Channel sparsification beamforming for internet-of-things systems

Abstract

In this paper, we propose a novel pilot beamforming and CSI acquisition strategy for IoT systems to achieve reduction in pilot overhead and enhancement in the channel estimation quality. Key idea of the proposed technique, called time-domain sparse beamforming (TDSB), is to sparsify the time-domain channel vector using the antenna-domain beamforming. As a result of TDSB, wideband channel information can be acquired with partial pilot symbols in time and frequency. From the numerical evaluations, we show that the proposed scheme outperforms conventional channel estimation schemes, and achieves substantial reduction in the pilot overhead.