协作多点(CoMP)系统在第 4 代无线通信网络 LTE- A 及更远演化的版本中用于提高系统容量或分集，特别适用于蜂窝边缘．然而，在 LTE- A CoMP 系统中分布着非理想回程，非理想回程存在带宽限制和时延问题，使用户反馈到基站的信道状态信息(CSI)不完整，导致 CoMP 性能下降．针对该问题，文中提出了一种基于格莱斯曼流型理论的 CSI量化方法，通过该方法对 CSI 进行量化及选择最优码书，以减小回程开销．数学分析和仿真结果说明，采用格莱斯曼流型法对 CSI 进行量化，非理想回程 CoMP 系统的性能可以得到改善．

Coordinated multi- point (CoMP) system has been applied to the 4th generation wireless communicationnetwork LTE- A and beyond networks to accommodate ever- growing need for system capacity and diversity.It is par-ticularly suitable for cell- edges.However,there exists bandwidth limit and transmission delay in the non- idealbackhauls of LTE- A CoMP system,which results in imperfect CSI (Channel State Information) feedback from userequipment to base stations and further causes the degradation of CoMP performance.In order to solve this problem,a CSI quantization method on the basis of Grassmann manifold theory is proposed.With this method,an optimalcode book can be obtained to reduce the CSI feedback overhead.Both mathematical analysis and simulation showthat the proposed method helps improve the CoMP performance under non- ideal backhaul constraint.