为了减小外辐射源雷达系统中常规杂波相消算法的运算量,该文利用数字电视地面广播(DTTB)照射源中的PN序列,提出了一种快速杂波相消算法。该算法基于PN序列良好的自相关特性,并考虑到DTTB信号对载频频偏(CFO)很敏感,提出2-D信道和CFO估计来提高估计精度;然后,利用估计的信道和CFO进行直达波重构和杂波相消,剩余目标回波和噪声。相比于传统的杂波相消算法,该方法运算量比较小,并且所有处理都基于预警天线,不需要参考天线,简化了系统模型。最后仿真实验验证了算法的有效性。
To reduce the computational complexity of conventional cancellation algorithm in passive radar system, a fast cancellation by the Pseudo-Noise (PN) sequence in the Digital Television Terrestrial Broadcasting (DTTB) illuminator is proposed. Based on the good correlation property of PN sequence, and the fact that DTTB illuminator is very sensitive to the Carrier Prequency Offset (CFO), the 2-D time delay and CFO estimation is proposed to improve the estimation accuracy. Once obtaining the time delay and CFO, the direct path signal reconstruction and cancellation can be made, remaining the target echoed signal and noise. Compared with the conventional cancellation method, the method has the smaller computational cost, and all the processing is on surveillance antenna, simplifying the passive radar system model by removing the reference antenna. Finally, the simulation experiments demonstrate the effectiveness of the method.