Lu, Xiaojia; Han, Jin; Juntti, Markku (Centre for Wireless Communications, P.O. Box 4500, 90014 University of Oulu, Finland)
This paper studies the downlink closed loop transmission in the 3G long term evolution (LTE) system. We propose a precoding matrix selection algorithm from a finite codebook. The precoding, antenna selection, adaptive modulation and coding (AMC) require the channel information fed back fromreceiver to optimize the system performance. We study the codebook design and precoding matrix selection in LTE system, particularly the single user (SU) in a fading channel scenario. As a comparison to precoding, the antenna subset selection is investigated. The link adaption based on the instantaneous signal-to-noise ratio is also studied. The proposed rank and link adaption algorithm select the precoding matrix and AMC that maximize the spectral efficiency under a certain frame error rate constraint.