CN108023600B - Airborne collision avoidance system receiving channel fusion system based on time division multiplexing - Google Patents

Abstract

The invention discloses a time division multiplexing-based airborne collision avoidance system receiving channel fusion system, which comprises a receiving signal selection switch network, a four-channel 1030MHz/1090MHz multi-mode receiver and a receiving channel real-time dynamic allocation strategy module, wherein the receiving channel real-time dynamic allocation strategy module controls the receiving signal selection switch network to receive 4-channel 1090MHz or 2-channel 1090MHz and 2-channel 1030MHz radio frequency signals; and controlling the four-channel 1030MHz/1090MHz multi-mode receiver to complete the frequency conversion processing of 4 paths of 1090MHz or 2 paths of 1090MHz and 2 paths of 1030MHz radio frequency signals. The invention can realize the real-time receiving and processing of 8 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals received by the antenna port only by four receiving channels, and supports the miniaturization of the airborne collision avoidance system.

Description

Airborne collision avoidance system receiving channel fusion system based on time division multiplexing

Technical Field

The invention belongs to the technical field of airborne collision avoidance, and particularly relates to a time division multiplexing-based airborne collision avoidance system receiving channel fusion system.

Background

At present, the air collision prevention of an airplane is to master flight dynamics through ground air traffic control monitoring equipment, allocate flight conflicts by an air traffic control system, and to avoid the air collision, an airborne collision avoidance system (TCAS) is generally installed in some airplanes. The system can establish an air-space monitoring tracking link between the aircraft and a cooperative aircraft in the operating airspace of the aircraft through a Mode A/C/S (analog/digital/analog) and other air management data chains, calculate the relative position between the aircraft and other aircraft in real time, evaluate the collision risk, and provide an avoidance maneuver suggestion cooperating with the other party in a scene where collision is likely to occur. Meanwhile, through a Mode A/C/S and other air traffic control data chain, the product can also establish a ground-air monitoring tracking link between the air-borne machine and the ground, and the real-time supervision requirement of an air traffic control unit on the air-borne machine is met.

In order to realize the functions, the TCAS system needs to have the capability of receiving and processing the empty pipe inquiry signal and the empty pipe response signal at the same time. The receiving processing of the air traffic control response signal refers to the simultaneous switch selection, filtering, down-conversion, logarithmic amplification and other processing of the eight paths of 1090MHz radio frequency signals of the other airspace machine received by the L-band four-unit directional upper antenna and the L-band four-unit directional lower antenna, four paths of amplitude information of the other airspace machine air traffic control response signal and four paths of phase information which are coherent are provided for the rear-end digital processing module, and the rear-end digital processing module is supported to carry out the digital processing processes of demodulation, decoding, ranging, phase discrimination and the like of the other airspace machine air traffic control response signal; the receiving processing of the air traffic control inquiry signal refers to the processing of simultaneously carrying out filtering, down-conversion, logarithmic amplification and the like on two paths of other space domain machine 1030MHz radio frequency signals received by an L-band omnidirectional upper antenna and an L-band omnidirectional lower antenna, providing two paths of amplitude information and two paths of phase information of other space domain machine air traffic control inquiry signals for a rear-end digital processing module, and supporting the digital processing processes of demodulating, decoding and the like on other space domain machine air traffic control inquiry signals.

Disclosure of Invention

The invention aims to provide a time division multiplexing-based airborne collision avoidance system receiving channel fusion system, which utilizes a controlled channel selection switch to be matched with a broadband filter and a controlled variable local oscillator structure, controls the radio frequency signal source accessed by each receiving channel and the receiving processing frequency band of each receiving channel in real time through a channel selection switch switching signal and a local oscillator switching signal which are fed back by a digital terminal based on the receiving processing of response information and inquiry information of an air traffic control, and realizes the real-time receiving processing of 8 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals received by an antenna port only by four receiving channels, thereby realizing the hardware fusion of an airborne collision avoidance system responder and a receiving and transmitting host and supporting the miniaturization of an airborne collision avoidance system.

The invention aims to be realized by the following technical scheme:

a time division multiplexing-based airborne collision avoidance system receiving channel fusion system comprises a receiving signal selection switch network, a four-channel 1030MHz/1090MHz multi-mode receiver and a receiving channel real-time dynamic allocation strategy module;

the receiving channel real-time dynamic allocation strategy module outputs a switch switching signal to the receiving signal selection switch network to control the receiving signal selection switch network to select 4 paths of 1090MHz air traffic control response signals or 2 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals from 10 paths of radio frequency signals output by an L-band four-unit directional antenna, an L-band omnidirectional upward antenna and an L-band all-downward antenna and input the signals into a four-channel 1030MHz/1090MHz multi-mode receiver; and outputting local frequency control signals to the four-channel 1030MHz/1090MHz multi-mode receiver to control the four-channel 1030MHz/1090MHz multi-mode receiver to complete the frequency conversion processing of 4 paths of 1090MHz air traffic control response signals or 2 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals.

Preferably, the received signal selection switch network comprises two first radio frequency switches, two second radio frequency switches and two third radio frequency switches;

the input ends of the two first radio frequency switches are respectively connected with 1L-band four-unit directional upper antenna and 1L-band four-unit directional lower antenna, and the output ends of the two first radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver;

the input ends of the two second radio frequency switches are respectively connected with 1L-band four-unit directional upper antenna and 1L-band four-unit directional lower antenna, and the output ends of the two second radio frequency switches are connected with the input end of the third radio frequency switch;

the input end of one of the third radio frequency switches is also connected with an L-band all-upward antenna, the input end of the other third radio frequency switch is also connected with an L-band all-downward antenna, and the output ends of the two third radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver;

the switch switching signals comprise 1090MHz upper and lower antenna selection switch signals and 1090MHz/1030MHz receiving switching switch signals;

1090MHz upper and lower antenna selection switch signals control the first radio frequency switch and the second radio frequency switch to selectively receive 1090MHz air traffic control response signals output by the L-band four-unit directional upper antenna or 1090MHz air traffic control response signals output by the L-band four-unit directional lower antenna;

and the 1090MHz/1030MHz receiving changeover switch signal controls the third radio frequency switch to selectively receive the output of the second radio frequency switch or the 1030MHz empty pipe inquiry signal output by the L-band omnidirectional antenna.

Preferably, the four-channel 1030MHz/1090MHz multi-mode receiver comprises two 1090MHz fixed receiving branches, two paths of 1030MHz/1090MHz dynamic receiving branches, a first frequency source and a second frequency source;

the 1090MHz fixed receiving branch and the 1030MHz/1090MHz dynamic receiving branch respectively comprise an L-band broadband filter, an L-band low-noise amplifier, an L-band mixer, an intermediate frequency filter and an intermediate frequency logarithmic amplifier which are connected in sequence;

the first frequency source comprises a first phase-locked loop and a one-to-two power divider, and the first phase-locked loop outputs fixed frequency signals to the L-band frequency mixers in the two 1090MHz fixed receiving branches through the one-to-two power divider according to the control of the local frequency control signal;

and the second frequency source comprises a second phase-locked loop and a one-to-two power divider, and the second phase-locked loop outputs signals which are the same as the frequency points of the first phase-locked loop or outputs signals which have a difference of 60MHz with the frequency points of the first phase-locked loop to the L-band mixers in the two 1030MHz/1090MHz dynamic receiving branches through the one-to-two power divider according to the control of the local oscillation frequency control signal.

Preferably, the control process of the switch switching signal and the local oscillator frequency control signal is as follows:

step 1: two paths of 1030MHz air pipe inquiry signals and two paths of 1090MHz air pipe response signals are provided for the four-channel 1030MHz/1090MHz multi-mode receiver through switch switching signals, two paths of 1090MHz fixed receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver are controlled to receive and process 1090MHz air pipe response signals through local frequency control signals, and two paths of 1030MHz/1090MHz dynamic receiving branches receive and process the 1030MHz air pipe inquiry signals.

Step 2: waiting for a lead code locking signal in the 1090MHz air traffic control response signal processing process, when receiving the lead code locking signal, indicating that a 1090MHz air traffic control response signal is received, at the moment, providing four paths of 1090MHz air traffic control response signals for the four-channel 1030MHz/1090MHz multi-mode receiver through a switch switching signal, and controlling all receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver to receive and process the 1090MHz air traffic control response signals through a local frequency control signal;

and step 3: and waiting for a direction finding end signal in the 1090MHz air traffic control response signal processing process, when receiving the end signal, indicating that the four-unit direction finding of the received 1090MHz air traffic control response signal is finished, and at the moment, returning the switch switching signal and the local oscillation frequency control signal to the state of the step 1.

Has the advantages that:

the receiving processing of 1090MHz air traffic control response signals and the receiving processing of 1030MHz air traffic control inquiry signals can be realized by adding a controlled variable local oscillator through a broadband filter under the condition that the layout of a single-path receiving channel is not changed; through time division multiplexing, the number of receiving channels is reduced from 10 channels to 4 channels, so that the hardware volume is reduced, the power consumption is reduced, and the cost is reduced; by real-time dynamic allocation of the 4-path receiving channels, under the condition that the number of the receiving channels is reduced, the requirements of performance requirements such as monitoring distance, monitoring capacity and direction finding precision on the number and the occupied time of 1090MHz receiving channels and the requirements of performance requirements such as response rate on the occupied time of 1030MHz receiving channels can be simultaneously met.

Drawings

FIG. 1 is a block diagram of an airborne collision avoidance system receiving channel fusion system based on time division multiplexing;

FIG. 2 is a block diagram schematic of a receive signal selection switch network;

FIG. 3 is a block diagram schematic diagram of a four channel 1030MHz/1090MHz multimode receiver.

Detailed Description

For a better understanding of the invention, reference is made to the following detailed description of the invention, which is to be read in connection with the accompanying drawings and examples.

As shown in FIG. 1, the time division multiplexing-based airborne collision avoidance system receiving channel fusion system is composed of a receiving signal selection switch network, a four-channel 1030MHz/1090MHz multi-mode receiver and a receiving channel real-time dynamic allocation strategy. The receiving channel real-time dynamic allocation strategy can be fused with the digital signal processing process of the rear-end air traffic control response information and the air traffic control inquiry information and is realized in the FPGA of the digital processing module.

The received signal selection switch network comprises two first radio frequency switches, two second radio frequency switches and two third radio frequency switches; the first radio frequency switch, the second radio frequency switch and the third radio frequency switch are L-band single-pole double-throw radio frequency switches. The input ends of the two first radio frequency switches are respectively connected with 1L-band four-unit directional upper antenna and 1L-band four-unit directional lower antenna, and the output ends of the two first radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver. The input ends of the two second radio frequency switches are respectively connected with the 1L-band four-unit directional upper antenna and the 1L-band four-unit directional lower antenna, and the output ends of the two second radio frequency switches are connected with the input end of the third radio frequency switch. The input end of one of the third radio frequency switches is also connected with an L-band all-upward antenna, the input end of the other third radio frequency switch is also connected with an L-band all-downward antenna, and the output ends of the two third radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver.

The switch switching signal comprises a 1090MHz upper and lower antenna selection switch signal and a 1090MHz/1030MHz receiving switching switch signal, the 1090MHz upper and lower antenna selection switch signal controls the first radio frequency switch and the second radio frequency switch, the 1090MHz/1030MHz receiving switching switch signal controls the third radio frequency switch, and the control program is as follows:

(1) and selecting upper and lower antennas for the empty pipe response signal. 1090MHz upper and lower antenna selection switch signals control the first radio frequency switch and the second radio frequency switch to switch between the L-band four-unit directional upper antenna and the L-band four-unit directional lower antenna, 1090MHz/1030MHz receiving switch signals control the third radio frequency switch to receive the output of the third radio frequency, and the first radio frequency switch and the third radio frequency switch output 4 paths of 1090MHz air traffic control response signals to be sent to a four-channel 1030MHz/1090MHz multi-mode receiver for receiving processing.

(2) The empty pipe interrogation signal receives a selection. 1090MHz upper and lower antenna selection switch signals control the first radio frequency switch to switch between an L waveband four-unit directional upper antenna and an L waveband four-unit directional lower antenna, 1090MHz/1030MHz receiving switch signals control the third radio frequency switch to receive the output of the L waveband omnidirectional antenna, and 2 paths of 1090MHz air traffic control response signals output by the first radio frequency switch and 2 paths of 1030MHz air traffic control inquiry signals output by the third radio frequency switch are sent to a four-channel 1030MHz/1090MHz multi-mode receiver to be received and processed.

As shown in FIG. 3, a four channel 1030MHz/1090MHz multi-mode receiver includes two 1090MHz fixed receive branches, two paths 1030MHz/1090MHz dynamic receive branches, a first frequency source, and a second frequency source. The 1090MHz fixed receiving branch and the 1030MHz/1090MHz dynamic receiving branch both comprise an L-band broadband filter, an L-band low-noise amplifier, an L-band mixer, an intermediate frequency filter and an intermediate frequency logarithmic amplifier which are connected in sequence. The first frequency source comprises a first phase-locked loop and a one-to-two power divider, and the first phase-locked loop outputs fixed frequency signals to the L-band mixers in the two 1090MHz fixed receiving branches through the one-to-two power divider according to the control of the local frequency control signal. And the second frequency source comprises a second phase-locked loop and a one-to-two power divider, and the second phase-locked loop outputs signals which are the same as the frequency points of the first phase-locked loop or outputs signals which have a difference of 60MHz with the frequency points of the first phase-locked loop to the L-band mixers in the two 1030MHz/1090MHz dynamic receiving branches through the one-to-two power divider according to the control of the local oscillation frequency control signal.

The receiving and processing steps are as follows:

step 1: and simultaneously carrying out filtering and low-noise amplification processing on the received 4 paths of radio frequency signals.

Step 2: for the two 1090MHz fixed receiving branches, a receiving channel real-time dynamic allocation strategy controls a first phase-locked loop to output a fixed frequency signal, and a two-way power divider provides down-conversion local oscillation for the two receiving branches.

And step 3: for the two 1090MHz/1030MHz dynamic receiving branches, when a receiving channel real-time dynamic allocation strategy requires that four paths are 1090MHz receiving branches, controlling a second phase-locked loop to output a signal which is the same as a phase frequency point of a first phase-locked loop, and providing down-conversion local oscillators for the two 1090MHz/1030MHz dynamic receiving branches through a two-part power divider; when a receiving channel real-time dynamic allocation strategy needs two 1090MHz receiving branches and two 1030MHz receiving branches, the second phase-locked loop is controlled to output a signal which has a difference of 60MHz with a frequency point of the first phase-locked loop, and a two-power divider is used for providing down-conversion local oscillation for the two 1090MHz/1030MHz dynamic receiving branches.

And 4, step 4: and simultaneously carrying out filtering and logarithmic amplification on the four paths of intermediate frequency signals subjected to down conversion.

Through the receiving channel real-time dynamic allocation strategy, all four receiving branches can be completely occupied when only a 1090MHz air traffic control signal four-unit direction finding algorithm is needed to be developed, and two paths are always used for receiving other 1030MHz inquiry signals possibly existing in an active air space and responding to the inquiry signals in time in the rest receiving time, so that the performance requirement of the response rate is considered on the premise of meeting the performance index of a monitoring range. The control steps of each signal are as follows:

1090MHz upper and lower antenna selection switch signals:

step 1: when the system is in a monitoring state, 1090MHz air traffic control broadcast signals transmitted by other machines possibly existing in the whole active airspace need to be received, and at the moment, the upper antenna and the lower antenna are controlled to receive periodic switching once per second so as to cover the upper airspace and the lower airspace of the carrier.

Step 2: when the system is in a monitoring state, in order to increase the quality of the received signal, the control uses the same upper antenna or lower antenna as the local device to receive the response signal returned by other devices in the airspace.

The 1030MHz/1090MHz receiving switch signal and the local frequency control signal are used in a matching way:

step 1: and the 1030MHz/1090MHz receiving switch signal controls to provide two paths of 1030MHz air pipe inquiry signals and two paths of 1090MHz air pipe response signals for the rear end. The two paths of 1090MHz fixed receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver are controlled by local oscillation frequency control signals to receive and process 1090MHz air pipe response signals, and the two paths of 1030MHz/1090MHz dynamic receiving branches receive and process 1030MHz air pipe inquiry signals.

Step 2: and waiting for a lead code locking signal in the 1090MHz air traffic control signal processing process, and indicating that a 1090MHz air traffic control response signal is received when the locking signal is received. At the moment, four paths of 1090MHz air traffic control response signals are provided for the rear end under the control of a 1030MHz/1090MHz receiving switch signal, and all receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver are controlled to receive and process the 1090MHz air traffic control response signals through a local frequency control signal.

And step 3: and waiting for a direction finding end signal in the 1090MHz air traffic control signal processing process, and when receiving the end signal, indicating that the signal processing algorithm finishes four-unit direction finding of the received 1090MHz air traffic control response signal. At this time, the state of step 1 is returned to by receiving the switching signal and the local oscillation frequency control signal at 1030MHz/1090 MHz.

Claims (4)

1. The utility model provides an airborne collision avoidance system receiving channel fusion system based on time division multiplexing, contains received signal selection switch network, four-channel 1030MHz/1090MHz multimode receiver and the real-time dynamic allocation strategy module of receiving channel which characterized in that:

the receiving channel real-time dynamic allocation strategy module outputs a switch switching signal to the receiving signal selection switch network to control the receiving signal selection switch network to select 4 paths of 1090MHz air traffic control response signals or 2 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals from 10 paths of radio frequency signals output by an L-band four-unit directional antenna, an L-band omnidirectional upward antenna and an L-band omnidirectional downward antenna and input the signals into a four-channel 1030MHz/1090MHz multi-mode receiver; and outputting local frequency control signals to the four-channel 1030MHz/1090MHz multi-mode receiver to control the four-channel 1030MHz/1090MHz multi-mode receiver to complete the frequency conversion processing of 4 paths of 1090MHz air traffic control response signals or 2 paths of 1090MHz air traffic control response signals and 2 paths of 1030MHz air traffic control inquiry signals.

2. The time-division-multiplexing-based airborne collision avoidance system receiving channel fusion system of claim 1, wherein the receiving signal selection switch network comprises two first radio frequency switches, two second radio frequency switches, and two third radio frequency switches;

the input ends of the two first radio frequency switches are respectively connected with 1L-band four-unit directional upper antenna and 1L-band four-unit directional lower antenna, and the output ends of the two first radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver;

the input ends of the two second radio frequency switches are respectively connected with 1L-band four-unit directional upper antenna and 1L-band four-unit directional lower antenna, and the output ends of the two second radio frequency switches are connected with the input end of the third radio frequency switch;

the input end of one of the third radio frequency switches is also connected with an L-band all-upward antenna, the input end of the other third radio frequency switch is also connected with an L-band all-downward antenna, and the output ends of the two third radio frequency switches are connected with a four-channel 1030MHz/1090MHz multi-mode receiver;

the switch switching signal comprises a 1090MHz upper and lower antenna selection switch signal and a 1090MHz/1030MHz receiving switching signal;

1090MHz upper and lower antenna selection switch signals control the first radio frequency switch and the second radio frequency switch to selectively receive 1090MHz air traffic control response signals output by the L-band four-unit directional upper antenna or 1090MHz air traffic control response signals output by the L-band four-unit directional lower antenna;

and the 1090MHz/1030MHz receiving changeover switch signal controls the third radio frequency switch to selectively receive the output of the second radio frequency switch or the 1030MHz empty pipe inquiry signal output by the L-band omnidirectional antenna.

3. The time division multiplexing-based airborne collision avoidance system receiving channel fusion system according to claim 1, characterized in that the four-channel 1030MHz/1090MHz multi-mode receiver comprises two 1090MHz fixed receiving branches, two paths of 1030MHz/1090MHz dynamic receiving branches, a first frequency source and a second frequency source;

the 1090MHz fixed receiving branch and the 1030MHz/1090MHz dynamic receiving branch respectively comprise an L-band broadband filter, an L-band low-noise amplifier, an L-band mixer, an intermediate frequency filter and an intermediate frequency logarithmic amplifier which are connected in sequence;

the first frequency source comprises a first phase-locked loop and a one-to-two power divider, and the first phase-locked loop outputs fixed frequency signals to the L-band frequency mixers in the two 1090MHz fixed receiving branches through the one-to-two power divider according to the control of the local frequency control signal;

and the second frequency source comprises a second phase-locked loop and a one-to-two power divider, and the second phase-locked loop outputs a signal which is the same as the frequency point of the first phase-locked loop or outputs a signal which has a difference of 60MHz with the frequency point of the first phase-locked loop to the L-band frequency mixers in the two 1030MHz/1090MHz dynamic receiving branches through the one-to-two power divider according to the control of the local oscillation frequency control signal.

4. The time division multiplexing-based airborne collision avoidance system receiving channel fusion system according to claim 1, characterized in that the control process of the switch switching signal and the local oscillator frequency control signal is as follows:

step 1: two paths of 1030MHz air pipe inquiry signals and two paths of 1090MHz air pipe response signals are provided for the four-channel 1030MHz/1090MHz multi-mode receiver through switch switching signals, two paths of 1090MHz fixed receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver are controlled to receive and process 1090MHz air pipe response signals through local frequency control signals, and two paths of 1030MHz/1090MHz dynamic receiving branches receive and process the 1030MHz air pipe inquiry signals;

step 2: waiting for a lead code locking signal in the 1090MHz air traffic control response signal processing process, when receiving the lead code locking signal, indicating that a 1090MHz air traffic control response signal is received, at the moment, providing four paths of 1090MHz air traffic control response signals for the four-channel 1030MHz/1090MHz multi-mode receiver through a switch switching signal, and controlling all receiving branches of the four-channel 1030MHz/1090MHz multi-mode receiver to receive and process the 1090MHz air traffic control response signals through a local frequency control signal;

and step 3: and waiting for a direction finding end signal in the 1090MHz air traffic control response signal processing process, when receiving the end signal, indicating that the four-unit direction finding of the received 1090MHz air traffic control response signal is finished, and at the moment, returning the switch switching signal and the local oscillation frequency control signal to the state of the step 1.

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