Space-time transmitter diversity schemes for wideband CDMA

Previous work on transmitter antenna diversity has shown that the use of multiple transmitter antennas at the base station results in improved performance due to increase of diversity (path diversity). This happens with no bandwidth cost, the signal quality along several paths is very poor, but the receiver estimates the channel with accuracy. This paper evaluates the effects of channel estimation errors in the performance of space-time transmitter diversity (STTD) for wideband code division multiple access (WCDMA). Comparison is made with the selective transmitter diversity (STD) scheme for different fading channel models.