MIMO (multiple input, multiple output) technology is becoming common in wireless networks based on the pre-802.11n standard. The existing technology, however, has limits in multi-user wireless networks.
Researchers at ETH in Zurich have constructed and demonstrated a MIMO WLAN system capable of data rates up to 216 Mbps in a multi-user network.
“For the first time, the Zurich-based researchers were able to demonstrate that the principle of multiple antenna systems is actually feasible for use in complex wireless networks both theoretically and using their test facility,” ETH Zurich said in a news release Wednesday (March 12). “In doing so, they succeeded in constructing a compact multi-user system, currently with three stations in a bench scale, where every station transmits or receives via four antennae. This meant that the utilization of the frequency range for each of the three users could be up to four times higher than with present-day WLAN networks.”
One of the goals of the project is to develop procedures to decode the MIMO signals as efficiently as possible. Adding more users and more antennas to the system increases the amount of data that can be transmitted but makes it more difficult to demodulate the signal.
The work is part of the MASCOT (Multiple-Access Space-Timing Coding Testbed) project. The three-year project started in 2006. In February, ETH Zurich held its first open house to demonstrate the technology. Presentations from the event are available on-line.
MIMO technology has uses beyond wireless networks. In unrelated projects, researchers elsewhere are investigating use of MIMO technology to increase the data capacity and robustness of terrestrial DTV transmission without increasing the amount of spectrum required.
