Performance of WCDMA HSDPA in a beamforming environment under code constraints

The application and performance of WCDMA HSPDA (high speed downlink packet access) in a beamforming environment is studied under channelization code constraints, using a blind and an intelligent packet scheduler. Results for the optimal number of beams and scrambling codes per cell are presented, where it is found that more scrambling codes and less beams are typically required when using intelligent scheduling, compared to blind scheduling. The cell capacity over single antenna transmission is observed to be larger for radio channels with low temporal dispersion, compared to scenarios with high temporal dispersion. Mainly because an additional code-efficiency gain is obtained over single antenna transmission for environments with low temporal dispersion. The code-efficiency gain originates from a lower selection probability of the higher modulation and coding schemes, when beamforming and multiple scrambling codes are used.