A State-space Approach To Semi-blind Signal Detection In Fast Frequency-selective Fading Mimo Channels

In this paper, we propose a semi-blind state-space based receiver that jointly performs channel estimation and data detection in MIMO systems subject to fast frequency-selective fading. To accomplish these two tasks, we first define state equations representing the dynamics of channel and transmitted signals. Then, we obtain the state vector by concatenating the transmitted signals and the channel coefficients. This choice of state vector leads to a nonlinear observation equation and hence to the use of the Extended Kalman Filter (EKF) to estimate the states variables. We then develop the EKF and show that the proposed receiver is a generalization of many similar receivers for SISO channels. We also develop a reduced complexity version of the proposed algorithm. Simulation results show the performance gains of the proposed receiver when compared to other commonly used receivers. ©2008 IEEE.276280Kailath, T., Sayed, A.H., Hassibi, B., (2000) Linear Estimation, , Prentice HallKomninakis, C., Fragouli, C., Sayed, A.H., Wesel, R.D., Multi-Input Multi-Output Fading Channel Tracking and Equalization Using Kalman Estimation (2002) IEEE Transactions on Signal Processing, 50 (5), pp. 1065-1076. , MayPiechocki, R.I., Nix, A.R., McGeehan, J.P., Armour, S.M.D., Joint Blind and Semi-Blind Detection and Channel Estimation for Space-Time Trellis Coded Modulation over Fast Faded Channels (2003) IEE Proceedings on Communications, 150 (6), pp. 419-426. , DecemberEnescu, M., Roman, T., Koivunen, V., State-space approach to spatially correlated MIMO OFDM channel estimation (2007) Signal Processing, 87 (9), pp. 2272-2279. , DOI 10.1016/j.sigpro.2007.03.004, PII S0165168407000953Roy, S., Duman, T.M., Soft Input Soft Output Kalman Equalizer for MIMO Frequency Selective Fading Channels (2007) IEEE Transactions on Wireless Communications, 6 (2), pp. 506-514. , FebruaryLi, X., Wong, T.F., Turbo Equalization with Nonlinear Kalman Filtering for Time-Varying FrequencySelective Fading Channels (2007) IEEE Transactions on Wireless Communications, 6 (2), pp. 691-700. , FebruaryGerlach, H., Dahlhaus, D., Pesce, M., Xu, W., Joint Kalman Channel Estimation and Equalization for the UMTS FDD Downlink Proc. IEEE 2003 Vehicular Technology Conference, VTC 2003, 2003, 2, pp. 1263-1267Kim, K.J., Litis, R.A., Joint Detection and Channel Estimation Algorithms for QS-CDMA Signals over Time-Varying Channels (2002) IEEE Transactions on Communications, 50 (5), pp. 845-855. , MaySchafbuber, D., Matz, G., Hlawatsch, F., Kalman Tracking of Time-Varying Channels in Wireless MIMOOFDM Systems Proceedings of the 37th Asilomar Conference on Signals, Systems, and Computers, 2003, 2, pp. 1261-1265Roman, T., (2006) Advanced Receiver Structures for Mobile MIMO Multicarrier Communication Systems, , PhD. Thesis, Helsinki University of Technology, Espoo, Finland, AprilJakes, W.C., (1974) Microwave Mobile Communications, , John Wiley and Sons, New YorkKarami, E., Shiva, M., Blind Multi-Input MultiOutput Channel Tracking Using Decision-Directed Maximum-Likelihood Estimation (2007) IEEE Transactions on Vehicular Technology, 56 (3), pp. 1447-1454. , Ma