基于时频二维训练信息的高谱效多天线TFT-OFDM技术研究

项目名称： 基于时频二维训练信息的高谱效多天线TFT-OFDM技术研究

项目编号： No.61201185

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 电子学与信息系统

项目作者： 戴凌龙

作者单位： 清华大学

项目金额： 27万元

中文摘要： 针对现有多天线OFDM系统中用于信道估计的训练信息开销较大这一技术难题，本项目在继承中国地面数字电视标准的核心调制技术时域同步正交频分复用（TDS-OFDM）基本信号结构的基础上，将传统OFDM技术中时域或频域一维的训练信息扩展到时频二维, 提出时频联合信道估计方法，即在无需干扰消除的前提下先通过时域正交训练序列来获取信道的各径时延，然后仅利用极少量的频域正交导频即可获取信道的各径系数，进而建立基于时频二维训练信息的高谱效多天线TFT-OFDM（Time-Frequency Training OFDM）传输理论和技术。该技术突破了传统TDS-OFDM技术中时域和频域处理相互制约的依赖关系，并大幅降低了多天线系统中的导频开销，且通过时频联合处理提高了信道估计的精度。本项目将为我国新一代数字电视标准在高谱效、高可靠传输等关键技术指标上优于国外最先进的数字电视标准提供重要的理论基础和技术储备。

中文关键词： 地面数字电视；正交频分复用；多天线技术；训练信息；

英文摘要： Traditional multi-antenna OFDM systems have the technical problem of large training information overhead. In this project, based on the signal structure of the time domain synchronous OFDM (TDS-OFDM), which is the key technology of Chinese digital television terrestrial broadcasting (DTTB) standard, we propose a fundamentally distinct OFDM-based transmission scheme called time-frequency training OFDM (TFT-OFDM) for multi-antenna systems with high spectral efficiency. Unlike the sole time-domain training sequence or frequency-domain pilots in conventional OFDM systems, every TFT-OFDM symbol has training information both in the time and frequency domains. We further propose the time-frequency joint channel estimation scheme, whereby the time-domain orthogonal training sequences are utilized to merely acquire the path delay information of the channel without interference cancellation, while the path coefficients are estimated by using the small amount of frequency-domain orthogonal pilots. This scheme could decouple the mutually conditional relationship of time- and frequency-domain processings in conventional TDS-OFDM systems, and the pilot overhead could be significantly reduced. Moreover, the accuracy of channel estimation in TFT-OFDM systems could be substantially improved by the time-frequency joint processi

英文关键词： Terrestrial digital television；OFDM；MIMO；Training information；