A Blind Iterative Hybrid Analog/Digital Beamformer for the Single User mmWave Reception using a Large Scale Antenna Array

This paper develops a blind single-user beamforming algorithm for partially-connected hybrid analog-digital (HAD) antenna arrays operating at millimeter wave (mmWave) frequencies. The proposed scheme is optimal and computationally efficient — it is shown to converge to the optimal eigenvector beamformer without requiring an explicit eigenvector decomposition (EVD) of the received signal's correlation matrix. The Direction of Arrival (DoA) is estimated using the Fast Fourier Transform (FFT) of the digitally-formed beam weight vector and it is used to continually update the analog beams formed by the subarrays of the large array in a tracking mode. The simulation of the proposed scheme shows the bit error probability and DoA estimation performance close to the theoretical limits.