A Low Complexity Scheme for Realistic Multi-cell Downlink Coherent Joint Transmission

As one of the major key LTE-A technologies, coordinated multi-point transmission (CoMP) has been extensively investigated. Among various CoMP schemes, coherent joint transmission scheme (CJT) shows the largest CoMP gains in both cell average performance and cell edge performance. However, due to the current CJT schemes exploit the joint multi-cell scheduling and joint transmit pre-coder design, the complexity is dramatically increasing with the cluster size increasing, and this become the major challenge for CJT implementation in realistic system. In this paper, a novel CJT scheme consisted by distributed scheduling and joint transmit pre-coder design is proposed. The complexity of the proposed scheme are theoretically analyzed and compared with the original scheme. Moreover, performances and robust of the proposed scheme are evaluated in multiple transmission scenarios. Taking the performance of single cell as the baseline, the proposed CJT scheme can achieve over 35% average gain and over 32% cell edge gain although there is around 8%􀀀10% cell edge gain loss than that of original CJT scheme.