Efficient Transmission Techniques for Digital Mobile Cellular and Digital Broadcast Applications

数字移动蜂窝和数字广播应用的高效传输技术

• 批准号: 9203131
• 负责人: John Cioffi
• 金额: $ 30万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-10-01 至 1996-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9203131&HistoricalAwards=false
• 关键词: Efficient; Transmission; Techniques; Digital; Mobile

This project has three specific areas of study: Efficient Channel-Based Equalization, the computation of the equalizer via channel characterization derived from embedded training data; Interference Rejection for Code-Division Multiple Access, near-far and intersymbol interference and interference from disparate users; and Multicarrier Methods for Broadcast Transmission, for mitigation of time-varying fading effects. The focus of the study is on the time-varying multipath data channel. At relatively low data rates, the time-varying nature of wireless communication channels often leads to channel variation over a small number of symbol intervals. In this case a significant amount of training data can be embedded in the transmitted packets of data to enable adjustments to be made at the receiver. An alternative, perhaps forced by the need for higher data rates, is to increase the bandwidth of the transmitted signal. Then the relative rate of channel variation is less compared to the symbol rate, and the fraction of training is reduced. As wider bandwidths are used, multipath effects become more important and more sophisticated receiver structures need to be used. The research studies both narrow and wideband transmission, for applications in digital cellular radio and digital broadcast channels.

该项目具有三个特定的研究领域：基于信道的有效均衡，通过嵌入式训练数据得出的通道表征计算均衡器的计算； 对代码分段多访问，近战和InterSymbol的干扰以及来自不同用户的干扰的干扰拒绝； 以及用于广播传输的多载波方法，用于缓解时变褪色效果。 该研究的重点是随时间变化的多径数据通道。 在相对较低的数据速率下，无线通信通道的时间变化性质通常会导致少数符号间隔的通道变化。 在这种情况下，可以将大量的培训数据嵌入到传输数据包中，以使接收器进行调整。 替代性，也许是由于需要更高的数据速率而迫使的，是增加传输信号的带宽。然后，与符号率相比，通道变化的相对速率较小，并且训练的比例降低。 随着使用更宽的带宽，需要使用多径效应，需要使用更复杂的接收器结构。研究研究狭窄和宽带传输，用于数字蜂窝无线电和数字广播渠道的应用。