Bandwidth efficient SDMA multicarrier systems with frequency domain diversity

Multiple receiving antennas increase the capacity of wireless medium by admitting multiple users in the SDMA mode and by reducing channel selectivity. Additionally, spectral diversity may be exploited via a frequency spreading of symbols in order to combat frequency selectivity. The structure of a frequency spreading allows to train the channel equalizer / multiuser interference chancellor with no substantial overhead. A multicarrier modulation scheme with frequency spreading is proposed which yields a simple and data efficient detection of a desired user due to its spreading signature only. A numerical study shows this method suitable for broadband wireless applications.