A generalized approach for narrowband interference （NBI） suppression in direct sequence spread spectrum （DSSS） communication systems using adaptive infinite impulse response （IIR） filter is presented. The excisi...A generalized approach for narrowband interference （NBI） suppression in direct sequence spread spectrum （DSSS） communication systems using adaptive infinite impulse response （IIR） filter is presented. The excision filter coefficients depend on both the jammer power and its instantaneous frequency. The dependency of the filter construction on the jammer power is significant as it allows optimal tradeoff between interference removal and signal distortion by maximizing the receiver signal to noise ratio improvement（SNRI）. Instead of traditional adaptive line enhancer （ALE） estimator, a preferable NBI estimator-Fourier interpolation estimator （FIE） is proposed. Closed-form expressions of the SNR improvement and theoretical bit error rate （BER） based on the assumption that the output of the correlator is Gaussian distributed are both derived. Performance results obtained by numerical simulation are also presented and compared with theoretical results.展开更多
为抑制白噪声和窄带干扰对局部放电脉冲信号能量测量的影响,提出了一种基于噪声参数的能量估计方法。研究了现场信号模型和信号能量谱系数的概率分布,得到噪声参数已知条件下脉冲信号能量的最大似然估计。同时为获得噪声参数,将采样数...为抑制白噪声和窄带干扰对局部放电脉冲信号能量测量的影响,提出了一种基于噪声参数的能量估计方法。研究了现场信号模型和信号能量谱系数的概率分布,得到噪声参数已知条件下脉冲信号能量的最大似然估计。同时为获得噪声参数,将采样数据划分成信号帧和噪声帧,采用3F–C法估计了白噪声和窄带干扰参数。通过仿真实验和实测数据处理,与传统小波包降噪方法的结果进行了对比。数据分析结果表明:无论是针对单一白噪声环境还是存在窄带干扰的混合噪声环境,该能量估计方法的准确性均优于传统小波包降噪方法,且随着信噪比的降低和信号时间窗口长度的增加,该方法表现出更明显的优势。在信噪比为–8 d B的条件下,使用该方法对实测局部放电脉冲信号进行能量估计的相对误差仅为4.07%,而使用小波包降噪方法时相对误差则达到44.12%。展开更多
基金Sponsored by the Beijing Municipal Natural Science Foundation(4052024)
文摘A generalized approach for narrowband interference （NBI） suppression in direct sequence spread spectrum （DSSS） communication systems using adaptive infinite impulse response （IIR） filter is presented. The excision filter coefficients depend on both the jammer power and its instantaneous frequency. The dependency of the filter construction on the jammer power is significant as it allows optimal tradeoff between interference removal and signal distortion by maximizing the receiver signal to noise ratio improvement（SNRI）. Instead of traditional adaptive line enhancer （ALE） estimator, a preferable NBI estimator-Fourier interpolation estimator （FIE） is proposed. Closed-form expressions of the SNR improvement and theoretical bit error rate （BER） based on the assumption that the output of the correlator is Gaussian distributed are both derived. Performance results obtained by numerical simulation are also presented and compared with theoretical results.
文摘为抑制白噪声和窄带干扰对局部放电脉冲信号能量测量的影响,提出了一种基于噪声参数的能量估计方法。研究了现场信号模型和信号能量谱系数的概率分布,得到噪声参数已知条件下脉冲信号能量的最大似然估计。同时为获得噪声参数,将采样数据划分成信号帧和噪声帧,采用3F–C法估计了白噪声和窄带干扰参数。通过仿真实验和实测数据处理,与传统小波包降噪方法的结果进行了对比。数据分析结果表明:无论是针对单一白噪声环境还是存在窄带干扰的混合噪声环境,该能量估计方法的准确性均优于传统小波包降噪方法,且随着信噪比的降低和信号时间窗口长度的增加,该方法表现出更明显的优势。在信噪比为–8 d B的条件下,使用该方法对实测局部放电脉冲信号进行能量估计的相对误差仅为4.07%,而使用小波包降噪方法时相对误差则达到44.12%。
