The Capacity Region of 3G CDMA Systems
with Macrodiversity and Power Constraints
Virgilio Rodriguez
Polytechnic University
ECE Department
5 Metrotech Center
Brooklyn, NY 11201
Email: vr <at> ieee <dot> org
Abstract
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.