9th International Conference on Communications and Networking in China

Research Article

Investigation of the Algorithm to Reduce the Impact of CSI-RS on LTE Legacy UEs

  • @INPROCEEDINGS{10.4108/icst.chinacom.2014.256295,
        author={Xin Lv and Xinyu Gu and Xiaofei Zhao and Lin Zhang and Wenyu Li and Xin Deng},
        title={Investigation of the Algorithm to Reduce the Impact of CSI-RS on LTE Legacy UEs},
        proceedings={9th International Conference on Communications and Networking in China},
        publisher={IEEE},
        proceedings_a={CHINACOM},
        year={2015},
        month={1},
        keywords={lte-a csi-rs link adaption higher-order mimo scheduling},
        doi={10.4108/icst.chinacom.2014.256295}
    }
    
  • Xin Lv
    Xinyu Gu
    Xiaofei Zhao
    Lin Zhang
    Wenyu Li
    Xin Deng
    Year: 2015
    Investigation of the Algorithm to Reduce the Impact of CSI-RS on LTE Legacy UEs
    CHINACOM
    IEEE
    DOI: 10.4108/icst.chinacom.2014.256295
Xin Lv1,*, Xinyu Gu1, Xiaofei Zhao1, Lin Zhang1, Wenyu Li2, Xin Deng1
  • 1: Beijing University of Posts and Telecommunications
  • 2: China Academy of Telecommunication Research
*Contact email: lvxin521@126.com

Abstract

CSI-RS (Channel State Information Reference Signal) is designed for higher-order MIMO in LTE-A. However, it could be problematic for LTE legacy UEs in a LTE-A network deployed higher-order MIMO because LTE UEs cannot distinguish CSI-RS from effectual data. In this paper, the impact of CSI-RS on LTE UEs are firstly evaluated by both link-level and system-level simulations. The evaluation results show that the degradation of LTE UEs' performance caused by CSI-RS is obvious when the coding rate and modulation scheme are too large. To reduce the performance degradation, two mechanisms, named SLA (Smart Link Adaption) and SS (Smart Scheduling), are investigated and compared. Furthermore, an adaptive ND (Novel Decision) algorithm is proposed to adaptively select a more suitable mechanism according to the proportion of the LTE legacy UEs in the system. Theoretical analysis and simulation results show that the proposed algorithm is effective to maximize the improvement of the system performance.