多小区Massive MIMO系统的分布式导频优化分配

(1.西安科技大学 通信与信息工程学院,陕西 西安 710054; 2.西安电子科技大学 ISN国家重点实验室,陕西 西安 710071; 3.东南大学 移动通信国家重点实验室,江苏 南京 210096)

大规模多输入多输出; 导频污染; 导频优化分配; 分布式算法

Distributed pilot optimizing assignment in multi-cell Massive MIMO systems
PANG Li-hua 1,2,WU Wen-jie 1,ZHANG Yang 2,3,GONG Wen-rong 1,WU Yan-hai 1,WANG An-yi 1

(1.College of Communication and Information Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.State Key Laboratory of Integrated Service Networks,Xidian University,Xi'an 710071,China; 3.National Mobile Communications Research Laboratory,Southeast University,Nanjing 210096,China)

Massive Multiple-Input-Multiple-Output(Massive MIMO); pilot contamination; pilot optimizing assignment; distributed algorithm

DOI: 10.13800/j.cnki.xakjdxxb.2019.0224

备注

研究了多小区大规模多输入多输出系统用于缓解导频污染问题的导频资源优化分配。在假定导频序列个数与单个小区内用户数相同的前提下,仅利用小区基站与用户终端之间的大尺度衰落信息,以提升用户平均传输速率为目标,提出2种可逐个小区执行的分布式导频优化方案:交换搜索与干扰度量。交换搜索算法通过将任意小区内任意2个用户的导频序列相交换进而搜索得到最佳导频分配方案,而干扰度量方案基于对不同小区用户间干扰值的度量来进行导频优化。数值结果显示,新提出的2种方案与已有方案相比能以更低的实现复杂度获得更好的性能。尤其是,若将2种方案结合起来使用,其性能甚至接近于穷举搜索方式。

Pilot optimizing assignment issue for multi-cell Massive Multiple-Input-Multiple-Output(Massive MIMO)systems is investigated to relieve pilot contamination problem.Under the assumption that the number of pilot sequences is identical with that of user terminals in each cell,two distributed algorithms,named exchanging search and interference measurement,are introduced to improve the average transmission rate of users.Specifically,the exchanging search algorithm searches for its optimal pilot assignment scheme by exchanging the pilot sequences of any two users in each cell.And the interference measurement scheme performs the pilot optimization on account of the evaluation of interference between users in different cells.Based on the large-scale fading coefficients between the base station and user terminals merely,the two algorithms can be cell-by-cell implemented.Numerical results show that compared with existing mechanisms,the proposed two schemes can achieve better performance with lower implementation complexity.Particularly,if the two schemes are used together,their performance is even close to exhaustive searching method.