CAREER: Adaptive Signal Processing for Coded Time-Varying Wireless Multiple-Access Communications Channels

目前，全世界都在努力开发下一代无线通信系统。据设想，许多未来的无线系统将包含相当大的信号处理智能，以提供先进的服务，如多媒体传输。一般来说，由于实质性的物理障碍，主要是无线电频率干扰和信道的时变性质，无线信道可以是非常敌对的媒介，通过它进行通信。以高数据速率提供通用无线接入的需求（这是许多新兴无线应用的目标）提出了一个重大的技术挑战，为了满足这一挑战，必须开发先进的信号处理技术，用于非固定干扰多的环境中的多址通信。本研究涉及自适应信号处理算法和架构的发展，以应用于未来具有高用户移动性、高数据速率和高服务质量的无线通信系统。本研究的重点是先进的接收信号处理技术和先进的无线系统发射信号处理技术。第一个重点是开发自适应信号接收技术，以共同对抗时变无线信道中的各种损伤，如射频干扰（窄带干扰、多址干扰、脉冲环境噪声）、多径衰落、信道色散等。将深入研究的一种特殊方法是利用接收机上信道编码引入的冗余，以减轻干扰和信道跟踪。第二部分涉及时变无线信道中用于提高网络容量的自适应信号传输技术。具体而言，研究了自适应天线阵列传输技术和自适应跳频技术，重点是对动态信道环境的快速自适应。这项研究预计将最终形成适用于未来无线通信系统的新型信号处理技术和系统设计概念。预计这项研究将影响许多当前和下一代通信系统的规划者和设计者，将许多新的研究技术带入无线通信领域。

There is at present a worldwide effort to develop next-generation wireless communication systems. It is envisioned that many of the future wireless systems will incorporate considerable signal processing intelligence in order to provide advanced services such as multimedia transmission. In general, wireless channels can be very hostile media through which to communicate, due to substantial physical impediments, primarily radio-frequency interference and the time-varying nature of the channel. The need to provide universal wireless access at high data rates (which is the aim of many emerging wireless applications) presents a major technical challenge, and meeting this challenge necessitates the development of advanced signal processing techniques for multiple-access communications in non-stationary interference-rich environments.This research involves the development of adaptive signal processing algorithms and architectures for application in future wireless communications systems featuring high user mobility, high data rate and high quality of service. The primary emphases of this research are on advanced receiver signal processing techniques, and on advanced transmitter signal processing techniques for wireless systems. The first of these focuses on developing adaptive signal reception techniques for jointly combating various impairments in time-varying wireless channels, such as radio-frequency interference (narrowband interference, multiple-access interference, impulsive ambient noise), multipath fading, channel dispersion, etc. A particular approach that will be examined in depth is the exploitation of the redundancy introduced by channel coding at the receiver for interference mitigation and channel tracking. The second addresses adaptive signal transmission techniques in time-varying wireless channels for improving network capacity. Specifically, adaptive antenna array transmission techniques and adaptive frequency hopping techniques are being studied, with the focus on rapid adaptivity to dynamic channel environments. This research is expected to culminate in the formulation of novel signal processing techniques and system design concepts applicable to future wireless communication systems. It is also anticipated that this research will influence many current and next generation communication systems planners and designers, to bring the promise of many new research techniques into the arena of wireless communications.