固定阈值的OFDM符号同步算法.doc

文档介绍：
固定阈值的 OFDM 符号同步算法#
覃建策1,2,罗涛1**
(1. 网络体系构建与融合北京市重点实验室,北京邮电大学,北京 100876;
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2. 综合业务网理论及关键技术国家重点实验室,西安 710071)
摘要:传统的基于时域训练序列自相关的正交频分复用(orthogonal frequency division
multiplexing,OFDM)符号同步算法中,自相关峰值会随着信道的变化而出现波动,使得实
现中使用固定判决阈值会降低其同步性能。为此,论文提出了一种固定阈值的 OFDM 符号
同步算法。结合 帧结构中短训练序列的特点,首先对接收到的 10 组短训
练序列进行累加,以平滑噪声。然后,累加值先量化再进行自相关运算,使自相关峰值不再
出现波动,便于设定固定阈值。最后,取自相关模值的平方,以加宽自相关峰与互相关峰间
的隔离带。理论分析和仿真结果均表明,该算法可以有效对抗信道衰落和噪声,尤其在低信
噪比下性能极佳。
关键词:通信技术;OFDM;符号同步;固定阈值
中图分类号:TN914
OFDM symbol synchronization algorithm with fixed
threshold
QIN Jiance1,2, LUO Tao1
(1. The Beijing Key Laboratory work System Architecture and Construction, Beijing
University of Posts and munications, Beijing 100876;
2. The State Key Laboratory of Integrated works, Xidian University, Xi’an 710071)
Abstract: In conventional orthogonal frequency division multiplexing (OFDM) symbol
synchronization algorithms based on preamble, the peak of correlation value always fluctuates
with channel’s change, so that using fixed threshold on it will decline the synchronization
performance. To solve this problem, an OFDM symbol synchronization algorithm with fixed
threshold is described. Considering the characteristic of short training sequence (STS) in
, it first accumulates 10 groups of received STS in order to smooth noise.
Second, the result is qu