Rate Adaptation for Time Variant MIMO Channels with Linear Receivers

In this paper we investigate MIMO spatial multiplexing transmission over slowly time-variant, block-static fading channels with linear receivers. The system can adapt the transmission rate per spatial layer based on outdated channel state information. Two approximate low complexity approaches, based on the log-transformed post equalization SINR, are presented to adjust the transmission rate adaptively on a per block basis. Both approaches can be applied in order to maintain a certain target outage probability or to maximize the mutual information with outage. The methodology is suited for arbitrary input alphabets.