Low-complexity overlapped position detection for single antenna ADS-B receivers

Overlapped Automatic Dependent Surveillance-Broadcasting (ADS-B) signals will cause errors in reading the information, so the separation technology is essential. The separating algorithm usually needs to detect the overlapped position firstly, and then the non-overlapping parts are used for separating. Therefore, the overlapped position detection is an important step in the separating algorithms. The existing methods of overlapped position detection are mainly based on the Singular Value Decomposition(SVD) method, however, this method is complicated and the position detection is not accurate. Therefore, this paper is based on the characteristics of the time domain waveforms of single antenna ADS-B signals. Using the waveform differences between the overlapped signals and the standard signals, a low-complexity method for detecting the overlapped position of signals is proposed. The overlapped position of the preamble is detected by using the fixity of the preamble pulse position, and then the data block of the signal is detected according to the characteristics of the pulse width and amplitude. The results of simulation and test experiments show that the algorithm proposed in this paper can accurately and efficiently detect the overlapped position of signals.