Multiple-access capacity gains using multiuser detection under uniform linear power spacing

This paper reviews the driving factors that affect performance gains in wireless networks when receivers are enabled by multiuser detection (MUD). Assuming the many-to-one, Gaussian multiple-access channel, we compare the capacity of a jointly optimal MUD receiver with the single user match filter using TDMA, FDMA and orthogonal CDMA access schemes. Comparisons are made under both equal power and unequal power conditions. Unequal power cases are constrained to uniform linear power spacing where the received powers are equally spaced over a given power spread. Motivation for this analysis is to better understand what multiple-access schemes will realize the highest potential improvements by incorporating MUD technology and under what system constraints those gains are maximized.