  Due to the nonlinearity of power amplifiers (PAs), the transmit signal is
distorted. Previous works have studied the spatial distribution of this
distortion for a central massive MIMO array. In this work, we extend the
analysis for distributed massive MIMO in a line-of-sight scenario. We show that
the distortion is not always uniformly distributed in space. In the single-user
case, it coherently combines at the user location. In the few users case, the
signals will add up at the user locations plus several others locations. As the
number of users increases, it becomes close to uniformly distributed. As a
comparison with a central massive MIMO system, having the same total number of
antennas, the distortion in distributed massive MIMO is considerably more
uniformly distributed in space. Moreover, the potential coherent combining is
contained in a zone rather than in generic directions, i.e., in a beamspot.
Furthermore, a small-scale fading effect is observed at unintended locations
due to the non-coherent combining of the signals. As a result, one can expect
that going towards distributed systems allows working closer to saturation,
increasing the PA operating efficiency and/or using low-cost PAs.
