Study of Communication Methods Combining Multiple Transmitted and Received Signals inside a Limited Space Region

实施室内无线电通信系统的想法似乎是一个有吸引力的建议。然而，室内无线电多径传播环境限制了这些系统的设计。因此，本项目的研究重点是澄清室内无线电传播的特性。为此，估计多径波的到达方向和延迟时间是最有效的方法。所得结果如下：1。我们首先提出了一种估计到达方向的方法。该方法利用MUSIC算法这一具有高分辨率的频谱分析技术，并将其应用于天线旋转扫描获得的数据。计算机仿真和实验结果表明，该方法具有5度的高分辨率，旋转半径为1波长。其次，我们提出了一种多径波传播时延估计方法，该方法将MUSIC算法应用于传统的扫频方法。计算机仿真和实验结果表明，该方法具有3ns的高分辨率，频率带宽为100MHz.3。最后，我们提出了一种同时估计多径波到达方向和延迟时间的方法。该方法的最大优点是可以根据估计结果很容易地识别出入射波的传播路径。该方法还利用了MUSIC算法。我们在有限的区域内进行实验。从估计结果中，我们识别出5 ~ 10个有效波，它们的方向在空间上几乎均匀分布，并且延迟时间小于50 ns。这些结果表明，室内无线电环境是非常复杂的。因此，我们证实了分集接收，特别是指向性分集，对于多径传播环境下的室内无线电通信系统是有效的。少

The idea of implementing indoor radio communication systems appears to be an attractive proposition. However, indoor radio multipath propagation environments limit the design of these systems. Therefore, this project of research is concerned with clarifying the characteristics of indoor radio propagation. For this purpose, it is most effective to estimate the directions of arrival and delay times of multipath waves. The results obtained are described below.1. We first proposed a method of estimating the directions of arrival. This method utilizes the MUSIC algorithm which is a spectrum analysis technique owning high resolution property and applied to the data obtained by the rotatory scanning of antenna. As a result of computer simulation and some experiments, it is shown that the proposed method has high resolution of 5 degrees with the rotation radius of 1 wavelength.2. Next, we proposed a method of estimating propagation delay time of multipath waves which also applies the MUSIC alg … More orithm to the conventional frequency sweeping method. The results of computer simulation and experiments have shown that the proposed method has high resolution of 3ns with the frequency bandwidth of 100MHz.3. Finally, we proposed a method of simultaneously estimating both the directions of arrival and delay times of multipath waves. The great advantage of this method is that we can easily identify the propagation paths of incident waves based on the estimation results. This method also utilizes the MUSIC algorithm. We carried out experiments in a limited region. From the estimation results, we recognized 5 to 10 significant waves, the directions of which are almost uniformly distributed in space and also the delay times of which are less than 50 ns. These results demonstrated the indoor radio environments are very complicated. Thus, we confirmed that diversity reception, especially the directivity diversity, is effective for indoor radio communication systems under multipath propagation environments. Less