Time-Varying MIMO Channels: Measurement, Analysis, and Modeling

Abstract—The temporal variation in measured multiple-input multiple-output (MIMO) wireless channels with moving commu-nication nodes is analyzed. A wide-band 8 8 sounder is em-ployed to measure the response of indoor and outdoor channels at 2.55 and 5.2 GHz. The rate of channel temporal variation is then quantified in terms of information theoretic metrics that indicate the loss in channel quality as transmit and receive channel state information becomes increasingly outdated. Finally, these metrics are used to investigate the ability of two different modeling strate-gies—a random matrix model and a physical time-varying cluster model—to capture the channel temporal variation. Index Terms—Information theory, multiple-input multiple-output (MIMO) systems, time-varying channels. I