一种基于低轨道卫星的Link22应用方案

    A Link22 application scheme based on low orbit satellites

    • 摘要: 为了解决现有Link22数据链信息传输受视距限制的问题,文章提出了一种在低轨卫星上直接搭载Link22节点来实现海域战术信息超视距传输的应用方案,该方案拓展了Link22系统的传播距离,提高了战术信息传输效率,扩大了海域舰艇编队的态势感知范围。针对该应用方案中LEO卫星的高速运动使得星载Link22节点的接收信号存在较大的多普勒频偏,以及星舰链路的更远传播距离使得传播时延比Link22海面节点时延更大的问题,文章分析了多普勒频偏和长时延对星舰链路的影响,提出了在LEO卫星上进行多普勒频偏预补偿和时隙校正的方案。星舰链路模拟实验结果表明,采用该方案进行时频同步后的QPSK误码率测试值与理论值接近,误码率为10−6时信噪比差距在0.5 dB以内,初步证明多普勒频偏预补偿和时隙校正的方案是正确的,从而表明提出的基于低轨道卫星的Link22应用方案是初步可行的。

       

      Abstract: Aiming at the problem that the existing Link22 data link information transmission is constrained by the visual distance, this article proposes an application scheme for deploying Link22 node on low orbit satellites to achieve over the horizon transmission of tactical information in the sea area. The scheme extends the transmission distance of Link22, improves the efficiency of tactical information transmission, and enhances the situational awareness range of surface warships. Aiming at the problem of the application scheme the that the high-speed movement of LEO satellites results in a significant Doppler frequency shift in the received signal of the space borne Link22 node, and the longer propagation distance of satellite-ship links results in the propagation delay greater than that of Link22 sea surface nodes, this article analyzes the impact of Doppler frequency shift and long delay on satellite-ship links, and proposes Doppler frequency shift pre-compensation and time slot correction schemes. The experimental results of star-ship link show that the OPSK bit error rate test value after time-frequency synchronization using this scheme is close to the theoretical value, and when the bit error rate is 10−6, the signal-to-noise ratio difference is within 0.5 dB, preliminarily proving that the proposed Doppler frequency shift pre-compensation and time slot correction schemes are correct and demonstrating that the proposed Link22 application scheme based on low orbit satellites is preliminarily feasible.