Clock detection method, control device, communication device and system

Abstract

The invention relates to a clock detection method, a control device, a communication device and a system, and relates to the technical field of communication. The method is applied to a slave communication device. The method comprises the following steps: receiving a first message, wherein the first message comprises a first timestamp and a first transmission delay; and receiving a second message, wherein the second message comprises a second timestamp and a second transmission delay. When a calculation difference value between the first time value and the second time value is greater than a preset threshold value, an abnormal event signal is sent, and the abnormal event signal is used for indicating that the clock of the slave communication device is abnormal; the value of the first time value is the sum of the first timestamp, the first transmission delay and a target interval duration, and the target interval duration is a time interval when the communication device receives the first message and the second message; the value of the second time value is the sum of the second timestamp and the second transmission delay. Therefore, interference caused by clock misalignment can be reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of communication technology, and in particular to a clock detection method, a control device, a communication device, and a system. Background Art

[0002] For time division duplexing (TDD) networks in wireless communication systems, the clock signals of uplink and downlink transmission signals need to be aligned. If the clock signals of the uplink and downlink transmission signals are not aligned, the transmission signals may fall into the time window of the reception signal of other devices, causing interference. The base station in the TDD system includes a main control unit, a baseband unit (BBU), and a remote radio unit (RRU). The main control unit and baseband unit are usually installed in the equipment room, and the main control unit and baseband unit can be installed in the same physical frame slot. The remote radio unit is usually installed on the top of a tower or on an antenna rack near the base station. The remote radio unit and the baseband unit are connected by transmission lines such as optical fiber. Optical relays and other equipment may also be installed between the remote radio unit and the baseband unit.

[0003] The master control unit (MCU) can be connected to an external clock source, allowing the MCU and baseband unit to obtain timing information. The RRU's clock is determined by the baseband unit's clock and the delay introduced by optical fiber transmission. Sometimes, the optical fiber length on the RRU's receiving side differs from the optical fiber length on the transmitting side, which can prevent the RRU from correctly detecting the delay introduced by optical fiber transmission. In this case, the RRU's clock may be inconsistent with the baseband unit's clock. As a result, the clock signals of the uplink and downlink transmit signals of the wireless communication system may be misaligned, causing interference. Summary of the Invention

[0004] The embodiments of the present application provide a clock detection method, a control device, a communication device, and a system, which solve the problem in the prior art that the clock signals of the uplink and downlink transmission signals of the wireless communication system may be misaligned, causing interference.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In a first aspect, a clock detection method is provided. The method is applied to a slave communication device. The slave communication device includes a first interface and a second interface. The first interface and the second interface are used to respectively couple to a first master communication device and the second master communication device. The method includes: receiving a first message from the first master communication device through the first interface, the first message including a first timestamp and a first transmission delay. The first timestamp indicates the time when the first message was sent, and the first transmission delay indicates half the round-trip time between the first interface and the first master communication device. Receiving a second message from the second master communication device through the second interface, the second message including a second timestamp and a second transmission delay. The second timestamp indicates the time when the second message was sent, and the second transmission delay indicates half the round-trip time between the second interface and the second master communication device. When the calculated difference between the first and second time values ​​is greater than a preset threshold, an abnormal event signal is transmitted, the abnormal event signal indicating a clock abnormality in the slave communication device. The first time value is the sum of the first timestamp, the first transmission delay, and a target interval duration. The target interval duration is the time interval between the reception of the first and second messages by the slave communication device. The second time value is the sum of the second timestamp and the second transmission delay.

[0007] In the above technical solution, when the slave communication device receives the second message, it is determined whether the calculated difference between the clock of the first interface and the clock of the second interface is greater than a preset threshold. If the calculated difference is greater than the preset threshold, the error between the two clocks is large, and the clock of the slave communication device is not aligned with the clock of the first master communication device or the second master communication device. At this time, the slave communication device sends an abnormal event signal to indicate the clock abnormality. On the one hand, there is no need to add new hardware, and only the existing hardware can be used to complete the operation of determining whether the clocks are aligned, which is low in cost. On the other hand, the slave communication device can report the abnormal event signal in a timely manner, and there is no need for maintenance personnel to regularly inspect the communication system. Therefore, there will be no problem that the length of the transmission line on the transmitting and receiving sides is different and difficult to detect. On the other hand, this embodiment is applicable to the situation where the lengths of the transmitting and receiving sides of the transmission line corresponding to one interface are inconsistent. This embodiment is also applicable to the situation where the lengths of the two sides of the transmission lines corresponding to multiple interfaces are inconsistent, but the degree of inconsistency is different.

[0008] In a possible implementation of the first aspect, the abnormal event signal includes a first time value. In the above possible implementation, a basis is provided for detecting whether there are other influencing factors at the moment corresponding to the first time value.

[0009] In a possible implementation of the first aspect, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (OFDM) symbol. Alternatively, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (FOFDM) symbol based on subband filtering. In the above possible implementations, an OFDM or FOFDM symbol is used to indicate an interference threshold. When the calculated difference between the first time value and the second time value is less than the OFDM or FOFDM symbol, the possibility of interference is small. In this way, interference caused by clock misalignment can be effectively reduced.

[0010] In one possible implementation of the first aspect, the slave communication device is a radio remote unit or an active antenna unit, and the master communication device is a baseband unit. In the above possible implementation, the method can be applied to a wireless communication system to provide a basis for high-precision clock alignment in the wireless communication system.

[0011] In a second aspect, a clock detection method is provided. The method is applied to a control device. The control device is used to couple a first master communication device, a second master communication device, and a clock source. The control device is used to generate clocks for the first master communication device and the second master communication device through the clock source. The first master communication device and the second master communication device are both coupled to a slave communication device. The method includes: receiving an abnormal event signal, the abnormal event signal being used to indicate that the clock of the slave communication device is abnormal. In response to the abnormal event signal, an alarm signal is sent when the clock source does not jump. In the above technical solution, in addition to considering the influence of the inconsistent lengths on the transmitting and receiving sides of the transmission line, the influence of the jump of the second clock source is also considered. If the second clock source does not jump, it is considered that the clock misalignment is caused by the inconsistent lengths on the transmitting and receiving sides of the transmission line, and the control device sends an alarm signal. This is more accurate and reliable.

[0012] In a possible implementation of the second aspect, the control device sends an alarm signal in response to the abnormal event signal when the clock source does not change, including: sending the alarm signal in response to the abnormal event signal when the clock source does not change and the clock of the first master communication device is synchronized with the clock of the second master communication device. This possible implementation also considers the influence of the clock asynchrony between the first master communication device and the second master communication device. Only if the clock source does not change and the clocks of the first master communication device and the second master communication device are synchronized is the clock misalignment considered to be caused by the length mismatch between the transmitting and receiving sides of the transmission line. This is more accurate and reliable.

[0013] In a possible implementation of the second aspect, the abnormal event signal includes a first time value. The method also includes: receiving a first transmission delay, the first transmission delay is used to indicate a value of half the round-trip time of the signal between the slave communication device and the first master communication device. In response to the abnormal event signal, when the clock source does not jump, an alarm signal is sent, including: in response to the abnormal event signal, when the clock source does not jump within the target time period, an alarm signal is sent. The minimum time value of the target time period is the first time value minus the first transmission delay, and the maximum time value of the target time period is the first time value plus the first transmission delay. In the above possible implementation, the above-mentioned influencing factors are considered within all possible times of the control device corresponding to the first time value (within the target time period), which is more accurate and reliable.

[0014] In a possible implementation of the second aspect, the slave communication device is a radio remote unit or an active antenna unit, and the master communication device is a baseband unit. In the above possible implementation, the method can be applied to a wireless communication system to provide a basis for high-precision clock alignment in the wireless communication system.

[0015] According to a third aspect, a communication device is provided, which is used to execute the method provided by the first aspect or any possible implementation of the first aspect.

[0016] In a fourth aspect, a control device is provided, which is used to execute the method provided by the second aspect or any possible implementation of the second aspect.

[0017] In a fifth aspect, a communication system is provided, comprising: a slave communication device, a first master communication device, and a second master communication device in the method provided in the first aspect or any possible implementation of the first aspect, and a control device provided in the second aspect or any possible implementation of the second aspect. The communication system is configured to perform the method provided in the first aspect, any possible implementation of the first aspect, the second aspect, or any possible implementation of the second aspect.

[0018] In a possible implementation manner of the fifth aspect, the first primary communication device is used to: receive an abnormal event signal, and send the abnormal event signal and a first transmission delay to the control device.

[0019] In the sixth aspect, a computer-readable storage medium is provided, which includes computer instructions. When the computer instructions are run on an electronic device, the electronic device executes the method provided by the first aspect, any possible implementation of the first aspect, the second aspect, or any possible implementation of the second aspect.

[0020] In the seventh aspect, a computer program product is provided, which, when the computer program product is run on a computer, enables the computer to execute the method provided by the first aspect, any possible implementation of the first aspect, the second aspect, or any possible implementation of the second aspect.

[0021] It can be understood that any of the communication devices, control devices, communication systems, computer storage media or computer program products provided above are used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A method for obtaining a clock according to an embodiment of the present invention is provided. Figure 1 ;

[0023] Figure 2 A method for obtaining a clock according to an embodiment of the present invention is provided. Figure 2 ;

[0024] Figure 3 A schematic diagram of a dual-satellite network structure provided in an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the structure of a communication system provided in an embodiment of the present application;

[0026] Figure 5 A schematic diagram of a clock detection method provided in an embodiment of the present application Figure 1 ;

[0027] Figure 6 A schematic diagram of a clock detection method provided in an embodiment of the present application Figure 2 ;

[0028] Figure 7 A schematic diagram of a clock detection method provided in an embodiment of the present application Figure 3 ;

[0029] Figure 8 A schematic diagram of a clock detection method provided in an embodiment of the present application Figure 4 . DETAILED DESCRIPTION

[0030] It should be noted that the terms "first", "second", etc. involved in the embodiments of the present application are only used to distinguish features of the same type and cannot be understood as indicating relative importance, quantity, order, etc.

[0031] The terms "exemplary" or "for example" in the embodiments of this application are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0032] The terms "coupling" and "connection" involved in the embodiments of the present application should be understood in a broad sense. For example, they may refer to a direct physical connection or an indirect connection achieved through electronic devices.

[0033] First, some basic concepts involved in this application are explained:

[0034] 1. Baseband unit (BBU), remote radio unit (RRU), and active antenna unit (AAU)

[0035] Distributed base stations divide traditional macro base station equipment into two functional units: the baseband unit (BMU) and the remote radio unit (RRU). Signals are transmitted between the BMU and the RRU using transmission lines (e.g., optical fiber). The RRU is coupled to the antenna via a coaxial cable. The BMU performs baseband signal processing (e.g., channel encoding and decoding, modulation and demodulation), provides transmission management and interfaces, manages radio resources, and provides clock signals. The RRU performs intermediate frequency (IF) signal processing (e.g., digital in-phase / quadrature (I / Q) modulation and demodulation, up- and down-conversion, and digital-to-analog / analog-to-digital conversion), RF processing, and duplexing. The active antenna unit (AAU) integrates the RRU and antenna. Thus, the AAU integrates the functions of both. Signals are transmitted between the BMU and the AAU using transmission lines (e.g., optical fiber).

[0036] 2. Single-star topology and dual-star topology

[0037] In a single-satellite networking scenario, the RF processing unit includes an interface (such as a common radio interface (common public radio interface, interface)). The RF processing unit is coupled to a baseband unit through an interface. The RF processing unit refers to a radio remote unit or an active antenna unit. The transmission line corresponding to the interface of the RF processing unit includes a transmitting side and a receiving side. The transmitting side in the embodiment of the present application refers to the side where the baseband unit sends a signal to the RF processing unit, and the receiving side refers to the side where the baseband unit receives a signal from the RF processing unit. Next, taking a single-satellite network including a baseband unit and a RF processing unit as an example, the process of the RF processing unit obtaining a clock is illustrated.

[0038] In one example, the length of the transmission line on the transmitting side is equal to the length of the transmission line on the receiving side. The clock of the radio remote unit can be determined by the clock of the baseband unit and the delay caused by the transmission. Figure 1 As shown. At time T1, the first baseband unit 101 sends a timing message to the first RF processing unit 111. The timing message is used to instruct the first RF processing unit 111 to send a processing delay. At time T2, the first RF processing unit 111 receives the timing message. At time T3, the first RF processing unit 111 sends the processing delay to the first baseband unit 101 in response to the timing message. The processing delay is T3-T2. At time T4, the first baseband unit 101 receives the processing delay. The first baseband unit 101 obtains the round trip time (RTT) of the signal between the first baseband unit 101 and the first RF processing unit 111. The round trip time (RTT) is (T1-T4)-(T3-T2). The first baseband unit 101 completes the timing of the first RF processing unit 111 according to half of the RTT. At time T5, the first baseband unit 101 sends a third message to the first RF processing unit 111. The third message includes the time T5 when the third message was sent and RTT / 2. At time T6, the first RF processing unit 111 receives the third message. Based on the third message, the first RF processing unit 111 determines that T6 of the first RF processing unit 111 corresponds to T5 + RTT / 2 of the first baseband unit 101. In this example, the length of the transmission line on the transmitting side of the first baseband unit 101 must be equal to the length of the transmission line on the receiving side so that the delay on the transmitting side of the first baseband unit 101 is equal to the delay on the receiving side. In this way, RTT / 2 is the correct transmission delay, and the corresponding relationship of T6 = T5 + RTT / 2 is correct. This is also described in the Institute of Electrical and Electronics Engineers (IEEE) 1588V2 protocol: To achieve optimal clock synchronization performance, the network delay between the master and slave devices should be symmetrical.

[0039] In another example, the length of the transmission line on the transmitting side of the first baseband unit 101 is not equal to the length of the transmission line on the receiving side. The clock of the first RF processing unit 111 is determined by the clock of the first baseband unit 101 and the delay caused by the transmission, which is inaccurate. Figure 2 As shown. Because the transmission line on the transmitting side is shorter than the transmission line on the receiving side, the transmission delay on the transmitting side is smaller than the transmission delay on the receiving side. For example, if time T5 is 0:0:0, the transmission delay on the transmitting side is 6 seconds (s), the transmission delay on the receiving side is 10 seconds, and RTT / 2 is 8 seconds. At time T5, the first baseband unit 101 sends the third message to the first RF processing unit 111. At time T6, the first RF processing unit 111 receives the third message. The time T6 obtained by the first RF processing unit 111 is T5 + RTT / 2, which means that the time T6 is 0:0:8. However, the actual time T6 should be 0:0:6. The time T6 obtained by the first RF processing unit 111 does not match the actual time. The first RF processing unit 111 spends 1 second processing the data signal, and the time T7 obtained by the first RF processing unit 111 is 0:0:9. At time T7, the first RF processing unit 111 sends the data signal to the first baseband unit 101. At time T8, the first baseband unit 101 receives the data signal. The first RF processing unit 111 considers time T8 to be 0:0:19, which is consistent with the actual time 0:0:19 on the first baseband unit 101 side.

[0040] In the above example, the length of the transmission line on the transmitting side is not equal to the length of the transmission line on the receiving side, which will cause a clock deviation between the first baseband unit 101 and the first RF processing unit 111, thereby causing interference caused by clock misalignment. Therefore, it is necessary to detect whether the lengths of the transmitting and receiving sides of a transmission line such as an optical fiber are consistent. Only by promptly discovering the inconsistency between the lengths of the transmitting and receiving sides can network risks introduced during network construction or modification be resolved. For a single-satellite networking scenario, if there is a clock deviation between the first baseband unit 101 and the first RF processing unit 111, such a deviation will exist at any time. When testing a single-satellite network, clock misalignment can be promptly discovered by observing interference indicators.

[0041] In a dual-satellite network, the RF processing unit (RPU) includes two interfaces. These interfaces connect the RF processing unit to the two baseband units (BBUs). This section describes a dual-satellite network consisting of a master control unit (MCU), baseband unit (BBU), and RF processing unit (RPU).

[0042] In one example, if Figure 3As shown, the dual-satellite network includes a second RF processing unit 112, a third RF processing unit 113, a fourth RF processing unit 114, the second baseband unit 102, the third baseband unit 103, a first main control unit 121, a second main control unit 122, and a first clock source 130. The first main control unit 121 is coupled to the second baseband unit 102, and the first main control unit 121, the third baseband unit 103, and the first clock source 130 are all coupled to the second main control unit 122. The second RF processing unit 112, the third RF processing unit 113, and the fourth RF processing unit 114 each include two interfaces. One interface is used to couple to the second baseband unit 102 via a transmission line, and the other interface is used to couple to the third baseband unit 103 via a transmission line. Specifically, the A1 interface of the second RF processing unit 112 is coupled to the B1 interface of the second baseband unit 102; the A2 interface of the second RF processing unit 112 is coupled to the B2 interface of the third baseband unit 103; the A3 interface of the third RF processing unit 113 is coupled to the B3 interface of the second baseband unit 102; the A4 interface of the third RF processing unit 113 is coupled to the B4 interface of the third baseband unit 103; the A5 interface of the fourth RF processing unit 114 is coupled to the B5 interface of the second baseband unit 102; and the A6 interface of the fourth RF processing unit 114 is coupled to the B6 interface of the third baseband unit 103.

[0043] Exemplarily, the second baseband unit 102 and the third baseband unit 103 can be different wireless standards, for example, the new radio (NR) standard and the long term evolution (LTE) standard. The second baseband unit 102 and the third baseband unit 103 can also be the same wireless standard. The clocks of the second baseband unit 102, the third baseband unit 103, the first main control unit 121 and the second main control unit 122 are provided by the first clock source 130. The clock co-frame interlocking is performed between the first main control unit 121 and the second main control unit 122. For example, the second baseband unit 102 and the first main control unit 121 are LTE standards, the third baseband unit 103 and the second main control unit 122 are NR standards, and the clock interlocking main standard is the LTE standard. One interface of each RF processing unit is used to couple the second baseband unit 102 of the LTE standard, and the other interface is used to couple the third baseband unit 103 of the NR standard.

[0044] As another example, in a dual-satellite network, the transmission line lengths on the transmitting and receiving sides of some RF processing units may be unequal. For example, the transmission line on the transmitting side between the B1 interface and the A1 interface is 4.5 kilometers (km), and the transmission line on the receiving side is 10.2 km. The transmission lines on both the transmitting and receiving sides between the B2 interface and the A2 interface are 4.5 km. The transmission lines on both the transmitting and receiving sides between the B3 interface and the A3 interface are 10.2 km. The transmission lines on both the transmitting and receiving sides between the B4 interface and the A4 interface are 4.5 km. The transmission lines on both the transmitting and receiving sides between the B5 interface and the A5 interface are 4.5 km. The transmission lines on both the transmitting and receiving sides between the B6 interface and the A6 interface are 4.5 km. The method for obtaining clocks by RF processing units in a dual-satellite network can refer to the method for obtaining clocks in a single-satellite network, and will not be further described in this embodiment of the present application.

[0045] In the above example, for a dual-satellite network scenario, the second RF processing unit 112 selects either the A1 or A2 interface to communicate with the baseband unit. During dual-satellite network testing, if the second RF processing unit 112 selects the A2 interface to communicate with the B2 interface of the third baseband unit 103, no problems will be detected. However, if the second RF processing unit 112 selects the A1 interface to communicate with the B1 interface of the second baseband unit 102, problems will be detected. Therefore, problems may not be detected promptly during dual-satellite network testing. Even if there are no problems at the time of testing, problems may arise after the test is complete. The second RF processing unit 112 lacks a reference clock and cannot use the reference clock to determine which interface's clock is functioning properly. Selecting an incorrect clock by the second RF processing unit 112 will cause clock interference.

[0046] The embodiment of the present application provides a communication system, which can be a wireless communication system or a fixed network system, or other communication systems, and the embodiment of the present application does not limit it. Figure 4 As shown, the communication system 2000 includes a first master communication device 201, a second master communication device 202, a slave communication device 211, a control device 221, and a second clock source 230. The slave communication device 211 includes a first interface C1 and a second interface C0. The first interface C1 is used to couple with the third interface D1 of the first master communication device 201, and the second interface C0 is used to couple with the fourth interface D0 of the second master communication device 202. The direction in which the third interface D1 sends signals to the first interface C1 is the transmitting side, and the direction in which the first interface C1 sends signals to the third interface D1 is the receiving side. The direction in which the fourth interface D0 sends signals to the second interface C0 is the transmitting side, and the direction in which the second interface C0 sends signals to the fourth interface D0 is the receiving side.

[0047] For example, assuming that the communication system 2000 is a wireless communication system, the first master communication device 201 and the second master communication device 202 may correspond to the aforementioned radio frequency processing unit. The slave communication device 211 may correspond to the aforementioned baseband unit. The control device 221 may correspond to the aforementioned master control unit.

[0048] In one possible implementation, an optical time domain reflectometer (OTDR) can be connected to the first and second primary communication devices 201 and 202. The OTDR can be used to detect the fiber path length, thereby verifying whether the lengths of the transmitting and receiving fibers are consistent. In this implementation, this testing requires engineering or maintenance personnel to carry OTDR equipment. This results in high labor costs and is not scalable.

[0049] In one possible implementation, an optical module with OTDR functionality can be installed on the first master communication device 201, the second master communication device 202, or the slave communication device 211. Software can be used to call the optical module to perform fiber length detection. This implementation requires additional hardware, and the added cost of the optical module is several times that of an ordinary optical module.

[0050] In one possible implementation, the optical power attenuation at each interface can be detected to determine whether the optical fiber lengths on the transmitting and receiving sides are inconsistent. In this implementation, the optical power attenuation is affected not only by distance but also by factors such as optical fiber quality and relay equipment, making this implementation unreliable.

[0051] In one possible implementation, the clocks of the first interface C1 and the second interface C0 can be compared for synchronization to determine whether the clocks of the slave communication device 211 are aligned with the clocks of the first master communication device 201 and the second master communication device 202. This can further determine whether the lengths of the transmission lines on the transmitting and receiving sides corresponding to the first interface C1 or the second interface C0 are different, thereby enabling remote identification and assessment of risks.

[0052] In one example, if Figure 5As shown. At time T10, the first master communication device 201 sends a first message to the slave communication device 211 via the third interface D1. The first message includes a first timestamp and a first transmission delay. The first timestamp indicates the time the first message was sent, i.e., time T10. The first transmission delay ST1 indicates half the round-trip time (RTT) between the first interface C1 and the third interface D1. The slave communication device 211 receives the first message from the first master communication device 201 via the first interface C1. The slave communication device 211 obtains the time of receiving the first message based on the first message as time T10+ST1. At time T11, the second master communication device 202 sends a second message to the slave communication device 211. The second message includes a second timestamp and a second transmission delay. The second timestamp indicates the time the second message was sent, i.e., time T11. The first transmission delay ST2 indicates half the round-trip time (RTT) between the second interface C0 and the fourth interface D0. The slave communication device 211 receives the second message from the second master communication device 202 via the second interface C0. The time when the slave communication device 211 receives the second message according to the second message is T11+ST2. When the slave communication device 211 receives the second message, the clock of the first interface C1 is the first time value, and the value of the first time value is the sum of the first timestamp, the first transmission delay and the target interval duration TX. The target interval duration TX is the time interval when the slave communication device 211 receives the first message and the second message. That is, the first time value is T10+ST1+TX. When the slave communication device 211 receives the second message, the clock of the second interface C2 is the second time value, and the value of the second time value is the sum of the second timestamp and the second transmission delay. That is, the second time value is T11+ST2. When the calculated difference between the first time value and the second time value is greater than the preset threshold, the slave communication device 211 sends an abnormal event signal, and the abnormal event signal is used to indicate that the clock of the slave communication device 211 is abnormal.

[0053] Exemplarily, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (OFDM) symbol. Alternatively, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (FOFDM) symbol based on subband filtering. For example, the preset threshold is one-tenth of an OFDM or FOFDM symbol. In this embodiment, the OFDM or FOFDM symbol is used to indicate an interference threshold. When the calculated difference between the first time value and the second time value is less than the OFDM or FOFDM symbol, the possibility of interference is small. In this way, the interference caused by clock misalignment can be effectively reduced.

[0054] For example, the time when the first master communication device 201 sends the first message and the time when the second master communication device 202 sends the second message can be controlled by the control device 221 or can be agreed upon by the protocol. The slave communication device 211 can perform the above-mentioned clock detection process during the initial service logic establishment phase and when the interface clock is switched. The initial service logic establishment phase can be a reset phase. The interface clock switch can be caused by external reasons such as a link interruption. The clock source of the slave communication device 211 can randomly select the clock of the first interface C1 or the clock of the second interface C0. Even if the clock of the slave communication device 211 may not be aligned with the clock of the master communication device, the slave communication device 211 can first perform signal processing using the randomly selected clock source.

[0055] In this embodiment, when the slave communication device 211 receives the second message, it determines whether the calculated difference between the clocks of the first interface C1 and the second interface C0 is greater than a preset threshold. If the calculated difference is greater than the preset threshold, the two clocks have a significant error, and the clock of the slave communication device 211 is not aligned with the clocks of the first master communication device 201 or the second master communication device 202. In this case, the slave communication device 211 transmits an abnormality event signal to indicate the clock anomaly. On the one hand, no new hardware is required; the clock alignment determination operation can be completed using only existing hardware, which is relatively cost-effective. On the other hand, the slave communication device 211 can promptly report the abnormality event signal, eliminating the need for maintenance personnel to regularly inspect the communication system 2000. Therefore, the problem of different transmission line lengths between the transmitting and receiving sides being difficult to detect is eliminated. On the other hand, this embodiment is applicable to situations where the transmission line corresponding to a single interface has inconsistent lengths on the transmitting and receiving sides. This embodiment is also applicable to situations where the lengths of the transmission lines corresponding to multiple interfaces are inconsistent, but the degree of inconsistency varies.

[0056] In a possible implementation, factors other than the inconsistency in the lengths of the transmitting and receiving sides of the transmission line need to be considered.

[0057] In one example, control device 221 receives an abnormal event signal. In response to the abnormal event signal, control device 221 sends an alarm signal when second clock source 230 fails to transition. In this embodiment, in addition to considering the influence of length inconsistencies between the transmitting and receiving sides of the transmission line, the influence of transitions of second clock source 230 is also considered. Only if second clock source 230 fails to transition is the clock misalignment considered to be caused by length inconsistencies between the transmitting and receiving sides of the transmission line, which is more accurate and reliable.

[0058] In another example, the control device 221 receives an abnormal event signal. In response to the abnormal event signal, the control device 221 sends an alarm signal when the second clock source 230 does not change and the clocks of the first master communication device 201 and the second master communication device 202 are synchronized. In this embodiment, the influence of the clock asynchrony between the first master communication device 201 and the second master communication device 202 is also considered. Only if the second clock source 230 does not change and the clocks of the first master communication device 201 and the second master communication device 202 are synchronized is the clock misalignment considered to be caused by the length mismatch between the transmitting and receiving sides of the transmission line. This is more accurate and reliable.

[0059] In another example, the abnormal event signal includes a first time value. The control device 221 receives the first transmission delay. In response to the abnormal event signal, the control device 221 sends an alarm signal when the second clock source 230 does not transition within a target time period. Alternatively, the control device 221 sends an alarm signal in response to the abnormal event signal when the second clock source 230 does not transition within a target time period and the clocks of the first master communication device 201 and the second master communication device 202 are synchronized. The minimum time value of the target time period is the first time value minus the first transmission delay, and the maximum time value of the target time period is the first time value plus the first transmission delay. Optionally, the first master communication device 201 receives the abnormal event signal. The first master communication device 201 sends the abnormal event signal and the first transmission delay to the control device 221. Alternatively, the slave communication device 211 sends the abnormal event signal and the first transmission delay to the control device 221. Optionally, the alarm signal can be a signal that informs personnel of a fault, accident, or other danger. Alarm signals can be sent using stimuli such as light, sound, machinery, electricity, and smell.

[0060] Exemplarily, the moment when the abnormal event signal is sent from the communication device 211 may deviate from the moment when the control device 221 receives the abnormal event signal. The control device 221 should consider the above-mentioned influencing factors when the abnormal event signal is sent from the communication device 211. The abnormal event signal includes a first time value, and the first time value corresponds to the clock of the control device 221 falling within the target time period. For example, consider two extreme cases of the target time period. In one case, the delay on the sending side from the first master communication device 201 to the slave communication device 211 is 0, and the delay on the receiving side is twice the first transmission delay (that is, the round-trip time). According to the aforementioned method of obtaining the clock from the communication device 211, the clock of the slave communication device 211 is calculated with the first transmission delay more than the clock of the first master communication device 201. Therefore, the first time value recorded by the slave communication device 211 corresponds to the clock of the control device 221 as: the first time value minus the first transmission delay. In another scenario, the transmitting-side delay from the first master communication device 201 to the slave communication device 211 is twice the first transmission delay (i.e., the round-trip time), and the receiving-side delay is zero. Due to the aforementioned method for obtaining a clock from the slave communication device 211, the clock of the slave communication device 211 is less than the clock of the first master communication device 201 by the first transmission delay. Therefore, the first time value recorded by the slave communication device 211 corresponds to the clock of the control device 221 as follows: the first time value plus the first transmission delay. In this embodiment, the aforementioned influencing factors are considered within all possible times (within the target time period) corresponding to the first time value of the control device 221, which is more accurate and reliable.

[0061] Based on the above Figure 4 The communication system 2000 shown in the figure and the embodiment of the present application provide Figure 4 The slave communication device 211 and the control device 221 in the embodiment can perform a clock detection method. Figure 6 As shown, the method may include the following steps.

[0062] S100: The slave communication device 211 receives a first message from the first master communication device 201 via the first interface. The first message includes a first timestamp and a first transmission delay. The first timestamp indicates the time the first message was sent. The first transmission delay indicates half the round-trip time between the first interface and the first master communication device 201.

[0063] S200: The slave communication device 211 receives a second message from the second master communication device 202 via the second interface. The second message includes a second timestamp and a second transmission delay. The second timestamp indicates the time when the second message was sent. The second transmission delay indicates half the round-trip time between the second interface and the second master communication device 202.

[0064] S300: When the calculated difference between the first time value and the second time value is greater than a preset threshold, the slave communication device 211 transmits an abnormality event signal, indicating a clock abnormality in the slave communication device 211. The first time value is the sum of the first timestamp, the first transmission delay, and the target interval duration. The target interval duration is the time interval between the reception of the first message and the second message by the slave communication device 211. The second time value is the sum of the second timestamp and the second transmission delay.

[0065] For example, Figure 7 If the calculated difference between the first time value and the second time value is greater than a preset threshold, this indicates that the clock of slave communication device 211 is abnormal and further identification of the cause of the abnormality is required. If the calculated difference between the first time value and the second time value is less than or equal to the preset threshold, this indicates that the clock of slave communication device 211 is aligned with the clocks of first master communication device 201 and second master communication device 202, and there is no interference.

[0066] Exemplarily, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (OFDM) symbol. Alternatively, the preset threshold is less than or equal to the length of a subband filtered orthogonal frequency division multiplexing (FOFDM) symbol. The slave communication device 211 transmits an abnormal event signal to the first master communication device 201, and the first master communication device 201 forwards the abnormal event signal to the control device 221.

[0067] S400: The control device 221 receives an abnormal event signal.

[0068] S600: In response to the abnormal event signal, the control device 221 sends an alarm signal when the second clock source 230 does not change.

[0069] Exemplarily, S600 specifically includes: in response to the abnormal event signal, sending an alarm signal when the second clock source 230 does not jump and the clock of the first master communication device 201 is synchronized with the clock of the second master communication device 202 .

[0070] In one possible implementation, the abnormal event signal includes a first time value. The method further includes S500: the control device 221 receives a first transmission delay. S600 specifically includes: in response to the abnormal event signal, sending an alarm signal when the second clock source 230 does not jump within a target time period.

[0071] For example, Figure 8If the second clock source 230 does not change within the target time period, this indicates that the abnormal event signal is valid, and the control device 221 needs to send an alarm signal. If the second clock source 230 changes within the target time period, this indicates that the abnormal event signal is caused by the change in the second clock source 230, and the control device 221 ignores the abnormal event signal.

[0072] For example, the first transmission delay may be sent by the first primary communication device 201. The minimum time value of the target time period is the first time value minus the first transmission delay, and the maximum time value of the target time period is the first time value plus the first transmission delay.

[0073] It is understandable that Figure 6 、 Figure 7 and Figure 8 The technical principles and technical effects of the method embodiment shown can be referred to the relevant description of the embodiment of the aforementioned communication system 2000, and will not be repeated in the implementation of this application.

[0074] The various components of the above-mentioned image processing device can be used to implement the corresponding steps in steps S210 to S250 in the above-mentioned method embodiment. Since each step has been described in detail in the above-mentioned image compression method embodiment, it will not be repeated here.

[0075] An embodiment of the present application also provides a computer-readable storage medium, which stores program code. When the computer-readable storage medium is run on a device (for example, the device can be a single-chip microcomputer, chip, computer or processor, etc.), the program code therein can be called by the processor to execute one or more steps in the above method embodiment.

[0076] Based on this understanding, the embodiments of the present application also provide a computer program product containing instructions. The technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or the processor therein to execute all or part of the steps of the method described in each embodiment of the present application.

[0077] The control device 221 involved in the embodiments of the present application can be a processor. The processor can have a single-processor structure, a multi-processor structure, a single-threaded processor, a multi-threaded processor, etc. The processor can include at least one of a central processing processor / unit (CPU), a general-purpose processor, a digital signal processor (DSP), a neural network processor, a graphics processing processor / unit (GPU), an image signal processor, a microcontroller, or a microprocessor. In addition, the processor can further include other hardware circuits or accelerators, such as application-specific integrated circuits, field-programmable gate arrays or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc. The control device 221 can be configured as two devices of different standards corresponding to the standards of the first main communication device 201 and the second main communication device 202. The control device 221 can also be integrated with the first main communication device 201 and the second main communication device 202 on the same device.

[0078] The clock source involved in the embodiments of the present application refers to a device that provides a clock standard. The clock source can be a global positioning system (GPS) clock source, an Internet Protocol (IP) clock source, or other clock sources. Clock synchronization refers to maintaining a certain strict specific relationship between signals in time or frequency. Clock synchronization includes time synchronization and frequency synchronization. In a digital communication network, the purpose of clock synchronization is to keep the clock differences of communication devices across the entire network within a reasonable error range. These clock differences include differences in time and frequency. This can avoid poor transmission performance due to inaccurate signal transmission timing.

[0079] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0080] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0081] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and modules described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is merely a logical function division. In actual implementation, there may be other division methods, such as multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0083] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules, that is, they may be located on a single device or distributed across multiple devices. Some or all of the modules may be selected to achieve the purpose of this embodiment based on actual needs.

[0084] In addition, the functional modules in the various embodiments of the present application may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0085] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using a software program, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a DVD), or a semiconductor medium (eg, a solid state disk (SSD)).

[0086] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A clock detection method, characterized in that: The method is applied to a slave communication device; the slave communication device includes a first interface and a second interface; The first interface and the second interface are used to respectively couple a first main communication device and a second main communication device; the method includes: receiving, through the first interface, a first message from the first primary communication device, the first message including a first timestamp and a first transmission delay, wherein the first timestamp is used to indicate a time when the first message is sent, and the first transmission delay is used to indicate half of a round-trip time of a signal between the first interface and the first primary communication device; receiving, through the second interface, a second message from the second primary communication device, the second message including a second timestamp and a second transmission delay, the second timestamp being used to indicate a time when the second message was sent, and the second transmission delay being used to indicate half a value of a round-trip time of a signal between the second interface and the second primary communication device; When the calculated difference between the first time value and the second time value is greater than a preset threshold, an abnormal event signal is sent, and the abnormal event signal is used to indicate that the clock of the slave communication device is abnormal; the value of the first time value is the sum of the first timestamp, the first transmission delay and the target interval duration, and the target interval duration is the time interval when the slave communication device receives the first message and the second message; the value of the second time value is the sum of the second timestamp and the second transmission delay.

2. The method according to claim 1, characterized in that The abnormal event signal includes the first time value.

3. The method according to claim 1 or 2, characterized in that The preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (OFDM) symbol; or, the preset threshold is less than or equal to the length of an orthogonal frequency division multiplexing (FOFDM) symbol based on subband filtering.

4. The method according to any one of claims 1 to 3, characterized in that The slave communication device is a remote radio unit RRU or an active antenna unit AAU, and the master communication device is a baseband unit BBU.

5. A clock detection method, characterized in that: The method is applied to a control device; the control device is used to couple a first master communication device, a second master communication device and a clock source; the control device is used to generate a clock for the first master communication device and the second master communication device through the clock source; The first master communication device and the second master communication device are both coupled to a slave communication device; the method comprising: receiving an abnormal event signal, wherein the abnormal event signal is used to indicate that a clock of the slave communication device is abnormal; In response to the abnormal event signal, when the clock source does not jump, an alarm signal is sent.

6. The method according to claim 5, characterized in that The control device sends an alarm signal in response to the abnormal event signal when the clock source does not jump, including: In response to the abnormal event signal, when the clock source does not jump and the clock of the first master communication device is synchronized with the clock of the second master communication device, an alarm signal is sent.

7. The method according to claim 5 or 6, characterized in that The abnormal event signal includes a first time value; the method further includes: receiving the first transmission delay, where the first transmission delay is used to indicate a value of half of a round-trip time of a signal between the slave communication device and the first master communication device; In response to the abnormal event signal, when the clock source does not jump, sending an alarm signal, including: In response to the abnormal event signal, when the clock source does not jump within the target time period, an alarm signal is sent; the minimum time value of the target time period is the first time value minus the first transmission delay, and the maximum time value of the target time period is the first time value plus the first transmission delay.

8. The method according to any one of claims 5 to 7, characterized in that: The slave communication device is a remote radio unit RRU or an active antenna unit AAU, and the master communication device is a baseband unit BBU.

9. A communication device, characterized in that: The communication device is configured to execute the method according to any one of claims 1 to 4.

10. A control device, characterized in that: The control device is used to execute the method according to any one of claims 5 to 8.

11. A communication system, characterized in that: The communication system includes: a slave communication device, a first master communication device, and a second master communication device in the method according to any one of claims 1 to 4, and a control device in the method according to any one of claims 5 to 8; the communication system is used to execute the method according to any one of claims 1 to 8.

12. The system according to claim 11, wherein: The first primary communication device is used for: receiving the abnormal event signal; The abnormal event signal and the first transmission delay are sent to the control device.

13. A computer-readable storage medium, characterized in that The method comprises computer instructions, which, when executed on an electronic device, enable the electronic device to execute the method according to any one of claims 1 to 8.

14. A computer program product, characterized in that When the computer program product is run on a computer, the computer is enabled to perform the method according to any one of claims 1 to 8.

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