摘要
针对正交频分复用系统,提出了一种基于训练序列的改进同步算法。通过在频域发送不经过星座映射的实数PN序列,构造具有共轭对称性的训练序列。结合稳健估计器的思想,改进了定时度量函数,把循环前缀与训练序列相结合进行联合定时和频偏估计,并且简化了整数倍频偏估计方法。仿真结果表明,联合同步方法在低信噪比下也具有较好的估计性能,增强了系统的稳健性。
This paper proposed an improved synchronization algorithm based on training sequences for orthogonal frequency division multiplexing system. Without constellation mapping , the PN sequence of real numbers was sent in the frequency domain. So that it can construct conjugate-symmetric training sequences. Combined with theory of robust estimator, the timing metric was improved. The cyclic prefixes and training sequences were combined and the integer frequency offset estimation was simplified. According to simulation results, joint synchronization method has better estimation performance at low signal to noise ratio and enhance the robustness of the system.
出处
《电视技术》
北大核心
2012年第19期146-150,共5页
Video Engineering
基金
国家自然科学基金项目(61172169)
航空基金资助课题(20112096016)
关键词
OFDM
训练序列
循环前缀
定时同步
频偏估计
联合同步
orthogonal frequency division multiplexing
training sequences
cycle prefix
timing synchronization
frequency offset estimation
conjugate synchronization
