可重复使用运载火箭再入段星箭协同可靠通信技术

Reliable communication technologies of reusable launch vehicles in cooperation with satellite during re-entry

可重复使用运载火箭是未来低成本火箭应用技术的必然发展趋势。其是一种典型的跨域可重复飞行器,在火箭以极高的速度再入大气过程中,包覆在箭体表面的等离子体鞘套会引起通信中断问题。这一问题困扰了航空航天领域几十年,至今尚未完全解决。可靠通信链路的建立和保持是实现可回收火箭再入过程中全时可测、全程可控的重要基础。近年来快速发展的低轨卫星系统为再入段测控链路设计提供了新思路,箭体背风面等离子体鞘套电子密度较低,有利于电磁波穿透鞘套与卫星建立链路,以解决再入段的“黑障”通信难题。然而,再入段星箭综合通信信道状况复杂,多种影响因素深度耦合。分别从综合信道模型与适应性通信方法这2个角度进行了阐述。首先,分析再入段星箭链路综合信道中影响通信信号的主要因素,建立不同尺度下的信道模型。然后,根据信道特点,从信道感知、编码、检测、调制体制等角度设计适应性通信方法。最后,在地面实验中复现了再入段通信场景并对所提出的通信方案进行了验证。实验结果表明,所提出的通信方案可大幅提高通信的可靠性,为运载火箭可重复使用提供了通信保障。

Reusable rockets have become an inevitable development trend of low-cost rocket application technology in the future.They are typical cross-domain reusable vehicles.When the rocket re-enters the atmosphere at a very high speed,the plasma sheath covering the surface of the rocket will cause the problem of communication interruption.This problem has plagued the aerospace field for decades and has not yet been fully resolved.The establishment and maintenance of a reliable communication link is an important basis for realizing full-time measurability and full-process controllability during the re-entry process of a reusable rocket.The development of the low-orbit satellite system in recent years provides a new idea for the design of the re-entry measurement and control link.The electron density of the plasma sheath on the leeward side of the rocket is low,so that the electromagnetic wave can penetrate the sheath to establish a link between the rocket and satellites,thus solving the black-out problem.However,in the re-entry phase,the composite satellite-rocket communication channel is complex,and various influencing factors are deeply coupled.The composite channel model and adaptive communication methods are elaborated separately.Firstly,the main influencing factors on the communication signal in the composite channel of the re-entry satellite-rocket link are analyzed,and the channel models at different scales are established.Then,according to the characteristics of the channel,an adaptive communication method is designed from the perspectives of channel sensing,coding,detection and modulation system.Finally,the re-entry communication scenario is reproduced in the ground experiment to verify the proposed communication methods.The experimental results show that the proposed communication methods can greatly improve the reliability of communication and provide guarantee for communication of rocket reuse.