MC-CDMA Based Architecture for the Downlink of Infrastructure WLANs

In this paper we propose a multicarrier code division multiple access (MC-CDMA) based architecture with variable spreading factor for the downlink of infrastructure wireless local area networks (WLANs). The objective of this proposal is to provide service simultaneously and within the same radio channel to several users even if their data rate requirements are different. In addition, the bit error rate (BER) performance of our proposal is analyzed for four combining techniques and two network scenarios, one without multiple user interference (MUI) and one where the MUI reaches its maximum value. We consider a wide-band Rician fading channel with both independent and correlated frequency selectivity for the BER computations. The main the purpose of the paper is to show how the MUI and the correlation among subchannels affect the BER performance of a downlink MC-CDMA system