Analysis of MRC for Mixed-ADC massive MIMO

Massive multiple-input multiple-output (MIMO) systems with one-bit analog-to-digital converters (ADCs) suffer from substantial channel estimation error caused by the coarse quantization which results in spectral efficiency (SE) loss. In this paper, we investigate the effectiveness of so-called mixed-ADC architectures to overcome this issue. We study to what extent one can combat the SE loss by exploiting just N ≪ M pairs of high-resolution ADCs, where M denotes the number of BS antennas. Unlike previous work on this problem, we incorporate both high-resolution and one-bit observations in the channel estimation algorithm, and we use a more accurate model for the quantization noise based on the Bussgang decomposition.