Cooperative spatial scheduling in distributed MIMO MAC with interference/concurrency awareness

Concurrent MIMO access is using MIMO-Beamforming vectors to mitigate interference on existing links and exploit spatial spectral opportunity. A novel distributed MIMO MAC, Net-Eigen MAC, was recently developed to (i) null interference on existing links, and (ii) maximize post-processing SNR within desired link, enjoying better throughput performance over conventional single link MAC or SPACEMAC (NullHoc). One key feature in Net-Eigen MAC, named as interference and concurrency awareness, can be utilized by network modules at MAC or higher layer as a powerful tool for network performance improvement. Inspired by such motivation, this paper will present a cooperative scheduling framework that closely utilizes the following two features in Net-Eigen MAC: (i) interference nulling on existing links; (ii) prioritized spatial concurrency among parallel links. Our design monitors all links´ performance status, and accordingly schedules each time frame´s prioritized concurrency/hierarchy, which naturally triggers two representative examples for practical applications: (i) max-min scheduling that optimizes fair throughput; and (ii) longest-queue-first scheduling that minimizes dropped packets. Extensive simulations show that our proposed design can help Net-Eigen MAC achieve a better performance than SPACEMAC or single link MAC in terms of throughput, delay, or loss ratio.