Performance of triply-Polarized MIMO-CDMA system for downlink communications

In this paper, we investigate the performance of a multi-user downlink (DL) multiple-input multiple-output (MIMO) aided code division multiple access (CDMA) using polarization multiplexing (PM). We consider triply-Polarized antennas to establish PM that possess the advantage of replacing the uni-Polarized antennas which impose space constraints. In order to accommodate more user populations, we consider orthogonal spreading sequence. At the receiver, we realize Zero forcing algorithm (ZF) based multi-user detection (MUD) to mitigate the effects of multistream interference (MSI) and multi-user interference (MUI). In particular, we evaluate the effects of three types of delay spread on MIMO-CDMA system in the context of downlink (DL) communications pertaining to the Stanford University Interim (SUI) channel model. Our simulations reveals that triply-Polarized MIMO-CDMA system is capable of supporting many users and provides better bit error rate performance for DL communications with reduced number of antennas.