基于突发OFDM系统的时域符号同步关键技术研究

项目名称： 基于突发OFDM系统的时域符号同步关键技术研究

项目编号： No.61301272

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 杨帆

作者单位： 电子科技大学

项目金额： 24万元

中文摘要： 正交频分复用（OFDM）由于具有很强的抗频率选择性衰落能力，已广泛被多种移动通信标准所采纳，它也是4G移动通信最具潜力的技术之一，其中关于突发OFDM系统的时域符号同步问题，是实现接收机可靠和稳定工作的关键，相关的基础性研究具有重要的科学和实际意义。由于传输训练符号数的限制，为应对现有同步算法在低信噪比严重多径衰落信道中，符号同步精度和稳定性受到较大影响的问题，本项目拟充分挖掘同步头内潜在的相关项，通过引入量化排序来解决"优选同步头相关项"关键技术，严格控制算法的实现复杂度；从产生单峰值和抵抗大频偏定时度量的角度出发，通过引入几何优化和延迟相关滤波等方法，来实现"稳定高效的符号粗同步算法"；拟通过联合优化概率建模和参数估计，突破"基于概率建模的符号精同步算法"，来进一步提高精同步算法性能。相应的关键基础问题的解决，将为突发OFDM系统的同步模块的研制打下坚实的基础。

中文关键词： 突发OFDM系统；电力线载波通信；符号定时估计；alpha稳定分布；脉冲干扰

英文摘要： The OFDM systems have the ability to overcome the channel frequency-selectivity, which have been widely adopted by many mobile telecommunication standards. The OFDM technique is also regarded as one of the most potential candidate techniques for 4G telecommunications. The symbol timing issue of the burst OFDM systems in the time-domain is crucial for reliable and stable reception, while the relatively fundamental research is very meaningful. Because of the limitation of the transmitting training symbols, the conventional symbol timing algorithms are highly influenced by severe multi-path fading channels in low SNR region. In our project, we plan to fully explore the correlation terms belonging to the preamble. By utilizing quantization for ranking the correlation characteristics, the "Optimum selecting for the correlation terms " technique can be solved. In order to generate the timing metric with one sharp peak in the presence of large carrier frequency offset (CFO), the "Stable and efficient coarse symbol timing algorithm" can be achieved by introducing geometry optimization and delayed correlation filtering. Further, we try to investigation the probabilistic modeling and parameter estimation jointly, and to work out "Probabilistic modeling based fine symbol timing algorithm" for performance improvement. After

英文关键词： burst OFDM system；power-line communication；symbol timing estimation；alpha-stable distribution；impulsive interference