Throughput Optimization of Wireless Mesh Networks with MIMO Links

Multiple input multiple output (MIMO) antennas use sophisticated physical layer techniques to provide significant benefits over conventional antenna technology. Multiple independent data streams can be sent over the MIMO antenna elements. MIMO link can also suppress interference from neighboring links as long as the total useful streams and interfering streams are no greater than the number of receiving antenna elements. For these reasons MIMO antennas are increasingly being considered for use in interference limited wireless mesh networks and have been adopted by WLAN and WIMAX standards. However, the benefits of the MIMO technology in improving network performance are limited unless the higher layer protocols also exploit these capabilities. In this paper we are interested in characterizing the benefits of cross-layer optimizations in interference limited wireless mesh networks with MIMO links. We formulate a framework where data routing at the protocol layer, link scheduling at the MAC layer and stream control at the physical layer can be jointly optimized for throughput maximization in the presence of interference. We then develop an efficient algorithm to solve the resulting throughput optimization problem subject to fairness constraints.