Channel Assignment of Digital Cellular Systems with 2- or 3-dimensional Cell Structure

由于移动通信服务是实现随时随地与任何人进行通信的理想通信方式的代名词，因此对移动通信服务的需求正在迅速增长。经济和社会活动的发展是移动通信服务需求不断增长的一个主要因素。这种需求刺激了包括个人通信服务在内的移动通信技术的发展。在蜂窝移动通信系统中，服务区域被划分为多个小小区，每个信道同时在一些小区内被重用。信道分配方法影响系统容量，分为固定信道分配和动态信道分配。通常，动态信道分配比固定信道分配提供更好的性能。然而，当动态信道分配应用于蜂窝系统时，很难在实际时间内获得解决方案。因此，在蜂窝系统中寻找算法是最重要的问题之一。今年我们取得了以下成果：1.提出了一种基于神经网络的动态信道分配算法。该算法的信道分配方案考虑了干扰程度。提出了一种三维小区结构模型，并将一些传统的信道分配算法应用于该模型。分析了阻塞传播动态信道分配的下界。

The demand for mobile communication services is rapidly increasing, because the mobile communication service is synonymy of an ideal communication style realizing communication in anytime, anywhere and with anyone. The development of economic and social activities is a primary factor of the increasing demand for mobile communication services. The demand stimulates the development of technology in mobile communication including personal communication services. Thus mobile communication has been one of the most active research in communications in the last several years.In cellular mobile communication systems, the service area is divided into many small cells and each channel is re-used in some cells, simultaneously. Channel assignment methods affect the system capacity and they are classified into fixed channel assignment and dynamic channel assignment. In general, dynamic channel assignment gives better performance than fixed channel assignment. However, it is difficult to obtain the soulution in a practical time when dynamic channel assignment is applied to the cellular system. Therefore, it is one of the most important problems to find the algorithms in a cellular system. We obtain following results in this year.1. We propose a dynamic channel assignment algorithm using neural networks. The channel assignment scheme in this algorithm takes the degree of interference into consideration.2. We propose a 3-dimensional cell structure model and apply some traditional channel assignment algorithms to this model.3. We analyze the lower bound of the blocking propagation dynamic channel assignment.