CN115173931A - Satellite-based VHF system and communication method thereof - Google Patents

Abstract

The invention provides a satellite-based VHF system and a communication method thereof, wherein the satellite-based VHF transceiver is loaded with responsibility to receive and forward VHF signals sent by an airplane; the low-orbit satellite constellation is responsible for realizing the global coverage of communication, and ensures that the airplane can receive signals wherever the airplane sends; the satellite space networking subsystem is responsible for forwarding the received signals to the nearest ground tower; the airborne VHF communication equipment is responsible for sending VHF signals and receiving the forwarded ground tower signals; the ground air traffic control comprehensive application subsystem is responsible for monitoring the state of the airplane, providing a solution when the airplane encounters a problem in flying and searching a nearest forced landing place for the airplane which cannot continuously fly. The method and the device ensure that the airplane can still get in touch with the ground tower in the communication blind area of high-frequency communication, have low communication cost, are not influenced by the burden of an ionosphere and atmospheric interference, and have reliable communication.

Description

Satellite-based VHF system and its communication method

technical field

The invention provides a satellite-based VHF system and a communication method thereof, belonging to the technical field of communication.

Background technique

In recent years, one of the main reasons for civil aviation flight accidents is the poor communication between the aircraft and the ground tower. The communication systems mainly equipped with civil aviation aircraft include high-frequency communication system, VHF communication system, selective calling system, and audio system. The high-frequency communication system is mainly used to communicate with the ground tower. This system uses the characteristics of high-frequency signal reflection in the ionosphere to carry out long-distance communication, but this kind of communication is not reliable. The ground towers on the route are insufficiently constructed, and the aircraft will lose contact with the ground towers when they enter these areas.

Some civil aviation aircraft are also equipped with maritime satellite communication systems, but maritime satellites provide services for users in various industries of sea, land and air. Aviation communication is not a high priority, and the frequency band occupies less resources. At the same time, the L-band communication used by maritime satellites is expensive and maritime. Satellites are greatly affected by ionospheric fluctuations and atmospheric interference, and the communication quality and reliability are not high, so it is still unable to effectively solve the problem of effective communication between civil aviation aircraft and the ground in emergency situations in the communication blind area of the ground tower.

SUMMARY OF THE INVENTION

The present invention provides a satellite-based VHF system and a communication method thereof, which (1) solve the problem of communication between an aircraft and a ground tower in a high-frequency communication blind area; (2) solve the problem of high cost of maritime satellite communication, and low communication quality and reliability question.

The specific technical solutions are:

Satellite-based VHF system, including satellite-based VHF transceiver payload, low-orbit satellite constellation, airborne VHF communication equipment and ground air traffic control integrated application subsystem;

in:

The satellite-based VHF transceiver payload is responsible for receiving and forwarding the VHF signals sent by the aircraft;

The low-orbit satellite constellation conducts satellite constellation networking through inter-satellite links. The low-orbit satellite constellation includes the inter-satellite link subsystem, which is responsible for achieving global communication coverage and ensuring that no matter where the aircraft sends signals, it can be received by satellites. Relay the received VHF communication signals from the aircraft to the nearest ground tower through a low-orbit satellite constellation;

Airborne VHF communication equipment is responsible for sending VHF signals and receiving and retransmitting ground tower signals;

The ground air traffic control integrated application subsystem is responsible for monitoring the status of the aircraft, proposing solutions when the aircraft encounters problems in flight, and finding the nearest forced landing site for the aircraft that cannot continue to fly.

Among them, each satellite in the low-orbit satellite constellation includes an antenna connected in sequence, a received signal Doppler frequency shift compensation module, an inter-satellite link communication module, a transmitted signal Doppler frequency shift compensation module, and control frequency adaptive switching. module;

The satellites in the low-orbit satellite constellation communicate with the inter-satellite network signal relay satellite through the inter-satellite link communication module.

The communication method of the above-mentioned satellite-based VHF system is that the satellite antenna in the low-orbit satellite constellation receives the data sent by the aircraft, and processes it through front-end reception, multi-channel voice communication strategy, Doppler frequency compensation, and communication frequency band adaptive switching strategy. , through signal transmission, it is forwarded to the nearest satellite above the domestic satellite ground control center through the inter-satellite network routing link, and then the satellite is downloaded to the ground station through the satellite-ground link; at the same time, the ground station also transmits the information through the uplink. It is transmitted to the satellite, and finally sent to the aircraft via the inter-satellite link and the star link.

in:

The strategy of multi-channel voice communication includes determining the sequence of satellite retransmission signals by comprehensively considering the sequence of sending signals and the type of signals.

Doppler frequency compensation, including performing fast Fourier transform on the received signal, comparing the calculation result with the spectrum of the signal without frequency offset, calculating the amount of spectrum shift, calculating the phase of the FFT spectrum peak, and generating the peak phase of the initial phase, A sine wave of frequency and spectral shift is compensated.

The communication frequency band adaptive switching strategy includes calculating the corresponding sub-satellite point coordinates according to its own orbital coordinates, and using a specific aviation VHF communication frequency band to receive and send information within the flight control area of the sub-satellite point coordinates.

The satellite-based VHF communication system of the present invention is based on satellite communication, which ensures that the aircraft can still get in touch with the ground tower in the communication blind area of high-frequency communication. Compared with the L-band, the VHF frequency band has lower communication costs, and is not affected by ionospheric bullying and atmospheric interference, and the communication is reliable. Civil aircraft are all equipped with VHF antennas, so the invention does not require additional design modifications to the surface of the aircraft, saving costs.

Description of drawings

FIG. 1 is a schematic flow chart of the present invention.

Detailed ways

The specific embodiments of the present invention will be described below with reference to the accompanying drawings. The described examples are only a part of the present invention. Based on the embodiments of the present invention, those of ordinary skill in the art can obtain all the Other embodiments fall within the protection scope of the present invention.

As shown in Figure 1, the present invention is a civil aviation communication system when the aircraft is blocked in ground-based VHF communication. The satellite-based VHF system is mainly composed of satellite-based VHF transceiver loads, low-orbit satellite constellations, airborne VHF communication equipment and The ground air traffic control integrated application subsystem consists of five major parts;

Among them, the satellite-based VHF transceiver load is responsible for receiving and forwarding the VHF signals sent by the aircraft, the low-orbit satellite constellation is responsible for achieving global communication coverage, ensuring that the aircraft can receive signals no matter where they are sent, and the satellite space networking subsystem is responsible for receiving The received signal is forwarded to the nearest ground tower. The airborne VHF communication equipment is responsible for sending the VHF signal and receiving the forwarded ground tower signal. The ground air traffic control integrated application subsystem is mainly responsible for monitoring the status of the aircraft, and proposes solutions when the aircraft encounters problems. Find the nearest forced landing site for an aircraft that cannot continue to fly, etc.

Among them, each satellite in the low-orbit satellite constellation includes an antenna connected in sequence, a received signal Doppler frequency shift compensation module, an inter-satellite link communication module, a transmitted signal Doppler frequency shift compensation module, and control frequency adaptive switching. module;

The satellites in the low-orbit satellite constellation communicate with the inter-satellite network signal relay satellite through the inter-satellite link communication module.

The satellite antenna in the low-orbit satellite constellation receives the data sent by the aircraft, and after the front-end reception, multi-channel voice communication strategy, Doppler frequency compensation, and adaptive switching strategy of the communication frequency band, through signal transmission, through the inter-satellite networking The routing link is forwarded to the nearest satellite above the domestic satellite ground control center, and then the satellite is downloaded to the ground station through the satellite-ground link; at the same time, the ground station also transmits the information to the satellite through the uplink, and via the inter-satellite link The link with Starlink is eventually sent to the aircraft.

The multi-channel voice communication strategy includes determining the sequence of satellite transponder signals through comprehensive consideration of the sequence of sending signals and signal types (such as VHF1 and VHF3).

Doppler frequency compensation, including performing fast Fourier transform on the received signal, comparing the calculation result with the spectrum of the signal without frequency offset, calculating the amount of spectrum shift, calculating the phase of the FFT spectrum peak, and generating the peak phase of the initial phase, A sine wave of frequency and spectral shift is compensated.

The communication frequency band adaptive switching strategy includes calculating the corresponding sub-satellite point coordinates according to its own orbital coordinates, and using a specific aviation VHF communication frequency band to receive and send information within the flight control area of the sub-satellite point coordinates.

Claims (6)

1. The system is characterized by comprising a satellite-based VHF transceiver load, a low-orbit satellite constellation, airborne VHF communication equipment and a ground air traffic control comprehensive application subsystem;

wherein:

the satellite-based VHF transceiver carries a load responsible receiving and forwarding plane-sent VHF signals;

the low-orbit satellite constellation carries out satellite constellation networking through an inter-satellite link, comprises an inter-satellite link subsystem and is responsible for realizing global communication coverage, ensuring that the airplane can be received by a satellite no matter where the airplane sends out signals, and transmitting the received VHF communication signals sent out by the airplane to a nearest ground tower station through the low-orbit satellite constellation;

the airborne VHF communication equipment is responsible for sending VHF signals and receiving the forwarded ground tower signals;

the ground air traffic control comprehensive application subsystem is responsible for monitoring the state of the airplane, providing a solution when the airplane encounters a problem in flying and searching a nearest forced landing place for the airplane which cannot continuously fly.

2. The satellite-based VHF system according to claim 1, wherein each satellite in the low earth orbit satellite constellation comprises an antenna, a received signal Doppler shift compensation module, an inter-satellite link communication module, a transmitted signal Doppler shift compensation module, and a regulated frequency adaptive switching module which are connected in sequence;

and the satellites in the low-orbit satellite constellation are in communication connection with the inter-satellite networking circuit signal transfer satellite through the inter-satellite link communication module.

3. The communication method of a satellite-based VHF system according to claim 1 or 2, characterized in that it comprises the following steps:

the method comprises the following steps that a satellite antenna in a low earth orbit satellite constellation receives data sent by an airplane, the data are processed by a front-end receiving strategy, a multi-path voice communication strategy, doppler frequency compensation and a communication frequency band self-adaptive switching strategy, then the data are transmitted to a satellite which is closest to the upper part of a domestic satellite ground control center through a satellite-to-ground network routing link through signal transmission, and then the satellite is downloaded to a ground station through a satellite-to-ground link; meanwhile, the ground station transmits information to the satellite through an uplink and finally sends the information to the airplane through an inter-satellite link and a starry-sky link.

4. The communication method of the satellite-based VHF system according to claim 3, wherein the multi-path voice communication strategy comprises determining the sequence of the satellite retransmission signals by comprehensively considering the sequence of the transmission signals and the type of the signals.

5. The communication method of the satellite-based VHF system according to claim 3, wherein the Doppler frequency compensation comprises fast Fourier transform of the received signal, comparison of the calculation result with the signal spectrum without frequency shift, calculation of the amount of frequency shift, calculation of the phase of the peak of the FFT spectrum, generation of the peak phase of the initial phase, and compensation of the sine wave of the frequency and the amount of frequency shift.

6. The communication method of the satellite-based VHF system according to claim 3, wherein the adaptive switching strategy of the communication frequency band comprises calculating corresponding coordinates of a sub-satellite point according to self orbital coordinates, and receiving and transmitting information by adopting a specific aviation VHF communication frequency band in a flight control area of the sub-satellite point coordinates.

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