On the Performance of Massive MIMO Systems With Low-Resolution ADCs and MRC Receivers Over Rician Fading Channels

Abstract

This article considers uplink massive multiple-input multiple-output (MIMO) systems with maximum-ratio-combining (MRC) receivers over Rician fading channels. Low-resolution analog-to-digital converters (ADCs) are considered for both data detection and channel estimation. Asymptotic approximations of the spectrum efficiency (SE) for large-scale MIMO systems are derived based on random matrix theory. With these closed-form expressions, we can provide insights into the tradeoffs between the SE and the ADC resolution and study the influence of the Rician K-factors on the performance. It is shown that a large value of K-factors may lead to a better performance and alleviate the influence of quantization noise on channel estimation. Moreover, we investigate the power-scaling laws for the system under imperfect channel state information and it shows that when the number of base station (BS) antennas is very large, without loss of the SE performance, the transmission power can be scaled by the number of BS antennas while the overall performance is limited by the resolution of ADCs. The asymptotic analysis is validated by numerical results. We also show that ADCs with intermediate resolutions lead to better energy efficiency than that with high-resolution or extremely low-resolution ADCs.