  Intelligent reflecting surface (IRS) is a proposing technology in 6G to
enhance the performance of wireless networks by smartly reconfiguring the
propagation environment with a large number of passive reflecting elements.
However, current works mainly focus on single IRS-empowered wireless networks,
where the channel rank deficiency problem has emerged. In this paper, we
propose a distributed IRS-empowered communication network architecture, where
multiple source-destination pairs communicate through multiple distributed
IRSs. We further contribute to maximize the achievable sum-rates in this
network via jointly optimizing the transmit power vector at the sources and the
phase shift matrix with passive beamforming at all distributed IRSs.
Unfortunately, this problem turns out to be non-convex and highly intractable,
for which an alternating approach is developed via solving the resulting
fractional programming problems alternatively. In particular, the closed-form
expressions are proposed for coordinated passive beamforming at IRSs. The
numerical results will demonstrate the algorithmic advantages and desirable
performances of the distributed IRS-empowered communication network.
