Algorithm of multi-signals separation for shortwave broadband receiver

In this paper, an algorithm of multi-signals separation for shortwave broadband receiver is proposed that is suitable for the case where the signals are not overlapped in frequency domain. Firstly, the algorithm uses morphological filter to estimate the noise floor which is then subtracted from the overall spectrum. Secondly, a multi-resolution analysis based on wavelet is implemented in order to reduce the interference further. After an improved Welch spectrum is obtained, thirdly, a two-step procedure including adaptive threshold setting and comparison is performed for final decision making. Simulation results have proved the feasibility and performances of the separation algorithm, especially the suitableness for very weak signals detection in non-flat noise environment.