A MIMO-OFDM prototype for next-generation wireless WANs

Coupled with a robust and efficient OFDM air interface, MIMO technologies lead to a very compelling high-speed data downlink solution for future wireless systems. This article presents Nortel Networks' MIMO-OFDM concept prototype and measured performance results. This prototype has been developed in the framework of a Nortel Networks system concept for 3G evolution systems and next-generation wide area wireless networks. The prototype is based on a shared access MIMO-OFDM physical layer in the downlink, supporting adaptive modulation and coding, with peak rates up to 37 Mb/s. The uplink is based on an enhanced UNITS WCDMA physical layer. Performance for the high-speed downlink has been measured under various emulated fading conditions. The measured performance illustrates the robustness of OFDM in frequency-selective channels and high-speed mobility channels, supporting speeds as high as 200 km/h. The prototype can also be used for over-the-air assessment of the technology.