In this paper an adaptive narrow-band interference (NBI) suppression scheme based on a code-aided technique in the global navigation satellite system inter-satellite links (ISLs) is proposed. Unlike the commonly used infinte impulse response (IIR) notch filter and frequency domain filtering, the code-aided technique does not require interference detection or fast Fourier transforms, and the adaptive performance is better. We introduce the principle and implementation of code-aided technique, and the concept of interference influence coefficient is proposed to evaluate the influence of residual interference on the carrier-to-noise ratio (CNR) at the receiving end. Through simulation and by combining the tracking CNR after antijamming, the optimal antijamming parameters and scheme are obtained. Meanwhile, we analyze the relationship between the loss of CNR caused by residual interference and the interference influence coefficient. The final results of the bit error rate (BER) and ranging error in ISLs indicate that the adaptive interference suppression scheme based on the code-aided technique can effectively suppress NBI and ensure the reliability of ISL communications. In the case where the pseudo code rate is 10.23 MHz and the BER does not exceed 1 × 10 ^-5 , for the NBI with a bandwidth of 2 MHz, the maximum interference-to-signal ratio (ISR) that can be suppressed by the proposed scheme is 40 dB. For the NBI with a bandwidth of 1 MHz, the maximum ISR that can be suppressed is 55 dB, and for single frequency interference, the maximum ISR that can be suppressed is 75 dB.

中文翻译：

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GNSS卫星间链路中基于代码的自适应窄带干扰抑制与性能评估

提出了一种基于码辅助技术的全球导航卫星系统星际链路（ISL）自适应窄带干扰抑制方案。与通常使用的无限脉冲响应（IIR）陷波滤波器和频域滤波不同，代码辅助技术不需要干扰检测或快速傅立叶变换，自适应性能更好。介绍了码辅助技术的原理和实现，提出了干扰影响系数的概念，以评估残余干扰对接收端载波噪声比（CNR）的影响。通过仿真并结合抗干扰后的跟踪CNR，获得了最佳的抗干扰参数和方案。与此同时，我们分析了残余干扰引起的CNR损失与干扰影响系数之间的关系。ISL中的误码率和测距误差的最终结果表明，基于代码辅助技术的自适应干扰抑制方案可以有效地抑制NBI，并确保ISL通信的可靠性。在伪码率为10.23 MHz且BER不超过1×10的情况下 ^-5 ，对于带宽为2 MHz的NBI，可以通过建议的方案抑制的最大干扰信号比（ISR）为40 dB。对于带宽为1 MHz的NBI，可以抑制的最大ISR为55 dB，对于单频干扰，可以抑制的最大ISR为75 dB。