Improving the Throughput of Single-hop Networks via Multi Antenna Techniques.

摘要

MIMO (Multi-Input Multi-Output) systems, SDMA (Space Division Multiple Access) techniques, and concurrent link communications have been jointly used as a powerful means in improving the throughput performance of single hop MIMO networks. This dissertation aims at presenting two system designs using concurrent link communications for network throughput improvement, and a special focus is put on dealing with realistic system conditions. We start by considering a generic SDMA MAC that is conventionally designed for concurrent link communications. Its throughput performance is investigated by taking into account various practical PHY conditions including: RX MIMO detection methods, channel estimation errors, link adaptation, and TX beamforming. In the sequel, findings derived from our investigation are then integrated as a Net-Eigen MAC, which implements the concurrent link scheme in a distributed way for TX beamforming based MIMO systems. Such Net-Eigen MAC's link throughput value is verified to be no less than single link MAC's counterpart, and its ergodic throughput value is 30% higher than that of single link MAC.;In addition, considering spatial multiplexing based MIMO systems, and inspired by the facts that existing MIMA-MAC strategy cannot always outperform the single link MAC in terms of link throughput, this dissertation will further present an adaptive MAC strategy intelligently switching between the single link scheme and the concurrent link scheme, where the objective is to improve the link throughput by guaranteeing each link's result to be no less than its single link scheme's counterpart. Performance of our proposed MAC is verified via extensive simulations, and its ergodic link throughput is shown to be 20% higher than that of single link MAC.