Frequency-domain equalisation for block CDMA transmission

In next generation wireless network, significantly higher rate data services of close to 1 Gpbs are expected. The wireless channels for such a broadband data transmission become severe frequency-selective. Frequency-domain equalisation (FDE) technique may play an important role for broadband data transmission using multi-carrier (MC)- and direct-sequence code division multiple access (DS-CDMA). The performance can be further improved by the use of multi-input/multi-output (MIMO) antenna diversity technique. The downlink performance is significantly improved with FDE. However, the uplink performance is limited by the multiple access interference (MAI). To remove the MAI while gaining the frequency diversity effect through the use of FDE, two-dimensional (2D) block spread CDMA can be used. Recently, particular attention has been paid to MIMO space division multiplexing (SDM) to significantly increase the throughput without expanding the signal bandwidth. In this paper, we present a comprehensive performance comparison of MC- and DS-CDMA using FDE.