高灵敏度星载ADS-B信号解调算法

High sensitivity detection algorithm for space-based ADS-B

摘要:

为提高星载自动相关广播监视系统(ADS-B)接收机的检测性能，研究了高灵敏度解调算法。利用基于匹配滤波的ADS-B信号帧头检测算法对信号准确定时和提取功率信息，该方法构建了特殊的帧头匹配脉冲序列，设计了信号控制状态机以确保在相关峰值最大处定位信号，并联合一部分数据位进行同步。利用多点加权振幅采样法提取比特信息和置信度。最后，采用基于置信度的纠错方法纠正校验错误的报文。板载验证表明，该解调算法能有效提升低信噪比条件下星载ADS-B信号的检测概率，最终接收机的灵敏度可达-95 dBm(数据包错误率5%)。

Abstract:

In order to detect signal of Automatic Dependent Surveillance-Broadcast(ADS-B) precisely, an improved detection algorithm is developed in this paper. And a special match filter for ADS-B is proposed, which benefits from the phase coherence of the pulse train from the first ADS-B preamble pulse to the third format bit. State machine is developed to ensure decode signal in correlate peak. The simulation results show that it is able to increase detection probability by this method under low ratio of signal to noise. The sensitivity of receiver using this method is -95 dBm(the packet error rate is 5%).