A Fractional Soft Handover Scheme for 3GPP LTE-Advanced System

Mobility enhancement and carrier aggregation are important aspects to investigate as part of the LTE-Advanced study. Hard handover is the only handover scheme in LTE Rel-8. Generally, hard handover is fairly simple, but its outage probability is high and the handover procedure may be unreliable, especially for VoIP service. In this paper, we propose a fractional soft handover scheme based on the carrier aggregation. The main idea is to partially perform soft handover for VoIP, but non-VoIP service is only transmitted from source eNodeB or target eNodeB. The theoretical analysis and simulation results show that the proposed fractional soft handover scheme not only attains the lowest handover outage probability, but also improve the reliability of VoIP service.