摘要
为提高正交频分复用(OFDM)在低信噪比环境下的同步性能和抗噪能力,提出了一种并行多延时相关帧同步算法。该算法充分利用帧的前导训练符号周期重复的特点,在接收端滑动窗中并行处理多种延时相关运算,通过阈值判决进行帧检测,同时完成载波频率同步,进而实现OFDM帧同步。该算法无须改动现有系统的物理帧结构,也不增加系统延时。理论分析和在加性G auss白噪声信道下的误帧率(FER)性能仿真证明:该算法的误帧率约为现有参考方案的1/10,信噪比(SNR)比参考方案提高约7 dB,能够工作在信噪比小于-1 dB的环境。
Parallel multiple delay correlations were used to analyze orthogonal frequency division multiplexing （OFDM） for frame synchronization in low signal to noise ratio （SNR） environments. Parallel multiple delay correlators and threshold detectors were used to analyze the periodically repeated sequences in the beginning of typical OFDM frame formats for packet detection, frequency synchronization, and frame synchronization with a moving window. The approach does not need to modify the current frame structure and does not increase the system synchronization time. Theoretical analyses and tests using additive white Gaussian noise show that the frame error ratio with the method is about 1/10 that of the reference scheme. The results are about 7 dB better than with the reference scheme, especially with SNR below - 1 dB.
出处
《清华大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2006年第10期1677-1680,共4页
Journal of Tsinghua University(Science and Technology)
关键词
正交频分复用(OFDM)
并行延时相关
帧同步
帧检测
频率同步
orthogonal frequency division multiplexing （OFDM）
parallel delay correlation
frame synchronization
frame detection
frequency synchronization
