  This paper addresses the problem of uplink transmit power optimization in
distributed massive multiple-input multiple-output systems, where remote radio
heads (RRHs) are equipped with 1-bit analog-to-digital converters (ADCs).
First, in a scenario where a single RRH serves a single user equipment (UE),
the signal-to-noise-and-distortion ratio (SNDR) is shown to be a non-monotonic
and unimodal function of the UE transmit power due to the quantization
distortion (QD). Upon the introduction of multiple RRHs, adding properly tuned
dithering at each RRH is shown to render the SNDR at the output of the joint
receiver unimodal. In a scenario with multiple RRHs and UEs, considering the
non-monotonic nature of the signal-to-interference-plus-noise-and-distortion
ratio (SINDR), both the UE transmit powers and the RRH dithering levels are
jointly optimized subject to the min-power and max-min-SINDR criteria, while
employing Bussgang-based maximum ratio combining (BMRC) and minimum mean
squared error (BMMSE) receivers. To this end, gradient and block coordinate
descent methods are introduced to tune the UE transmit powers, whereas a line
search coupled with gradient updates is used to adjust the RRH dithering
levels. Numerical results demonstrate that jointly optimizing the UE transmit
power and the RRH dithering levels can significantly enhance the system
performance, thus facilitating joint reception from multiple RRHs across a
range of scenarios. Comparing the BMMSE and BMRC receivers, the former offers a
better interference and QD alleviation while the latter has a lower
computational complexity.
