The aim of this work is to study the impact of small receiver displacement on a signal propagation in a typical conference room environment at a millimeter wave frequency of 60 GHz. While channel measurements provide insights on the propagation phenomena, their use for the wireless system performance evaluation is challenging. Whereas, carefully executed three-dimensional ray tracing (RT) simulations represent a more flexible option. Nevertheless, a careful validation of simulation methodology is needed. The first target of this article is to highlight the benefits of an in-house built three-dimensional RT tool at 60 GHz and shows the effectiveness of simulations in predicting different characteristics of the channel. To validate the simulation results against the measurements, two different transmitter (Tx) positions and antenna types along with ten receiver (Rx) positions are considered in a typical conference room. In first system configuration, an omnidirectional antenna is placed in the middle of the table, while in the second system configuration a directed horn antenna is located in the corner of the meeting room. After validating the simulation results with the measurement data, in the second part of this work, the impact of a small change, i.e., 20 cm in the receiver position, is studied. To characterize the impact, we apply as performance indicators the received power level, root mean square delay spread (RMS-DS) and RMS angular spread (RMS-AS) in azimuth plane. The channel characteristics are considered with respect to the direct orientation (DO), i.e., the Rx antenna is directed toward the strongest incoming path. Different antenna configurations at the Tx and Rx side are applied to highlight the role of antenna properties on the considered channel characteristics. Especially, in the second system configuration the impact of different antenna half power beamwidth on different considered channel characteristics is highlighted through acquired simulation results. The validation of results shows the RMS error of only 2–3 dB between the measured and simulated received power levels for different Tx configurations in the direction of DO. Results indicate that only a small change of the Rx position may result a large difference in the received power level even in the presence of line-of-sight between the Tx and Rx. It is found that the STD of received power level across the room increases with the decrease in HPBW of the antenna. As can be expected, directed antennas offer lower value of RMS-DS and RMS-AS compared with isotropic antenna.

这项工作的目的是研究在60 GHz毫米波的典型会议室环境中，小接收机位移对信号传播的影响。尽管信道测量提供了有关传播现象的见解，但将其用于无线系统性能评估仍具有挑战性。而精心执行的三维射线追踪（RT）模拟则代表了更为灵活的选择。尽管如此，仍需要仔细验证仿真方法。本文的第一个目标是强调内部自建的60 GHz三维RT工具的好处，并展示仿真在预测通道不同特性方面的有效性。要根据测量结果验证仿真结果，在典型的会议室中，考虑了两个不同的发射器（Tx）位置和天线类型以及十个接收器（Rx）位置。在第一种系统配置中，全向天线放置在桌子的中间，而在第二种系统配置中，定向喇叭天线位于会议室的角落。在用测量数据验证了仿真结果之后，在本工作的第二部分中，研究了微小变化（即接收器位置20厘米）的影响。为了描述影响的特征，我们将接收功率水平，均方根延迟扩展（RMS-DS）和RMS角扩展（RMS-AS）在方位平面中用作性能指标。考虑到直接定向（DO）的信道特性，即 Rx天线指向最强的进入路径。在Tx和Rx侧应用不同的天线配置，以突出显示天线属性在所考虑的信道特性上的作用。尤其是，在第二种系统配置中，通过获取的仿真结果可以突出显示不同天线半功率波束宽度对不同考虑信道特性的影响。结果验证表明，在DO方向上，不同Tx配置的实测功率和模拟接收功率电平之间的RMS误差仅为2-3 dB。结果表明，即使在Tx和Rx之间存在视线的情况下，Rx位置的很小变化也可能导致接收功率电平的较大差异。可以发现，随着天线HPBW的减小，整个房间的接收功率水平的STD会增加。可以预期，与各向同性天线相比，定向天线的RMS-DS和RMS-AS值更低。