Uplink CoMP for HSPA

Uplink co-ordinated multipoint reception (UL CoMP) has received attention recently, especially for LTE Advanced, due to its promise of increasing spectral efficiency. In this paper, UL CoMP for HSPA networks is considered. UL CoMP for HSPA may be deployed without changes to the standard, and may be applied also for legacy UEs. Comparisons and contrasts of CoMP with conventional soft/soft handover are discussed as well as practical receiver structures incorporating antenna selection within the pool of antennas available in a CoMP cell. Radio resource management issues are discussed including mobility, power control, load control, and scheduling. It is concluded that UL CoMP requires only minimal changes to these algorithms. In a practical scenario, gains in cell-edge throughput of at least 118% and 144% are demonstrated for CoMP-3 and CoMP-6, respectively, for the case of full buffer traffic. The gains are even larger for the case of short files uploads where the conventional network suffers from the inability to exploit soft/softer handover due to latencies involved in updating a UE´s active set.