Adaptive modulation for multiple antenna systems

Abstract

We present a simple adaptive modulation scheme for multiple antenna systems. Assuming a linear MMSE receiver and a QoS requirement, we show how to use the signal to interference and noise ratio (SINR) information at the receiver output to optimize the data rate for each transmit antenna. Next, we present an iterative adaptive modulation scheme that provides better throughput when compared to the previous scheme, but takes a hit in implementation complexity. We assume perfect channel knowledge at the receiver and the existence of some minimal feedback link to the transmit antennas.