Multiuser Millimeter-Wave Massive MIMO Uplink Systems With Dynamic-Resolution ADCs

The design of a hybrid precoder/combiner is developed for the multiuser millimeter-wave (mmWave) massive MIMO uplink systems with the assistance of low-precision phase shifters (PSs) and variant-resolution analog-to-digital converters (ADCs). To enhance channel gain and reduce inner interference among users, an iterative phase matching algorithm (IPMA) is employed to sequentially design analog precoders and combiners. Additionally, the minimum mean square error (MMSE) baseband digital combiner is used to suppress user interference. By reason of the impacts of each ADC-pair precision and energy, a low-complexity dynamic-resolution ADC algorithm, namely, the coordinate update algorithm (CUA), is utilized to maximize the energy efficiency (EE) while sustaining the achievable sum-rate (ASR) capacity and minimizing the total power load simultaneously. Simulation results indicate that a substantial growth in the ASR is accomplished as a function of an increasing user antennas. Besides, with the aid of a mixed-precision ADC mechanism, the mmWave MIMO system yields an optimal EE.