  The issue of non-cooperative transceiver optimization in the uplink of a
multiuser wireless code division multiple access data network with
widely-linear detection at the receiver is considered. While previous work in
this area has focused on a simple real signal model, in this paper a baseband
complex representation of the data is used, so as to properly take into account
the I and Q components of the received signal. For the case in which the
received signal is improper, a widely-linear reception structure, processing
separately the data and their complex conjugates, is considered. Several
non-cooperative resource allocation games are considered for this new scenario,
and the performance gains granted by the use of widely-linear detection are
assessed through theoretical analysis. Numerical results confirm the validity
of the theoretical findings, and show that exploiting the improper nature of
the data in non-cooperative resource allocation brings remarkable performance
improvements in multiuser wireless systems.
