A Method for Full Coverage of Beidou Signals in Highway Tunnels

Abstract

The present application relates to a method for full coverage of Beidou signals in highway tunnels. The method includes: for each signal transmitter among L shared-channel signal transmitters in a highway tunnel, when time-synchronized, detecting the usage status of the channel in each of the L time segments within each cycle period; 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 since the start time of the signal transmitter's previous signal transmission, the signal transmitter continuously transmits a signal within the time segment and stops transmitting the signal at the end of the time segment; 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 since the start time of the signal transmitter's previous signal transmission, the signal transmitter remains silent in the time segment; when the channel is in an occupied state in a time segment, the signal transmitter remains silent in the time segment. Using this method can improve the positioning accuracy in highway tunnels.

Description

Technical Field

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

[0002] With the development of communication technologies, wireless communication technologies have emerged. Wireless communication technologies are a type of communication method that utilizes the characteristic that electromagnetic wave signals can propagate in free space for information exchange. Wireless communication technologies can be widely applied to wireless communication systems such as navigation systems, satellite communication systems, radar systems, and mobile communication systems. In the Beidou satellite navigation system, a receiver can receive Beidou signals to achieve positioning. However, in a highway tunnel, due to the blocked environment, the Beidou signals transmitted by the Beidou satellite navigation system are difficult to reach the receiver. Therefore, in a highway tunnel, multiple signal transmitters are usually set up to simulate the transmission of Beidou signals based on pseudolite technology to achieve positioning.

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

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

[0005] In a first aspect, the present application provides a method for full coverage of Beidou signals in highway tunnels, including:

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

[0007] 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 duration from the start time of the previous signal transmission of the signal transmitter, the signal transmitter continuously transmits a 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 an analog Beidou signal;

[0008] When the channel is idle during the time segment, and the current time of the signal transmitter is less than L times the duration since the start time of the previous signal transmission by the signal transmitter, the signal transmitter remains silent during the time segment;

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

[0010] In a second aspect, the present application also provides a Beidou signal full-coverage system for a highway tunnel. The system includes L signal transmitters sharing a channel. The L signal transmitters are signal transmitters among a plurality of signal transmitters arranged in the highway tunnel, and the degree of mutual interference among them meets a preset condition. L is a positive integer greater than 2; each signal transmitter is configured to: under time synchronization, in each cycle period, detect the usage status of the channel in each of the L time segments of the same duration within the cycle period; when the channel is idle during the time segment, and the current time of the signal transmitter is not less than L times the duration since the start time of the previous signal transmission by the signal transmitter, continuously transmit a signal during the time segment and stop transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is an analog Beidou signal; when the channel is idle during the time segment, and the current time of the signal transmitter is less than L times the duration since the start time of the previous signal transmission by the signal transmitter, remain silent during the time segment; when the channel is occupied during the time segment, remain silent during the time segment.

[0011] In a third aspect, the present application also provides a signal transmitter, including a transmitting circuit, a transceiver antenna, a detection module, a memory, and a processor. 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 usage status of the channel. When the processor executes the computer program, the following steps are implemented:

[0012] Each of the L signal transmitters sharing a channel, under time synchronization, in each cycle period, detects the usage status of the channel in each of the L time segments of the same duration within the cycle period; the L signal transmitters are signal transmitters among a plurality of signal transmitters arranged in the highway tunnel, and the degree of mutual interference among them meets a preset condition. 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 duration from the start time of the previous signal transmission by the signal transmitter, the signal transmitter continuously transmits a signal within the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is an analog Beidou signal;

[0014] When the channel is in an idle state during the 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 by the signal transmitter, 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, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0017] Each of the signal transmitters among the signal transmitters of L shared channels, under the condition of time synchronization, detects the usage status of each time segment among L time segments of the same duration within each cycle period; the L signal transmitters are signal transmitters among multiple signal transmitters arranged in a highway tunnel, and the degree of mutual interference meets a preset condition, 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 duration from the start time of the previous signal transmission by the signal transmitter, the signal transmitter continuously transmits a signal within the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is an analog Beidou signal;

[0019] When the channel is in an idle state during the 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 by the signal transmitter, 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. When the computer program is executed by a processor, the following steps are implemented:

[0022] Each of the signal transmitters of the L shared channels, under the condition of time synchronization, detects the usage status of each of the L time segments of the same duration within each cycle period of the channel; the L signal transmitters are signal transmitters among multiple signal transmitters installed in a highway tunnel that meet the preset condition of mutual interference degree, 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 duration from the start time of the signal transmitter's previous signal transmission, the signal transmitter continuously transmits a signal within the time segment and stops transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is an analog Beidou signal;

[0024] When the channel is in an idle state during the time segment, and the current time of the signal transmitter is less than L times the duration from the start time of the signal transmitter's previous signal transmission, 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] For the above-mentioned Beidou signal full-coverage method, system, signal transmitter, computer-readable storage medium and computer program product in the highway tunnel, since the L signal transmitters are signal transmitters among multiple signal transmitters installed in the highway tunnel that meet the preset condition of mutual interference degree, the signal transmitted by the signal transmitter is an analog Beidou signal, and moreover, each of the L signal transmitters detects the usage status of each of the L time segments of the same duration within each cycle period of the channel under the condition of time synchronization. Furthermore, when it is detected that the channel is in an idle state, if the time from the start time of the previous signal transmission is not less than L times the duration, the signal transmitter transmits the signal until the end of the time segment, and if the time from the start time of the previous signal transmission 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. In this way, in the highway tunnel, it is possible to achieve that the L signal transmitters alternately transmit analog Beidou signals within each cycle period, which can avoid the mutual interference problem caused by the simultaneous signal transmission of the L signal transmitters, enabling the receiver in the highway tunnel to accurately receive the analog Beidou signal, improving the positioning accuracy in the highway tunnel while covering the Beidou signal in the highway tunnel. Description of the Drawings

[0027] To more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the accompanying drawings required for the description of the embodiments of the present application or related technologies. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related accompanying drawings can also be obtained based on these drawings.

[0028] Figure 1 It is a schematic flow chart of the method for full coverage of Beidou signals in a highway tunnel in an embodiment;

[0029] Figure 2 It is a schematic diagram of the system framework for full coverage of Beidou signals in a highway tunnel in an embodiment;

[0030] Figure 3 It is a schematic diagram of the emission mode in asynchronous mode in an embodiment;

[0031] Figure 4 It is a schematic diagram of the emission mode in synchronous mode in an embodiment;

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

[0033] Figure 6 It is an internal structure diagram of the signal transmitter in an embodiment. Specific embodiments

[0034] In order to make the purpose, technical solutions and advantages of the present application more clear and understandable, the following further details the present application in combination 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, as Figure 1 shown, a method for full coverage of Beidou signals in a highway tunnel is provided. In this embodiment, the method is illustrated by taking its application to a signal transmitter as an example. In this embodiment, the method includes the following steps:

[0036] Step 102, each of the signal transmitters in L common-channel signal transmitters detects the usage status of each time segment in L time segments of the same duration within each cycle period under the condition of time synchronization; the L signal transmitters are those with a mutual interference degree meeting the preset conditions among the multiple signal transmitters set in the highway tunnel, 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 may be used to generate a signal to be transmitted. The transceiver antenna may be used to radiate the signal to be transmitted generated by the transmitting circuit outward to transmit the signal. The transceiver antenna can also receive signals, and moreover, the transceiver antenna can transmit and receive signals simultaneously. The detection module may be used to detect the usage state of the channel. The detection module may be set independently of the transceiver antenna or integrated in the transceiver antenna. The channel is a passage for transmitting the signals of each of the L signal transmitters.

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

[0039] Time synchronization means that the local times of the L signal transmitters are the same. The cycle period is the period for the L signal transmitters to cyclically transmit signals. 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 signals is 1 / L. In some scenarios, the time segment can be called a time slot. The duration of a cycle period can be, for example, 1 s (second), 500 ms (millisecond), or others. The duration of each time segment can be, for example, 100 ms, 200 ms, or others.

[0040] A highway tunnel is a passage for vehicles to travel. A highway tunnel can be an undersea tunnel, a mountain tunnel, a cross-river tunnel or others. The full coverage in the full coverage of Beidou signals in a highway tunnel means that Beidou signals can completely cover the receivers in the highway tunnel. Since the signals transmitted by the signal transmitters are analog Beidou signals, the receivers in the highway tunnel can receive Beidou signals for positioning; through the signals transmitted by multiple signal transmitters in the highway tunnel respectively, each driving position in the highway tunnel can receive analog Beidou signals, realizing the full coverage of Beidou signals to the receivers in the highway tunnel. The receivers are, for example, mobile phones, positioning terminals on vehicles or others.

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

[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, and the detection module detects the power value of the signal transmitted in each of the L time segments of the same duration within the cycle period of the channel.

[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 L signal transmitters are time-synchronized. Among them, the management device can be a server or a control terminal.

[0044] In one embodiment, the L signal transmitters can perform synchronous time processing through a preset time synchronization protocol. The preset time synchronization protocol is, for example, the PTP protocol (Precision Timing Protocol), the NTP protocol (Network Time Protocol) or others.

[0045] In one embodiment, the L signal transmitters each have different priorities. During the process of synchronous time processing of the L signal transmitters, among every two signal transmitters with adjacent priorities in 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 adjacent signal transmitters in terms of priority, including a signal transmitter with a higher priority and a signal transmitter with a lower priority, the signal transmitter with the lower priority can be used as the slave clock in the PTP protocol, and the signal transmitter with the higher priority can be used as the master clock in the PTP protocol. By transmitting signals with timestamps, the time difference between the signal transmitter acting as the slave clock and the signal transmitter acting as the master clock can be determined, and based on the time of the signal transmitter acting as the master clock, the time of the signal transmitter acting as the slave clock can be synchronized. Among them, the detection module of the signal transmitter can also measure time. Specifically, the detection module can identify the timestamps in the signals received through the transceiver antenna to perform synchronized time processing.

[0047] The process of performing synchronized time processing on L signal transmitters can last for a preset duration, and every two adjacent signal transmitters in terms of priority can start performing synchronized time processing lasting for the preset duration simultaneously. For example, the preset duration can be 30 seconds. Generally, two signal transmitters can complete a time synchronization within 2 to 3 seconds, so multiple time synchronizations can be performed within 30 seconds, improving the reliability of time synchronization.

[0048] Step 104, 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 duration from the start time of the previous signal transmission by the signal transmitter, the signal transmitter continuously transmits signals within the time segment and stops transmitting signals at the end of the time segment; the signals transmitted by the signal transmitter are simulated Beidou signals.

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

[0050] Exemplarily, 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 duration from the start time of the previous signal transmission by the signal transmitter, the processor of the signal transmitter can control the signal transmitter to continuously transmit signals within the time segment starting from the starting point of the time segment through the transmitting circuit and transceiver antenna of the signal transmitter, and stop transmitting signals at the end of the time segment.

[0051] In one embodiment, the signal transmitter controls signal transmission by controlling the state of the transmission enable switch in the signal transmitter. Specifically, when the channel is in an idle state during 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, the signal transmitter sets the transmission enable switch to the on state and keeps the transmission enable switch in the on state within the time segment to continuously transmit signals within the time segment; at the end of the time segment, the transmission enable switch is set to the off state to stop transmitting signals at the end of the time segment. Among them, the state of the transmission enable switch can be controlled by the processor of the signal transmitter.

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

[0053] Step 106, when the channel is in an idle state during 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, the signal transmitter remains silent during the time segment.

[0054] Among them, remaining silent means that the signal transmitter does not transmit signals. 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, indicating that the time interval between the current time of the signal transmitter and the start time of the previous signal transmission of the signal transmitter is less than L times the duration, which can be denoted as tK < L * tW.

[0055] Exemplarily, when the channel is in an idle state during the 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, the signal transmitter sets the transmission enable switch to the off state during the time segment to remain silent during the time segment.

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

[0057] Among them, the occupied state means that the channel is occupied by a signal transmitter among L signal transmitters to transmit signals.

[0058] Exemplarily, when the channel is in an occupied state during a time segment, the signal transmitter sets the transmission enable switch to the off state during the time segment to remain silent 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 itself during the time segment, the signal transmitter may determine that the channel is in an occupied state during the time segment.

[0060] In the above method for full coverage of Beidou signals in highway tunnels, since the L signal transmitters are signal transmitters that meet the preset condition of mutual interference degree among multiple signal transmitters set in the highway tunnel, the signals transmitted by the signal transmitters are simulated Beidou signals. Moreover, each of the L signal transmitters, under the condition of time synchronization, detects the usage state of the channel in each of the L time segments with the same duration in each cycle period. Furthermore, when it is detected that the channel is in an idle state, if the start time from the previous signal transmission is not less than L times the duration, the signal transmitter transmits the signal until the end of the time segment; if the start time from the previous signal transmission 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. Thus, in the highway tunnel, it is possible to achieve that the L signal transmitters alternately transmit simulated Beidou signals in each cycle period, which can avoid the mutual interference problem caused by the simultaneous signal transmission of the L signal transmitters, enabling the receivers in the highway tunnel to accurately receive the simulated Beidou signals, and improving the positioning accuracy in the highway tunnel while covering the Beidou signals in the highway tunnel.

[0061] In an exemplary embodiment, step 102 includes: each of the L signal transmitters sharing the channel, under the condition of time synchronization, detects the power value of the signal transmitted in each of the L time segments with the same duration in each cycle period; when the power value is less than a pre-determined first power value, the signal transmitter determines that the channel is in an idle state during the time segment; when the power value is greater than a pre-determined 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.

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

[0063] In this embodiment, under the condition of time synchronization, within each cycle period, the power values of the signals transmitted in each of the L time segments of the same duration within the cycle period of the detection channel are detected. Then, the power values are compared with the first power value and the second power value, so that 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. Thus, subsequently, the signal transmitter can determine whether to transmit a signal to achieve the alternating transmission of signals by L signal transmitters.

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

[0065] In one embodiment, the step that when the power value is greater than a pre-determined second power value, the signal transmitter determines that the channel is in an occupied state in the time segment includes: when the detection module of the signal transmitter detects that the power value is greater than the pre-determined 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 designed in advance by the engineer according to the hardware state of the device.

[0066] In an exemplary embodiment, the above-mentioned method for full coverage of Beidou signals in highway tunnels further includes the following steps: obtaining a set formed by the respective historical power values detected by L signal transmitters; determining a plurality of first historical power values that are less than a preset power median value in the set, and determining a plurality of second historical power values that are greater than the preset power median value in the set; determining the first power value according to 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; determining the second power value according to 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.

[0067] Among them, the steps of this embodiment can be executed by the management device corresponding to L signal transmitters, can be executed by any one of the L signal transmitters, or can 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 carried out in the initialization stage before the actual operation of J signal transmitters, or can be carried out during the actual operation of J signal transmitters. The first power value and the second power value can be determined through the steps of this embodiment. In some 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 can include the historical power values detected by each of the L signal transmitters in each time segment of multiple historical time segments. The preset power median can be preset based on engineering experience. The first historical power value can also be referred to as the low power value, and the second historical power value can also be referred to as the high power value.

[0069] The Root Mean Squared Error (RMSE) can also be referred to as the standard error. The calculation method of the root mean squared error of multiple first historical power values can be as follows: first, calculate the average value of multiple first historical power values, and then calculate the square value of the difference between each first historical power value and this average value among multiple first historical power values. After taking the average of the square values corresponding to multiple first historical power values and then taking the square root value, the root mean squared error of multiple first historical power values is obtained. The calculation method of the root mean squared error of multiple second historical power values is similar to that of the root mean squared error of multiple first historical power values, and will not be elaborated here.

[0070] In this embodiment, taking the preset power median as the intermediate value, each historical power value in the set formed by the historical power values detected by L signal transmitters is divided into multiple first historical power values and multiple second historical power values. Furthermore, according to the root mean squared error of multiple first historical power values and the average value of multiple first historical power values, the first power value is determined, and according to the root mean squared error of multiple second historical power values and the average value of multiple second historical power values, the second power value is determined, which can more accurately determine the first power value and the second power value adapted to L signal transmitters, creating conditions for accurately determining the usage state of the channel subsequently.

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

[0072] Formula (1)

[0073] Wherein, can represent the first power value; can represent the average value of multiple first historical power values; can represent the root mean square error of multiple first historical power values; can represent 3 multiplied by , representing 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 according to the root mean square error of multiple second historical power values and the average value of multiple second historical power values may include: subtracting three times the root mean square error of multiple second historical power values from the average value of multiple second historical power values to obtain the second power value. This embodiment can be represented by the following formula (2).

[0075] Formula (2)

[0076] Wherein, can represent the second power value; can represent the average value of multiple second historical power values; can represent the root mean square error of multiple second historical power values; can represent 3 multiplied by , representing 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 further includes the following transmission initialization steps: Each of the L signal transmitters that are time synchronized 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 the signals transmitted by other signal transmitters except itself among the L signal transmitters in the selected time segment, the signal transmitter continuously transmits the signal in the selected time segment until the selected time segment ends and stops transmitting the signal; When the signal transmitter receives the signals transmitted by other signal transmitters in the selected time segment and the priority of the signal transmitter is higher than that of other signal transmitters, the signal transmitter continuously transmits the signal in the selected time segment until the selected time segment ends and stops transmitting the signal; When the signal transmitter receives the signals 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, re-selects a time segment in which no other signal transmitter transmits a signal among the L time segments, and returns to the step of transmitting a signal in the selected time segment to continue execution.

[0078] Among them, the above emission initialization step can be understood as an asynchronous mode. When each of the L signal transmitters continuously emits signals until the end of one of the L time segments within one of the L time segments, it can be determined that the L signal transmitters have completed the emission initialization. Subsequently, steps 102 to 108 can be executed, improving the emission efficiency. Steps 102 to 108 can also be understood as a synchronous mode.

[0079] If the L signal transmitters each have different priorities, the L signal transmitters can be sorted from high to low according to the priorities. The priority order of the L signal transmitters can be determined according to the serial numbers of the L signal transmitters. For example, in the order from smallest to largest serial number, the priorities of the L signal transmitters decrease in turn. Another example is that in the order from largest to smallest serial number, the priorities of the L signal transmitters decrease in turn. The priority order of the L signal transmitters can also be determined by specifying the priority rankings of each of 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, these three signal transmitters are arranged as B, C, and A in turn.

[0080] The L time segments can be, for example, 5 time segments. Specifically, for example, they can be time segments with start time points of 100ms, 200ms, 300ms, 400ms, and 500ms respectively, and each time segment can last for 100ms. It can be understood that reselecting a time segment among the L time segments where no other signal transmitter emits a signal means reselecting a time segment where no other signal transmitter emits a signal from the time segments after the time segment currently selected by this signal transmitter among the L time segments.

[0081] Each signal transmitter can receive the signals transmitted in the channel through the transceiver antenna. When a signal is received, the identification information of the signal transmitter from which the signal originates can be parsed from the signal. By comparing the parsed identification information with the respective identification information of the L signal transmitters pre-stored, it can be determined whether signals emitted by other signal transmitters among the L signal transmitters are received. The identification information is information for distinguishing different signal transmitters. For example, the identification information can be a serial number, a number, etc.

[0082] In this embodiment, each of the L signal transmitters for time synchronization first randomly selects one time segment from L consecutive time segments and transmits a signal in the selected time segment. In this way, different signal transmitters among the L signal transmitters may not select the same time segment, or may select the same time segment. When different signal transmitters select the same time segment to transmit a signal, a collision will occur. At this time, the signal transmitter with a higher priority can continue to transmit a signal in this time segment, while the signal transmitter with a lower priority stops transmitting a signal and re-selects a time segment. In this way, without the need to agree on the transmission order of the L signal transmitters, automatic collision detection and avoidance among the L signal transmitters can be achieved, so that only one signal transmitter continuously transmits a signal in each of the L time segments. Thus, the L signal transmitters do not need to be specified the transmission rhythm by an additional device, and the L signal transmitters can adaptively complete the initial signal transmission rhythm. Then, by executing step 102, the L signal transmitters can alternately transmit signals in each cycle period, avoiding the interference caused by the synchronous signal transmission of the L signal transmitters.

[0083] In one embodiment, when the signal transmitter receives a signal transmitted by another signal transmitter in the selected time segment and the priority of the signal transmitter is lower than that of the other signal transmitter, the signal transmitter stops transmitting the signal. For the time segments after the currently selected time segment among the L time segments, the usage status of the channel in the targeted time segment is detected. When the channel is idle in the targeted time segment, the signal transmitter can determine that no other signal transmitter has transmitted a signal in the targeted time segment, re-selects the targeted time segment, and returns to the step of transmitting a signal in the selected time segment to continue execution.

[0084] In one embodiment, when the channel is occupied in the targeted time segment, the signal transmitter can determine that there is another signal transmitter transmitting a signal in the targeted time segment, and continues 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 transmitter has transmitted a signal in the targeted time segment.

[0085] In one embodiment, when the L signal transmitters change, the changed L signal transmitters perform resynchronization time processing again. When the changed L signal transmitters are time-synchronized, the changed L signal transmitters execute the above-mentioned transmission initialization step, and after executing the transmission initialization step, steps 102 to 108 are executed. 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. It is possible to detect whether a signal transmitter goes offline or online through a management device to determine whether a change has occurred, or it is also possible to detect signals of other signal transmitters within the L signal transmitters to which the signal transmitter belongs to determine whether there is an old signal transmitter going offline or a new signal transmitter going online within the L signal transmitters to which it belongs.

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

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

[0088] In an exemplary embodiment, multiple signal transmitters are sequentially installed in the highway tunnel at a preset interval, 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 interval is a pre-set interval, for example, it can be 15 meters, 20 meters or others. The preset height is a pre-set height, for example, it can be 3 meters, 4 meters or others. Sequentially installing multiple signal transmitters in the highway tunnel at a preset interval means that in the highway tunnel, a signal transmitter is installed every preset interval, so that the distance between adjacent signal transmitters among the multiple signal transmitters is the preset interval. 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 sequentially installed in the highway tunnel at a preset interval. The intervals between adjacent signal transmitters are the same, and the interference situations among different L signal transmitters are the same. There is no need to set multiple transmission mechanisms in the highway tunnel, which improves the 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 the actual scenario, due to the relatively far distance of the Beidou satellite's orbit from the earth's surface, the actual propagation distance of the Beidou signal is relatively far, and the signal received by ground users is weak. In the highway tunnel, it is difficult for the actual Beidou signal to reach the users to achieve positioning. The pseudolite technology can be adopted. By deploying pseudolites (such as signal transmitters) to simulate the actual Beidou satellites, the coverage range and service area of the actual Beidou satellites can be extended. For example, the pseudolite technology can be used to sample the entire highway tunnel at a certain interval to obtain multiple reference points, and set pseudolites at each reference point to obtain the characteristics such as the ephemeris, carrier Doppler, and code phase of the visible Beidou satellites at each reference point, so as to simulate and transmit the Beidou signal through the pseudolites at each reference point, thereby realizing positioning in the tunnel.

[0092] However, since the intervals between each reference point are usually small, the signals emitted by each pseudolite are highly similar. In the prior art, the signal emission mechanism of pseudolites in the highway tunnel is usually continuous emission, and the pseudolites at each reference point will interfere with each other. Moreover, in a complex electromagnetic environment with a high reflectivity such as a steel shell immersed tube, for example, the highway tunnel usually adopts a closed cavity structure and uses steel shell immersed tubes and metal decorative surfaces more. In this environment, due to the relatively wide beam of the pseudolite and the high reflectivity of this environment, the degree of signal mutual interference is further increased. After the signal is emitted multiple times and multiple signals are superposed, the signal quality deteriorates severely, resulting in correlation peak distortion and increased tracking error, making it difficult to achieve stable reception and high-precision positioning, leading to problems such as loss of lock, loss of satellite, or positioning fly-off.

[0093] Different from the continuous emission signal emission mechanism in the prior art, when multiple signal transmitters are installed in the highway tunnel and the signals emitted by the signal transmitters are simulated Beidou signals, in this application, since the mutual interference degree of the L signal transmitters meets the preset conditions, each signal transmitter among the L signal transmitters only continuously emits signals in one of the L time segments in each cycle period. In this way, the L signal transmitters alternately emit signals in each cycle period, which can avoid mutual interference among the L signal transmitters. Regardless of the performance of the receiver in the highway tunnel, precise positioning in the highway tunnel can be achieved without changing the receiver, and it can be applied to various application scenarios with high-precision requirements and good coverage requirements.

[0094] In a specific application scenario, the signal transmitter can be referred to as a Beidou signal transmitter. Inside a highway tunnel, Beidou signal transmitters can be installed every 15 meters at a height of 4 meters from the ground. Through simulation analysis, L can be 5, that is, the interference degree among 5 adjacent Beidou signal transmitters (such as Beidou signal transmitters numbered 1 to 5 in sequence) is relatively large. After exceeding 5, the signal-to-interference ratio exceeds 30 dB and 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. Refer to the schematic diagram of the highway tunnel Beidou signal full-coverage system framework as shown in Figure 2 The Beidou signal transmitter can 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 time stamp in the signal during time synchronization processing. The value of L can be determined through simulation or actual measurement according to the actual situation. For example, only consider the mutual interference situation among 3 Beidou signal transmitters. Figure 2 In it, C1~C5 can represent the areas where each Beidou signal transmitter transmits signals for the receiver to receive, and it can be found that 3 adjacent Beidou signal transmitters interfere with each other.

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

[0097] In the initialization stage, L signal transmitters can be in an asynchronous mode. In the asynchronous mode, among the L signal transmitters, a preset time synchronization protocol can be used to perform synchronous time processing. During the synchronous time processing, among every two adjacent signal transmitters with different 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. The synchronous time processing can last for a preset duration (such as 30 seconds).

[0098] In the asynchronous mode, when the L signal transmitters are time-synchronized, each transmitter among the L signal transmitters can transmit signals in one or more of M time segments and detect the power value of the signals transmitted by the shared channel of the L signal transmitters in each of the M time segments. Among them, M is a positive integer. To improve the accuracy of the determined first power value and second power value, M can be set to a larger value, such as 100.

[0099] After the end of M time segments, the power values detected by each of the L signal transmitters are obtained, and a set formed by the respective historical power values detected by the L signal transmitters can be obtained. A plurality of historical power values in the set that are less than the preset power median are determined as a plurality of first historical power values, and a plurality of historical power values in the set that are greater than the preset power median are determined as a plurality of second historical power values; a first power value is determined according to 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; a second power value is determined according to 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.

[0100] In the asynchronous mode, when the L signal transmitters are time synchronized, enter the transmission initialization step. Specifically, each signal transmitter randomly selects one 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 the signals transmitted by other signal transmitters among the L signal transmitters in the selected time segment, the signal transmitter continuously transmits the signal in the selected time segment until the end of the selected time segment, and then stops transmitting the signal.

[0102] When the signal transmitter receives the signals transmitted by other signal transmitters in the selected time segment and the priority of the signal transmitter is higher than that of other signal transmitters, the signal transmitter continuously transmits the signal in the selected time segment until the end of the selected time segment, and then stops transmitting the signal.

[0103] When the signal transmitter receives the signals 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, reselects a time segment in the L time segments where no other signal transmitter transmits a signal, and returns to the step of transmitting a signal in the selected time segment to continue execution.

[0104] For example, the L time segments can be 5 time segments. Specifically, for example, they can be time segments starting at 100 ms, 200 ms, 300 ms, 400 ms, and 500 ms respectively, and each time segment can last for 100 ms. The 5 signal transmitters can have decreasing priorities in ascending order of their serial numbers. That is to say, when at least two signal transmitters transmit signals within the same time segment, the signal transmitter with a larger serial number gives way to the signal transmitter with a smaller serial number, that is, the signal transmitter with a larger serial number stops transmitting within the time segment, and the signal transmitter with a smaller serial number keeps transmitting until the end of the time segment. See Figure 3Schematic diagram of the asynchronous mode transmission method. Within 5 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 transmitting a signal in one of the L consecutive time segments, the transmission initialization can be determined. The L signal transmitters can enter the synchronous mode.

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

[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 from the start time of the previous signal transmission of the signal transmitter, the signal transmitter continuously transmits a signal within the time segment and stops transmitting 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 from the start time of the previous signal transmission of the signal transmitter, the signal transmitter remains silent within the time segment.

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

[0110] See, for example, Figure 4 Schematic diagram of the synchronous mode transmission method shown. Within 5 consecutive time slots (i.e., time segments) in each cycle period, 5 signal transmitters N1, N2, N3, N4, and N5 transmit in an orderly manner. It can be understood that Figure 4 The sequential transmission shown in the order of signal transmitters N1, N2, N3, N4, and N5 is just one case. The respective transmission order of the 5 signal transmitters within a cycle period can be determined by their respective orders at the time of completing the transmission initialization.

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

[0112] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown in sequence according to the indications of the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, there is no strict order limit for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of the steps or stages in other steps or other steps.

[0113] Based on the same inventive concept, the embodiments of the present application also provide a highway tunnel Beidou signal full coverage system for implementing the above-mentioned highway tunnel Beidou signal full coverage method. The implementation solutions provided by this system to solve problems are similar to the implementation solutions described in the above method. Therefore, the specific limitations in one or more embodiments of the highway tunnel Beidou signal full coverage system provided below can refer to the limitations on the highway tunnel Beidou signal full coverage method in the above text, and will not be elaborated here.

[0114] In an exemplary embodiment, as Figure 5As shown, a Beidou signal full-coverage system 500 for highway tunnels is provided, including: 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 among multiple signal transmitters set in the highway tunnel, and the degree of mutual interference meets the preset conditions, where L is a positive integer greater than 2; among them, each signal transmitter is used to detect the usage status of each time segment in L time segments of the same duration within each cycle period under time synchronization; the degree of mutual interference of the L signal transmitters meets the preset conditions, and 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 continuously transmit a signal within the time segment and stop transmitting the signal at the end of the time segment; the signal transmitted by the signal transmitter is an analog 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 remain silent in the time segment; when the channel is in an occupied state in a time segment, then remain silent in the time segment.

[0115] In an exemplary embodiment, each of the L signal transmitters sharing a channel is further used to detect the power value of the signal transmitted in each time segment in L time segments of the same duration within each cycle period under time synchronization; when the power value is less than a pre-determined 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 pre-determined 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, one of the L signal transmitters can be used to obtain a set formed by the respective historical power values detected by the L signal transmitters; determine multiple first historical power values as the multiple historical power values in the set that are less than the preset power median, and determine multiple second historical power values as the multiple historical power values in the set that are greater than the preset power median; determine the first power value 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; determine the second power value 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.

[0117] In an exemplary embodiment, each of the L signal transmitters has a different priority. Each of the L time-synchronized signal transmitters randomly selects one time segment from L consecutive time segments of the same duration and transmits a signal in the selected time segment. When a signal transmitter does not receive signals transmitted by other signal transmitters among the L signal transmitters in the selected time segment, it continuously transmits the signal until the selected time segment ends and then stops transmitting the signal. When a signal transmitter receives signals transmitted by other signal transmitters in the selected time segment and the priority of the signal transmitter is higher than that of other signal transmitters, it continuously transmits the signal until the selected time segment ends and then stops transmitting the signal. When a signal transmitter receives signals 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, it stops transmitting the signal, re-selects a time segment in which no other signal transmitter transmits a signal from the L time segments, and returns to the step of transmitting a signal in the selected time segment to continue execution.

[0118] In an exemplary embodiment, the signal transmitter is further configured to detect 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 in the selected time segment, it is determined that no signals are received from other signal transmitters in the selected time segment. When the channel is in an occupied state in the selected time segment, it is determined that signals are received from other signal transmitters in the selected time segment.

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

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

[0121] In an exemplary embodiment, a signal transmitter is provided, and its internal structure diagram can be as Figure 6As shown in the figure. The signal transmitter includes a transmitting circuit, a transceiver antenna, a memory, and a processor. Among them, the processor, the memory, 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 computer programs. The internal memory provides an environment for the operation of the operating system and computer programs 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, and the detection module 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, it implements a method for full coverage of Beidou signals in highway tunnels.

[0122] Those skilled in the art can understand that Figure 6 the structure shown in the figure is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this 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 different component arrangements.

[0123] In one embodiment, a signal transmitter is further provided, including a transmitting circuit, a transceiver antenna, a detection module, a memory, and a processor. 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 signals and receive signals. The detection module is used to detect the usage status of the channel. When the processor executes the computer program, it implements the steps in the above method embodiments.

[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 the processor, it implements the steps in the above method embodiments.

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

[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 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 need to comply with relevant regulations.

[0127] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. 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 methods. Among them, any reference to a 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), magnetoresistive 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. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0128] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, 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, it should be considered to be within the scope recorded in the present application.

[0129] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended 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; the multiple signal transmitters are installed in sequence in the highway tunnel at a preset spacing, and the distance between each of the signal transmitters and the ground of the highway tunnel is a preset height greater than zero; 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. A Beidou signal full coverage system for highway tunnels, characterized in that: The system comprises L signal transmitters sharing a channel, wherein the L signal transmitters are signal transmitters whose mutual interference degree meets a preset condition among a plurality of signal transmitters arranged in the highway tunnel, and L is a positive integer greater than 2; the plurality of signal transmitters are sequentially installed in the highway tunnel at a preset spacing, and the distance between each of the signal transmitters and the ground of the highway tunnel is a preset height greater than zero; Each of the signal transmitters is used for: in the case of time synchronization, within each cycle, detecting the usage status of each time segment of 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 continuously transmitting the signal in the time segment, and stopping 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 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 keeping silent in the time segment; when the channel is in an occupied state in the time segment, then keeping silent in the time segment.

7. The system according to claim 6, characterized in that Each of the L signal transmitters of the 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 the L time segments of the same length in the cycle; 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.

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 5 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 5 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 5 are implemented.

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