Young-lak Kim

Inter-RAT Handover Technique from WCDMA Network to CDMA2000 Network

Inter-RAT handover technique from the WCDMA network to the CDMA network is developed. Two systems are linked and inter-worked with each other. The UE which gets out of the WCDMA area changes its radio network to the CDMA system and maintains the call without seams. Through the field test in the commercial network we got a high success rate of the handover

Performance analysis of LTE multi-antenna technology in live network

In this paper, we present several field trial results of LTE multi-antenna technology such as downlink 4×4 MIMO and uplink multi-user MIMO. At field trial, downlink 4×4 MIMO provides an average throughput increase of 42% compared to downlink 2×2 MIMO and uplink multi-user MIMO provides an average throughput increase of 33% compared to uplink 1×2 MIMO. In spite of these gains of LTE multi-antenna technologies, nearly all LTE base stations still use 2Tx and 2Rx antennas. Recently, LTE release 13 standard starts to support 16Tx base station, there is huge gap between standard and live network. By comparing the performance of LTE multi-antenna technologies with an alternative solution which has same network impacts, i.e., horizontal and vertical cell splitting, we provide what are the obstacles and which parts are needed to study further for commercialization of LTE multi-antenna technology.