基于响应估计频域拟合的通道均衡方法

阵列各个天线、射频组件等在大信号带宽下引起的响应不同, 造成了通道的不一致性, 使得阵列的谱估计性能严重恶化。针对内定标无法校准天线馈线、已有外校准方法的性能受噪声影响严重和盲自适应过程依赖参考信号的问题, 提出基于单一外部线性调频连续三角波信号源响应估计频域拟合的通道均衡方法。首先通过滑动协方差矩阵特征值分解和已知信源的理想导向矢量得到通道响应的粗估计, 然后基于最小二乘准则利用谐波模型拟合得到通道响应的精准估计, 最后结合带外线性扩展和频域多项式拟合得到均衡器响应。实测数据处理结果表明, 在谱估计时利用所提方法均衡通道不一致性比其他方法有更高的输出信噪比和更小的角度估计均方误差。

Channel equalization method based on response estimation and frequency domain fitting

The response of each antenna and radio frequency component of the array is different under large signal bandwidth,resulting in channel inconsistency and serious deterioration of the spectrum estimation performance of the array.Aiming at the problems that the antenna feeder cannot be calibrated by internal calibration,the performance of the existing external calibration methods is seriously affected by noise,and the blind adaptive process depends on the reference signal,a channel equalization method based on frequency domain fitting of response estimation of single external linear frequency modulation continuous triangular wave signal source is proposed.Firstly,the rough estimation of the channel response is obtained by the eigenvalue decomposition of the sliding covariance matrix and the ideal guidance vector of the known source.Then,based on the least square criterion,the accurate estimation of the channel response is obtained by harmonic model fitting.Finally,the equalizer response is obtained by combining out of band linear expansion and frequency domain polynomial fitting.The measured data processing results show that the proposed method has higher output signal to noise ratio and smaller angle estimation mean square error than other methods.