RECEIVER ARCHITECTURE FOR TRANSMIT DIVERSITY IN CDMA SYSTEM

摘要

A transmit diversity scheme for a CDMA system uses space-time codes to obtain diversity gain. Combined diversity signals encoded according to a space-time code are received at the mobile terminal during first and second symbol periods. The mobile terminal includes a first Rake receiver matched to a first transmit antenna and a second Rake receiver matched to a second transmit antenna. The first Rake receiver combines multipath echoes of the first combined signal during the first symbol period to obtain a first value and combines the multipath echoes corresponding to the second combined signal during the second symbol period to obtain a second value. The second Rake receiver combines multipath echoes corresponding to the first combined signal to obtain a third value and combines multipath echoes corresponding to the second combined signal to obtain a fourth value. A decoder decodes the first, second, third, and fourth values to obtain final estimates of the transmitted symbols.