Resource allocation scheme with proportional fairness for multi-user downlink MIMO-OFDMA-CDM systems

In this paper, we propose a new resource allocation scheme that enhances a diversity effect with taking into account a proportional fairness (PF) in downlink MIMO-OFDMA-CDM (multiple input multiple output - orthogonal frequency division multiple access - code division multiplexing) systems. In the proposed scheme, spectral resources are allocated per subcarrier unit and full code-spreading is done for each user using all allocated subcarriers. This maximizes a frequency diversity effect and also enhances a multi-user diversity effect. Furthermore, the subcarrier allocation is based on the PF scheme which is not consider in conventional OFDMA-CDM schemes. The improvement performances of BER and capacity are shown through computer simulations.