HSUPA 5,76 Mbps mobiles: Throughputs evaluation on a live network

The E-DCH transport channel uses multi-code transmission together with a special kind of QPSK modulation (BPSK modulation on I and Q axis) to achieve high throughput. On frequency selective channels the orthogonality between the spreading codes is lost and inter-code-interference (ICI) arises. This interference limits performances in case the base stations have a classical receiver (Rake), especially for HSUPA 5,76 Mbps mobiles. Realistic performances of those mobiles are shown in this paper. A new kind of simulation method, based on existing drive test measurements, is used. The measurements are combined with link level simulation results to obtain reliable performance estimation. Simulation results show that the throughput does not exceed 2,5 Mbps if the base stations have a Rake receiver.