Propagation graphs (PGs) serve as a frequency-selective, spatially consistent channel model suitable for fast channel simulations in a scattering environment. So far, however, the parametrization of the model, and its consequences, have received little attention. In this contribution, we propose a new parametrization for PGs that adheres to the doubly exponentially decaying cluster structure of the Saleh-Valenzuela (SV) model. We show how to compute the newly proposed internal model parameters based on an approximation of the $K$-factor and the two decay rates from the SV model. Furthermore, via the singular values of multiple-input multiple-output (MIMO) channels, we compare the degrees of freedom (DoF) between our new and another frequently used parametrization. Specifically, we compare the DoF loss when the distance between antennas within the transmitter and receiver arrays or the average distance between scatterers decreases. Based on this comparison, it is shown that, in contrast to the typical parametrization, our newly proposed parametrization loses DoF in both scenarios, as one would expect from a spatially consistent channel model.

中文翻译：

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传播图的参数化与统计

传播图（PG）用作频率选择，空间一致的信道模型，适用于散射环境中的快速信道仿真。但是，到目前为止，该模型的参数化及其后果尚未引起足够的重视。在此贡献中，我们为PG提出了一种新的参数化方法，该方法遵循Saleh-Valenzuela（SV）模型的双指数衰减簇结构。我们展示了如何基于$ K $因子和SV模型的两个衰减率的近似值来计算新提出的内部模型参数。此外，通过多输入多输出（MIMO）通道的奇异值，我们比较了新的和另一个常用的参数化之间的自由度（DoF）。特别，当发射器和接收器阵列中的天线之间的距离或散射体之间的平均距离减小时，我们比较DoF损耗。基于此比较，结果表明，与典型的参数化相比，我们新提出的参数化在两种情况下都失去了DoF，正如人们从空间一致性通道模型中所期望的那样。