Asymptotic Analysis for Cell-Free Massive MIMO With MMSE Combining and Low-Resolution ADCs

This letter analyses the asymptotic performance of cell-free massive multiple-input and multiple-output (MIMO) with low-resolution analog-to-digital converters (ADCs) over spatially correlated channels. Specifically, we first introduce a quantization-aware technique for channel estimation based on linear minimum mean-square error (LMMSE) theory. On the basis of imperfect channel estimation, we then propose a quantization-aware MMSE combining and derive the asymptotic expression of achievable uplink rate over spatially correlated Rayleigh fading channels. Finally, simulation results validate our theoretical analysis and corroborate that the quantization-aware MMSE combiner can improve performance to a certain extent.