Cooperative Transmission: A Reality Check Using Experimental Data

Wireless transmission based on cooperation promises to bring performance improvements in multi-node networks. Several cooperative schemes have appeared in the literature, and in most cases have been assessed under simplified assumptions for the channel model. Experimental data for cooperative transmission are difficult to obtain because they should provide simultaneous characterization of at least three links. In this paper we present measurements that involve two access points (APs) and two user terminals, each of which is equipped with 4 antennas, in an indoor office environment. The data indeed allow for the simultaneous characterization of the multiple input-multiple output (MIMO) links from the APs to the user terminals and between the user terminals. We use these measurements to practically assess several schemes for cooperative transmission.