In this paper, we focus on the transmit diversity
technologies in WCDMA system. There are two
schemes: open loop and closed loop transmit diversity
simulated in this paper. We simulated with various
conditions to consider the applicability of transmit
diversity in WCDMA system. The simulation conditions
contain different feedback delays, feedback error rates,
and velocities of fading channel. We also propose two
kinds of channel estimation mechanisms into the
simulation: one incur little delay but inaccuracy, the
other incur one frame time delay but is much more
accurate.
From the simulation results, we can know that in
closed loop transmit diversity mode, the pilot symbol of
DL DPCH seems not very helpful for channel estimation
purpose. The CPICH will lead better performance for
the system.
