Ngara broadband access system for rural and regional areas

Multi-user multiple-input multiple-output (MU-MIMO) systems have been proposed as a solution for increasing bandwidth efficiency in wireless networks. In this paper we describe a new approach to MU-MIMO for rural and regional areas that we have developed and implemented. The proposed system has achieved six-user MU-MIMO with 12 Mb/s per user data rate in each direction (uplink and downlink, ie. symmetric) over a single 7 MHz channel in an actual rural environment for the first time in the world. The system is in fact capable of providing 50 Mb/s symmetric broadband access for up to 12 simultaneous users over a 28 MHz channel from a single access point. The key aspects of the new system are a synchronisation technology, an access point multi antenna design, an accurate channel estimation and feedback algorithm, and a low computational complexity implementation of crucial signal processing components.