In this work, we introduce the pattern-domain pilot design paradigm based on a "superposition of orthogonal-building-blocks" with significantly larger contention space to enhance the massive machine-type communications (mMTC) random access (RA) performance in massive multiple-input multiple-output (MIMO) systems.Specifically, the pattern-domain pilot is constructed based on the superposition of $L$ cyclically-shifted Zadoff-Chu (ZC) sequences. The pattern-domain pilots exhibit zero correlation values between non-colliding patterns from the same root and low correlation values between patterns from different roots. The increased contention space, i.e., from N to $\binom{N}{L}$, where $\binom{N}{L}$ denotes the number of all L-combinations of a set N, and low correlation valueslead to a significantly lower pilot collision probability without compromising excessively on channel estimation performance for mMTC RA in massive MIMO systems.We present the framework and analysis of the RA success probability of the pattern-domain based scheme with massive MIMO systems.Numerical results demonstrate that the proposed pattern division random access (PDRA) scheme achieves an appreciable performance gain over the conventional one,while preserving the existing physical layer virtually unchanged. The extension of the "superposition of orthogonal-building-blocks" scheme to "superposition of quasi-orthogonal-building-blocks" is straightforward.

翻译：在这项工作中,我们引入模式-域试点设计模式,其依据是“超置正态建筑区块”的模型-域域试点设计模式,其争议空间大得多,以在大规模多投入多输出系统(MIIMO)中增强大规模机器型通信(MMTC)随机访问(RA)性能。具体地说,模式-域试点的构建依据是,以周期性变换的Zadoff-Chu(ZC)等值的叠加值为基础。模式-域域试点显示了来自同一根基的非串联模式与不同根基模式之间低关联值之间的零相关值。增加的争议空间,即从N美元到$\binom{N ⁇ L}(RA)随机访问空间,即$\binom{N ⁇ L}(RA),即显示一套常规系统的所有L组合数,低相关值导致试点碰撞概率大大降低,同时不影响大型IMIMO系统中MTC RA的频道估计性业绩。我们介绍了“基于模式-O级建设的模型-级扩展模式-级计划”的RA成功概率概率概率概率概率概率概率,即显示,一个常规系统正在取得一个常规系统。