摘要
在非协作通信系统中,信号解调需要对载波频率进行估计。提出了一种结合信噪比估计的希尔伯特-黄变换(Hilbert-Huang transform,HHT)的载波频率估计方法,通过信噪比合理选择固有模态分量(intrinsic mode function,IMF)对信号进行时域滤波,再求边际谱来估计载波频率,并与其他几种方法进行比较。仿真结果表明,在信噪比低于-5 d B时,文中提出的相位调制信号(phase shift keying,PSK)载频估计方法,归一化均方根误差小于10-1,相对误差小于5%,优于其他方法。
In a non-cooperative communication system,it is necessary to estimate the carrier frequency for blind signal demodulation. In combination with SNR estimation,this paper proposes a carrier frequency estimation method based on Hilbert-Huang transform,and compares it with several other methods. It chooses intrinsic mode function component properly for time domain filtering under SNR estimation,and then estimates carrier frequency by marginal spectrum. The simulation results show that when the SNR is lower than-5 d B,the normalized root mean square error is less than 10-1and relative error is less than 5%,which illustrates that the proposed method of PSK carrier frequency estimation works better than the others.
出处
《应用科技》
CAS
2015年第4期37-42,共6页
Applied Science and Technology
基金
国家自然科学基金资助项目(61201237)
