针对L频段数字航空通信系统1(L-DACS1)以内嵌方式部署在航空无线电导航频段而产生的测距仪脉冲干扰(DME)正交频分复用(OFDM)接收机的问题,提出联合压缩感知与残留干扰白化的测距仪脉冲干扰抑制方法.首先接收机通过空子载波信道来观测测距仪脉冲干扰,并利用测距仪脉冲干扰在时域的稀疏特性,基于l1范数最小化约束的凸优化方法重构测距仪脉冲干扰;然后将重构的脉冲干扰转换到频域进行干扰消除;最后,接收机通过信号解交织器与逆正交变换器将残留的脉冲干扰转换为高斯白噪声,避免了残留干扰信号造成的突发性解调错误.仿真研究表明:联合干扰抑制方法可有效消除测距仪脉冲信号干扰,显著提高L-DACS1系统链路传输的可靠性.
To mitigate the deleterious influence of distance measure equipment (DME) interference on orthogonal frequency division multiplexing (OFDM) receiver of L-band digital aeronautical communications system 1 (L-DACS1) operating as an inlay system, a new DME interference suppression method was proposed based on joint compressed sensing and whitening of residual interference. Firstly, the DME impulse interference was observed via null subcarriers channel of the OFDM receiver and reconstructed with convex optimization constrained ll norm minimization method based on the sparse property of the DME impulse interference in time domain. Then the reconstructed DME impulse interference was transformed to frequency domain and eliminated from the received signal. Finally, to avoid burst errors of demodulator, the residual impulse interference was converted to white Gaussian noise by using the de-interleaver and inverse orthogonal transformer. The computer simulation indicates that the proposed method can reduce the impact of DME interference effectively, and improve the reliability of OFDM receiver of the L-DACS1 system significantly.