Jaekwon Kim, Robert W. Heath Jr and Ed Powers
to Journal of Communication Networks vol. 9, no. 1, pp.75-83, Mar. 2007.
Orthogonal frequency division multiplexing (OFDM) systems with multiple transmit antennas can exploit space-time block coding on each subchannel for reliable data transmission. Space-time coded multiple-input multiple-output (MIMO) OFDM systems, however, are very system to time variant channels because the channels need to be static over multiple OFDM symbol periods. In this paper we propose to mitigate the channel variations in the frequency domain using a linear filter. Our approach has reduced complexity compared with alternative approaches based on time domain block-linear filters. The new frequency domain filter is based on the sparse structure of the system matrix in the frequency domain. Simulation results demonstrate that our proposed frequency domain block-linear filter reduces computational complexity by more than a factor of ten at the cost of small performance degradation compared with a time domain block-linear filter.
This paper is available as a postscript .
MIMO systems, space-time codes, OFDM, ICI, channel tracking