Project on CDMA and Array Antennas for Mobile Communications

本研究的目的是探讨日本与欧洲在基于扩频技术的自适应阵列天线和码分多址领域的国际合作，以期为克服移动通信等无线通信需求迅速增长而导致的频谱短缺提供非常有用的对策。例如，在码分多址技术中，(1)引入多媒体通信质量评估的优化准则并对无线通信信道进行建模，(2)提出了一种测量多媒体CDMA无线通信系统的业务量变化的方法和针对单个媒体的处理增益和发射功率的自适应控制方法，(3)提出了基于自适应数字滤波器和自适应阵列天线的空时信号处理方法，以抑制窄带干扰和衰落。其次，在阵列天线中，(1)时变多径衰落信道的空间和时间域建模，(2)基于自适应阵列天线的频率效率改善分析，(3)空时最优均衡器、接收机、信道编译码的提出和分析，(4)自适应阵列天线体系结构和自适应算法的提出和评价，(5)在码分多址环境下的应用和性能分析。

The aim of this study is to international cooperation between Japan and Europe in fields of adaptive array antennas and CDMA (Code Division Multiple Access) based on spread spectrum technique in order to provide extremely useful countermeasures to overcome a lack of frequency spectrum due to rapid increase of demands in wireless communications such as mobile communications. For instance, in a CDMA technique, (1) The way of leading the optimization criterion of the communication quality evaluation of the multimedia and modeling the wireless communication channel, (2) Proposal of a method of measuting traffic variance of multimedia CDMA wireless communication systems and a method of adaptive controlling the processing gain and transmission power for individual media, (3) Proposal of the signal processing in space and time domains based on adaptive digital filter and adaptive array antenna for rejection to narrow band interference and fading. Second, in a array antenna, (1) Modeling of time-varying multipath fading channel in space and time domains, (2) Analysis of improvement of frequency efficiency based on application of adaptive array antennas, (3) Proposal and analysis of space and time optimum equalizer, receiver, channel coding and decoding, (4) Proposal and evaluation of adaptive array antenna architectures and adaptive algorithms, (5) Application and performance analysis to CDMA environment.