Performance evaluation of space-time spreading and orthogonal transmit diversity in CDMA2000

Space-time spreading (STS) and orthogonal transmit diversity (OTD) are two transmit diversity schemes proposed by the cdma2000 standard. In this paper, performance comparison analysis of the two transmit diversity schemes in multipath channels under multiuser situation are carried out. Link level simulation in forward link cdma2000 is performed in IMT-2000 channel. Performance analysis and simulation results show that the performance improvement provided by STS over OTD decreases as the increase of propagation path number and decrease of the user number.