Field Evaluations on a Prototype System of Cooperative Multi-Cell MIMO Transmission for Asynchronous Inter-Site Base Station Networks

For next generation cellular mobile communication systems, cooperative multi-cell MIMO transmission (cooperative MIMO) technologies, in which multiple Base Stations (BSs) coordinate their wireless transmission, have recently been receiving considerable attention due to their potential cell-boundary throughput improvement. However, there are few studies that provide field evaluation of cooperative MIMO in real radio-propagation environments. To evaluate cooperative MIMO in a real field, BSs located at different sites should be synchronized to each other with high accuracy in asynchronous inter-site BS networks. The authors develop a prototype of an experimental system by using a GPS (Global Positioning System)-based inter-BS synchronous controller.