基于累加分类的ADS-B交织信号处理方法

广播式自动相关监视作为国际民航组织主推的监视技术，越来越多的飞行器配备了ADS-B收发设备，此外，介于ADS-B信号的广播体制以及空域流量的不断增加，不同的ADS-B信号之间将会发生交织，这种情况同样也会发生在直达信号与多径信号之间；以上两种情况均会给ADS-B信号的解码带来严重影响，相应地会造成信息的错误读取或丢失。本文提出了一种单天线下基于累加判决的解交织算法:首先通过单天线下的有效脉冲位置检测以及基于希尔伯特变换的交织检测分别获得信号的起始位置以及信号交织位置，进而得到两条信号之间的相对时延，从而对数据进行累加并利用K-means方法进行分类，最终得到比特位判决结果以实现交织信号分离。 

A Method of Overlapped ADS-B Signal Processing Based on Accumulation and Classification

As a major surveillance technique in the future recommended by ICAO, Automatic Dependent Surveillance Broadcast (ADS-B) is being paid much more attention in the world, it is incorporated to the growing number of aircraft. As the broadcast property and the increasing of the aircraft, there will be overlapping among the different ADS-B signal, which will lead to a serious problem for the decoding of ADS-B signals. If the ADS-B signal cannot be properly decoded, the information of target will be lost or error recorded. In this paper, the method of overlapped signal processing is presented for single antenna ADS-B receiver. Firstly, this paper estimate the start time of the signal by the detection of valid pulse position and lead edge, the overlapping position is detected by Hilbert transform, then the time delay between the overlapped signals is obtained; secondly, divide the sample points into intervals based on the estimated time delay and the pulse width, and the signal power on each interval can be obtained by adopting step by step integration. Finally, the data of different signal can be determined by the classification results of integral values. The method is compared with those of the presented approaches, the result of the simulation shows that if there is a certain power difference between the overlapping signals, then the separation is effective.