系统工程与电子技术 ›› 2018, Vol. 40 ›› Issue (12): 2839-2844.doi: 10.3969/j.issn.1001-506X.2018.12.31

• 通信与网络 • 上一篇    下一篇

基于最大输出信噪比的L-DACS1接收机盲自适应波束形成算法

王磊, 李广雪, 李冬霞, 刘海涛   

  1. 中国民航大学智能信号与图像处理天津市重点实验室, 天津 300300
  • 出版日期:2018-11-30 发布日期:2018-11-30

Blind adaptive beamforming for L-DACS1 receiver based on maximum output signal-to-noise ratio#br#

WANG Lei, LI Guangxue, LI Dongxia, LIU Haitao   

  1. Tianjin Key Laboratory for Advanced Signal Processing, Civil Aviation University of China, Tianjin 300300, China
  • Online:2018-11-30 Published:2018-11-30

摘要:

由于L频段数字航空通信系统1(L-band digital aeronautical communication system1, L-DACS1)和民航测距机(distance measuring equipment,DME)系统的频谱有部分重叠,因此在L-DACS1接收机中需要考虑DME干扰的抑制问题。提出了基于最大输出信噪比的干扰抑制和盲波束形成算法。由于DME脉冲干扰的功率较大,首先采用子空间跟踪算法来得到干扰子空间,然后将接收数据向干扰子空间的正交补空间进行投影以抑制DME干扰。干扰抑制后,接收数据中只剩下正交频分复用(orthogonal frequency division multiplexing, OFDM)信号和噪声了。为了充分利用阵列天线的优势,采用了输出信噪比最大准则来进行波束形成,将天线方向图的主瓣对准OFDM信号来向,以提高接收机输出信号的信噪比。仿真表明,该方法不需要先验信息就能够在抑制干扰的同时进行盲波束形成,在OFDM信号来向上获得高增益的主瓣,进而提高输出信噪比;另外,所提的波束形成方法在输入信噪比较低的环境下依然能够形成稳定的波束,将主瓣对准信号来向。

Abstract:

As a result of the partial spectrum overlap between the L-band digital aeronautical communication system 1 (L-DACS1) and the distance measuring equipment (DME) system, it is necessary to suppress the DME interference in the L-DACS1 receiver. An interference suppression and blind beamforming algorithm based on the maximum output signal-to-noise ratio (SNR) is proposed. Firstly, the interference subspace is obtained using the subspace tracking algorithm, then the received data is projected into its orthogonal complement space to suppress the DME interference. The resulting interferencefree data is then used to form beamforming based on the maximum SNR criterion, with the main lobe pointing to the direction of the orthogonal frequency division multiplexing signal. Simulation results show that the proposed blind beamforming approach results in the preferred gain of the signal and hence, increase the output SNR. In addition, the method of beamforming can play a very good role even in the environment with low input SNR.