摘要
对跳频信号进行短时傅立叶变换,提取变换后的时频脊线,再利用小波变换提取该脊线的边沿信息,进而进行傅立叶变换,这是信噪比较高时已有的一种实现跳速精确估计的有效方法。针对实际中信噪比较低的情况,文章在此基础上提出了一种新的提取时频脊线的方法。实验表明采用新的提取脊线方法后,在较低信噪比下,跳速的估计也能保证较高的精度。最后,还对影响估计精度的各个因素进行了分析和仿真。
The FH signals with the short-time Fourier transform （STFT） is used to yield its time-frequency backbone curve, whose edge information is abstracted by the wavelet transform （WT） , to which the FFT is applied -- this is a known method to implement the hop rate accurate estimation when the SNR is high. Aimed at low SNR condition, a new method to abstract the time-frequency backbone curve is proposed. The simulations show that the estimation of hop rate is efficient even if the SNR is low. Finally, some facts are analyzed to see the relation with the performance.
出处
《信息工程大学学报》
2008年第4期397-400,共4页
Journal of Information Engineering University
基金
军队科研基金资助项目
关键词
跳频
跳速估计
短时傅立叶变换
时频脊线
frequency hopped signals
hop rate estimation
STFT
time-frequency backbone curve
