Improvement of LTE Handover Performance through Interference Coordination

An Orthogonal Frequency Division Multiple Access (OFDMA) based radio-interface is specified by 3GPP for LTE system. OFDMA provides efficient spectral efficiency by reusing complete frequency band in all cells. However it projects high inter cell interference (ICI) especially on cell borders. ICI not only minimizes the cell border throughput but also effects on the handover performance in LTE. Hard handover is standardized for LTE systems using L3-filter, hysteresis, and time-to-trigger mechanisms. The UE needs to receive error free handover command message for successful handover. This becomes critical when high interference is present on cell borders. Inter cell interference coordination (ICIC) is a technique that has been proposed to overcome ICI problems. We have investigated the improvements of LTE handover performance through ICIC. We have shown that significant gain can be achieved by the use of ICIC while maintaining very low handover rates.