Pilot contamination has come up as one of the major limitations of massive multiple‐input multiple‐output. In the recent past, the pilot contamination resulted by the pilot reuse in inter‐cell system has been successfully handled. In this paper, three efficient algorithms have been proposed to reduce the pilot contamination in intra‐cell system. These schemes emphasize on assigning the available pilots to the users based upon their channel qualities by considering the interfering degree of the various pilot sequences. The first proposed algorithm is based on water filling approach, which attains the system throughput very close to that of brute‐force exhaustive search algorithm (ESA) and performs the best among the three proposed algorithms in terms of system throughput. The second algorithm is designed for achieving better user fairness (by assigning less interfering pilots to the poor channel conditioned users). The third algorithm improves the system throughput as compared to the second algorithm without losing much in terms of user fairness. Furthermore, the computational complexity incurred by all the proposed algorithms is much less than that of ESA.

中文翻译：

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大规模MIMO蜂窝系统的高效导频重用算法

飞行员污染已成为大规模多输入多输出的主要限制之一。最近，成功解决了小区间系统中飞行员重用导致的飞行员污染。本文提出了三种有效的算法来减少小区内的导频污染系统。这些方案强调通过考虑各种导频序列的干扰程度，根据用户的信道质量将可用的导频分配给用户。最早提出的算法是基于注水方法的，该算法获得的系统吞吐量非常接近于蛮力穷举搜索算法（ESA），并且在系统吞吐量方面在三种算法中表现最佳。第二种算法旨在实现更好的用户公平性（通过为条件较差的信道用户分配较少的干扰导频）。与第二算法相比，第三算法提高了系统吞吐量，而在用户公平性方面没有太多损失。此外，所有提出的算法所引起的计算复杂度远小于ESA。