Low-Feedback Multiple-Access and Scheduling via Location and Geometry Information

This paper exploits the use of location information of wireless terminals to improve the performance of a beamforming system and support multiple access. Based on a system providing real-time 3D coordinate information of all terminals in the environment, a novel feedback-free multi-user scheduler is proposed. It chooses a set of angularly separated wireless terminals for simultaneous transmission in order to reduce the impact of mutual interference on overall system performance. If additional feedback of signal-to-interference and noise ratio is available, a location-assisted multi-user scheduler is also suggested to further improve the overall system performance. Both multi-user schedulers are based on a rate-greedy approach. To improve the fairness in resource allocation without introducing additional feedback overhead, a modified proportional fair algorithm (PFA) based on location information can be applied to a beamforming OFDMA system. By scaling the window length of PFA, a range of trade-offs between fairness and rate can be achieved.