According to research, the performance of the massive MIMO system is constrained by pilot contamination. Recent developments in massive MIMO provide a variety of methods for the reduction of pilot contamination with diverse performances. There is a trade-off between the complexity of the system, the time-frequency resources needed to estimate the channel, and the effectiveness of pilot contamination mitigation. Limited research exists on the analysis of the combined effect of the three parameters, despite the impact of the parameters on the performance of massive MIMO multi-cell networks. Therefore, in this research, an algorithm consisting of a combined adaptive linear precoding and pilot assignment methods was designed for the reduction of pilot contamination in the massive MIMO multi-cellular network. The Maximum ratio Transmission (MRT) and Zero Forcing (ZF) precoding schemes were incorporated in the algorithm to diminish interfering signals from other cells while amplifying the intended signal, to improve the BER at low computational complexity. Pilot assignment methods of frequency reuse and the Zadoff–Chu sequence facilitated the optimal allocation of resources and reduced interference to improve spectral efficiency. The pilot assignment method ensures an optimal number of pilots are assigned to guarantee the efficient use of resources while precoding schemes eliminate interference. The effectiveness of the proposed algorithm was evaluated based on the ability to reduce BER, increase spectral efficiency, and reduce computational complexity. The results show improved performance of the proposed algorithm, compared to the conventional MRT and ZF precoders. Accordingly, this study contributes to the investigation of the impact of integrating adaptive linear precoding and pilot assignment methods for pilot contamination mitigation in massive MIMO systems.

研究表明，大规模MIMO系统的性能受到导频污染的制约。大规模 MIMO 的最新发展提供了多种方法来减少导频污染，并具有不同的性能。在系统的复杂性、估计信道所需的时频资源以及导频污染缓解的有效性之间存在权衡。尽管这三个参数对大规模 MIMO 多小区网络的性能有影响，但对这三个参数的综合影响的分析研究仍然有限。因此，在本研究中，设计了一种由自适应线性预编码和导频分配方法相结合的算法来减少大规模MIMO多蜂窝网络中的导频污染。算法中加入了最大比传输（MRT）和迫零（ZF）预编码方案，以减少来自其他小区的干扰信号，同时放大预期信号，从而以低计算复杂度提高误码率。频率复用和Zadoff-Chu序列的导频分配方法有利于资源的优化分配，减少干扰，提高频谱效率。导频分配方法确保分配最佳数量的导频以保证资源的有效利用，同时预编码方案消除干扰。基于降低 BER、提高频谱效率和降低计算复杂度的能力来评估所提出算法的有效性。结果表明，与传统的 MRT 和 ZF 预编码器相比，该算法的性能有所提高。因此，本研究有助于研究集成自适应线性预编码和导频分配方法对大规模 MIMO 系统中导频污染减轻的影响。