Reduced Feedback MIMO-OFDM Precoding and Antenna Selection

Transmitter precoding for multiple-input-multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is an effective way of leveraging the diversity gains afforded by a multiple-transmit multiple-receive antenna system in a frequency selective environment. In the limited feedback scenario, optimal precoder representation for narrowband MIMO systems using moderately sized codebooks designed on the Grassmann manifold has been shown to perform remarkably well. In MIMO-OFDM systems, precoder matrices have to be designed for all subcarriers and the amount of feedback can get prohibitively large. This is especially true for next generation wireless local area networks and wireless metropolitan area networks which have a large number of subcarriers. In this paper, we present techniques to reduce this feedback requirement and the performance of these algorithms is numerically shown to provide improvement over existing schemes