Multiuser Transmit Beamforming for Maximum Sum Capacity in Tactical Wireless Multicast Networks

摘要

Tactical wireless networks often comprise clusters of nodes, which are fed information from a head node. Transmit antenna arrays mounted on the head node (e.g., unmanned aerial vehicle) offer an attractive means of boosting capacity and assuring quality of service through transmit beamforming. The central goal of our research was to investigate efficient multiuser transmit beamforming strategies, and develop high-throughput low-complexity algorithms that will meet the needs of future tactical wireless networks. Sum capacity, quality of service, and fair service objectives were considered, under unicast and multicast scenarios. A key innovation of our work is the concept of physical layer multicasting, which affords significant capacity gains. A number of effective and efficient algorithms were developed, drawing upon and contributing to semidefinite relaxation (SDR) tools. Closely-related added- value topics of our research program included: (i) computationally efficient quasi-optimal multiple input multiple output detection (using lattice search, data association, and SDR tools); (ii) accurate and scalable node localization from pairwise distance estimates; and (iii) tracking of time-varying carrier signals (using and developing associated particle filtering tools). Our work on these topics has been reported in seven (IEEE, SIAM) journal papers and seven IEEE conference papers. Variants of some of our published algorithms are currently considered for adoption by industry.