利用谱熵解决零前缀正交频分复用系统的符号盲同步算法

针对低信噪比多径条件下的ZP OFDM系统符号盲同步问题，提出了基于谱熵的ZP OFDM系统的符号盲同步算法。该算法不需要数据辅助，对接收到的ZP OFDM信号进行双滑动窗的谱熵比运算，通过寻找其峰值点来实现符号同步。给出了算法的具体步骤和性能分析。算法是对接收信号的功率谱进行求熵运算，可以有效克服能量检测法易受信道噪声影响的缺点，并且不需要针对信道调整窗口宽度。仿真结果表明，在低信噪比多径信道条件下，算法仍然具有较好的同步性能。

A Blind Symbol Synchronization Algorithm for ZP-OFDM Systems Based on Spectral Entropy

In view of the blind symbol synchronization problem of ZP OFDM system in low SNR and multipath channels, a blind symbol synchronization algorithm for ZP OFDM systems based on spectral entropy is proposed. The training data are not needed and the ZP OFDM signal is calculated by using the double windows to get the spectral entropy ratio. The symbol synchronization is implemented by finding the peak point. The steps and capability analysis are provided in the paper. The disadvantage of the energy detection method affected easily by the channel noise is overcome by the algorithm which calculates the entropy with power spectrum of received signal. The window width is not needed to be adjusted according to channels. The simulation results show that this algorithm has superior performance in low SNR and multipath channels.