Evaluation of load balancing in HSUPA

The paper considers a problem of load balancing, i.e. allocation of single-carrier User Equipment (UE) entities over multiple available carriers in the Wideband Code Division Multiple Access (W-CDMA) High Speed Uplink Packet Access (HSUPA) system. Performance of different load balancing approaches is numerically evaluated by means of System Level Simulations (SLS) of W-CDMA HSUPA. The simulation results demonstrate a sufficient performance gain due to optimal carrier selection at the beginning of a packet call compared to random carrier selection at the beginning of a call. An additional minor gain is achievable for high traffic loads if optimal carrier reassignment is allowed also during the packet calls. The gains in both cases are explained by better equalization of physical resources assigned to different UEs and by suppression of the intra-cell interference at the most loaded carriers.