论文标题
结构化大规模访问无细胞的大型MIMO系统
Structured Massive Access for Scalable Cell-Free Massive MIMO Systems
论文作者
论文摘要
如何满足超越第五代（B5G）网络中用户数量增加的需求，更高的数据速率和严格的服务质量（QoS）？无细胞的大规模多输入多输出（MIMO）被视为一种有前途的解决方案，其中许多无线访问点可以通过利用相干信号处理来配合共同为用户服务。但是，在无细胞的大型MIMO系统中仍然存在许多未解决的实际问题，其中可扩展的大规模访问实施是最重要的之一。在本文中，我们提出了一个新的框架，用于在无细胞的大规模MIMO系统中进行结构化大规模访问，该框架包括一种初始访问算法，一种部分大规模褪色解码（P-LSFD）策略，两个试点分配方案，以及一个分数权力控制策略。得出具有最大比率（MR）组合的新的闭合光谱效率（SE）表达式。模拟结果表明，我们提出的框架使用局部部分最小均时误差（LP-MMSE）和MR组合时提供了高SE。具体而言，提议的初始访问算法和试点分配方案的表现优于其相应的基准测试，而P-LSFD可实现可伸缩性，而与传统的最佳大规模淡出解码（LSFD）相比，可忽略不计的性能损失（LSFD），而可扩展的分数功率控制则提供了可控的权衡，从而提供了可控的权衡权衡。
How to meet the demand for increasing number of users, higher data rates, and stringent quality-of-service (QoS) in the beyond fifth-generation (B5G) networks? Cell-free massive multiple-input multiple-output (MIMO) is considered as a promising solution, in which many wireless access points cooperate to jointly serve the users by exploiting coherent signal processing. However, there are still many unsolved practical issues in cell-free massive MIMO systems, whereof scalable massive access implementation is one of the most vital. In this paper, we propose a new framework for structured massive access in cell-free massive MIMO systems, which comprises one initial access algorithm, a partial large-scale fading decoding (P-LSFD) strategy, two pilot assignment schemes, and one fractional power control policy. New closed-form spectral efficiency (SE) expressions with maximum ratio (MR) combining are derived. The simulation results show that our proposed framework provides high SE when using local partial minimum mean-square error (LP-MMSE) and MR combining. Specifically, the proposed initial access algorithm and pilot assignment schemes outperform their corresponding benchmarks, P-LSFD achieves scalability with a negligible performance loss compared to the conventional optimal large-scale fading decoding (LSFD), and scalable fractional power control provides a controllable trade-off between user fairness and the average SE.
