Design of Beamspace Massive Access for Cellular Internet-of-Things

In order to support massive connections over limited radio spectrum for the cellular Internet-of-Things (IoT) in the fifth-generation (5G) wireless network, we propose a new non-orthogonal beamspace multiple access framework. First, we analyze the performance of the proposed non-orthogonal beamspace multiple access scheme, and derive an upper bound on the weighted sum rate in terms of channel conditions and system parameters. Then, we provide a transmit beam construction algorithm for further improving the overall performance. Finally, extensive simulation results show that substantial performance gain can be obtained by the proposed non-orthogonal beamspace multiple access scheme over the baseline ones.