中国空间科学技术

中国空间科学技术 ›› 2017, Vol. 37 ›› Issue (6): 17-.doi: 10.16708/j.cnki.1000-758X.2017.0089

• 研究探讨 • 上一篇    下一篇

无源互调对直扩系统伪码捕获性能的影响

 孙灿灿, 田露, 王漪   

  1. 1.北京理工大学 信息与电子学院，北京100081
    2.中国电子科技集团公司 电子科学研究院，北京100041
  • 收稿日期:2017-06-23 修回日期:2017-11-03 出版日期:2017-12-25 发布日期:2017-11-20

Effect of passive intermodulation on peudonoise code acquisition performance in direct sequence spread spectrum systems

 SUN  Can-Can, TIAN  Lu, WANG  Yi   

  1. 1.School of information Science and Electronics，Beijing Institute of Technology University，Beijing 100081，China
    2.China Academy of Electronics and Information Technology，Beijing 100041，China
  • Received:2017-06-23 Revised:2017-11-03 Published:2017-12-25 Online:2017-11-20

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摘要： 无源互调干扰信号会对无线通信系统造成不同程度的影响，轻则干扰无线通信系统，严重时阻塞无线通信系统信号传输通道。为了定量分析无源互调干扰信号对直扩系统伪码捕获性能的影响，建立了无源互调干扰下直扩系统模型，考虑卫星接收机中噪声的影响，采用修正柯西分布概率密度模型，分别对平方律检波器捕获方法和平方检波累积器捕获方法在无源互调干扰下的捕获性能进行了理论推导和仿真验证。仿真结果表明，高信干噪比下无源互调干扰对通信系统的影响比噪声小，90%捕获检测概率下相差2.92dB；采用平方检波累积方法可获得一定的累积增益，90%捕获检测概率下的累积增益为2.36dB。

关键词: 无源互调, 直扩系统, 伪码捕获, 修正柯西分布, 捕获检测概率

Abstract: The satellite communication systems can be jammed by passive intermodulation (PIM) interference signals，and the transmission channel may be blocked at worst. In order to analyze the performance of peudonoise (PN) code acquisition with the passive intermodulation interference quantitatively，the model of direct sequence spread spectrum (DSSS) systems with interference was established. The common methods of PN code acquisition were square law detection and square accumulation detection. The modified Cauchy distribution model was proposed to describe the statistical property of PIM. In consideration of PIM and the receiver noise，the acquisition performances of both detection methods were derived and simulated. The simulation results show that in the case of high signal to interference plus noise ratio(SINR)，the noise has a worse effect on PN acquisition performance than PIM. When the detection probability is 90%，the difference is 2.92dB. The performance of detection method with accumulation is better than that without accumulation，and achieves an accumulation gain. When the detection probability is 90%，the accumulation gain is 2.36dB.

Key words: passive intermodulation, direct sequence spread spectrum system, peudonoise code acquisition, modified Cauchy distribution, acquisition detection probability