A Novel Solution for Inter-Technology Handover

We present a novel solution to the problem of handover between two different wireless technologies. We illustrate this solution with the example of LTE (Long Term Evolution) to CDMA (Code Division Multiple Access) handover. Current inter-technology handover can take approximately 6 to 7 seconds and hence can heavily impact the network performance. We assume that two receivers (primary and secondary) are used in LTE, and that the UE performs an inter-technology handover between LTE and CDMA. The basic concept is that the UE uses two receivers (which are needed in MIMO mode) to enhance the network capacity when at the cell center but switches the secondary receiver, to the other network, when at the network border to obtain system information, signal strength, and perform CDMA synchronization. This switching function can be controlled by either the network or the UE. In this paper, the switching function is evaluated for the network controlled scenarios and is compared with non-switched scenarios. This study focuses on the effects on diversity gain and network coverage. Simulation results show that the loss in diversity gain has minimal impact on the network performance and the inter-technology handover delay can be reduced to less than 1 second.