一种抗窄带干扰的OFDM符号定时同步改进算法

为了提高正交频分复用(OFDM)系统定时同步的抗窄带干扰能力,利用加扰的思想对Park算法的前导符号进行了改进,并提出了新的定时测度函数. 通过TU-6多径信道下的仿真表明,在窄带干扰的影响下改进算法仍能保持尖锐的相关峰值特性,实现准确的定时估计,同时其性能会随着子载波数的增加得到提升. 此外,改进算法也降低了相关旁峰的大小,提高了定时同步的抗噪声能力.

Improved Symbol Timing Synchronization Algorithm for OFDM Systems Mitigating Narrowband Interference

In orthogonal frequency division multiplexing ( OFDM) systems, the validity and accuracy of symbol timing synchronization is seriously impacted by narrowband interference that cannot be eliminated by conventional algorithms. To improve the performance, a new timing metric was proposed with help of a scrambling operation to the preamble symbol in Park’ s algorithm. Simulations are carried out in TU-6 multipath channel under the narrowband interference. It is shown that the improved algorithm successfully obtains the needed sharp correlation peak to realize accurate timing synchronization. Furthermore, with increase of the number of sub-carriers, the anti-narrowband-interference performance can be obviously promoted. In addition, the improved algorithm also reduces the size of the correlation sub-peaks, which improves the anti-noise performance.