Uplink spatio-temporal interference rejection combining for WCDMA

Uplink RAKE combining with receiver diversity for a WCDMA FDD radio link in the presence of interference is considered. Expressions for the correlation between interference of different fingers after despreading are presented. By taking the correlation into account when combining the fingers, interference can be rejected. Spatial interference rejection combining (IRC), which accounts only for spatial correlation of the interference, and spatio-temporal IRC, which accounts also for correlation between fingers with different delays, are compared for rejection of both narrowband and wideband external interference. External interference may stem from narrowband communication systems operating in the same or distant frequency bands and by spectral regrowth from wideband systems operating in adjacent bands.