  Obtaining accurate Channel State Information (CSI) at the transmitters (TX)
is critical to many cooperation schemes such as Network MIMO, Interference
Alignment etc. Practical CSI feedback and limited backhaul-based sharing
inevitably creates degradations of CSI which are specific to each TX, giving
rise to a distributed form of CSI. In the Distributed CSI (D-CSI) broadcast
channel setting, the various TXs design elements of the precoder based on their
individual estimates of the global multiuser channel matrix, which intuitively
degrades performance when compared with the commonly used centralized CSI
assumption. This paper tackles this challenging scenario and presents a first
analysis of the rate performance for the distributed CSI multi-TX broadcast
channel setting, in the large number of antenna regime. Using Random Matrix
Theory (RMT) tools, we derive deterministic equivalents of the Signal to
Interference plus Noise Ratio (SINR) for the popular regularized Zero-Forcing
(ZF) precoder, allowing to unveil the price of distributedness for such
cooperation methods.
