Fully-digital millimeter-wave receivers with low-resolution analog-to-digital converters

In this paper we consider the problem of designing practical beamforming solutions for millimeter-wave communications. While previous works focused on analog and hybrid digital/analog solutions, herein we consider fully digital solutions. Driven by the fact that at high frequencies energy consumption increases rapidly as a function of the analog-to-digital/digital-to-analog converter resolution, we study the effectiveness at millimeter-wave frequencies of low-resolution implementations, where the converters are realized with only 2 or 3 bits. We carry out both an analytical and a simulation-based performance assessment, with both perfect and realistic channel estimation. Moreover, we compare the proposal with state-of-art analog and hybrid digital/analog schemes. The results show the effectiveness of the low-resolution converter approach, in particular in the low-SNR region, that is typical of millimeter-wave transmissions.