Channel estimation for hybrid multi-carrier mmwave MIMO systems using three-dimensional unitary esprit in DFT beamspace

In this paper we study the channel estimation problem for a CP-OFDM based mmWave hybrid analog-digital MIMO system, where the analog processing is achieved using only phase shift networks. A two-stage three-dimensional (3-D) Unitary ESPRIT in DFT beamspace based channel estimation algorithm is proposed to estimate the angular-delay profile and subsequently the unknown frequency-selective channel. The required training protocol, analog precoding and decoding matrices, as well as pilot patterns are discussed. Simulation results show that the proposed multi-stage 3-D Unitary ESPRIT in DFT beamspace based channel estimation algorithm provides high resolution channel estimates.