  In this paper, we investigate the capacity of massive multiple-input
multiple-output (MIMO) systems corrupted by complex-valued additive white
Gaussian noise (AWGN) when both the transmitter and the receiver employ 1-bit
digital-to-analog converters (DACs) and 1-bit analog-to-digital-converters
(ADCs). As a result of 1-bit DACs and ADCs, the transmitted and received
symbols, as well as the transmit- and receive-side channel state information
(CSI), are assumed to be quantized to 1-bit of information. The derived results
show that the capacity of the considered massive MIMO system is $2N$ and $2M$
bits per channel use when $N$ is fixed and $M\to\infty$ and when $M$ is fixed
and $N\to\infty$, respectively, where $M$ and $N$ denote the number of transmit
and receive antennas, respectively. These coincide with the respective
capacities with full CSI at both the transmitter and the receiver. In both
cases, we showed that the derived capacities can be achieved with noisy 1-bit
CSI at the transmitter-end or at the receiver-end, and without any CSI at the
other end. Moreover, we showed that the capacity can be achieved in one channel
use without employing channel coding, which results in a latency of one channel
use.
