Discussion on Satellite Communication Jamming Technology

UoG of UESTC 2017 Yixiao Zhong
Introduction
Cruise missile has become an important weapon in warfare. It can smash the enemy’s military and communication targets accurately. In this paper, the satellite communication based on cruise missile and its communication guidance effect on missile are introduced. Finally, several methods of jamming cruise missile are put forward.
Three of the World’s Most Advanced Cruise Missiles. The first,Russian X-101 Cruise Missile, is a new Russian air-based strategic cruise missile. It is manufactured with modern technology that can reduce radar reflection. Its range is over 5500 kilometers. It is twice the range of the “caliber” cruise missile launched by the Russian army at sea. It is said that the accuracy of 10,000 kilometers is less than 10 meters. The missile has a launching weight of 4000 kilograms and a warhead weight of 400 kilograms. It can be loaded with high explosive warheads, ground penetrating explosive warheads or cluster warheads. It can be launched from the lowest 3000 meters and the highest 120,000 meters in the air. The missile uses an image matching system to carry out accurate terminal attack with a hitting accuracy of 5-6 meters. The most important thing is the special stealth technology of X-101 missile, which can reduce its radar cross-section to 0.01 square meters. In addition, it uses the ground-to-ground flight mode and changes the weakness of the cruise missile in using fixed routes. It can change the flight trajectory independently. Such performance will make the anti-missile system of the United States feel huge. Pressure. Second place, China Changjian 10 Cruise Missile. Third place, Tomahawk Cruise Missile

1.Brief Introduction of Satellite Communication System
Satellite communication system is composed of communication satellite, communication earth station, tracking telemetry command subsystem and monitoring management subsystem. The main body of communication satellite is communication device, relay station is completed by transmitter and antenna of communication device. A satellite communication device may include one or more transponders, each of which can receive and transmit signals from multiple earth stations at the same time. Users access satellite lines through earth stations (microwave radio receiving and transmitting stations) to communicate. The tracking telemetry command subsystem tracks and measures the satellite, and regularly controls the satellite’s orbit modification and attitude maintenance. The monitoring and management subsystem is to monitor and control the communication performance of fixed-point satellites before and after service opening, so as to ensure normal communication. The satellite communication channel includes the terminal earth station, the upstream link, the satellite transponder, the downlink and the receiving earth station. Assuming that Earth Station 1 is the origin and Earth Station 2 is the receipt, the channel terminal equipment of Earth Station 1 multiplexes the multi-channel telephone signals into baseband signals and sends them to the modulator for carrier modulation. The up-converter converts them into the up-link carrier signals with carrier frequency of f1, then passes through the microwave high power amplifier, and finally passes through the duplexer from day to day. The line is launched. The up-going carrier signal from Earth Station 1 is transmitted to the satellite transponder over a long distance. The satellite transponder receives the signal using a low noise receiver and converts the microwave signal with carrier frequency f1 into the signal with downlink carrier frequency f2. The signal is amplified to the required level by the output power amplifier of the transmitting device, which is transmitted to the ground via the antenna. Launch. Earth Station 2 receives downlink carrier frequency f2 signal with high gain antenna and low noise receiver, amplifies and converts it into intermediate frequency signal through duplexer, low noise amplifier and down converter, then sends it to demodulator to recover baseband signal, finally divides it by multiplexing device, and passes through ground microwave relay line or other. Type of long-distance lines, etc. transmit baseband signals to the terminals concerned.

2.Communication Function of Cruise Missile in Flight
（1）loopback status
It can be judged whether the missile is flying normally or if something unexpected happens. Preliminary estimates of the amount of data required for the return of status messages are about 200 bits per message. Frequency division and time division are usually used to share communication links in order to achieve simultaneous transmission of multiple missile messages.
(2) Retargeting in flight
As mentioned above, by communicating the data obtained, the commander can control the missile status and change the missile attack target according to the missile status information. In the case of multi-missile attack, the commander can modify the target of the succeeding missile according to the attack effect of the front missile, so as to improve the overall effect of multi-missile. Retargeting the target requires missile identifiers and tasks to be performed, and the amount of data is within 200 bits. Of course, the problem of simultaneous transmission of multiple missile data should also be considered.
(3) End-segment Sensor Image Retrieval
If the missile is equipped with an imaging terminal self-sensor, the missile can send the image to the commander. These images can be used to evaluate the killing effect of the missile, or to evaluate the killing effect of the front missile, or to make the rear missile attack the newly discovered target. The amount of data to be transmitted per frame is 432 Kbits, which can be reduced by using compression technology. But each missile needs one or more images, and at the same time there are many missiles flying, so the data volume is large.
(4) Quasi-Real-Time Manned Terminal Guidance
When the missile is equipped with an image terminal sensor and has a broadband data link, the missile can quickly transmit the image to the commander and enable it to follow the missile on time. Commanders can also transmit information to missiles and direct them to selected targets. This can achieve high-precision strike. Therefore, destroying its communication, in a sense, destroys the precise strike, which will make cruise missiles “blind” and can not find targets, thus greatly reducing the strike effect.
3.Jamming Satellite Communication of Cruise Missile in Flight
Satellite communication jamming is an attack means in satellite communication countermeasure. It uses satellite communication jamming equipment placed on the ground or in the air to launch special jamming signal to destroy or disturb the enemy according to the information obtained by satellite communication reconnaissance equipment about the enemy satellite communication system automatically or manually by selecting the best jamming countermeasures. Military satellite communication system makes it unable to work properly. According to the composition and working process of military satellite communication system, the operational objects of military satellite communication countermeasure system as a means of “soft killing” can be remote control and Telemetry Command subsystem, upstream line, downlink line, satellite transponder and ground satellite communication equipment or network.
(1)Interference repeater
Processing transponder has signal processing function besides signal forwarding. After receiving the signal from the ground, the signal is demodulated, processed and then returned to the ground by modulation, frequency conversion and power amplification. For orthogonal frequency hopping (FH) processing transponder, only multiple carrier interference is needed to saturate the transponder and produce combined interference to destroy the normal operation of FH demodulation channel.
(2)Interference uplink
Because of the characteristics of satellite communication, electronic attack on the upstream line of enemy satellite communication system becomes the focus of interference, which can affect many communication links at the same time. When jamming the upstream line, the jammer first intercepts its communication signal, and then jams the satellite receiver to destroy the whole communication process. The transmitting end of the upstream signal is the earth station, and the receiving end is the satellite. The main lobe of the transmitting antenna beam points to the satellite. The ground reconnaissance station can only detect its side lobe signal. In addition, it is difficult to directly detect the upstream signal of the satellite communication on the ground due to the transmission loss and the sensitivity of the reconnaissance receiver. In fact, frequency guidance technology is used to detect the downlink signal frequency to determine the upstream signal frequency. In addition, unmanned aerial vehicle and satellite reconnaissance station can also be used to detect the upstream signal of satellite.
(3)Interference downlink
To interfere with the downlink communication line is to reconnoiter the signal transmitted by satellite to the ground terminal and to interfere with the ground receiving terminal so as to destroy its communication. For reconnaissance of downlink signals of enemy satellites, it is advisable to use lift-off platforms, such as unmanned aerial vehicles, to enter the area covered by the main lobe width of launch antenna of enemy satellites. When the sensitivity of receiving equipment on the aircraft is close to that of ground terminal equipment of enemy satellites, the downlink signals of the enemy can be effectively reconnaissance. When the reconnaissance antenna can not target the main lobe of the enemy satellite, it becomes extremely difficult to reconnaissance because the side lobe level is much lower than the main lobe level. The air platform jamming station should also be used to jam satellite downlink signals. At this time, the jamming station is close to the enemy ground terminal and has wide coverage. The jamming signal can be directed at the enemy satellite ground station to receive the main lobe of the antenna. When the jamming power is large enough, the ground terminal amplifier of the enemy satellite can be saturated, so that the system can not work properly and good jamming effect can be achieved. Because of long-distance loss and obstacles, even if the ground jamming station is made into a high-power and high-gain antenna, it can not guarantee good jamming effect.

summary
Cruise missile-based mid-range and long-range precision strike has become an important form of high-tech war in the future. Destroying its precise guidance will affect the process of war. Military communication satellites can provide guidance information for cruise missiles. Therefore, it is of great practical significance to study and destroy the precise guidance of medium and long range missiles, which is the guidance of military communication satellites.

Reference Documentation
1.https://baijiahao.baidu.com/s?id=1583422438946970985&wfr=spider&for=pc
2.Zhao Zhuyan, Zhou Tianyu, Geng Hongjian. Reflections on the Development of Missile and Precision Guidance Technology [J]. Digital Communication World, 2016 (10).
3.https://baike.baidu.com/item/卫星通信系统/3114637?fr=aladdin
4.Lu Jiuming, Luo Jingqing. Research on Satellite Communication Jamming Technology Based on Cruise Missile [J]. Modern Defense Technology, 2004, 32 (6): 43-47.
5.Xing Lixin, Gao Shanqing, Wu Xinming. Analysis of firing characteristics of radio communication jamming projectiles [J]. Journal of Missiles and Guidance, 2007, 27 (4): 157-159.
6.Yu Rusheng. Research on Communication Signal Processing Based on Guidance Radar [D]. Nanjing University of Technology, 2012.