Interpolation-based multiuser precoding for MIMO-OFDM system with limited feedback

In practical multiuser MIMO-OFDM system, due to the bandwidth limits of the feedback channel, only the partial channel state information is available at the transmitter. In this paper, we propose a low-cost precoding scheme, which only needs partial channel state information on a fraction of all subcarriers. Channel state information on other subcarriers is recovered by interpolating and making full use of channel frequency-domain correlations. Thus multiuser zero-forcing precoding can be simply implemented on all subcarriers. The proposed scheme not only significantly reduces the feedback bits, but also effectively cancels multiuser cochannel interference.