为解决测距仪脉冲信号干扰L频段数字航空通信系统1(L-band digital aeronautical communications system 1,L-DACS1)正交频分复用接收机的问题,提出一种基于特征矩阵联合对角化(joint approximate diagonalization of eigen-matrices,JADE)的测距仪脉冲干扰抑制方法。首先将干扰抑制问题转化为盲源分离问题,在接收端建立频域盲分离模型,利用JADE算法将接收到有用信号与测距仪干扰信号分离;然后根据干扰信号的功率特性进行分离后信号的识别;最后通过训练序列解决盲源分离固有的幅度模糊性问题,最终恢复出有用接收信号。仿真结果表明:所提出的基于JADE的干扰抑制方法可有效消除测距仪脉冲信号干扰,改善系统的误比特性能,增加传输可靠性。
In order to solve the problem that the distance measure equipment (DME) impulse signal pro- duces serious interference on the orthogonal frequency division multiplexing receiver of L-band digital aeronauti- cal communications system 1 (L-DACS1), a DME interference mitigation method based on joint approximate di- agonalization of eigen-matrices(JADE) is proposed. Firstly, the problem of interference suppression is trans- formed into blind source separation. After establishing the frequency domain separation model at the receiver, the JADE method is used to separate the useful received signal and DME impulse interference. Then, the sepa- rated signal is identified by using the power characteristic of the interference signal. Finally, the inherent ambi- guity problem of blind source separation is solved by using training-sequence, and eventually the useful received signal is recovered. It can be indicated by simulation that the proposed JADE method can eliminate the DME im- pulse interference effectively, and improve the bit-error performance and the reliability of transmission link.