论文标题
可伸缩的URLLC超过5G的非正交和非相关大型MIMO的设计
Design of Non-orthogonal and Noncoherent Massive MIMO for Scalable URLLC Beyond 5G
论文作者
论文摘要
本文是为了在5G以外的无线系统中设计和优化非正交和非合并大规模多输入多输出（MIMO）框架，以启用可伸缩的超级可靠的低延迟通信（SURLLC）。在此框架中，利用了与大型MIMO系统中的大规模天线阵列相关的巨大多样性增益，以确保超高的可靠性。为了减少通道估计过程引起的开销和潜伏期，我们主张不需要瞬时通道状态信息（CSI）的非合并通信技术，但仅取决于信息解码的大规模褪色系数。为了提高所考虑的系统的可扩展性，我们通过设计新的差调制方案来确保在无噪声的情况下可以唯一确定每个传输信号矩阵，从而启用多个用户的非正交通道访问权限，并在噪音的情况下可靠地确定天线阵列大小时噪声估计。关键的想法是，将来自多个用户的传输信号正确叠加在空气中，以便当正确检测到汇总信号时，所有用户发送的信号都可以唯一地确定。为了进一步提高阵列天线数量较大时的平均误差性能，我们通过共同优化所有用户的传输幂以及其中的子构造分配，提出了基于基于差异的Max-min Kullback-Leibler（KL）差异。仿真结果表明，在错误性能方面，所提出的设计显着优于现有的基于欧几里得的最大欧几里得距离。此外，我们所提出的方法的错误性能也比传统的连贯零效力（ZF）接收器具有正交通道训练，特别是针对细胞边缘用户的传统相干性能。
This paper is to design and optimize a non-orthogonal and noncoherent massive multiple-input multiple-output (MIMO) framework towards enabling scalable ultra-reliable low-latency communications (sURLLC) in wireless systems beyond 5G. In this framework, the huge diversity gain associated with the large-scale antenna array in massive MIMO systems is leveraged to ensure ultrahigh reliability. To reduce the overhead and latency induced by the channel estimation process, we advocate the noncoherent communication technique which does not need the knowledge of instantaneous channel state information (CSI) but only depends on the large-scale fading coefficients for information decoding. To boost the scalability of the system considered, we enable the non-orthogonal channel access of multiple users by devising a new differential modulation scheme to assure that each transmitted signal matrix can be uniquely determined in the noise-free case and be reliably estimated in noisy cases when the antenna array size is scaled up. The key idea is to make the transmitted signals from multiple users be superimposed properly over the air such that when the sum-signal is correctly detected, the signals sent by all users can be uniquely determined. To further improve the average error performance when the array antenna number is large, we propose a max-min Kullback-Leibler (KL) divergence-based design by jointly optimizing the transmitted powers of all users and the sub-constellation assignment among them. Simulation results show that the proposed design significantly outperforms the existing max-min Euclidean distance-based counterpart in terms of error performance. Moreover, our proposed approach also has a better error performance than the conventional coherent zero-forcing (ZF) receiver with orthogonal channel training, particularly for cell-edge users.
