Highway tunnel Beidou signal full coverage method

Abstract

The invention relates to a road tunnel Beidou signal full coverage method. The method comprises the following steps: detecting the use state of each time slice in L time slices in each cycle period of a channel by each signal transmitter in L signal transmitters sharing a channel in a highway tunnel under the condition of time synchronization; when the channel is in an idle state in the time slice, and the distance between the current time of the signal transmitter and the starting time of transmitting the signal last time by the signal transmitter is not less than L times of the duration, the signal transmitter continuously transmits the signal in the time slice, and stops transmitting the signal at the end of the time slice; when the channel is in an idle state in the time slice, and the distance between the current time of the signal transmitter and the starting time of transmitting the signal last time by the signal transmitter is less than L times of the duration, the signal transmitter keeps silent in the time slice; when the channel is in an occupied state during the time slice, the signal transmitter remains silent during the time slice. By adopting the method, the positioning precision in the highway tunnel can be improved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a method, system, signal transmitter, computer-readable storage medium and computer program product for full Beidou signal coverage in a highway tunnel. Background Art

[0002] With the development of communication technology, wireless communication technology has emerged. Wireless communication technology is a communication method that uses the characteristics of electromagnetic wave signals that can propagate in free space to exchange information. Wireless communication technology can be widely used in wireless communication systems such as navigation systems, satellite communication systems, radar systems, and mobile communication systems. In the Beidou satellite navigation system, the receiver can receive Beidou signals to achieve positioning. However, in highway tunnels, due to the obstructed environment, the Beidou signals emitted by the Beidou satellite navigation system are difficult to reach the receiver. Therefore, in highway tunnels, multiple signal transmitters are usually set up to simulate the emission of Beidou signals based on pseudo-satellite technology to achieve positioning.

[0003] However, in the prior art, when multiple signal transmitters transmit signals, there is interference with each other. When used for Beidou signal coverage in tunnels, the mutual interference causes a significant decrease in positioning accuracy. Summary of the invention

[0004] Based on this, it is necessary to provide a Beidou signal full coverage method, system, signal transmitter, computer-readable storage medium and computer program product for highway tunnels that can improve positioning accuracy in response to the above-mentioned technical problems.

[0005] In a first aspect, the present application provides a method for full Beidou signal coverage in a highway tunnel, comprising:

[0006] Each of the L signal transmitters sharing the same channel detects the usage status of each of the L time segments of the same duration of the channel in each cycle under time synchronization; the L signal transmitters are signal transmitters whose mutual interference degree meets the preset conditions among the multiple signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2;

[0007] When the channel is in an idle state during the time segment, and the current time of the signal transmitter is not less than L times the start time of the last signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal during the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal;

[0008] When the channel is in an idle state during the time segment, and the distance between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times of the duration, the signal transmitter remains silent during the time segment;

[0009] When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

[0010] In the second aspect, the present application also provides a Beidou signal full coverage system for a highway tunnel, the system comprising L signal transmitters sharing a channel, the L signal transmitters being signal transmitters whose mutual interference degree among a plurality of signal transmitters arranged in the highway tunnel meets preset conditions, and L is a positive integer greater than 2; each of the signal transmitters is used to: in the case of time synchronization, within each cycle, detect the usage status of each time segment of the L time segments of the same duration of the channel within the cycle; when the channel is in an idle state in the time segment, and the current time of the signal transmitter is not less than L times the start time of the previous signal transmission of the signal transmitter, then the signal is continuously transmitted in the time segment, and the signal is stopped at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal; when the channel is in an idle state in the time segment, and the current time of the signal transmitter is less than L times the start time of the previous signal transmission of the signal transmitter, then the signal remains silent in the time segment; when the channel is in an occupied state in the time segment, then the signal remains silent in the time segment.

[0011] In a third aspect, the present application further provides a signal transmitter, including a transmitting circuit, a transceiver antenna, a detection module, a memory and a processor, wherein the memory stores a computer program, the transmitting circuit is used to generate a signal to be transmitted, the transceiver antenna is used to transmit and receive signals, the detection module is used to detect the use status of a channel, and the processor implements the following steps when executing the computer program:

[0012] Each of the L signal transmitters sharing the same channel detects the usage status of each of the L time segments of the same duration of the channel in each cycle under time synchronization; the L signal transmitters are signal transmitters whose mutual interference degree meets the preset conditions among the multiple signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2;

[0013] When the channel is in an idle state during the time segment, and the current time of the signal transmitter is not less than L times the start time of the last signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal during the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal;

[0014] When the channel is in an idle state during the time segment, and the distance between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times of the duration, the signal transmitter remains silent during the time segment;

[0015] When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

[0016] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0017] Each of the L signal transmitters sharing the same channel detects the usage status of each of the L time segments of the same duration of the channel in each cycle under time synchronization; the L signal transmitters are signal transmitters whose mutual interference degree meets the preset conditions among the multiple signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2;

[0018] When the channel is in an idle state during the time segment, and the current time of the signal transmitter is not less than L times the start time of the last signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal during the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal;

[0019] When the channel is in an idle state during the time segment, and the distance between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times of the duration, the signal transmitter remains silent during the time segment;

[0020] When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

[0021] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0022] Each of the L signal transmitters sharing the same channel detects the usage status of each of the L time segments of the same duration of the channel in each cycle under time synchronization; the L signal transmitters are signal transmitters whose mutual interference degree meets the preset conditions among the multiple signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2;

[0023] When the channel is in an idle state during the time segment, and the current time of the signal transmitter is not less than L times the start time of the last signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal during the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal;

[0024] When the channel is in an idle state during the time segment, and the distance between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times of the duration, the signal transmitter remains silent during the time segment;

[0025] When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

[0026] The above-mentioned Beidou signal full coverage method, system, signal transmitter, computer-readable storage medium and computer program product for highway tunnels, since the L signal transmitters are signal transmitters with preset mutual interference levels among multiple signal transmitters arranged in the highway tunnel, the signal transmitted by the signal transmitter is a simulated Beidou signal, and each of the L signal transmitters, under the condition of time synchronization, detects the usage status of each time segment of the L time segments of the same duration in the cycle period in each cycle period, and then, when it is detected that the channel is in an idle state, if it is not more than the start time of the last transmitted signal, the channel is detected in an idle state. If the time from the start of the last signal transmission is less than L times the time length, the signal transmitter continues to transmit the signal until the end of the time segment. If the time from the start of the last signal transmission is less than L times the time length, the signal transmitter remains silent. When it is detected that the channel is occupied, the signal transmitter remains silent. In this way, in the highway tunnel, L signal transmitters can alternately transmit simulated Beidou signals in each cycle, which can avoid the mutual interference problem caused by L signal transmitters transmitting signals at the same time, so that the receiver in the highway tunnel can accurately receive the simulated Beidou signal, while covering the Beidou signal in the highway tunnel, the positioning accuracy in the highway tunnel is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 A schematic diagram of a process for providing full Beidou signal coverage in a highway tunnel in an embodiment;

[0029] Figure 2 A schematic diagram of a Beidou signal full coverage system framework for a highway tunnel in one embodiment;

[0030] Figure 3 A schematic diagram of an asynchronous mode transmission method in an embodiment;

[0031] Figure 4 A schematic diagram of a synchronous mode transmission method in an embodiment;

[0032] Figure 5 It is a structural block diagram of a Beidou signal full coverage system for a highway tunnel in one embodiment;

[0033] Figure 6 FIG. 4 is a diagram showing the internal structure of a signal transmitter in one embodiment. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] In one embodiment, Figure 1 As shown, a method for full coverage of Beidou signals in a highway tunnel is provided. This embodiment uses the method applied to a signal transmitter as an example. In this embodiment, the method includes the following steps:

[0036] Step 102, each of the L signal transmitters sharing the same channel, under time synchronization, detects the usage status of each of the L time segments of the same duration in each cycle; the L signal transmitters are multiple signal transmitters arranged in the highway tunnel, the degree of mutual interference of which meets the preset conditions, and L is a positive integer greater than 2.

[0037] Among them, the signal transmitter may include a transmitting circuit, a transceiver antenna, a detection module, a memory and a processor. The transmitting circuit can be used to generate a signal to be transmitted. The transceiver antenna can be used to radiate the signal to be transmitted generated by the transmitting circuit to transmit the signal, and the transceiver antenna can also receive the signal, and the transceiver antenna can transmit and receive the signal at the same time. The detection module can be used to detect the usage status of the channel. The detection module can be set independently of the transceiver antenna, or it can be integrated in the transceiver antenna. The channel is a channel for transmitting the signal of each signal transmitter in the L signal transmitters.

[0038] Multiple signal transmitters in a highway tunnel may be distributed flat networking structures, and L signal transmitters may be regarded as a group of networks therein. In some scenarios, the closer the distance between the signal transmitters, the greater the degree of mutual interference, and the farther the distance between the signal transmitters, the smaller the degree of mutual interference. The degree of mutual interference is the degree of signal interference when different signal transmitters in the L signal transmitters transmit signals. The preset condition for the degree of mutual interference of the L signal transmitters can characterize that the degree of mutual interference of the L signal transmitters is large. The degree of mutual interference can be measured by the signal to interference ratio (Signal to Interference Ratio, referred to as SIR). The signal to interference ratio is the ratio of the useful signal power measured at a specified point of the transmission channel under specified conditions to the total power of the interference signal and noise. Specifically, the signal to interference ratio may be the ratio of the power value of the signal transmitted by the signal transmitter itself to the total power of the interference signal and noise, the interference signal may be the power value of the signal transmitted by other signal transmitters, and the noise may be the noise generated when the signal transmitter transmits the signal. The preset condition may be that the signal to interference ratio of the signal transmitter in the L signal transmitters does not exceed the preset value. The preset value is, for example, 30dB.

[0039] Time synchronization means that the local times of L signal transmitters are the same. The cycle period is the period in which L signal transmitters transmit signals cyclically. A cycle period can be divided into L time segments, and each signal transmitter occupies one of the L time segments to transmit signals. It can be understood that the duty cycle of each signal transmitter when transmitting a signal is 1 / L. In some scenarios, a time segment can be called a time slot. The duration of a cycle period can be, for example, 1s (second), 500ms (millisecond), or other. The duration of each time segment can be, for example, 100ms, 200ms, or other.

[0040] A highway tunnel is a passage for vehicles to travel. A highway tunnel can be an undersea tunnel, a mountain tunnel, a river crossing tunnel or other types. The full coverage of Beidou signals in highway tunnels means that Beidou signals can fully cover the receivers in the highway tunnels. Since the signals transmitted by the signal transmitters are simulated Beidou signals, the receivers in the highway tunnels can receive Beidou signals for positioning; through the signals transmitted by multiple signal transmitters in the highway tunnels, each driving position in the highway tunnel can receive simulated Beidou signals, achieving full coverage of Beidou signals to the receivers in the highway tunnels. Receivers include mobile phones, positioning terminals on vehicles or other types.

[0041] Exemplarily, each of the signal transmitters of L shared channels, under time synchronization, detects, within each cycle, the power value of the transmitted signal of each of L time segments of the same duration of the channel within the cycle, and determines the usage status of the channel in the time segment based on the detected power value.

[0042] In one embodiment, the detection module of the signal transmitter can be used to detect the power value. In this embodiment, the transceiver antenna of the signal transmitter can receive the signal transmitted in the channel, and the transceiver antenna can transmit the received signal to the detection module of the signal transmitter. The detection module detects the power value of the transmitted signal in each time segment of L time segments of the same length in the channel within the cycle period.

[0043] In one embodiment, the L signal transmitters can communicate with the management device respectively, and the management device can transmit the local time of the management device to the L signal transmitters to instruct the L signal transmitters to adjust according to the local time of the management device, so that the time of the L signal transmitters is synchronized. The management device can be a server or a control terminal.

[0044] In one embodiment, the L signal transmitters may perform time synchronization processing through a preset time synchronization protocol, such as a PTP (Precision Timing Protocol), an NTP (Network Time Protocol), or others.

[0045] In one embodiment, L signal transmitters each have a different priority. During the process of the L signal transmitters performing synchronization time processing, among every two signal transmitters with adjacent priorities among the L signal transmitters, the signal transmitter with a lower priority can synchronize its own time based on the time of the signal transmitter with a higher priority.

[0046] For example, for every two signal transmitters with adjacent priorities, including a signal transmitter with a higher priority and a signal transmitter with a lower priority, the signal transmitter with a lower priority can be used as a slave clock in the PTP protocol, and the signal transmitter with a higher priority can be used as a master clock in the PTP protocol. By transmitting a signal with a timestamp, the time difference between the signal transmitter as the slave clock and the signal transmitter as the master clock is determined, so as to synchronize the time of the signal transmitter as the slave clock based on the time of the signal transmitter as the master clock. Among them, the detection module of the signal transmitter can also measure time, and the detection module can specifically identify the timestamp in the signal received by the transceiver antenna to perform synchronization time processing.

[0047] The process of L signal transmitters performing synchronization time processing can last for a preset time, and every two signal transmitters with adjacent priorities can simultaneously start the synchronization time processing for a preset time. For example, the preset time length can be 30 seconds. Usually, two signal transmitters can complete time synchronization once within 2 seconds to 3 seconds, so multiple time synchronizations can be performed within 30 seconds, thereby improving the reliability of time synchronization.

[0048] Step 104, when the channel is in an idle state in a time segment, and the current time of the signal transmitter is not less than L times the duration of the start time of the previous signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal in the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal.

[0049] Among them, the idle state means that the channel is not occupied by any of the L signal transmitters. Duration is the time length of the time segment. The current time of the signal transmitter is not less than L times the duration from the start time of the last signal transmitted by the signal transmitter. This means that the time interval between the current time of the signal transmitter and the start time of the last signal transmitted by the signal transmitter is greater than or equal to L times the duration. The time interval can be recorded as tK, and the duration of the time segment is recorded as tW. Then, the current time of the above-mentioned signal transmitter is not less than L times the duration from the start time of the last signal transmitted by the signal transmitter, which can be expressed as tK≥L*tW. The simulated Beidou signal refers to the signal transmitted by the Beidou satellite in the simulated Beidou satellite navigation system.

[0050] Exemplarily, when the channel is in an idle state in a time segment, and the current time of the signal transmitter is not less than L times the duration of the start time of the last signal transmitted by the signal transmitter, the processor of the signal transmitter can control the signal transmitter to continuously transmit signals within the time segment through the transmitting circuit and the transceiver antenna of the signal transmitter from the starting point of the time segment, and stop transmitting signals at the end of the time segment.

[0051] In one embodiment, the signal transmitter controls the signal transmission by controlling the state of the transmission enable switch in the signal transmitter. Specifically, when the channel is in an idle state in a time segment, and the current time of the signal transmitter is not less than L times the time length from the start time of the last signal transmission of the signal transmitter, the signal transmitter sets the transmission enable switch to an on state, and keeps the transmission enable switch in an on state during the time segment to continuously transmit the signal during the time segment; and sets the transmission enable switch to an off state at the end of the time segment to stop transmitting the signal at the end of the time segment. The state of the transmission enable switch can be controlled by a processor of the signal transmitter.

[0052] In one embodiment, when the signal transmitter does not receive signals transmitted by other signal transmitters among the L signal transmitters except the signal transmitter in the time segment, the signal transmitter may determine that the channel is in an idle state in the time segment.

[0053] Step 106, when the channel is in an idle state in the time segment, and the current time of the signal transmitter is less than L times the duration of the start time of the previous signal transmission of the signal transmitter, the signal transmitter remains silent in the time segment.

[0054] Among them, silence means that the signal transmitter does not transmit a signal. The current time of the signal transmitter is less than L times the duration from the start time of the last signal transmission of the signal transmitter, indicating that the time interval between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times the duration, which can be recorded as tK<L*tW.

[0055] Exemplarily, when the channel is idle in this time segment, and the current time of the signal transmitter is less than L times the duration of the start time of the last signal transmitted by the signal transmitter, the signal transmitter sets the transmission enable switch to the off state in this time segment to remain silent in this time segment.

[0056] Step 108: When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

[0057] The occupied state indicates that the channel is occupied by a signal transmitter among the L signal transmitters to transmit a signal.

[0058] Exemplarily, when the channel is in an occupied state during a time segment, the signal transmitter sets the transmission enable switch to a closed state during the time segment to maintain silence during the time segment.

[0059] In one embodiment, when the signal transmitter receives signals transmitted by other signal transmitters among the L signal transmitters except the signal transmitter itself in the time segment, the signal transmitter may determine that the channel is in an occupied state in the time segment.

[0060] In the above-mentioned Beidou signal full coverage method for highway tunnels, since the L signal transmitters are signal transmitters with preset conditions for the degree of mutual interference among multiple signal transmitters arranged in the highway tunnel, the signals transmitted by the signal transmitters are simulated Beidou signals, and each of the L signal transmitters, under the condition of time synchronization, detects the usage status of each time segment of the L time segments of the same duration in the cycle period of the channel in each cycle period, and then, when it is detected that the channel is in an idle state, if the time from the start time of the last transmitted signal is not less than L times the duration, the signal transmitter transmits the signal until the end of the time segment, if the time from the start time of the last transmitted signal is less than L times the duration, the signal transmitter remains silent, and when it is detected that the channel is in an occupied state, the signal transmitter remains silent, so that in the highway tunnel, the L signal transmitters can alternately transmit simulated Beidou signals in each cycle period, and the mutual interference problem caused by the L signal transmitters transmitting signals at the same time can be avoided, so that the receiver in the highway tunnel can accurately receive the simulated Beidou signal, and the positioning accuracy in the highway tunnel is improved while covering the Beidou signal in the highway tunnel.

[0061] In an exemplary embodiment, step 102 includes: each signal transmitter of the L shared channels, under time synchronization, detects, within each cycle, the power value of the transmitted signal in each of the L time segments of the same duration in the cycle; when the power value is less than a predetermined first power value, the signal transmitter determines that the channel is in an idle state in the time segment; when the power value is greater than a predetermined second power value, the signal transmitter determines that the channel is in an occupied state in the time segment; the second power value is greater than the first power value.

[0062] The signal transmitter may detect the power value of the signal transmitted by the channel through the detection module. The detection module may detect the power value in real time or at the starting point of each time segment. When detecting in real time, detection may be performed once every millisecond. In some scenarios, the first power value may be referred to as a low power threshold, and the second power value may be referred to as a high power threshold.

[0063] In this embodiment, under the condition of time synchronization, within each cycle period, the power value of the transmitted signal of each time segment of L time segments of the same duration of the channel within the cycle period is detected, and then the power value is compared with the first power value and the second power value. It can be quickly determined whether the channel is in an idle state or an occupied state in each time segment of each cycle period, so that the subsequent signal transmitter can determine whether to transmit a signal, so as to realize the alternating transmission of signals by L signal transmitters.

[0064] In one embodiment, the step of the signal transmitter determining that the channel is in an idle state in the time segment when the power value is less than a predetermined first power value includes: when the detection module of the signal transmitter detects that the power value is less than a predetermined first power value, the detection module of the signal transmitter may output a low-level pulse, and the processor of the signal transmitter may determine that the channel is in an idle state in the time segment. The low-level pulse is used to indicate that the channel is in an idle state.

[0065] In one embodiment, the above-mentioned step of the signal transmitter determining that the channel is in an occupied state in the time segment when the power value is greater than a predetermined second power value includes: when the detection module of the signal transmitter detects that the power value is greater than the predetermined second power value, the detection module of the signal transmitter can output a high-level pulse, and the processor of the signal transmitter can determine that the channel is in an occupied state in the time segment. Among them, the high-level pulse is used to indicate that the channel is in an occupied state. The voltage of the high-level pulse is greater than the voltage of the low-level pulse, and the voltage of the high-level pulse can be pre-designed by the engineer according to the hardware status of the device.

[0066] In an exemplary embodiment, the above-mentioned Beidou signal full coverage method for highway tunnels also includes the following steps: obtaining a set formed by each historical power value detected by L signal transmitters; determining multiple historical power values ​​in the set that are less than a preset power median as multiple first historical power values, and determining multiple historical power values ​​in the set that are greater than the preset power median as multiple second historical power values; determining the first power value based on the root mean square error of the multiple first historical power values ​​and the average value of the multiple first historical power values; determining the second power value based on the root mean square error of the multiple second historical power values ​​and the average value of the multiple second historical power values.

[0067] Among them, the steps of this embodiment can be executed by the management device corresponding to the L signal transmitters, can be executed by any signal transmitter among the L signal transmitters, and can also be executed by the signal transmitter with the highest priority among the L signal transmitters. It can be understood that the steps of this embodiment can be performed in the initialization stage before the actual operation of the J signal transmitters, or can be performed during the actual operation of the J signal transmitters. The first power value and the second power value can be determined by the steps of this embodiment. In other embodiments, the first power value and the second power value can also be pre-configured.

[0068] The historical power value is the power value of the signal transmitted by the channel detected by the signal transmitter in the historical time segment before the current time. The set may include the historical power values ​​detected by L signal transmitters in each time segment in multiple historical time segments. The preset power median value may be preset based on engineering experience. The first historical power value may also be referred to as a low power value, and the second historical power value may also be referred to as a high power value.

[0069] The root mean square error (RMSE) can also be called the standard error. The root mean square error of multiple first historical power values ​​can be calculated by first averaging the multiple first historical power values, and then calculating the square value of the difference between each first historical power value in the multiple first historical power values ​​and the average value, averaging the square values ​​corresponding to each of the multiple first historical power values, and then calculating the square root value to obtain the root mean square error of the multiple first historical power values. The root mean square error of multiple second historical power values ​​is calculated in a similar way to the root mean square error of multiple first historical power values, and will not be repeated here.

[0070] In this embodiment, the preset power median is used as the intermediate value, and each historical power value in the set formed by the historical power values ​​detected by the L signal transmitters is divided into multiple first historical power values ​​and multiple second historical power values. Then, the first power value is determined according to the root mean square error of the multiple first historical power values ​​and the average value of the multiple first historical power values, and the second power value is determined according to the root mean square error of the multiple second historical power values ​​and the average value of the multiple second historical power values. The first power value and the second power value suitable for the L signal transmitters can be determined more accurately, creating conditions for subsequently accurately determining the usage status of the channel.

[0071] In one embodiment, the step of determining the first power value based on the root mean square error of the plurality of first historical power values ​​and the average value of the plurality of first historical power values ​​may include: adding the average value of the plurality of first historical power values ​​to three times the root mean square error of the plurality of first historical power values ​​to obtain the first power value. This embodiment may be represented by the following formula (1).

[0072] Formula (1)

[0073] in, A first power value may be represented; An average value of a plurality of first historical power values ​​may be represented; A root mean square error may be characterized for a plurality of first historical power values; Can represent 3 times , represents three times the root mean square error of multiple first historical power values.

[0074] In one embodiment, the step of determining the second power value based on the root mean square error of the plurality of second historical power values ​​and the average value of the plurality of second historical power values ​​may include: subtracting three times the root mean square error of the plurality of second historical power values ​​from the average value of the plurality of second historical power values ​​to obtain the second power value. This embodiment may be represented by the following formula (2).

[0075] Formula (2)

[0076] in, A second power value may be represented; An average value of a plurality of second historical power values ​​may be represented; A root mean square error may be characterized for a plurality of second historical power values; Can represent 3 times , represents three times the root mean square error of multiple second historical power values.

[0077] In an exemplary embodiment, each of the L signal transmitters has a different priority. Before step 102, the above-mentioned Beidou signal full coverage method for highway tunnels also includes the following transmission initialization step: each of the L time-synchronized signal transmitters randomly selects a time segment from L consecutive time segments with the same duration, and transmits a signal in the selected time segment; when the signal transmitter does not receive a signal transmitted by other signal transmitters except the signal transmitter among the L signal transmitters in the selected time segment, the signal transmitter continues to transmit the signal in the selected time segment until the selected time segment ends, and stops transmitting the signal. ; When the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is higher than the priorities of other signal transmitters, the signal transmitter continues to transmit the signal in the selected time segment until the selected time segment ends, and then stops transmitting the signal; when the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is lower than the priorities of other signal transmitters, the signal transmitter stops transmitting the signal, reselects a time segment in which no other signal transmitters transmit signals among the L time segments, and returns to the step of transmitting the signal in the selected time segment to continue execution.

[0078] Among them, the above-mentioned transmission initialization step can be understood as an asynchronous mode. When each of the L signal transmitters continuously transmits signals in one of the L time segments until the end of the time segment, it can be determined that the L signal transmitters have completed the transmission initialization, and then steps 102 to 108 can be executed to improve the transmission efficiency. Steps 102 to 108 can also be understood as a synchronous mode.

[0079] The L signal transmitters each have a different priority, and the L signal transmitters can be sorted from high to low according to the priority. The priority order of the L signal transmitters can be determined according to the sequence numbers of the L signal transmitters. For example, in the order from small to large, the priorities of the L signal transmitters decrease in sequence. For example, in the order from large to small, the priorities of the L signal transmitters decrease in sequence. The priority order of the L signal transmitters can also be determined by specifying the priority ranking of each signal transmitter in the L signal transmitters. For example, for three signal transmitters A, B, and C, it can be specified that in the order from high to low priority, the three signal transmitters are arranged in sequence as B, C, and A.

[0080] The L time segments may be, for example, 5 time segments, specifically, time segments with 100ms, 200ms, 300ms, 400ms, and 500ms as start time points, and each time segment may last for 100ms. It can be understood that reselecting a time segment in which no other signal transmitter transmits a signal from the L time segments means reselecting a time segment in which no other signal transmitter transmits a signal from the time segment after the time segment currently selected by the signal transmitter from the L time segments.

[0081] Each signal transmitter can receive the signal transmitted in the channel through the transceiver antenna. When receiving the signal, the identification information of the signal transmitter from which the signal comes can be parsed from the signal. By comparing the parsed identification information with the pre-stored identification information of each of the L signal transmitters, it can be determined whether the signal transmitted by other signal transmitters in the L signal transmitters is received. The identification information is the information that distinguishes different signal transmitters, for example, the identification information can be a sequence number, a serial number, etc.

[0082] In this embodiment, each of the L time-synchronized signal transmitters first randomly selects a time segment from the L consecutive time segments and transmits a signal in the selected time segment. In this way, different signal transmitters in the L signal transmitters may not select the same time segment, but may select the same time segment. When different signal transmitters select the same time segment to transmit signals, a collision will occur. At this time, the signal transmitter with a high priority can continue to transmit signals in the current time segment, while the signal transmitter with a low priority stops transmitting signals and reselects a time segment. In this way, without having to agree on the transmission order of the L signal transmitters, automatic collision detection and avoidance can be achieved between the L signal transmitters, so that only one signal transmitter in each of the L time segments continuously transmits signals. Therefore, the L signal transmitters do not need to be specified by an additional device for the transmission rhythm. The L signal transmitters can adaptively complete the initial signal transmission rhythm, and then execute step 102. In each cycle, the L signal transmitters can alternately transmit signals to avoid interference caused by the synchronous transmission of signals by the L signal transmitters.

[0083] In one embodiment, when the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment and the priority of the signal transmitter is lower than that of other signal transmitters, the signal transmitter stops transmitting the signal, and for the time segment after the currently selected time segment among the L time segments, detects the usage status of the channel in the targeted time segment. When the channel is in an idle state in the targeted time segment, the signal transmitter can determine that no other signal transmitters transmit signals in the targeted time segment, reselect the targeted time segment, and return to the step of transmitting the signal in the selected time segment to continue execution.

[0084] In one embodiment, when the channel is in an occupied state in the targeted time segment, the signal transmitter may determine that other signal transmitters transmit signals in the targeted time segment, and continue to execute the step of detecting the usage status of the channel in the targeted time segment for the next time segment among the L time segments until it is determined that no other signal transmitters transmit signals in the targeted time segment.

[0085] In one embodiment, when the L signal transmitters change, the changed L signal transmitters re-synchronize the time processing, and when the changed L signal transmitters are time synchronized, the changed L signal transmitters perform the above-mentioned transmission initialization step, and after performing the transmission initialization step, perform steps 102 to 108. Among them, when a new signal transmitter joins and / or an old signal transmitter exits the L signal transmitters, it can be determined that the L signal transmitters have changed. The management device can be used to detect the offline or online of the signal transmitter to determine whether there is a change, and the signal transmitter can also detect the signals of other signal transmitters in the L signal transmitters to determine whether the old signal transmitter is offline or the new signal transmitter is online among the L signal transmitters.

[0086] In an exemplary embodiment, the above-mentioned Beidou signal full coverage method for highway tunnels also includes the following steps: the signal transmitter detects the usage status of a channel shared by L signal transmitters in a selected time segment; when the channel is in an idle state in the selected time segment, the signal transmitter determines that no signal transmitted by other signal transmitters is received in the selected time segment; when the channel is in an occupied state in the selected time segment, the signal transmitter determines that a signal transmitted by other signal transmitters is received in the selected time segment.

[0087] In this embodiment, the signal transmitter can efficiently determine whether a signal transmitted by other signal transmitters is received in the selected time segment by detecting the usage status of the channel shared by L signal transmitters in the selected time segment, so as to avoid or continue to transmit the signal.

[0088] In an exemplary embodiment, a plurality of signal transmitters are installed in sequence in a highway tunnel at preset intervals, and the distance between each signal transmitter and the ground of the highway tunnel is a preset height greater than zero.

[0089] Among them, the preset spacing is a preset spacing, for example, it can be 15 meters, 20 meters or others. The preset height is a preset height, for example, it can be 3 meters, 4 meters or others. Multiple signal transmitters are installed in sequence according to the preset spacing in the highway tunnel, which means that in the highway tunnel, a signal transmitter is installed at every preset spacing, so that the distance between adjacent signal transmitters in the multiple signal transmitters is the preset spacing. It can be understood that the closer the distance between two signal transmitters, the higher the degree of mutual interference between them, and the farther the distance between two signal transmitters, the lower the degree of mutual interference between them.

[0090] In this embodiment, multiple signal transmitters are installed in sequence in the highway tunnel at preset intervals, the intervals between adjacent signal transmitters are the same, and the interference conditions between different L signal transmitters are the same. There is no need to set up multiple transmission mechanisms in the highway tunnel, thereby improving system efficiency and stability. Moreover, the distance between each signal transmitter and the ground of the highway tunnel is a preset height greater than zero, and the signal coverage range is wider.

[0091] In actual scenarios, since the orbit of Beidou satellites is far from the surface, the actual Beidou signal propagation distance is far, and the ground users receive weak signals. In highway tunnels, the actual Beidou signal is difficult to reach users to achieve positioning. Pseudo-satellite technology can be used to simulate the actual Beidou satellite by deploying pseudo-satellites (such as signal transmitters), which can extend the coverage and service area of ​​the actual Beidou satellite. For example, pseudo-satellite technology can be used to sample the entire highway tunnel at a certain interval to obtain multiple reference points, set pseudo-satellites at each reference point, obtain the telegram, carrier Doppler, code phase and other characteristics of each reference point to the visible Beidou satellite, so as to simulate the Beidou signal through the pseudo-satellites at each reference point and transmit it, so as to achieve positioning in the tunnel.

[0092] However, since the spacing between each reference point is usually small, the signals emitted by each pseudo-satellite are highly similar. In the prior art, the signal emission mechanism of pseudo-satellites in highway tunnels is usually continuous emission, and the pseudo-satellites at each reference point will interfere with each other. Moreover, in complex electromagnetic environments with high reflectivity such as steel shell immersed tubes, for example, highway tunnels usually adopt a closed cavity structure, and steel shell immersed tubes and metal decorative surfaces are used more frequently. In this environment, due to the wide beam of the pseudo-satellite and the high reflectivity characteristics of this environment, the degree of mutual interference of the signals is further increased. After multiple transmissions and multiple superpositions of multiple signals, the signal quality is seriously deteriorated, resulting in correlation peak distortion and increased tracking errors, making it difficult to achieve stable reception and high-precision positioning, leading to problems such as loss of lock, satellite loss or positioning flying points.

[0093] Different from the continuous signal transmission mechanism of the prior art, when multiple signal transmitters are set in a highway tunnel and the signals transmitted by the signal transmitters are simulated Beidou signals, in the present application, since the degree of mutual interference among the L signal transmitters meets the preset conditions, each of the L signal transmitters only continuously transmits signals in one time segment among the L time segments in each cycle. In this way, the L signal transmitters transmit signals alternately in each cycle, which can avoid mutual interference between the L signal transmitters. Regardless of the performance of the receiver in the highway tunnel, accurate positioning in the highway tunnel can be achieved without changing the receiver. It can be suitable for various application scenarios with high precision requirements and good coverage requirements.

[0094] In a specific application scenario, the signal transmitter can be called a Beidou signal transmitter. In a highway tunnel, Beidou signal transmitters can be installed at intervals of 15 meters and at a height of 4 meters from the ground. After simulation analysis, L can be 5, that is, the interference degree of the five adjacent Beidou signal transmitters (for example, Beidou signal transmitters numbered 1 to 5) is relatively large. When there are more than five, the signal-to-interference ratio exceeds 30dB, which can be ignored. The main interference comes from adjacent Beidou signal transmitters. For example, the Beidou signal transmitter numbered 1 and the Beidou signal transmitter numbered 3 have the greatest interference on the Beidou signal transmitter numbered 2.

[0095] Among them, the Beidou signal transmitter can be used to simulate Beidou satellites and transmit simulated Beidou signals. Figure 2 The schematic diagram of the framework of the Beidou signal full coverage system for highway tunnels shown in FIG. 1 shows that the Beidou signal transmitter may include a transmitting circuit, a transceiver integrated Beidou antenna, and a detection module integrated in the transceiver integrated Beidou antenna. The detection module can be used to detect the power transmitted by the channel, and can also be used to identify the timestamp in the signal when performing time synchronization processing. The value of L can be determined by simulation or actual measurement based on actual conditions, for example, only considering the mutual interference between the three Beidou signal transmitters. Figure 2 In the figure, C1~C5 can represent the area where each Beidou signal transmitter transmits signals to the receiver. It can be found that the three adjacent Beidou signal transmitters interfere with each other.

[0096] In a specific embodiment, the above-mentioned Beidou signal full coverage method for highway tunnels may include the following steps:

[0097] In the initialization phase, the L signal transmitters may be in an asynchronous mode. In the asynchronous mode, the L signal transmitters may perform synchronization time processing through a preset time synchronization protocol. During the synchronization time processing, the signal transmitter with a lower priority among every two signal transmitters with adjacent priorities among the L signal transmitters may synchronize its own time based on the time of the signal transmitter with a higher priority. The synchronization time processing may last for a preset duration (e.g., 30 seconds).

[0098] In the asynchronous mode, when the L signal transmitters are time synchronized, each of the L signal transmitters may transmit a signal in one or more time segments in the M time segments, and detect the power value of the signal transmitted by the shared channel of the L signal transmitters in each time segment in the M time segments. Wherein, M is a positive integer, and in order to improve the accuracy of the determined first power value and the second power value, M may be set to a larger value, for example, to 100.

[0099] After the end of M time segments, the power value detected by each transmitter in the L signal transmitters is obtained, and a set formed by the historical power values ​​detected by the L signal transmitters can be obtained. Multiple historical power values ​​in the set that are less than the preset power median are determined as multiple first historical power values, and multiple historical power values ​​in the set that are greater than the preset power median are determined as multiple second historical power values; the first power value is determined based on the root mean square error of the multiple first historical power values ​​and the average of the multiple first historical power values; the second power value is determined based on the root mean square error of the multiple second historical power values ​​and the average of the multiple second historical power values.

[0100] In asynchronous mode, when L signal transmitters are time synchronized, the transmission initialization step is entered. Specifically, each signal transmitter randomly selects a time segment from L consecutive time segments with the same duration and transmits a signal in the selected time segment.

[0101] When the signal transmitter does not receive signals transmitted by other signal transmitters among the L signal transmitters except the signal transmitter in the selected time segment, the signal transmitter continues to transmit signals in the selected time segment until the selected time segment ends and stops transmitting signals.

[0102] When the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is higher than the priority of other signal transmitters, the signal transmitter continues to transmit the signal in the selected time segment until the selected time segment ends and stops transmitting the signal.

[0103] When the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is lower than the priority of other signal transmitters, the signal transmitter stops transmitting the signal, reselects a time segment among the L time segments in which no other signal transmitters transmit signals, and returns to the step of transmitting the signal in the selected time segment to continue execution.

[0104] For example, the L time segments may be 5 time segments, specifically, the time segments may be 100ms, 200ms, 300ms, 400ms, and 500ms as the start time points, and each time segment may last for 100ms. The 5 signal transmitters may be arranged in descending order of sequence number, that is, when at least two signal transmitters transmit signals in the same time segment, the signal transmitter with a larger sequence number shall give way to the signal transmitter with a smaller sequence number, that is, the signal transmitter with a larger sequence number shall stop transmitting in the time segment, and the signal transmitter with a smaller sequence number shall keep transmitting in the time segment until the end of the time segment. See, for example, Figure 3As shown in the schematic diagram of the asynchronous mode transmission method, in five consecutive time slots (i.e., time segments), signal transmitters N1, N2, N3, N4, and N5 transmit in an unordered manner.

[0105] When each of the L signal transmitters completes continuous signal transmission in one time segment in the L consecutive time segments, it can be determined that the transmission initialization is completed. The L signal transmitters can enter the synchronization mode.

[0106] In the synchronous mode, each of the L signal transmitters sharing the same channel detects, in each cycle, the power value of the transmitted signal in each of the L time segments of the same duration in the cycle.

[0107] When the power value is less than a predetermined first power value (the channel is idle in the time segment), and the current time of the signal transmitter is not less than L times the duration of the start time of the previous signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal within the time segment and stops transmitting the signal at the end of the time segment.

[0108] When the power value is less than a predetermined first power value (the channel is idle in the time segment), and the current time of the signal transmitter is less than L times the duration of the start time of the previous signal transmission of the signal transmitter, the signal transmitter remains silent in the time segment.

[0109] When the power value is greater than a predetermined second power value (the channel is in an occupied state during the time segment), the signal transmitter remains silent during the time segment.

[0110] See Figure 4 As shown in the schematic diagram of the synchronous mode transmission mode, in each cycle period, within 5 consecutive time slots (i.e., time segments), 5 signal transmitters N1, N2, N3, N4, and N5 transmit in an orderly manner. It can be understood that Figure 4 The sequence of transmission by the signal transmitters N1, N2, N3, N4, and N5 shown is only one of the cases. The transmission sequence of each of the five signal transmitters within a cycle can be determined by the sequence when the transmission initialization is completed.

[0111] For example, one cycle may include time slot 1, time slot 2, time slot 3, time slot 4, and time slot 5 from earliest to latest. When the transmission initialization is completed, it is determined that N2 continues to transmit signals in time slot 1, N3 continues to transmit signals in time slot 2, N5 continues to transmit signals in time slot 3, N4 continues to transmit signals in time slot 4, and N1 continues to transmit signals in time slot 5. According to this transmission rhythm, that is, the rhythm of alternating transmission in the order of N2, N3, N5, N4, and N1 in one cycle, the synchronization mode is entered, and each transmitter transmits the next signal at an interval of 5 time slots, thus realizing the rhythm of alternating transmission in the order of N2, N3, N5, N4, and N1 in one cycle.

[0112] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0113] Based on the same inventive concept, the embodiment of the present application also provides a highway tunnel Beidou signal full coverage system for realizing the above-mentioned highway tunnel Beidou signal full coverage method. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme recorded in the above-mentioned method, so the specific limitations in one or more highway tunnel Beidou signal full coverage system embodiments provided below can refer to the limitations of the highway tunnel Beidou signal full coverage method above, and will not be repeated here.

[0114] In an exemplary embodiment, Figure 5As shown, a highway tunnel Beidou signal full coverage system 500 is provided, comprising: L signal transmitters, including signal transmitter 1, signal transmitter 2... signal transmitter L, a total of L signal transmitters; the L signal transmitters are signal transmitters whose mutual interference degree among multiple signal transmitters arranged in the highway tunnel meets the preset conditions, and L is a positive integer greater than 2; wherein each signal transmitter is used to detect the use status of each time segment of L time segments of the same duration of the channel in each cycle period under the condition of time synchronization; the mutual interference degree of the L signal transmitters meets the preset conditions Condition, L is a positive integer greater than 2; when the channel is in an idle state in a time segment, and the current time of the signal transmitter is not less than L times the duration from the start time of the previous signal transmission of the signal transmitter, then the signal is continuously transmitted in the time segment, and the signal transmission is stopped at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal; when the channel is in an idle state in a time segment, and the current time of the signal transmitter is less than L times the duration from the start time of the previous signal transmission of the signal transmitter, then the time segment remains silent; when the channel is in an occupied state in a time segment, then the time segment remains silent.

[0115] In an exemplary embodiment, each of the signal transmitters of L shared channels is also used to detect, in the case of time synchronization, within each cycle, the power value of the transmitted signal in each of L time segments of the same length in the channel; when the power value is less than a predetermined first power value, it is determined that the channel is in an idle state in the time segment; when the power value is greater than a predetermined second power value, it is determined that the channel is in an occupied state in the time segment; the second power value is greater than the first power value.

[0116] In an exemplary embodiment, a signal transmitter among L signal transmitters can be used to obtain a set formed by each historical power value detected by the L signal transmitters; determine multiple historical power values ​​in the set that are less than a preset power median as multiple first historical power values, and determine multiple historical power values ​​in the set that are greater than the preset power median as multiple second historical power values; determine the first power value based on the root mean square error of the multiple first historical power values ​​and the average value of the multiple first historical power values; determine the second power value based on the root mean square error of the multiple second historical power values ​​and the average value of the multiple second historical power values.

[0117] In an exemplary embodiment, L signal transmitters each have a different priority, and each of the L time-synchronized signal transmitters randomly selects a time segment from L consecutive time segments with the same duration, and transmits a signal in the selected time segment; when the signal transmitter does not receive a signal transmitted by a signal transmitter other than the signal transmitter among the L signal transmitters in the selected time segment, it continues to transmit the signal in the selected time segment until the selected time segment ends, and stops transmitting the signal; when the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is higher than the priority of other signal transmitters, it continues to transmit the signal in the selected time segment until the selected time segment ends, and stops transmitting the signal; when the signal transmitter receives a signal transmitted by other signal transmitters in the selected time segment, and the priority of the signal transmitter is lower than the priority of other signal transmitters, it stops transmitting the signal, reselects a time segment in which no other signal transmitter transmits a signal among the L time segments, and returns to the step of transmitting the signal in the selected time segment to continue execution.

[0118] In an exemplary embodiment, the signal transmitter is also used to detect the usage status of a channel shared by L signal transmitters in a selected time segment; when the channel is in an idle state in the selected time segment, it is determined that no signals transmitted by other signal transmitters are received in the selected time segment; when the channel is in an occupied state in the selected time segment, it is determined that signals transmitted by other signal transmitters are received in the selected time segment.

[0119] In an exemplary embodiment, the plurality of signal transmitters are installed in sequence in the highway tunnel at preset intervals, and the distance between each of the signal transmitters and the ground of the highway tunnel is a preset height greater than zero.

[0120] Each module in the above-mentioned highway tunnel Beidou signal full coverage system can be implemented in whole or in part by software, hardware and their combination. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0121] In an exemplary embodiment, a signal transmitter is provided, and its internal structure diagram can be as follows: Figure 6As shown. The signal transmitter includes a transmitting circuit, a transceiver antenna, a memory and a processor. Among them, the processor, the memory and the transmitting circuit and the transceiver antenna are connected through a system bus, and the transmitting circuit can be electrically connected to the transceiver antenna. Among them, the processor of the signal transmitter is used to provide computing and control capabilities. The memory of the signal transmitter includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The transmitting circuit of the signal transmitter is used to generate a signal to be transmitted. The transceiver antenna of the signal transmitter can be used to transmit signals and receive signals. The transceiver antenna is integrated with a detection module, which can be used to detect the usage status of the channel used by the signal transmitter, and to perform time synchronization processing. When the computer program is executed by the processor, a method for full coverage of Beidou signals in a highway tunnel is implemented.

[0122] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0123] In one embodiment, a signal transmitter is also provided, including a transmitting circuit, a transceiver antenna, a detection module, a memory and a processor, wherein a computer program is stored in the memory, the transmitting circuit is used to generate a signal to be transmitted, the transceiver antenna is used to transmit and receive signals, the detection module is used to detect the usage status of the channel, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0124] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0125] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0126] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0127] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0128] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0129] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for full coverage of Beidou signals in highway tunnels, characterized in that: The method comprises: Each of the L signal transmitters sharing the same channel detects the usage status of each of the L time segments of the same duration of the channel in each cycle under time synchronization; the L signal transmitters are signal transmitters whose mutual interference degree meets the preset conditions among the multiple signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2; When the channel is in an idle state during the time segment, and the current time of the signal transmitter is not less than L times the start time of the last signal transmission of the signal transmitter, the signal transmitter continues to transmit the signal during the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal; When the channel is in an idle state during the time segment, and the distance between the current time of the signal transmitter and the start time of the last signal transmission of the signal transmitter is less than L times of the duration, the signal transmitter remains silent during the time segment; When the channel is in an occupied state during the time segment, the signal transmitter remains silent during the time segment.

2. The method according to claim 1, characterized in that Each of the signal transmitters of the L shared channels, in the case of time synchronization, detects, within each cycle, a usage status of each of the L time segments of the same duration of the channel within the cycle, including: Each of the signal transmitters of the L common channels detects, in a time-synchronized manner, within each cycle, a power value of a transmitted signal of each of the L time segments of the same duration within the cycle; When the power value is less than a predetermined first power value, the signal transmitter determines that the channel is in an idle state in the time segment; When the power value is greater than a predetermined second power value, the signal transmitter determines that the channel is in an occupied state during the time segment; the second power value is greater than the first power value.

3. The method according to claim 2, characterized in that The method further comprises: Acquire a set formed by each historical power value detected by the L signal transmitters; Determine a plurality of historical power values ​​in the set that are smaller than a preset power median value as a plurality of first historical power values, and determine a plurality of historical power values ​​in the set that are larger than the preset power median value as a plurality of second historical power values; Determine a first power value according to a root mean square error of the plurality of first historical power values ​​and an average value of the plurality of first historical power values; The second power value is determined according to a root mean square error of the plurality of second historical power values ​​and an average value of the plurality of second historical power values.

4. The method according to claim 1, characterized in that The L signal transmitters each have a different priority, and each of the signal transmitters of the L shared channels, in the case of time synchronization, detects the use status of each time segment of the L time segments of the same duration of the channel in each cycle, the method further includes: Each of the L time-synchronized signal transmitters randomly selects a time segment from L consecutive time segments with the same duration, and transmits a signal in the selected time segment; When the signal transmitter does not receive a signal transmitted by any signal transmitter other than the signal transmitter among the L signal transmitters in the selected time segment, the signal transmitter continues to transmit the signal in the selected time segment until the selected time segment ends, and stops transmitting the signal; When the signal transmitter receives the signal transmitted by the other signal transmitters in the selected time segment, and the priority of the signal transmitter is higher than the priority of the other signal transmitters, the signal transmitter continues to transmit the signal in the selected time segment until the selected time segment ends, and stops transmitting the signal; When the signal transmitter receives the signal transmitted by the other signal transmitters in the selected time segment, and the priority of the signal transmitter is lower than the priority of the other signal transmitters, the signal transmitter stops transmitting the signal, reselects a time segment in which no other signal transmitters transmit signals among the L time segments, and returns to the step of transmitting the signal in the selected time segment to continue execution.

5. The method according to claim 4, characterized in that The method further comprises: The signal transmitter detects the usage status of the channel shared by the L signal transmitters in the selected time segment; When the channel is in an idle state during the selected time segment, the signal transmitter determines that no signal transmitted by the other signal transmitter is received during the selected time segment; When the channel is in an occupied state during the selected time segment, the signal transmitter determines that the signal transmitted by the other signal transmitter is received during the selected time segment.

6. The method according to any one of claims 1 to 5, characterized in that: The plurality of signal transmitters are installed in sequence in the highway tunnel at preset intervals, and the distance between each of the signal transmitters and the ground of the highway tunnel is a preset height greater than zero.

7. A Beidou signal full coverage system for highway tunnels, characterized in that: The system includes L signal transmitters sharing a common channel, wherein the L signal transmitters are signal transmitters whose mutual interference degree meets preset conditions among a plurality of signal transmitters arranged in a highway tunnel, and L is a positive integer greater than 2; each of the signal transmitters is used to: in the case of time synchronization, detect the usage status of each time segment of the L time segments of the same duration of the channel in each cycle period; when the channel is in an idle state in the time segment, and the current time of the signal transmitter is not less than L times the start time of the previous signal transmission of the signal transmitter, then the signal is continuously transmitted in the time segment, and the signal transmission is stopped at the end of the time segment; the signal transmitted by the signal transmitter is a simulated Beidou signal; when the channel is in an idle state in the time segment, and the current time of the signal transmitter is less than L times the start time of the previous signal transmission of the signal transmitter, then the signal is kept silent in the time segment; when the channel is in an occupied state in the time segment, then the signal is kept silent in the time segment.

8. A signal transmitter, comprising a transmitting circuit, a transceiver antenna, a detection module, a memory and a processor, wherein the memory stores a computer program, characterized in that: The transmitting circuit is used to generate a signal to be transmitted, the transceiver antenna is used to transmit and receive signals, the detection module is used to detect the usage status of the channel, and the processor implements the steps of any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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