A non-stationary channel model for 5G massive MIMO systems

We propose a novel channel model for massive multiple-input multiple-out （MIMO） communication systems that incorporate the spherical wave-front assumption and non-stationary properties of clusters on both the array and time axes. Because of the large dimension of the antenna array in massive MIMO systems, the spherical wave-front is assumed to characterize near-field effects resulting in angle of arrival （AoA） shifts and Doppler frequency variations on the antenna array. Additionally, a novel visibility region method is proposed to capture the non-stationary properties of clusters at the receiver side. Combined with the birth-death process, a novel cluster evolution algorithm is proposed. The impacts of cluster evolution and the spherical wave-front assumption on the statistical properties of the channel model are investigated. Meanwhile, corresponding to the theoretical model, a simulation model with a finite number of rays that capture channel characteristics as accurately as possible is proposed. Finally, numerical analysis shows that our proposed non-stationary channel model is effective in capturing the characteristics of a massive MIMO channel.

本文提出一种新型的大规模多输入多输出(massive multiple-input multiple-output,MIMO)通信系统信道模型,同时考虑了球面波假设以及随着天线阵列和时间变化的散射体非稳定特性。由于大规模天线阵列的引入,会导致接收端的不同天线阵子的到达角和多普勒频移不同,因此,采用球面波假设来刻画近场效应。此外,为在接收端刻画不同散射体对天线阵子的可见性,本文提出一种散射体可见区域法同时,对应于理论模型,本文提出了一种有限散射体仿真信道模型。最后,以统计特性作为指标,研究了球面波假设和散射体非稳定性对massive MMO信道模型的影响。研究结果表明,本文提出的信道模型可以很好地刻画massive MIMO信道特性。