Transmission diversity in wideband CDMA
M. Raitola, Ari Hottinen, Risto Wichman · 2003
We study two transmission diversity techniques in wideband CDMA system. The studied techniques are time switched transmission diversity (TSTD) and selection transmission diversity (STD). In TSTD encoded bits are distributed between all transmission antennas. In STD encoded bits are transmitted through the best transmission antenna. STD requires that a mobile measures which is the best antenna and transmits this information to the base station. We have compared these two methods and a single antenna case and found that TSTD is over 2 dB better and STD 3 dB better than the single antenna case. We have also found that in WCDMA STD can tolerate relatively high amount of feedback signaling errors.