Channel modeling and capacity evaluation for relay-aided MIMO systems in LOS environments

We examine relay-aided MIMO systems in light-of-sight (LOS) environments. In conventional MIMO systems, the channel response matrix is always rank deficient in LOS environments so no multiplexing gain can be provided. By introducing relays, which amplify and forward the received signals from the source, to "create" dominant reflectors. In this paper, we consider the MIMO system aided by several location-fixed relays. We present a channel model to describe such a relay-aided MIMO channel in a LOS environment. Based on the channel model, we analyze the statistical channel behavior when mobile station is randomly located in a specified region. We show that the relays can help improve the orthogonality among spatial subchannels.