Energy Efficient Spatial Stream Allocation for Multi-User MIMO in 802.11ac Networks

Abstract

In this paper, we propose a new energy efficient strategy for 802.11ac networks. 802.11ac uses multi-user MIMO (MU-MIMO) technique for throughput enhancement. When multiplexing spatial streams of different lengths, 802.11ac pads additional bits for shorter streams to equalize the sizes of all streams. The padding method incurs redundant energy consumption for a receiver while listening useless data. To alleviate the problem, we propose Energy efficient Spatial stream Allocation (ESA). When serving multiple spatial streams, ESA provide energy optimal transmission by minimizing padded bits. To this end, ESA controls both the number of antenna and modulation and coding scheme (MCS). Our simulation result reveals that ESA can significantly reduce energy consumption of receivers without throughput degradation in 802.11ac networks.