On Design of Tanner-Graph Detector For Triple Mixed-ADC Large-Scale MIMO Systems

Large-scale multiple-input multiple-output (MIMO) transmission is a widely adopted technique for the current and future communication systems as it offers possibilities to increase the system capacity and quality of services for the radio networks. One-bit analog-to-digital converters (ADCs) and mixed-resolution ADCs have been proposed to reduce the power consumption and hardware cost when a large number of receive antennas are proposed to use in the system. In this paper, we introduce a triple mixed-ADC system, where the receiver side partitions the set of receive antennas into three subsets and utilizes the extremely low-resolution, low-resolution, and high-resolution ADCs to those three subsets. The core idea of this proposal is to use a large portion of receive antennas with 1-bit and 2-bit ADCs, which were proven to have the best energy efficiency, and only a small number of antennas are equipped with 5-bit ADCs, instead of conventional resolution of from 10 to 12 bits, to save power consumption of the ADCs. Additionally, the proposed triple mixed-ADC system offers more options to tune for performance improvement. The experiment results verify the advantages of the triple mixed-ADC system over the single low-resolution ADC and dual mixed-ADC systems in all considered test cases.