基于最小描述长度准则的数字信道化接收机频谱检测方法

Spectrum Sensing Method Used in Digital Channelized Receiver Based on Minimum Description Length Criterion

中文关键词:  数字信道化  频谱检测  特征值  最小描述长度准则

英文关键词:digital channelization  spectrum sensing  eigenvalues  minimum description length criterion

中文摘要:

      数字信道化接收机常采用频谱检测方法判断其分析滤波器组中的输出子带信号的存在。为解决现有基于特征值的频谱检测方法由于采用最大和最小特征值的近似值而导致采样点数较少时性能无法满足要求的问题，提出了一种适用于数字信道化接收机的基于最小描述长度(MDL)准则的子带频谱检测方法。基于子带过采样数据构建协方差矩阵，计算矩阵特征值的平均值以减少噪声带来的波动。将矩阵特征值的平均值作为MDL准则的参数估计所有子带的平均特征值中包含信号的个数，以此确定包含信号的子带。仿真实验表明，该方法比现有的频谱检查方法具有更好的检测性能，且克服了需要设置固定门限的缺点，对噪声和信号波动具有较强的适应能力。

英文摘要:

      The digital channelized receiver usually uses spectrum sensing technique to decide the existence of signal in output sub-band of the analysis filter bank.To solve the problem that the eigenvalue-based method obtains the maximum and minimum eigenvalues based on approximation,resulting in its performance degrades when the number of samples is small,a sub-band spectrum sensing method based on the minimum description length (MDL) criterion for digital channelized receiver is proposed.The covariance matrix was constructed with the oversampled data of the sub-band output.The average eigenvalue of each sub-band was calculated to reduce the fluctuation caused by noise.The number of eigenvalues containing signals was estimated by MDL criterion,and used to confirm the existence of signal in each sub-band.The simulation results show that the proposed method has better performance than the existing spectrum sensing methods.It overcomes the shortcomings of fixed detection threshold and has better adaptability to noise and signal fluctuations.