ITR Collaborative Research: Achieving the Rate-Diversity Tradeoff in Space-Time Codes

衰落一词是用来描述在无线通信环境中遇到的接收信号强度的不可预测的且通常是快速的波动。蜂窝通信中的掉话通常可归因于衰落。一种非常有效和最新的抗衰落技术是在输入(发送端)和输出(接收端)使用多个天线。术语空时通信信道用于描述存在多个输入和输出天线的衰落的无线通信信道。可以使用多个输入和输出来增加无线通信信道的可靠性，或者以可能等于发射天线数量的系数来增加信息可以被发射的速率。当用于提高信息传输的可靠性和速率时，在信息速率的增加和通信链路的相应可靠性之间存在权衡。这种权衡被称为速率分集权衡。本项目的主要目标是设计允许用户沿着速率分集折衷曲线选择工作点的信号集。其他目标包括帮助定义和实现空时通信信道的极限。更具体的目标包括设计实现速率分集折衷且易于译码的信号集，研究诸如延迟受限信道容量等其他相关的信道容量概念，研究其他相关的信道模型，包括那些包含信道记忆和相关路径增益的模型，以及在存在反馈以及存在具有多分辨率能力的信源的情况下研究空时信道。

ABSTRACT0325180Xiang-gen XiaUniversity of DelawareThe term fading is used to describe the unpredictable and often rapid fluctuation in received signal strength encountered in a wireless communication environment. Dropped calls in cellular communication are often attributable to fading. A very effective and recent technique used to combat fading is to use multiple antennas at both input (transmitter end) and output (receiver end). The term space-time communication channel is used to describe the fading, wireless communication channel in the presence of multiple input and output antennas. Multiple input and output can be used to either increase the reliability of a wireless communication channel or else increase the rate at which information can be transmitted by a factor potentially equal to the number of transmit antennas. When used to both increase reliability and rate of information transfer, there is a tradeoff between the increase in information rate and the corresponding reliability of the communication link. This tradeoff is referred to as the rate-diversity tradeoff. A principal goal in the present project is the design of signal sets that will allow the user to pick an operating point along the rate diversity tradeoff curve. Other goals include helping define and achieve the limits of the space-time communication channel.More specific objectives include the design of signal sets that achieve the rate-diversity tradeoff and that are easy to decode, the study of alternative relevant notions of channel capacity such as delay-limited channel capacity, the study of other relevant channel models including those incorporating channel memory and correlated path gains, the study of the space-time channel in the presence of feedback as well as in the presence of sources having a multi-resolution capability.