The capacity region of 3G CDMA systems with macrodiversity and power constraints

Under macro-diversity, the cellular structure is removed and each transmitter is jointly decoded by all "receivers" (base stations, or antennas in a single cell). This scheme has been shown to increase the capacity of CDMA wireless networks. However, the available macrodiversity capacity results rely on a "self-interference" approximation, which may not be appropriate in CDMA system in which the spreading gain is low for some transmitters. This is expected in 3rd generation cellular systems. Explicitly considering power constraints, and without recurring to the above approximation, this note applies well established "fixed point" theorems to derive less conservative results defining the macrodiversity capacity region.