针对卫星信号监测中监视频带宽、背景噪声非平坦造成的信号漏检和误检的问题,结合卫星通信信号的特点提出了一种频谱校正的新方法.该方法将接收的频谱信号视为一维灰度图像,通过改进的形态学滤波检测法,估算出信号中非平坦的背景噪声基底,利用估计的噪声基底完成对原频谱信号的修正,可提高信号检测的准确性.仿真结果表明,该方法降低了信号带宽对传统形态学滤波中结构元素长度选择的影响,计算量小,能高效地实现非平坦频谱信号的底噪校正.
In satellite signal spectrum monitor, due to the wide monitor bandwidth and non-flat noise, there is the problem of miss and error detection of carriers. In combination with the character of satellite communication, a new method of automatical pre-revise of spectrums is proposed. First the non-flat noise floor is estimated by use of an improved morphological filter when the received spectrum is viewed as one-dimensional gray-scale image, and then the spectrum with non-flat noise is revised by using the estimated noise floor. Simulation results show that the proposed method has low computational complexity and reduce difficulty of choosing the structure element when there are many different bandwidths in present spectrum.