CN114158128B - Asymmetric dynamic time slot communication method and device for covert communication of synchronous orbit satellite - Google Patents

Abstract

The present invention provides an asymmetric dynamic time slot communication method and device for synchronous orbit satellite covert communication. The asymmetric dynamic time slot communication method for synchronous orbit satellite covert communication includes: receiving a target frame corresponding to first uplink data sent by a terminal ; Based on the target frame corresponding to the first uplink data, generate time delay pre-compensation; Based on the time delay pre-compensation, send the first downlink data for responding to the target frame corresponding to the first uplink data to the terminal; wherein, the first downlink The data includes rate information and frame length information used to instruct the terminal to send the second uplink data; delay pre-compensation is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to the receiving state . The asymmetric dynamic time slot communication method for concealed communication of synchronous orbit satellites of the present invention can flexibly support asymmetric services, improve the utilization rate of time-frequency resources, shorten the duration of the signal in the air, and improve the anti-detection capability.

Description

Asymmetric dynamic time-slot communication method and device for covert communication of geostationary orbit satellites

technical field

The invention relates to the technical field of communication satellites, in particular to an asymmetric dynamic time slot communication method and device for concealed communication of synchronous orbit satellites.

Background technique

The satellite communication system is an important part of the global communication system. In the related art, miniaturized terminals generally work in half-duplex mode, that is, they can only receive data or send data at the same time, but cannot receive and send data at the same time; traditional satellite network protocols use fixed uplink and downlink symmetrical time slots. , for some systems that focus on uplink data backhaul, the allocated fixed downlink time-frequency resources are wasted and the data throughput of the system is reduced.

SUMMARY OF THE INVENTION

The present invention provides an asymmetric dynamic time slot communication method and device for synchronous orbit satellite covert communication, which is used to solve the defect of high waste rate of time-frequency resources in satellite communication in the prior art and realize efficient resource allocation.

The present invention provides an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites, comprising:

receiving the target frame corresponding to the first uplink data sent by the terminal;

generating delay pre-compensation based on the target frame corresponding to the first uplink data;

Based on the delay pre-compensation, send the first downlink data for responding to the target frame corresponding to the first uplink data to the terminal; wherein,

The first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

The delay pre-compensation is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to a receiving state.

According to an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the present invention, the generation of delay pre-compensation based on the target frame corresponding to the first uplink data includes:

Calculate the communication distance between the satellite and the terminal;

generating a propagation delay between the satellite and the terminal based on the communication distance;

The delay pre-compensation is generated based on the frame length of the target frame corresponding to the first uplink data and the propagation delay.

According to an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the present invention, the rate information is determined in the following manner:

Perform signal-to-noise ratio calculation on the target frame corresponding to the first uplink data to generate a prediction result of the channel state of the next time slot;

The rate information is generated based on the prediction result.

According to an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the present invention, before the target frame corresponding to the first uplink data sent by the receiving terminal, the method includes:

broadcast pilot;

receiving a request signal sent by the terminal, where the request signal is generated by the terminal based on the pilot frequency;

analyzing the request signal to generate a response signal;

Send the response signal to the terminal; wherein, the response signal includes rate information and frame length information used to instruct the terminal to send the first uplink data.

According to an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the present invention, the target frame includes: a frame header and a data segment,

The transmission rate of the data segment is determined based on the rate information;

The data segment includes at least one data packet of a target length, the number of which is determined based on the frame length information.

The present invention also provides another asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites, including:

receiving the first downlink data sent by the satellite, where the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

Based on the first downlink data, a target frame corresponding to the second uplink data is sent to the satellite.

According to an asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the present invention, the sending, based on the first downlink data, the target frame corresponding to the second uplink data to the satellite includes:

processing the first downlink data to generate the second uplink data;

After processing the target duration of the first downlink data, the target frame corresponding to the second uplink data is sent to the satellite.

The present invention also provides an asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites, comprising:

a first receiving module, configured to receive a target frame corresponding to the first uplink data sent by the terminal;

a first generation module, configured to generate delay pre-compensation based on the target frame corresponding to the first uplink data;

a first sending module, configured to send, to the terminal based on the delay pre-compensation, the first downlink data used to respond to the target frame corresponding to the first uplink data; wherein,

The first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

The delay pre-compensation is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to a receiving state.

The present invention also provides another asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites, comprising:

a second receiving module, configured to receive first downlink data sent by the satellite, where the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

A second sending module, configured to send a target frame corresponding to the second uplink data to the satellite based on the first downlink data.

The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, when the processor executes the program, the above-mentioned geostationary orbit satellite is implemented Steps of an asymmetric dynamic slotted communication method for covert communication.

The present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, realizes asymmetric dynamic time slot communication of covert communication of geostationary orbit satellites as described above. steps of the method.

The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements the steps of the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites as described above.

The asymmetric dynamic time-slot communication method and device for synchronous orbit satellite covert communication provided by the present invention significantly improves the flexibility and reliability of data transmission by using adaptive variable rate to control the transmission of uplink data in the data transmission stage; and By setting delay pre-compensation to control the time when the satellite transmits the first downlink data, the terminal can start to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent, thereby effectively improving the uplink time-frequency resource utilization.

Description of drawings

In order to explain the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are of the present invention. For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is one of the schematic flow charts of the asymmetric dynamic time slot communication method of synchronous orbit satellite covert communication provided by the present invention;

Fig. 2 is the second schematic flow chart of the asymmetric dynamic time slot communication method of synchronous orbit satellite covert communication provided by the present invention;

3 is the third schematic flow chart of the asymmetric dynamic time slot communication method for synchronous orbit satellite covert communication provided by the present invention;

Fig. 4 is one of the schematic diagrams of the asymmetric dynamic time slot communication method of synchronous orbit satellite covert communication provided by the present invention;

5 is the fourth schematic flow chart of the asymmetric dynamic time slot communication method for synchronous orbit satellite covert communication provided by the present invention;

Fig. 6 is the second principle diagram of the asymmetric dynamic time slot communication method of synchronous orbit satellite covert communication provided by the present invention;

7 is one of the structural schematic diagrams of the asymmetric dynamic time slot communication device for synchronous orbit satellite covert communication provided by the present invention;

8 is the second structural schematic diagram of the asymmetric dynamic time slot communication device for synchronous orbit satellite covert communication provided by the present invention;

FIG. 9 is a schematic structural diagram of an electronic device provided by the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention. , not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites of the present invention will be described below with reference to FIG. 1 and FIG. 3 to FIG. 6 .

It should be noted that the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites proposed in this embodiment is applied to the satellite side.

The asymmetric dynamic time-slot communication method for covert communication of synchronous orbit satellites is mainly applied to application scenarios focusing on uplink data backhaul services.

As shown in FIG. 1 , the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites includes: step 110 , step 120 and step 130 .

Step 110, the satellite receives the target frame corresponding to the first uplink data sent by the terminal;

In this step, it can be understood that the terminal may be a ground terminal, and the satellite communication process generally involves data interaction between the satellite and other terminals. Other terminals may be servers, communication devices, or user terminals connected to satellite communication, where user terminals include non-mobile terminals such as desktop computers and mobile terminals such as mobile phones, tablet computers, vehicle-mounted terminals, and watches.

The uplink data is the data uploaded by the terminal, that is, the data sent by the terminal to the satellite. The uplink data may include uplink service information or uplink response.

The first uplink data is used to represent the uplink data received by the satellite.

The target frame is the frame structure representation of uplink data.

It should be noted that, in this embodiment, the satellite covert communication adopts a short frame burst system, and the basic unit of communication is a frame.

By using the short frame burst system, it is helpful to improve the anti-detection capability of the system. By maximizing the overlapping of the downlink time slot and the uplink time slot, the total air duration of the uplink and downlink signals can be shortened, thereby improving the concealment of the system.

As shown in FIG. 4, in some embodiments, the target frame may include: a frame header and a data segment.

In this embodiment, the frame length of the entire target frame is T _f .

The frame header belongs to the overhead part of the target frame. The accuracy of the frame header information transmission determines whether subsequent data information can be received correctly. The frame header length is _Th .

In the actual implementation process, the frame header is generally transmitted at the lowest rate allowed by the system to ensure high accuracy.

The data segment contains the main information that the terminal needs to upload to the satellite, and the length of the data segment is (T _f -T _h ).

，帧标识的时 长为

，勤务段的时长为

。 Wherein, the frame header may include: a synchronization header, a frame identifier and a service segment; the duration of the synchronization header is

, the duration of the frame identification is

, the duration of the duty segment is

.

The sync header is used for signal acquisition, tracking and carrier recovery;

The frame identifier is used to indicate the beginning of the frame;

The service segment is used to indicate information such as rate gear, frame length and number of data packets.

A data segment includes one or more packets of target length.

The length of each data packet in the same data segment is the same, which is the target length, and the target length can be user-defined. For example, the bit length of each data packet can be fixed to n bits, where n>0.

It can be understood that, by changing the number N of data packets in the data segment, the frame length T _f of the target frame can be changed, where N≧0 and N is an integer.

It should be noted that, in the transmission process, the transmission rate of the data segment may be determined based on the transmission rate information; the number N of data packets may be determined based on the frame length information of the target frame.

For example, after the frame length information of the target frame is determined, the number of data packets in the data segment is adjusted based on the frame length information, so that the frame length of the target frame reaches the frame length specified by the frame length information.

The manner of determining the transmission rate information and the frame length information of the target frame will be described in subsequent embodiments, and will not be described here.

According to the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the embodiment of the present invention, by designing the structure of the target frame as a special structure, the target frame can better cooperate with the delay pre-compensation to control the satellite transmission The time of the first downlink data enables the terminal to start receiving and processing the first downlink data just when the target frame corresponding to the first uplink data is sent, thereby effectively improving the uplink time-frequency resource utilization; By adjusting the number of data packets in the target frame, the frame length of the target frame can be adjusted, so that in the data transmission stage, the adaptive variable rate can be used to control the transmission of uplink data, so as to improve the flexibility and reliability of data transmission.

Step 120: The satellite generates delay pre-compensation based on the target frame corresponding to the first uplink data, and the delay pre-compensation is used to enable the terminal to receive the first downlink when the target frame corresponding to the first uplink data is sent and switched to the receiving state. data;

As shown in FIG. 5 , in this step, the delay pre-compensation is the duration of the time period from when the satellite receives the first uplink data to returning the first downlink data generated based on the first uplink data to the terminal.

The delay pre-compensation is used to enable the terminal to receive the first downlink data and process the first downlink data just when the target frame corresponding to the first uplink data is sent and switched to the receiving state.

The first downlink data is data received by the terminal, that is, data received by the terminal and generated by the satellite based on the first uplink data and used to respond to the first uplink data.

The first downlink data may be downlink service information or response information.

In this embodiment, after receiving the first uplink data sent by the terminal, the satellite generates delay pre-compensation by analyzing and processing the target frame corresponding to the first uplink data, and determines the moment when the first downlink data is initiated .

The steps of generating the delay pre-compensation will be specifically described below through embodiments.

As shown in FIG. 6, in some embodiments, step 120 may include:

Calculate the communication distance between the satellite and the terminal;

Based on the communication distance, the propagation delay between the satellite and the terminal is generated;

Delay pre-compensation is generated based on the frame length and propagation delay of the target frame corresponding to the first uplink data.

In this embodiment, the communication distance is the theoretical maximum communication distance between the satellite and the ground terminal.

In the actual execution process, the formula can be used:

为卫星和地面终端之间通信距离，

为地球半径，h为卫星轨道高度，

为卫星的最小仰角。 Determine the communication distance between the satellite and the ground terminal, where

is the communication distance between the satellite and the ground terminal,

is the radius of the earth, h is the height of the satellite orbit,

is the minimum elevation angle of the satellite.

Among them, through the formula:

为地心角，

为地球半径，h为卫星轨道高度，

为卫星的 最小仰角。The geocentric angle can be determined, where,

for the center of the earth,

is the radius of the earth, h is the height of the satellite orbit,

is the minimum elevation angle of the satellite.

Via the formula:

为半视角，

为地球半径，h为卫星轨道高度，

为 卫星的最小仰角。 The half angle of view of the satellite can be determined, where,

is a half angle of view,

is the radius of the earth, h is the height of the satellite orbit,

is the minimum elevation angle of the satellite.

和卫星的半视角

之后，即可确定卫星的最小仰角

，然后基于最 小仰角

即可得到卫星和地面终端之间通信距离

。 getting the geocentric angle

and satellite half perspective

After that, the minimum elevation angle of the satellite can be determined

, then based on the minimum elevation angle

The communication distance between the satellite and the ground terminal can be obtained

.

为71°，

为8.5°，从而得到通信距离

为40586km。 For example, when the parameters of the synchronous orbit satellite are: the orbit height is 35786km, and the minimum elevation angle of the satellite is 10°, the above formula can be used to calculate

is 71°,

is 8.5°, thus obtaining the communication distance

It is 40586km.

After the communication distance between the satellite and the ground terminal is obtained, the propagation delay between the satellite and the terminal can be generated based on the communication distance.

Among them, the propagation delay is used to characterize the communication delay between the satellite and the ground terminal.

In the actual execution process, the formula can be used:

1为信号单向传输延迟时间，

为卫星和地面终端之间通 信距离，c为光速。 Determine the propagation delay, where,

1 is the one-way transmission delay time of the signal,

is the communication distance between the satellite and the ground terminal, and c is the speed of light.

的基础上，进一步预留终端内部时钟误差和其他传 输估算误差时间等裕量时间ε，以增加一定的裕量时间作为传输延迟时隙。 In some embodiments, it is also possible to

On the basis of , further reserve the margin time ε such as the terminal internal clock error and other transmission estimation error time, so as to add a certain margin time as the transmission delay time slot.

Among them, the margin time ε can be user-defined, or can be determined by testing in the actual environment.

。 The propagation delay can be obtained by adding and summing the one-way propagation delay time and the slack time of the signal.

.

之后，通过计算第一上行数据对应的目标帧的帧长和传播时延 的时间差，即可得到时延预补偿。 getting the propagation delay

After that, delay pre-compensation can be obtained by calculating the time difference between the frame length of the target frame corresponding to the first uplink data and the propagation delay.

Specifically, the formula can be used:

为时延预补偿，

为目标帧的帧长，

为同步头的时长，

为帧标识的时长，

为传播时延。 Determine the delay pre-compensation, where

For delay pre-compensation,

is the frame length of the target frame,

is the duration of the sync header,

is the duration of the frame identification,

is the propagation delay.

的第一上行数据对应的目标帧，在 卫星捕获到第一上行数据对应的目标帧后，在目标帧同步成功后从勤务段开始计数，当接 收的第一上行数据对应的目标帧计时到

时刻，卫星向终端发射第一下行数据，从而使得终 端恰好发完第一上行数据对应的目标帧时开始接收并处理第一下行数据。In the actual execution process, the terminal transmits the frame length to the satellite as

The target frame corresponding to the first uplink data, after the satellite captures the target frame corresponding to the first uplink data, starts counting from the service segment after the target frame synchronization is successful, when the target frame corresponding to the received first uplink data is counted up

At the moment, the satellite transmits the first downlink data to the terminal, so that the terminal starts to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent.

为40586km，从而计算得到信号单向传输延迟时间

为135ms，且 通过测试确定裕量时间ε为15ms，则可以确定传播时延

为150ms。 For example, when the parameters of the synchronous orbit satellite are: the orbit height is 35786km, and the minimum elevation angle of the satellite is 10°, the communication distance is calculated.

is 40586km, so the one-way transmission delay time of the signal is calculated

is 135ms, and the margin time ε is determined to be 15ms through testing, then the propagation delay can be determined

is 150ms.

时刻时，卫星向终端发射第一下行数据，从而使 得终端恰好发完第一上行数据对应的目标帧时开始接收并处理第一下行数据。 When the satellite captures the target frame corresponding to the first uplink data, it starts counting from the service segment after the target frame is successfully synchronized.

At the time, the satellite transmits the first downlink data to the terminal, so that the terminal starts to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent.

The inventor found in the research and development process that in the related art, the dynamic adjustment of the switching point of the uplink and downlink time slots is mainly based on the ratio of the number of users and the number of uplink and downlink services to support the information transmission of asymmetric services. Uplink time slots are independently occupied. For services that focus on uplink data backhaul, downlink time slots still occupy a certain amount of overhead, resulting in low resource utilization.

In the embodiment of the present invention, the time for the satellite to transmit the first downlink data is controlled by setting the delay pre-compensation, that is, the first downlink data is controlled to be initiated in advance by the delay pre-compensation t, and the first downlink data is indicated through the control protocol. Initiation time, so as to realize the pre-compensation for the propagation delay, so that the terminal can start to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent, and maximize the overlap of uplink and downlink time slots. Shorten the air duration of the signal, thereby improving the concealment of the system; for data transmission that focuses on the uplink data backhaul service, it can effectively reduce the overhead of downlink time slot occupation, improve the utilization rate of uplink time-frequency resources, and thus improve the flexibility of resource allocation. sex and rationality.

Step 130: Based on the delay pre-compensation, send the first downlink data to the terminal for responding to the target frame corresponding to the first uplink data; wherein the first downlink data includes rate information used to instruct the terminal to send the second uplink data and frame length information.

In this step, the first downlink data is data received by the terminal, that is, data received by the terminal and generated by the satellite based on the first uplink data and used to respond to the first uplink data.

The first downlink data may be downlink service information or response information.

The frame structure of the target frame corresponding to the first downlink data is the same as that in the above-mentioned embodiment, and may include a frame header and a data segment, which will not be repeated here.

It should be noted that the first downlink data includes instruction information used to instruct the terminal to generate the second uplink data, for example, may include rate information used to instruct the terminal to send the second uplink data, and the frame of the target frame corresponding to the second uplink data. long information and power information for sending the second uplink data, etc.

The second uplink data is data generated by the terminal based on the first downlink data and used for sending to the satellite after receiving the first downlink data.

The second uplink data may be new service information, or may also be the same information as the service information corresponding to the previously transmitted uplink data.

The content of the second uplink data may be determined based on the content of the first downlink data received by the terminal.

The frame structure of the target frame corresponding to the second uplink data is the same as that in the above-mentioned embodiment, and may include a frame header and a data segment, which will not be repeated here.

It can be understood that the first uplink data and the second uplink data are uplink data corresponding to two consecutive transmission time slots, wherein the second uplink data is transmitted by the terminal in the next transmission time slot after sending the first uplink data. upstream data.

The rate information is the data sending rate when the terminal sends the second uplink data to the satellite.

In some embodiments, the rate information may include rates for multiple gears.

The frame length information is the frame length of the target frame of the second uplink data sent by the terminal to the satellite.

It should be noted that for the uplink data sent by the terminal received by the satellite at any time slot, the satellite will generate the rate information and frame length information corresponding to the uplink data received in the next time slot based on the uplink data received in the time slot. .

Then, the satellite stores the rate information and frame length information corresponding to the second uplink data generated based on the first uplink data in the first downlink data, and sends it to the terminal.

After receiving the first downlink data, the terminal parses to obtain the rate information and frame length information corresponding to the second uplink data, and adjusts the number of data packets in the data segment in the second uplink data based on the frame length information, so as to generate a frame that meets the The target frame with the target frame length in the long information, and the second uplink data with the target frame length is transmitted to the satellite according to the target rate in the rate information.

The manner of determining the rate information will be described below through specific embodiments.

In some embodiments, the rate information is determined by:

Perform signal-to-noise ratio calculation on the target frame corresponding to the first uplink data to generate a prediction result of the channel state of the next time slot;

Rate information is generated based on the prediction result.

In this embodiment, the prediction result of the channel state is used to characterize the communication quality and the communication speed.

The measurement standard of the channel state is that the receiving end estimates the signal-to-noise ratio according to the received signal, and uses the estimation result as the prediction result of the channel state of the next time slot.

In the actual execution process, after receiving the first uplink data, the satellite can estimate the signal-to-noise ratio of the first uplink data, and use the estimated result as the prediction result of the channel state of the next time slot to determine the terminal Rate information when transmitting the second uplink data.

For example, if the prediction result is good, the gear with the faster rate is determined as the rate information corresponding to the second uplink data; after receiving the rate information, the terminal sends the second uplink data to the satellite at a faster rate rate, thereby increasing the rate of data transmission.

Or if the prediction result is not good, the gear with the lower rate is determined as the rate information corresponding to the second uplink data; after receiving the rate information, the terminal appropriately reduces the rate of sending the second uplink data to the satellite to The loss of the second uplink data is avoided, thereby improving the quality of data transmission.

During the research and development process, the inventor also found that in the related art, a single fixed rate is mainly used for data transmission, resulting in poor data transmission effect and inability to adapt to complex and changeable channel states.

In the embodiment of the present invention, in the data transmission stage, the adaptive variable rate is used to control the transmission of uplink data, and the information rate and data frame length are flexibly adjusted according to the channel state, which can adapt to the real-time changing service requirements and the channel environment to achieve Dynamic allocation of time slots; when the channel environment is good, transmit as much information as possible to improve the efficiency of data transmission; when the channel environment is deteriorating, reduce the rate of information transmission to ensure the accuracy and reliability of data transmission, thereby It can effectively improve the adaptability to the channel, and improve the quality, efficiency and reliability of data transmission.

For example, as shown in FIG. 3 , in the actual execution process, the satellite receives the first frame sent by the terminal, that is, the first uplink data sent in the current time slot.

为135ms，且通过测试确定裕量时间ε为 15ms，则可以确定传播时延

为150ms。 The one-way transmission delay time of the signal is obtained by calculation

is 135ms, and the margin time ε is determined to be 15ms through testing, then the propagation delay can be determined

is 150ms.

时刻时，卫星向终端发射第一下行数据，从而使得终端恰 好发完第一帧时开始接收并处理第一下行数据。 When the satellite captures the target frame of the first frame, it starts counting from the service segment after the target frame is successfully synchronized.

At the time, the satellite transmits the first downlink data to the terminal, so that the terminal starts to receive and process the first downlink data just after the terminal has sent the first frame.

In addition, the satellite also generates a prediction result of the channel state of the next time slot based on the signal-to-noise ratio of the currently received first frame, and generates rate information based on the prediction result.

Based on the content of the currently received first uplink data, the instruction information for instructing the terminal to generate the second uplink data is generated, that is, the instruction information for instructing the terminal to generate the second frame is generated.

The satellite sends the above information to the terminal through the first downlink data, and the first downlink data includes indication information from the satellite to the terminal, such as whether to switch the transmission rate, whether to change the transmission power, and whether to change the frame length of the target frame.

After receiving the first downlink data, the terminal generates, based on the content of the first downlink data, second uplink data to be sent in the next time slot, that is, a second frame.

For example, in the case where the first downlink data includes instruction information for determining the switching transmission rate, transmit power or frame length, the terminal completes framing in a new mode, and generates a frame according to the frame length information included in the first downlink data For the second uplink data, the second frame is transmitted to the satellite according to the rate information included in the downlink data.

After receiving the second frame transmitted by the satellite, the satellite updates the second frame to the first uplink data in the current time slot, and repeats the above steps to return the first downlink data generated based on the first uplink data to the terminal .

Wherein, the first downlink data further includes confirmation information for the received service information in the first frame.

The confirmation information is used to indicate whether the terminal needs to retransmit the first uplink data sent in the first frame.

In the process of transmitting the second frame, the terminal receives the downlink response based on the second frame returned by the satellite, that is, the first downlink data generated by the satellite based on the second frame, and the first downlink data includes the service in the first frame. For confirmation of the information, if retransmission is required, the terminal sends the retransmission information of the first frame in the time slot of the third frame.

If retransmission is not required, the terminal sends new service information in the third frame.

In the above embodiments of the present invention, a control protocol is introduced to pre-compensate for the propagation delay to reduce the time slot resource overhead by facing the asymmetric service requirements of the synchronous orbit satellite covert communication. For example, for application scenarios that focus on uplink data backhaul services and fast data backhaul requirements, control the initiation time of downlink signals so that the downlink signals just arrive at the terminal when the terminal switches to the receiving state after sending the uplink service, thereby reducing the waiting time for receiving downlink signals. , which improves the utilization of time-frequency resources.

In addition, by pre-compensating the transmission delay to maximize the overlap of the uplink and downlink time slots, the total air duration of the uplink and downlink signals can be effectively reduced, and the concealment of the system can be improved.

In addition, in the time slot resource allocation stage, the size of the service frame is adjusted according to the channel environment to ensure data transmission, the signal-to-noise ratio estimation is introduced to estimate and predict the channel state, and the information rate and frame length of the signal are adjusted accordingly, increasing flexibility. sex.

According to the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the embodiment of the present invention, by adopting adaptive variable rate to control the transmission of uplink data in the data transmission stage, the flexibility and reliability of data transmission are significantly improved; and By setting the delay pre-compensation to control the time when the satellite transmits the first downlink data, the terminal can start to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent, so that the terminal can adapt to the channel state Adjust the time slot and flexibly support asymmetric services, thereby effectively improving the utilization rate of time-frequency resources, shortening the air duration of the signal, and improving the anti-detection capability.

According to some embodiments of the present invention, before step 110, the method may further include:

satellite broadcast pilot;

The satellite receives the request signal sent by the terminal, and the request signal is generated by the terminal based on the pilot frequency;

Analyze the request signal and generate a response signal;

A response signal is sent to the terminal, wherein the response signal includes rate information and frame length information used to instruct the terminal to send the first uplink data.

In this embodiment, the pilot frequency includes information such as non-interference frequency points.

The request signal is a signal generated by the terminal and used to initiate an access request to the satellite.

The request signal carries information such as traffic volume.

A reply signal is a signal generated by a satellite in response to an access request.

After the satellite receives the request signal, it performs spectrum sensing and signal-to-noise ratio estimation on the request signal, and analyzes the traffic and other information carried in the request signal. The rate information and frame length information of the uplink data.

The satellite generates a response signal based on the above information, and transmits the response signal to the terminal.

After receiving the response signal, the terminal parses the response signal, generates and sends the first uplink data to the satellite based on the rate information and frame length information in the response signal.

The satellite receives the first uplink data, enters the service transmission stage, and starts to perform steps 110 and 120 cyclically until the service transmission is completed.

It can be understood that this embodiment is used in the matching stage between the satellite and the terminal before the service data transmission is performed.

For example, continuing to refer to FIG. 3 , in the actual execution process, the satellite broadcasts the pilot frequency periodically. Since the satellite performs real-time spectrum sensing on the received signal, the pilot frequency carries information such as non-interference frequency points at this time.

The terminal is powered on, receives the pilot frequency, extracts the non-interference frequency point to initiate an uplink access request signal, and the request frame carries information such as traffic volume.

Among them, the terminal can use the access by chance or reservation access mode, and after the access is successful, the terminal and the satellite establish time synchronization.

It should be noted that, in the access phase, the terminal may transmit an access request signal to the satellite using the default rate and frame length.

After receiving the request signal, the satellite returns a response signal to the terminal. In this step, the satellite performs spectrum sensing and signal-to-noise ratio estimation on the received request signal, and makes a decision based on the traffic volume, indicating which rate gear and frame length to use by the terminal, and the response frame contains rate information and frame length information. and other adjustment information.

When the terminal receives the response signal of successful access, it starts to transmit the uplink service signal, that is, transmits the first uplink data, and performs matching and transmission based on the rate information and frame length information indicated by the response signal when uploading.

The satellite receives the uplink backhaul service, and sends the response or downlink service data through downlink signaling, that is, the first downlink data. In this process, the satellite will pre-compensate the propagation delay, generate the delay pre-compensation, and initiate the downlink signal based on the delay pre-compensation, that is, when the satellite returns the downlink data, the terminal is also transmitting the uplink data to realize the downlink. The time slot overlaps with the uplink time slot to the maximum extent, so that the moment when the downlink signal reaches the terminal is exactly the moment when the terminal switches to the receiving state after sending the uplink service, which shortens the total air duration of the uplink and downlink signals.

The terminal starts to receive and process the first downlink data when it just finishes sending the first uplink data, and reserves a certain guard interval after the processing delay.

If the satellite sends downlink service data to the terminal, the terminal decides whether to send the uplink response through signaling or continue to send the uplink service data according to the situation, and matches based on the rate information and frame length information indicated by the downlink signal.

If necessary, repeat steps 110 and 120 until the business process ends.

It should be noted that fixed reserved time slots can be used in the access process to simplify protocol control and frame overhead; while in the stage of transmitting service data, dynamic time slot allocation can be used.

According to the asymmetric dynamic time-slot communication method for covert communication of synchronous orbit satellites provided by the embodiment of the present invention, in the matching stage before service transmission, the satellite generates the first frame of service information for instructing the terminal to send the first frame of service information based on the received request signal. The rate information and frame length information of the uplink data can realize the dynamic allocation of time slots based on the real-time changing service requirements and the channel environment, thereby improving the flexibility and reliability of data transmission. The asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites provided by the present invention will be described below. The dynamic time slot communication methods may refer to each other correspondingly.

It should be noted that the asymmetric dynamic time-slot communication device for covert communication of synchronous orbit satellites is applied to satellites.

As shown in FIG. 7 , the asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites includes: a first receiving module 710 , a first generating module 720 and a first sending module 730 .

a first receiving module 710, configured to receive a target frame corresponding to the first uplink data sent by the terminal;

a first generation module 720, configured to generate delay pre-compensation information based on the target frame corresponding to the first uplink data;

The first sending module 730 is configured to send the first downlink data for responding to the target frame corresponding to the first uplink data to the terminal based on the delay pre-compensation information; wherein,

The first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

The delay pre-compensation information is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to the receiving state.

According to the asymmetric dynamic time slot communication device for synchronous orbit satellite covert communication provided by the embodiment of the present invention, the flexibility and reliability of data transmission are significantly improved by adopting adaptive variable rate to control the transmission of uplink data in the data transmission stage; And by setting the delay pre-compensation to control the time when the satellite transmits the first downlink data, the terminal can start to receive and process the first downlink data just when the target frame corresponding to the first uplink data is sent, thereby effectively improving the uplink time. frequency resource utilization.

In some embodiments, the first generation module 720 can also be used to:

Calculate the longest communication distance between the satellite and the terminal;

Based on the longest communication distance, the propagation delay between the satellite and the terminal is generated;

Based on the duration and propagation delay of the target frame corresponding to the first uplink data, delay pre-compensation information is generated.

In some embodiments, the apparatus may further include a second generation module for:

Perform signal-to-noise ratio calculation on the target frame corresponding to the first uplink data to generate a prediction result of the channel state of the next time slot;

Rate information is generated based on the prediction result.

In some embodiments, the apparatus may also include:

a first broadcast module, configured to broadcast a pilot before receiving the target frame corresponding to the first uplink data sent by the terminal;

a third receiving module, configured to receive a request signal sent by the terminal, where the request signal is generated by the terminal based on the pilot frequency;

The third generation module is used to analyze the request signal and generate the response signal;

The third sending module is configured to send a response signal to the terminal, wherein the response signal includes rate information and frame length information used to instruct the terminal to send the first uplink data.

In some embodiments, the target frame includes: a frame header and a data segment,

The transmission rate of the data segment is determined based on the rate information;

The data segment includes at least one data packet of a target length, and the number of the data packet is determined based on the frame length information.

The following describes another asymmetric dynamic time slot communication method for covert communication of geostationary orbit satellites provided by the present invention with reference to FIGS. 2 to 6 . The asymmetric dynamic time slot communication method for covert communication of geostationary orbit satellites described below is the same as that described above. The asymmetric dynamic time slot communication method for covert communication of geostationary orbit satellites can be referred to each other correspondingly.

It should be noted that the asymmetric dynamic time-slot communication method for covert communication of synchronous orbit satellites described below is applied to a terminal, and its execution subject is a terminal, wherein the terminal may be a non-mobile terminal, such as a computer or a server, or it may also be It is a mobile terminal, including but not limited to a mobile phone, a tablet computer, a vehicle terminal or a watch, etc.

As shown in FIG. 2 , the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites includes: step 210 and step 220 .

Step 210, the terminal receives the first downlink data sent by the satellite, where the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

In this step, the first downlink data is data received by the terminal, that is, data received by the terminal and generated by the satellite based on the first uplink data and used to respond to the first uplink data.

The first downlink data may be downlink service information or response information.

The first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data.

The methods for determining the rate information and the frame length information have been described in the above embodiments, and are not repeated here.

In some embodiments, the first downlink data further includes acknowledgment information for indicating whether the terminal needs to retransmit the first uplink data sent in the last time slot.

The second uplink data is data sent by the terminal to the satellite in the next time slot, and the second uplink data may be service information.

Based on the confirmation information in the first downlink data sent by the satellite, the second uplink data may be new service information, or may also be service information sent by the terminal to the satellite in the previous time slot of the current time slot.

Step 220: Based on the first downlink data, the terminal sends a target frame corresponding to the second uplink data to the satellite.

In this step, the frame structure of the target frame corresponding to the second uplink data is similar to the frame structure of the target frame corresponding to the first uplink data, and may include a frame header and a data segment.

The frame length of the target frame corresponding to the second uplink data is determined based on the frame length information in the first downlink data.

The data transmission rate when the terminal sends the second uplink data to the satellite is determined based on the rate information in the first downlink data.

The specific content of the second uplink data is determined based on the confirmation information in the first downlink data of the last time slot received by the terminal.

For example, when the acknowledgment information in the first downlink data received in the previous time slot is the service information that needs to be retransmitted, the terminal determines that the second uplink data sent in the current time slot is sent in the previous time slot business information.

If the confirmation information is that retransmission is not required, the terminal determines the second uplink data sent in the current time slot as new service information.

According to the asymmetric dynamic time slot communication method for covert communication of synchronous orbit satellites provided by the embodiment of the present invention, the flexibility and reliability of data transmission can be significantly improved by adopting adaptive variable rate to control the transmission of uplink data in the data transmission stage. .

In some embodiments, step 220 may further include:

The terminal processes the first downlink data to generate the second uplink data;

After processing the target duration of the first downlink data, the terminal sends the target frame corresponding to the second uplink data to the satellite.

In this embodiment, the target duration is a guard interval.

The target duration can be determined based on actual measurement results.

In the actual execution process, after the terminal has processed the first downlink data, a certain guard interval may be reserved, that is, after the target duration, the second uplink data will be sent to the satellite.

The satellite receives the second uplink data, and starts to execute step 120. The specific implementation steps have been described in the above embodiments, and are not repeated here.

In this embodiment, by setting the guard interval, data loss can be avoided, and the reliability of data transmission can be improved.

The asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites provided by the present invention will be described below. The dynamic time slot communication methods may refer to each other correspondingly.

It should be noted that the asymmetric dynamic time-slot communication device for covert communication of synchronous orbit satellites is applied to a terminal.

As shown in FIG. 8 , the asymmetric dynamic time slot communication device for covert communication of synchronous orbit satellites includes: a second receiving module 810 and a second sending module 820 .

The second receiving module 810 is configured to receive the first downlink data sent by the satellite, where the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data;

The second sending module 820 is configured to send the target frame corresponding to the second uplink data to the satellite based on the first downlink data.

According to the asymmetric dynamic time slot communication device for synchronous orbit satellite covert communication provided by the embodiment of the present invention, the flexibility and reliability of data transmission can be significantly improved by using adaptive variable rate to control the transmission of uplink data in the data transmission stage .

In some embodiments, the apparatus may also include:

The fourth generation module is used to process the first downlink data and generate the second uplink data;

The second sending module 820 may also be configured to send a target frame corresponding to the second uplink data to the satellite after processing the target duration of the first downlink data.

FIG. 9 illustrates a schematic diagram of the physical structure of an electronic device. As shown in FIG. 9 , the electronic device may include: a processor (processor) 910, a communication interface (Communications Interface) 920, a memory (memory) 930, and a communication bus 940, The processor 910 , the communication interface 920 , and the memory 930 communicate with each other through the communication bus 940 . The processor 910 can invoke the logic instruction in the memory 930 to execute the asymmetric dynamic time slot communication method for covert communication of the synchronous orbit satellite, the method comprising: receiving a target frame corresponding to the first uplink data sent by the terminal; based on the first uplink data For the corresponding target frame, delay pre-compensation information is generated; based on the delay pre-compensation information, first downlink data for responding to the target frame corresponding to the first uplink data is sent to the terminal; wherein the first downlink data includes Instruct the terminal to send the rate information and frame length information of the second uplink data; the delay pre-compensation information is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to the receiving state, or, The method includes: receiving first downlink data sent by a satellite, where the first downlink data includes rate information and frame length information used to instruct a terminal to send the second uplink data; based on the first downlink data, sending the second uplink data to the satellite The target frame corresponding to the data.

In addition, the above-mentioned logic instructions in the memory 930 may be implemented in the form of software functional units and may be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, Read-Only Memory (ROM, Read-Only Memory), Random Access Memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes .

In another aspect, the present invention also provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, when the program instructions are executed by a computer When executing, the computer can execute the asymmetric dynamic time slot communication method of synchronous orbit satellite covert communication provided by the above-mentioned methods, the method includes: receiving the target frame corresponding to the first uplink data sent by the terminal; based on the corresponding target frame of the first uplink data; the target frame, generating delay pre-compensation information; based on the delay pre-compensation information, sending first downlink data for responding to the target frame corresponding to the first uplink data to the terminal; wherein the first downlink data includes instructions for indicating the terminal Send the rate information and frame length information of the second uplink data; the delay pre-compensation information is used to enable the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and switched to the receiving state, or, this method It includes: receiving the first downlink data sent by the satellite, where the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data; based on the first downlink data, sending the second uplink data to the satellite corresponds to target frame.

In yet another aspect, the present invention also provides a non-transitory computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the computer program is implemented to perform the asymmetric dynamics of the above-mentioned concealed communication of geostationary orbit satellites. A time slot communication method, the method includes: receiving a target frame corresponding to first uplink data sent by a terminal; generating delay pre-compensation information based on the target frame corresponding to the first uplink data; In response to the first downlink data of the target frame corresponding to the first uplink data; wherein, the first downlink data includes rate information and frame length information used to instruct the terminal to send the second uplink data; delay pre-compensation information is used to make The terminal receives the first downlink data when the target frame corresponding to the first uplink data is sent and switches to the receiving state. Alternatively, the method includes: receiving the first downlink data sent by the satellite, where the first downlink data includes an indication The terminal sends rate information and frame length information of the second uplink data; and based on the first downlink data, sends a target frame corresponding to the second uplink data to the satellite.

The device embodiments described above are only illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in One place, or it can be distributed over multiple network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment. Those of ordinary skill in the art can understand and implement it without creative effort.

From the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and certainly can also be implemented by hardware. Based on this understanding, the above-mentioned technical solutions can be embodied in the form of software products in essence or the parts that make contributions to the prior art, and the computer software products can be stored in computer-readable storage media, such as ROM/RAM, magnetic A disc, an optical disc, etc., includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments or some parts of the embodiments.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (8)

1. An asymmetric dynamic time slot communication method for covert communication of a synchronous orbit satellite is characterized by comprising the following steps:

receiving a target frame corresponding to first uplink data sent by a terminal;

generating time delay precompensation based on a target frame corresponding to the first uplink data;

based on the time delay precompensation, sending first downlink data for responding to a target frame corresponding to the first uplink data to the terminal; wherein,

the first downlink data comprises rate information and frame length information for indicating the terminal to send second uplink data;

the time delay precompensation is used for enabling the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and the receiving state is switched;

generating a delay precompensation based on the target frame corresponding to the first uplink data, including:

calculating a communication distance between the satellite and the terminal;

generating a propagation delay between a satellite and the terminal based on the communication distance;

generating the delay precompensation based on the frame length of a target frame corresponding to the first uplink data and the propagation delay;

the rate information is determined by:

performing signal-to-noise ratio calculation on a target frame corresponding to the first uplink data to generate a prediction result of a channel state of a next time slot;

generating the rate information based on the prediction result.

2. The asymmetric dynamic timeslot communication method for hidden communication of geostationary orbiting satellite according to claim 1, wherein before the target frame corresponding to the first uplink data transmitted by said receiving terminal, said method comprises:

broadcasting a pilot frequency;

receiving a request signal sent by the terminal, wherein the request signal is generated by the terminal based on the pilot frequency;

analyzing the request signal to generate a response signal;

sending the response signal to the terminal; wherein, the response signal includes rate information and frame length information for instructing the terminal to send the first uplink data.

3. The asymmetric dynamic timeslot communication method for geostationary orbit satellite covert communication of claim 1, wherein said target frame comprises: the frame header and the data segment are transmitted,

a transmission rate of the data segment is determined based on the rate information;

the data segment includes at least one data packet of a target length, and the number of the data packets is determined based on the frame length information.

4. An asymmetric dynamic time slot communication method for covert communication of a synchronous orbit satellite is characterized by comprising the following steps:

receiving first downlink data sent by a satellite based on time delay precompensation, wherein the first downlink data comprises rate information and frame length information for indicating a terminal to send second uplink data;

based on the first downlink data, sending a target frame corresponding to the second uplink data to the satellite;

wherein the time delay precompensation is determined for the satellite based on the following steps:

calculating a communication distance between the satellite and a terminal;

generating a propagation delay between the satellite and the terminal based on the communication distance;

generating the delay precompensation based on the frame length of a target frame corresponding to the first uplink data and the propagation delay;

the rate information is determined for the satellite based on the steps of:

performing signal-to-noise ratio calculation on a target frame corresponding to the first uplink data to generate a prediction result of a channel state of a next time slot;

generating the rate information based on the prediction result.

5. The asymmetric dynamic timeslot communication method for blind communication of a geostationary orbit satellite of claim 4, wherein said transmitting the target frame corresponding to the second uplink data to the satellite based on the first downlink data comprises:

processing the first downlink data to generate second uplink data;

and after the first uplink data target time length is processed, sending a target frame corresponding to the second uplink data to the satellite.

6. An asymmetric dynamic timeslot communication device for covert communication of geostationary orbiting satellites, comprising:

the first receiving module is used for receiving a target frame corresponding to first uplink data sent by a terminal;

a first generating module, configured to generate a delay precompensation based on a target frame corresponding to the first uplink data;

a first sending module, configured to send, to the terminal, first downlink data for responding to a target frame corresponding to the first uplink data based on the delay precompensation; wherein,

the first downlink data comprises rate information and frame length information for indicating the terminal to send second uplink data;

the time delay precompensation is used for enabling the terminal to receive the first downlink data when the target frame corresponding to the first uplink data is sent and the receiving state is switched;

the first generating module is further configured to:

calculating a communication distance between the satellite and the terminal;

generating a propagation delay between a satellite and the terminal based on the communication distance;

generating the delay precompensation based on the frame length of a target frame corresponding to the first uplink data and the propagation delay;

further comprising a second generating module for:

performing signal-to-noise ratio calculation on a target frame corresponding to the first uplink data to generate a prediction result of a channel state of a next time slot;

generating the rate information based on the prediction result.

7. An asymmetric dynamic timeslot communication device for covert communication of geostationary orbiting satellites, comprising:

the second receiving module is used for receiving first downlink data sent by a satellite based on time delay precompensation, wherein the first downlink data comprises rate information and frame length information used for indicating a terminal to send second uplink data;

a second sending module, configured to send, to the satellite, a target frame corresponding to the second uplink data based on the first downlink data;

wherein the time delay precompensation is determined for the satellite based on the following steps:

calculating a communication distance between the satellite and a terminal;

generating a propagation delay between the satellite and the terminal based on the communication distance;

generating the delay precompensation based on the frame length of a target frame corresponding to the first uplink data and the propagation delay;

the rate information is determined for the satellite based on the steps of:

performing signal-to-noise ratio calculation on a target frame corresponding to the first uplink data to generate a prediction result of a channel state of a next time slot;

generating the rate information based on the prediction result.

8. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor when executing the program implements the steps of the asymmetric dynamic time slot communication method for geostationary orbiting satellite covert communication according to any one of claims 1 to 5.

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