A Random Access Method Oriented to LEO Satellite Communication System

Abstract

The invention provides a random access method for a low-orbit satellite communication system, and belongs to the technical field of satellite communication. According to the random access method provided by the invention, the working state information of an on-board demodulator is mainly used for assisting a user terminal to perform link state sensing, and meanwhile a probability parameter P is dynamically broadcasted according to the satellite position to improve the system throughput of an access link. When the on-board demodulator performs uplink signal demodulation, a channel busy state isindicated according to the actual state of the demodulator and is broadcasted to a ground terminal through a downlink together with a terminal identification data block. The channel busy state sharesa 2-bit identifier. In addition, by using the global terminal location management feature of a constellation system service operation center, terminal number parameter data within the dynamic satellite beam coverage are formed and are broadcasted to the user terminal in real time through the satellite for dynamically changing the data sending probability parameter P of the terminal, and the throughput of random access of the user link is optimized from the system level.

Description

technical field

[0001] The invention relates to a random access method for a low-orbit satellite communication system, belonging to the technical field of satellite communication. Background technique

[0002] The multiple access method is the main composition method of the entire low-orbit communication satellite communication system, which is related to the access efficiency of the entire communication system. The multiple access methods commonly used in low-orbit satellite communication systems in the world are divided into service access multiple access methods and signaling access multiple access methods. The business access multiple access methods usually use TDMA, CDMA, and FDMA. Access generally adopts the ALOHA mode of random competition.

[0003] Typical links of low-orbit satellites for data collection and short message exchange are as follows: figure 1 As shown, on-board processing methods are generally used, such as Orbcomm, Argos abroad, and the Hongyan const...

Examples

Embodiment Construction

[0033] According to the characteristics of the two-way link of the low-orbit satellite communication, the present invention utilizes the working state information of the on-board demodulator to assist the user terminal to perceive the link state, forms a SAT-CSMA random access system suitable for satellite applications, and broadcasts the information dynamically according to the satellite position The probability parameter P thus increases the system throughput of the entire link.

[0034] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0035] Such as figure 1 As shown in , the simplified composition diagram of a typical low-orbit satellite communication system is as follows:

[0036]A typical low-orbit satellite communication system mainly includes satellite processing loads and multiple ground terminals, and the satellites and the ground are interconnected through satellite communication links...

technical field

[0001] The invention relates to a random access method for a low-orbit satellite communication system, belonging to the technical field of satellite communication. Background technique

[0002] The multiple access method is the main composition method of the entire low-orbit communication satellite communication system, which is related to the access efficiency of the entire communication system. The multiple access methods commonly used in low-orbit satellite communication systems in the world are divided into service access multiple access methods and signaling access multiple access methods. The business access multiple access methods usually use TDMA, CDMA, and FDMA. Access generally adopts the ALOHA mode of random competition.

[0003] Typical links of low-orbit satellites for data collection and short message exchange are as follows: figure 1 As shown, on-board processing methods are generally used, such as Orbcomm, Argos abroad, and the Hongyan const...

Examples

Embodiment Construction

[0033] According to the characteristics of the two-way link of the low-orbit satellite communication, the present invention utilizes the working state information of the on-board demodulator to assist the user terminal to perceive the link state, forms a SAT-CSMA random access system suitable for satellite applications, and broadcasts the information dynamically according to the satellite position The probability parameter P thus increases the system throughput of the entire link.

[0034] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0035] Such as figure 1 As shown in , the simplified composition diagram of a typical low-orbit satellite communication system is as follows:

[0036]A typical low-orbit satellite communication system mainly includes satellite processing loads and multiple ground terminals, and the satellites and the ground are interconnected through satellite communication links...

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