Achievable Rates of Full-Duplex Massive MIMO Systems with Mixed-ADC/DAC

In this paper, we consider a full-duplex (FD) large-scale multi-input multi-output (MIMO) system with a mixed analog-to-digital converters/digital-to-analog converters (ADCs/DACs) architecture. Specially, some of the antennas are used to connect with high-resolution ADCs/DACs, while the others are used to connect with low-resolution ADCs/DACs. Maximum ratio combining/maximum ratio transmission (MRC/MRT) are employed in the considered system. By adopting the additive quantization noise model (AQNM), under the perfect channel state information (CSI), we derive approximate expressions for the uplink and downlink rates, considering the loop interference (LI) and the influence of quantization error. The results indicate that in this system model, the rates of the uplink and downlink are proportional to the antennas at the base station (BS). In addition, the LI, which is an important parameter in the FD model, has an attenuation impact on the sum rate, and the greater the ratio of high-resolution ADCs/DACs, the more obvious the attenuation. Moreover, we study the impact of quantization bits on the downlink achievable rates. The results show that in different antenna allocation schemes, as the proportion of high-resolution ADC increases, the starting value of the downlink rate increases. We can also conclude that the achievable rate of each allocation scheme tends to be the same as the quantization bits increase in the case of the same total number of antennas.