Study on Spatial and Temporal Signal Processing and Protocol for Multimedia Wireless Network

本研究的目的是从自适应信号处理、信息理论和网络理论的角度，全面探讨物理层的时空信号处理和网络层的协议，作为实现更快、更可靠的多媒体无线通信的关键技术。时空信号处理包括适合多媒体信息源和移动无线电信道的信息压缩、误差控制和滤波。该协议应考虑有线网络的透明度和移动无线电信道的固有特性，涵盖访问控制。首先，在物理层，我们研究了基于适用于任何信息媒体源的通用信息压缩和自适应阵列天线、自适应数字滤波器以及抗多径衰落和干扰的编解码器（编码器和解码器）的空间和时间域信号处理。例如：(1)多媒体信息源的数学建模，提出并研究了基于改进算术编码和LZW编码的新型通用信息压缩方案，其中采用数学建模和模型识别方法。(2)利用自适应阵列天线和自适应控制算法在空间和时间域上推导出最优接收机。(3)自适应阵列天线时空信道编码的提出与优化。(4)提出了一种多媒体CDMA无线通信系统流量方差的测量方法以及对单个媒体的处理增益和传输功率的自适应控制方法。(5)为提高CDMA系统的频率效率，提出了一种新的产生扩频码的方案和一种在空间和时间域中消除干扰的方案。其次，在网络层，我们研究了由于无线移动信道固有属性（如多径衰落）导致的数据包中断概率和处理延迟的各种问题，以及有线网络访问控制和路由保持透明度的问题。例如，(1)针对多媒体无线CDMA网络提出了自适应控制传输功率、分组长度、处理增益的新方案。(2)目前CSMA/CD、ALOHANET、DS/CDNA、多载波FH/CDMA系统等各种混合方案的分类和性能分析。少

The aim of this study is to globally investigate both spatial and temporal signal processing in a physical layer and protocol in a network layer in viewpoints of adaptive signal processing, information theory, and network theory as key technologies for higher speed and more reliable multimedia wireless communications. The spatial and temporal signal processing covers information compression, error control, and filtering suitable for multimedia information sources and mobile radio channels. The protocol should cover access control considering transparency with wired networks and inherent properties of mobile radio channels. First, in a physical layer, we have studies signal processing in space and time domains based on universal information compression adaptable to any information media source and adaptive array antenna, adaptive digital filter, and codec (encoder and decoder) robust against multipath fading and interference. For instance, (1) mathematical modeling of multimedia informa … More tion source, and proposal and investigation of novel universal information compression schemes based on modification of arithmetic coding and LZW coding in which the mathematical modeling and a method to identify each model are used. (2) Derivation of optimum receivers in space and time domains using adaptive array antenna and adaptive controlling algorithms. (3) Proposal and optimization of space and time channel coding using adaptive array antenna. (4) Proposal of a method of measuring traffic variance of multimedia CDMA wireless communication systems and a method of adaptive controlling the processing gain and transmission power for individual media. (5) Proposal of a novel scheme of generating a group of spreading codes and a scheme of canceling interference in space and time domains for the purpose of improving frequency efficiency in CDMA systems. Second, in a network layer, we have investigated various problems in outage probability of packets and processing delay due to inherent properties of wireless mobile channels such as multipath fading, problems in access control and routing maintaining transparency with wired networks. For instance, (1) Proposal of novel schemes of adaptive controlling transmission power, packet length, processing gain for multimedia wireless CDMA network. (2) Classification and performance analysis of various hybrid schemes such as CSMA/CD, ALOHANET, DS/CDNA, multi-carrier FH/CDMA system and so far. Less