WLC04-3: Dual Branch Receivers for Enhanced Voice and Data Communications in WCDMA

The system benefits of using an advanced dual-branch diversity receiver at the mobile terminal are studied in a Wideband Code-Division Multiple-Access (WCDMA) cellular system. The receiver considered is an extension of the generalized Rake (G-Rake) receiver which provides a form of array processing. In addition to exploiting the temporal correlation in receiver impairments and the orthogonality between spreading codes, spatial correlation is also accounted for in the formulation of finger combining weights. We show that this dual-branch G-Rake receiver, even with a pessimistic antenna configuration, has a potential to increase the system capacity, relative to the conventional single-branch Rake receiver, by 94% for voice communications. For data communications, high-data-rate availability can be significantly improved. This allows a HSDPA user at the cell border to enjoy a data rate close to 4 Mbps in dispersive channels. For end-user performance of TCP/IP applications, users with a dual-branch G- Rake receiver experience significantly higher packet bit rates and shorter download times.