.49069.