一种ADS-B报头互相关检测方法

广播式自动相关监视( ADS-B )报头检测方法的优劣直接决定着接收机的性能。为了解决脉冲匹配检测方法受脉冲能量影响较大的不足，提出了一种基带归一化的互相关报头检测方法。首先将基带信号根据动态门限进行归一化，然后将其与标准报头作互相关，最后通过相关峰检测来判定信号的存在和到达时间。与主流基于脉冲位置和上升沿的检测方法相比，该方法隐含地利用了脉冲位置、上升沿、下降沿、脉冲宽度、非脉冲区等多个信息用于检测报头，且无需进行下行格式( DF )认证。仿真结果表明：该方法在信噪比大于2 dB时检测性能略优，在信噪比小于2 dB时检测性能与主流检测方法相差1 dB。在实际接收实验中，以该方法为基础的信号接收效果良好，在视距内可以形成稳定连续的航迹，证明了该方法的实用性。

A novel ADS-B preamble detection method based on cross-correlation

The capability of Automatic Dependent Surveillance-Broadcast ( ADS-B ) preamble detection method directly determines the performance of the receiver. This paper proposes a cross-correlation method for detecting ADS-B preamble based on baseband normalized,which makes up the deficiency of pulse matc-hing method. Firstly,the baseband signal is normalized with dynamic threshold. Secondly,the normalized signal is cross-correlated with standard preamble. Finally,the presence and the arrival time of the signal is determined by cross-correlation peak detection. This method impliedly uses the pulse position,rising edge, falling edge,pulse width and no-pulse zone to detect the preamble and does not need downlink format( DF) certification compared with the conventional detection method. The simulation results show that the detection capability of this method is slightly better than that of the conventional method,but with 1 dB lower than that of the conventional method for detecting the ADS-B preamble when signal-to-noise ratio( SNR) is less than 2 dB. The performance of the ADS-B receiver is good in actual reception experiment. It can get a stable and continuous track when the plane is in sight distance,which indicates the usefulness of this method.