Blind Channel Identification and Equalization in OFDM-Based Multi-Antenna Systems


Helmut Boelcskei, Robert W. Heath Jr, and Arogyaswami J. Paulraj


IEEE Trans. on Signal Processing, vol. 50, no. 1, pp. 96-109, January 2002. 


Wireless systems employing multiple antennas at the transmitter and the receiver have been shown to have the potential of achieving extraordinary bit rates. Orthogonal frequency division multiplexing (OFDM) significantly reduces the receiver complexity in multiantenna broadband systems. We introduce an algorithm for blind channel identification and equalization in OFDM-based multiantenna systems. Our approach uses second-order cyclostationary statistics, employs antenna precoding, and yields unique channel estimates (up to a phase rotation for each transmit antenna). Furthermore, it requires only an upper bound on the channel order, it does not impose restrictions on channel zeros, and it exhibits low sensitivity to stationary noise. We present simulation results demonstrating the channel estimator and the corresponding multichannel equalizer performance.


OFDM, MIMO systems, blind channel identification, blind equalization

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