  In this work, we explore the potential and optimal use of transmitter
cooperation in wireless interference networks with deep fading conditions. We
consider a linear interference network with K transmitter-receiver pairs, where
each transmitter can be connected to two neighboring receivers. Long-term
fluctuations (shadow fading) in the wireless channel can lead to any link being
erased with probability p. Each receiver is interested in one unique message
that can be available at two transmitters. The considered rate criterion is the
average per user degrees of freedom (puDoF) as K goes to infinity. Prior to
this work, the optimal assignment of messages to transmitters were identified
in the two limits as p goes to 0 and as p goes to 1. We identify new schemes
that achieve average puDoF values that are higher than the state of the art for
a significant part of the range 0 < p < 1. The key idea to our results is to
understand that the role of cooperation shifts from increasing the probability
of delivering a message to its intended destination at high values of p, to
interference cancellation at low values of p. Our schemes are based on an
algorithm that achieves the optimal DoF value in any network realization, when
restricted to a given message assignment as well as the use of zero-forcing
schemes.
