Clock calibration method and device

Abstract

The invention discloses a clock calibration method and device. The method comprises the following steps: respectively creating a first clock calibration task and a second clock calibration task; distributing the first clock calibration task to a target core in a multi-core processor of the base station equipment, and executing the first clock calibration task; and in response to a clock calibration request initiated by the cellular service of the base station equipment, switching the first clock calibration task to the second clock calibration task, and executing the second clock calibration task. According to the method and the device, the clock precision can be kept under the condition that the base station equipment does not run any cellular service, a processor core is not preempted to stabilize a communication system, and at least one periodic clock calibration task is run on the base station equipment, so that the clock precision of the base station equipment is improved, upper-layer service and clock calibration are decoupled, and the service performance of the base station equipment is improved. And the stability and reliability of the system are ensured.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a clock calibration method and apparatus. Background Technology

[0002] In mobile communication systems, when satellite signals are weak and cannot provide a clock reference, and ground synchronization fails, periodic clock reference calibration tasks are required to maintain the clock signal synchronization of base station equipment.

[0003] In existing technologies, after the initial clock synchronization of the base station is completed, a periodic clock calibration task can be performed based on the requests of upper-layer services in the communication system. For example, when a cell is established, a periodic clock calibration task is initiated to calibrate the local clock of the base station equipment. However, if the cell is deleted or not established, the periodic clock calibration task cannot be initiated.

[0004] This approach results in the base station clock offset over time not being calibrated in real time when no cells are established. This not only reduces the stability of the communication system and affects normal network communication services, but also increases clock synchronization time and reduces the reliability of the communication system because it relies on upper-layer services to perform clock calibration. Summary of the Invention

[0005] The main purpose of this application is to provide a clock calibration method and apparatus, which aims to solve the problem that base station equipment cannot calibrate in real time due to clock offset and clock synchronization coupling with upper-layer services caused by the passage of time in mobile communication systems.

[0006] To achieve the above objectives, this application provides a clock calibration method applied to base station equipment in a mobile communication system, comprising creating a first clock calibration task and a second clock calibration task respectively; The first clock calibration task is assigned to a target core in the multi-core processor of the base station device and executed; the first clock calibration task calibrates the local clock of the base station device at a first time period. In response to a clock calibration request initiated by the cellular service of the base station equipment, the first clock calibration task is switched to the second clock calibration task; Perform the second clock calibration task; the second clock calibration task is to calibrate the local clock of the base station equipment at a second time period.

[0007] In one possible implementation, performing the first clock calibration task includes: The base station device acquires clock synchronization signals from surrounding macro stations at the first time period through the sniffer channel; and performs calibration operations on the local clock of the base station device based on the clock synchronization signals.

[0008] In one possible implementation, performing the second clock calibration task includes: The base station device acquires clock synchronization signals from surrounding macro stations through its sniffer channel at the second time period; the second time period satisfies the service timing of the base station device; and a calibration operation is performed on the local clock of the base station device based on the clock synchronization signals.

[0009] In one possible implementation, a calibration operation is performed on the local clock of the base station device based on the clock synchronization signal, including: extracting a reference clock from the clock synchronization signal; comparing the reference clock with the local clock of the base station device to obtain a clock deviation value; and when the clock deviation value is less than a clock threshold, executing a clock calibration command to synchronize the local clock as the reference clock.

[0010] In one possible implementation, obtaining the clock synchronization signal from the surrounding macro base stations includes: scanning the synchronization signal block signals of the surrounding macro base stations based on the frequency band supported by the base station equipment; selecting a valid synchronization signal block signal that meets the signal quality condition from multiple synchronization signal block signals, wherein the signal quality condition is that the reference signal reception quality of the synchronization signal block signal is greater than a quality threshold; and using the valid synchronization signal block signal as the clock synchronization signal.

[0011] In one possible implementation, switching the first clock calibration task to the second clock calibration task includes: terminating the first clock calibration task to stop data acquisition from the sniffer channel; loading the configuration parameters of the second clock calibration task; and configuring the sniffer channel based on the configuration parameters.

[0012] In one possible implementation, assigning the first clock calibration task to a target core in the multi-core processor of the base station device includes: selecting a core whose load rate meets a load threshold condition from multiple cores of the multi-core processor of the base station device as the target core; configuring core binding parameters for the first clock calibration task; and establishing a binding relationship with the target core through a binding interface.

[0013] In one possible implementation, before creating the first clock calibration task and the second clock calibration task, the method further includes: initiating the initialization of the base station device; and after completing the initialization of the base station device, aligning and locking the local clock of the base station device with the reference clock by initiating an initial clock synchronization task.

[0014] In one possible implementation, the cellular services of the base station equipment include at least one of cell establishment, cell operation, and cell fault recovery.

[0015] In addition, this application also provides a clock calibration device, comprising: A creation module is used to create a first clock calibration task and a second clock calibration task, wherein the first clock calibration task and the second clock calibration task perform clock calibration with different clock cycles; A binding execution module is used to assign the first clock calibration task to a target core in the multi-core processor of the base station device and execute the first clock calibration task; the first clock calibration task calibrates the local clock of the base station device at a first time period. The switching module is used to switch the first clock calibration task to the second clock calibration task in response to a clock calibration request initiated by the cellular service of the base station equipment. An execution module is used to execute the second clock calibration task, which calibrates the local clock of the base station device at a second time period.

[0016] This application proposes a clock calibration method and apparatus for use in base station equipment in a mobile communication system. It can create a permanently online first clock calibration task and a temporarily online second clock calibration task. When there is no service demand, the first clock calibration task is activated, and then the second clock calibration task is switched to when cellular services are in operation. This allows for periodic calibration of the base station equipment's local clock while meeting the service timing requirements of the base station equipment. This solves the problem that clock reference calibration tasks rely on higher-layer service requests, leading to unstable communication services due to accumulated clock deviations when core services are not being executed. It decouples the base station equipment's clock calibration task from higher-layer services. By creating two logically independent and functionally complete periodic clock calibration tasks, it ensures that at least one periodic clock calibration task runs during base station equipment operation to provide accurate clock signals. This decoupling of upper-layer services and clock calibration improves the stability and reliability of the communication system. Attached Figure Description

[0017] Figure 1 A flowchart illustrating a clock calibration method provided in this application embodiment; Figure 2 A flowchart illustrating another clock calibration method provided in this application embodiment; Figure 3 A flowchart illustrating another clock calibration method provided in this application embodiment; Figure 4This is a structural block diagram of a clock calibration device provided in an embodiment of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0020] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] In related technologies, clock synchronization is a core foundation for base station equipment to provide normal communication services in mobile communication systems. According to the 3GPP (3rd Generation Partnership Project) standard, the deviation between the base station and the standard clock must not exceed ±1.5μs, and the time deviation between base stations must not exceed 3μs. Currently, macro base stations can use GPS (Global Positioning System) / GNSS (Global Navigation Satellite System) satellite clock signals as the primary synchronization source, achieving high-precision clock alignment with the timing center directly by receiving satellite signals. However, micro base stations, due to their large number of deployments and complex environments, can only search for and receive calibrated time synchronization signals from surrounding macro stations. In scenarios where GPS / GNSS signals are weak and cannot provide clock calibration, and the local clock lacks additional calibration methods, clock synchronization failures or errors in oscillation frequency and accuracy degradation due to crystal oscillator aging directly cause timing disorders in the base station's air interface. This leads to system switching between service and no-service states, resulting in long synchronization times between the local clock and the reference clock, which severely impacts the quality of normal communication services.

[0023] Figure 1 This is a flowchart illustrating a clock calibration method provided in an embodiment of this application.

[0024] Reference Figure 1 A clock calibration method is provided, applied to base station equipment of a mobile communication system, the method comprising: Step 101: Create the first clock calibration task and the second clock calibration task respectively.

[0025] It should be noted that a mobile communication system includes terminal equipment and base station equipment; the terminal equipment is the initiator and receiver of the communication link. Regarding clock synchronization, there is no independent high-precision clock; it relies entirely on synchronization signals issued by the base station equipment, such as 4G PSS (Primary Synchronization Signal) / SSS (Secondary Synchronization Signal) and 5G SSB (Synchronization Signal Block), to achieve clock alignment with the base station. The base station equipment is the wireless bridge between the terminal equipment and the core network, and is the core carrier for wireless-side clock synchronization in the mobile communication system. The base station equipment is divided into macro base stations and micro base stations.

[0026] In this embodiment, after the base station equipment completes hardware resource and software environment initialization, a first clock calibration task and a second clock calibration task can be created respectively. This can be achieved after the base station equipment processor has completed full initialization, the multi-core processor's RTOS (Real-Time Operating System) has completed kernel initialization, and the task management module, process scheduling module, and kernel binding module are all enabled. The L1 physical layer has reserved dedicated resources for the clock calibration task, and the basic configuration parameters and links required for the clock calibration task are in place. Furthermore, the initial clock synchronization scan task is executed for the first time to obtain a clock synchronization signal from surrounding macro base stations, and at least one valid clock synchronization signal in the scan results meets the quality and accuracy threshold standards for 4G or 5G communication synchronization signals. Dedicated and independent logical and hardware resources are allocated to the clock calibration management module, including task IDs, task scheduling queues, parameter configuration spaces, etc. It can be initiated through the task management module of the base station equipment, and completed by calling the standardized task creation API or kernel interface provided by the real-time operating system. The first clock calibration task and the second clock calibration task are immediately created in the clock synchronization domain of the L1 physical layer through atomic operations. The second clock calibration task can enter a dormant state after pre-creation and wait for the handover operation to activate it directly.

[0027] For example, taking the sniffer task management module as an example, it can complete the initialization based on the loaded preset parameters and the global configuration of the base station device, and create a first clock calibration task and a second clock calibration task. The first clock calibration task is a periodic sniffer synchronization task that is not dependent on the upper layer service requests of the base station device and can be permanently online. The second clock calibration task is a temporary online periodic sniffer synchronization task that is bound to the cell status. It will only be triggered when the base station device performs cell establishment or cell reconstruction after cell failure, and the establishment process has entered the air interface synchronization signal configuration stage and access has not been opened to the terminal device.

[0028] Step 102: Assign the first clock calibration task to the target core in the multi-core processor of the base station device and execute the first clock calibration task; the first clock calibration task calibrates the local clock of the base station device at a first time period.

[0029] It should be noted that the target core in a multi-core processor is a computing core with unused or low load for core services, and it is included in the idle computing resource pool for scheduling. The core services include communication-related core services such as cell establishment, resource scheduling, air interface signaling parsing, data modulation and demodulation, and clock calibration. The target core, on the other hand, is in a dynamically idle state, executing non-core services and being activated and used on demand.

[0030] In this embodiment, the first clock calibration task can be assigned to a target core in the multi-core processor of the base station device, and the first clock calibration task can be executed. That is, the first clock calibration task can be loaded onto a core in the multi-core processor of the base station device that is not occupied by core services; or a core in an independent coprocessor equipped with the base station device, physically isolated from the core service computing power of the main processor of the base station device, not participating in the processing of any core communication services, with all physical or logical cores in a permanently idle state. Executing the first clock calibration task enables the base station device to search for clock synchronization signals of surrounding macro stations within its supported frequency band at a first time period.

[0031] For example, taking a 5G communication system, the first clock calibration task, such as the first periodic sniffer task, can be bound to the processor core of the base station equipment, including the binding of the CU (Central Unit) side and the DU (Distribution Unit) side. The CU side can select unoccupied logical cores with sufficient computing power from the logical idle core resource pool, and can match them according to task priority, with permanently online tasks matching high-priority logical cores; and when logical idle core resources are insufficient, it can trigger physical idle core fallback, matching from the physical idle cores reserved by the CU side processor. The CU side can perform high-level logic processing of the sniffer task, including task creation, parameter configuration, optimal signal selection, and result reporting, and can allocate dedicated logical target cores to isolate them from core services. The DU side can independently bind to the underlying hardware computing power slices and can perform low-level hardware processing of the sniffer task, including SSB signal exploration, clock synchronization, RSRP (Reference Signal Receiving Power) / RSRQ (Reference Signal Receiving Quality) detection, and raw data acquisition. The sniffer task can be run independently, with low latency and without interference, in the target core through layered independent binding. After the base station equipment initially locks the clock, the upper layer service sends a periodic sniffer request to execute the first clock calibration task. At this time, the cell state is not ready, there is no service execution in the L1 physical layer, and the timing requirements are relatively relaxed. A core with no service operation, such as core 1, can be selected to run the permanently online periodic sniffer task with a periodic time of 0.

[0032] Step 103: In response to the clock calibration request initiated by the cellular service of the base station equipment, switch the first clock calibration task to the second clock calibration task.

[0033] It should be noted that the cellular services of base station equipment include cellular cell management and air interface resource scheduling services. The cell management services include cell establishment, reconstruction, deactivation, and blocking. To ensure the normal operation of cellular services, clock calibration requests need to be initiated to execute time periods that meet service timing requirements.

[0034] In this embodiment, the entire process of cellular services in the base station equipment relies on high-precision clock synchronization across the entire network, and the clock is the core timing reference for cellular services. When the local clock of the base station deviates and the synchronization source fails, clock correction can be triggered through a clock calibration request. Since the base station equipment lacks a high-precision clock reference when the primary synchronization source, such as GPS / GNSS, fails, and external factors such as the continuous accumulation of local clock deviations cause timing anomalies, the base station cellular service management module can initiate a clock calibration request to switch the base station equipment from the first clock calibration task to the second clock calibration task, that is, to terminate the first clock calibration task and load the second clock calibration task. This is because the second clock calibration task has a time period of time 1 that satisfies the service timing requirements.

[0035] For example, taking cell establishment as an example, after the base station equipment initially locks the clock, the upper-layer service issues a periodic sniffer request to execute the first clock calibration task. At this time, the cell state is not ready, there is no service execution at the L1 physical layer, and the timing requirements are relatively relaxed. A core without service operation, such as core 1, can be selected to run a permanently online periodic sniffer task with a period of time0. When the base station cellular service management module initiates a clock calibration request according to the cell establishment requirements, it can terminate the currently running first clock calibration task and load the second clock calibration task. This is because the second clock calibration task has a time period of time1 that meets the service timing requirements. It performs scanning and sniffing within its own frequency band range to obtain clock synchronization signals, such as SSB signals, where time0 > time1. The value range of time0 and time1 varies depending on the performance of different chips.

[0036] Step 104: Execute the second clock calibration task, which calibrates the local clock of the base station equipment using a second time period.

[0037] It should be noted that the second time period is the execution period of the second clock calibration task. The execution time of a single task (SSB scan + synchronization time) is ≤ 1 / 3 of the corresponding period to avoid continuous occupation of computing power.

[0038] In this embodiment, a second clock calibration task is activated in any core of the multi-core processor of the base station device. The following operations can be performed periodically: First, the base station device searches for clock synchronization signals transmitted by surrounding macro stations based on its supported scanning frequency bands to ensure the collaborative operation of the heterogeneous network. Clock synchronization signals can be obtained through methods such as air interface synchronization. Second, a reference clock is extracted from the clock synchronization signal, and the reference clock is compared with the local clock. Finally, when a clock deviation value reaches an error threshold, clock calibration is performed to adjust the local clock to be consistent with the reference clock.

[0039] For example, taking a 5G mobile communication system as an example, the local clock of the base station equipment can be calibrated using a second time period. The first time period is longer than the second time period. Specifically, this includes: based on the supported frequency band range pre-configured by the periodic sniffing task of the base station equipment, searching for SSB signals transmitted by macro base stations in the surrounding coverage area of ​​the micro base station, identifying only macro base station SSB signals within the supported frequency band, and receiving the corresponding macro base station SSB signals through the sniffing channel; for each valid SSB signal, an independent clock synchronization process can be initiated, performing clock deviation calculation, synchronization connection, and other operations, without distinguishing between signal sources and frequency points, to achieve full coverage synchronization attempts for all receivable SSB signals. In the valid list of all successfully synchronized macro base station frequencies, an optimal synchronization signal is selected from multiple received SSB signals based on preset optimization rules (such as signal strength, synchronization stability, frequency priority, etc.). This optimal synchronization signal is continuously monitored for a second time period. This optimal synchronization signal is used as the reference signal for clock adjustment in the current and subsequent periods. A reference clock is extracted from this reference signal, and the clock deviation value is obtained by comparing it with the local clock. Therefore, the local clock of the base station equipment can be precisely adjusted through the clock calibration module to maintain clock synchronization accuracy.

[0040] In this embodiment, a first clock calibration task and a second clock calibration task can be created respectively; the first clock calibration task is assigned to a target core in the multi-core processor of the base station device and executed; the first clock calibration task calibrates the local clock of the base station device at a first time period; in response to a clock calibration request initiated by the cellular service of the base station device, the first clock calibration task is switched to the second clock calibration task. The second clock calibration task is executed; the second clock calibration task calibrates the local clock of the base station equipment using a second time period, where the first time period is longer than the second time period. On the base station equipment in the mobile communication system, a first clock calibration task and a second clock calibration task can be created respectively. The first clock calibration task is bound to an idle core of a multi-core processor to calibrate the local clock of the base station equipment using a first time period. Since the first clock calibration task starts running with system startup and does not occupy processor cores for core services, the base station equipment maintains clock accuracy even when not running any cellular services, and does not preempt processor cores to ensure communication system stability. In response to a clock calibration request initiated by the cellular service of the base station equipment, the periodic clock calibration of the base station equipment can be switched from the first clock calibration task to the second clock calibration task to calibrate the local clock of the base station equipment using a second time period, ensuring that the base station equipment runs at least one periodic clock calibration task, thereby guaranteeing time synchronization and system reliability.

[0041] Figure 2 A flowchart of another clock calibration method provided in an embodiment of this application.

[0042] Reference Figure 2 This application provides another clock calibration method, including: Step 201: Create the first clock calibration task and the second clock calibration task respectively.

[0043] This step can be referred to as step 101 above, and will not be repeated here.

[0044] Step 202: Assign the first clock calibration task to the target core in the multi-core processor of the base station device, and execute the first clock calibration task.

[0045] This step can be referred to step 201 above, and will not be repeated here.

[0046] Optionally, step 202 further includes: Sub-step 2021: Select the core whose load rate meets the load threshold condition from the multiple cores of the multi-core processor of the base station device as the target core.

[0047] It should be noted that the multiple cores of the multi-core processor in the base station equipment are divided into physical layer core groups according to the service modules of the base station equipment. These groups are responsible for time synchronization signals, such as SSB signal acquisition, demodulation, and clock offset calculation. The core load rate is the core operating rate specific to the base station task, that is, the proportion of time the core actually runs the task within a single acquisition cycle to the total acquisition cycle.

[0048] In this embodiment, the load rate of the cores can be collected through the hardware counter of the performance monitoring unit of the multi-core processor in the base station equipment, and the collected data can be written into the core dynamic status table in shared memory. The load rate of a core can be compared with a load threshold, such as 10%, and if the load rate of a core is less than 10%, it is selected as the target core. Alternatively, the filtered candidate core list can be traversed, the real-time load rate of each core can be read from the core dynamic status table, all cores with load rates less than the load threshold can be selected, and a list of available idle cores can be generated. When there are multiple cores in the list of available idle cores, the core with the lowest load rate can be selected first. If the load rates are the same, the core with hardware acceleration can be preferred to meet the clock synchronization signal calculation requirements of the clock calibration task.

[0049] Sub-step 2022: Configure core binding parameters for the first clock calibration task and establish a binding relationship with the target core through the binding interface.

[0050] In this embodiment, core binding parameters can be configured for the first clock calibration task. These core binding parameters establish a binding relationship between the clock calibration task and the core. The core binding parameters include: task identifier, core identifier, binding type, resource reservation parameters, and exception callback parameters. The unique ID of the first clock calibration task is used by the binding interface to identify the target task; the unique ID of the target core is used by the binding interface to locate the target core; the binding type is exclusive binding, used exclusively for the clock calibration task. On the clock calibration task device, this core does not receive any other tasks, ensuring system real-time performance. Then, by calling the core binding interface, the complete core binding parameters are passed to the interface, allocating dedicated resources (such as cache or bus bandwidth) to the first clock calibration task, mapping the task's address space to the core's memory management unit, thereby establishing a dedicated scheduling link between the clock calibration task and the core. This ensures that the relevant instructions of the clock calibration task are executed only by the bound core and do not participate in the global core scheduling. Alternatively, the core resource management table can be queried to determine that the task bound to the target core is the first clock calibration task.

[0051] Sub-step 2023: Obtain clock synchronization signals from surrounding macro stations through the sniffer channel of the base station equipment at the first time period.

[0052] It should be noted that the clock synchronization signal can be the clock synchronization field in the SSB synchronization signal or the PSS / SSS synchronization sequence. The sniffer channel is a dedicated configuration of base station equipment used for receiving downlink signals at the physical layer, such as for passively sniffing downlink synchronization signals of surrounding macro stations.

[0053] In this embodiment, core binding, parameter configuration, and acquisition enable can be completed in the sniffer channel of the base station equipment, and the target synchronization frequency of the surrounding macro station has been locked, with the sniffer channel in normal receiving mode. The sniffer channel can receive the clock synchronization signal of the surrounding macro station itself from the locked synchronization frequency of the surrounding macro station at a first time period. This clock synchronization signal is a reference clock synchronization signal calibrated by the surrounding macro station itself through satellite calibration or fiber optic communication. The reference clock synchronization signal includes a local reference clock.

[0054] Sub-step 2024: Based on the clock synchronization signal, perform a calibration operation on the local clock of the base station equipment.

[0055] In this embodiment, the macro base station reference clock can be extracted from the received clock synchronization signals of surrounding macro base stations. The SSB synchronization signals of surrounding macro base stations are generated by GPS / GNSS precision clocks. The frequency reference can be extracted from the PSS, and the time reference from the SSS. Then, by collecting the local clock status, the deviations in frequency, time, and phase are calculated respectively. When the deviation exceeds a calibration threshold, the local clock deviation is determined to be excessive, triggering a precise calibration command for the L1 layer. If the deviations in all dimensions are within the calibration threshold range and the trend is stable, only the three-dimensional deviation needs to be recorded. The frequency calibration threshold is |ΔF|. th |≤0.01 Hz; time calibration threshold is |△T th |≤1.5 ns; Phase calibration threshold is |△Φ th |≤0.01 rad. Priorities can be set for calibration operations, such as phase > time > frequency. This means that phase deviations can be compensated for first, followed by time and frequency deviations during calibration.

[0056] For example, taking the calibration of 5G base station equipment as an example, the 5G base station equipment adopts a high-stability OCXO (Oven-Controlled Crystal Oscillator) / rubidium clock, combined with a high-precision DPLL (Digital Phase-Locked Loop) and a sub-nanosecond phase adjustment unit. Regarding the phase deviation ΔΦ... opt The sub-nanosecond phase micro-step adjustment can be performed through the DPLL phase compensation unit to ensure the beam pointing accuracy of 5G base stations in large-scale MIMO (Multiple-Input Multiple-Output) operations, with an adjustment step size of 0.01 rad / step (corresponding to a time deviation of ≤0.05 ns); for the time deviation ΔT optWithout interrupting clock operation, sub-nanosecond time compensation is achieved through phase-time conversion to avoid interruptions to low-latency services caused by clock transitions, with an adjustment step size of 0.1 ns / step; this addresses the frequency deviation ΔF. opt The core of ensuring long-term clock stability lies in achieving 0.001 Hz-level fine-tuning by adjusting the oscillation control parameters of the high-stability clock. The adjustment targets are the control voltage (VCO) or frequency division coefficient of the high-stability OCXO / rubidium clock. Furthermore, by sampling multiple SSB cycles, the clock calibration operation can be considered successful if the three-dimensional deviation value is less than the calibration threshold.

[0057] Step 203: In response to the clock calibration request initiated by the cellular service of the base station equipment, terminate the first clock calibration task to stop data acquisition of the sniffer channel.

[0058] In this embodiment, the L1 layer task management module receives a clock calibration request forwarded by the cellular service. Upon successful acceptance of the cellular service's feedback request, it issues a pre-termination command to the L1 layer task management module and the sniffing channel management module. It writes a termination flag to the task control module of the first clock calibration task, triggers a task interruption, completes the calibration data recording for the current cycle, releases the L1 layer computing resources temporarily occupied during task execution, and returns termination-ready feedback to the task management module. At this point, the status of the first clock calibration task is changed from running to terminated, and the task is removed from the RTOS real-time task scheduling list. After the first clock calibration task terminates, the sniffer channel management module stops data acquisition and clears the sniffer channel's dedicated cache data. After all resources are released, the execution status of each task management module is fully synchronized and updated, and the task termination feedback is sent to the cellular service.

[0059] Step 204: Load the configuration parameters for the second clock calibration task.

[0060] It should be noted that the configuration parameters are related to setting the hardware and software resources invoked by the clock calibration task.

[0061] In this embodiment, the complete configuration parameters of the second clock calibration task can be read from the task configuration storage module, such as a local configuration file or a remote management platform. These configuration parameters include: supported frequency band range, SSB signal scan period, clock synchronization threshold, optimal frequency point filtering rules, and sniffer channel acquisition rate. In other words, the L1 layer task management module reads the structured configuration parameters of the second clock calibration task from the specified parameter storage address and performs data verification on the read configuration parameters to ensure integrity. The configuration parameters of the second clock calibration task are then loaded into the corresponding hardware and software modules.

[0062] Step 205: Configure the sniffer channel based on the configuration parameters.

[0063] It should be noted that high-level structured configuration parameters can be converted into a hardware-executable binary configuration instruction set, which is a set of instructions executable by the channel hardware.

[0064] In this embodiment, configuration parameters extracted from the storage module, such as structured configuration data, can undergo secondary verification and parsing to convert higher-level configuration parameters into lower-level parameter instructions recognizable by the sniffer channel hardware. Structured configuration parameters can be parsed hierarchically by channel hardware module; for example, periodic acquisition parameters can be mapped to a hardware timer module, frequency configuration parameters to an RF front-end module, and signal verification parameters to a DSP parsing unit. Each higher-level parameter corresponds to a unique hardware configuration instruction and register address. Frequency binary parameters can be written to the RF front-end phase-locked loop to configure single / multi-frequency receiving modes, enable multi-frequency polling, and lock the corresponding frequency's RF receiving link. The transmit link can be disabled to maintain a pure receive mode by configuring the low-noise amplifier gain and RF filter bandwidth. A sampling period matching the second clock calibration task can be generated by configuring the timer division coefficient and counting frequency. The timer trigger mode can be configured for continuous periodic triggering, directly linking the trigger signal to the RF front-end and ADC, automatically triggering RF reception and analog-to-digital conversion upon reaching the acquisition period.

[0065] Step 206: Execute the second clock calibration task; the second clock calibration task is to calibrate the local clock of the base station equipment using a second time period.

[0066] It should be noted that the second clock calibration task is a periodic sniffer task that is created and awaits activation in order to meet the high-precision clock synchronization requirements of cellular services and initiate a hard real-time emergency calibration task. The entire process is based on the configured sniffer channel and the pre-created dormant second task resources.

[0067] In this embodiment, the L1 layer task management module receives a hard real-time command from the cellular service to start the second clock calibration task. This command can directly switch the second clock calibration task from a dormant state to a running state, skipping parameter reloading and sniffer channel reconfiguration. It can receive clock synchronization signals, such as SSB signals, from surrounding macro base stations via the sniffer channel. Full hardware parsing is performed on valid SSB signals, and the parsed SSB signal characteristics, such as center frequency, transmission timestamp, and phase information, are reported to the clock calibration module in real-time via the high-speed communication interface within the core, in a structured format. The base station's clock calibration module can extract the high-precision reference clock of the macro base station in real-time based on the SSB signal characteristics reported by the channel, and perform closed-loop calibration of the base station's local clock in three dimensions: frequency, time, and phase. Therefore, while meeting the timing requirements of the cellular service, real-time switching of periodic clock calibration tasks can be achieved, ensuring high-precision clock calibration, improving the stability of the communication system, and guaranteeing the reliability of temporary online tasks.

[0068] Optionally, step 206 further includes: Step 2061: Obtain clock synchronization signals from surrounding macro base stations through the sniffer channel of the base station equipment at the second time period; the second time period satisfies the service timing of the base station equipment.

[0069] It should be noted that the second time period is dynamically configured based on the timing characteristics of cellular services, and the selectable range is from 0.5 ms to 5 ms, which is different from the first time period with a fixed sampling period.

[0070] In this embodiment, a clock synchronization signal, such as an SSB signal, can be received from a surrounding macro base station in a locked frequency band via a second time period dynamically configured according to the timing characteristics of cellular services through a pre-configured sniffer channel. The second time period is matched with the timing scheduling period of the base station equipment at the same frequency or multiples thereof, and the data collection time window must fall within the service timing idle window to avoid the data collection operation occupying the core time and frequency resources of the service and interfering with the service data transmission and reception. Specifically, for URLLC (Ultra-Reliable and Low-Latency Communications) low-latency services (timing scheduling period is usually 1ms or less), the second time period is selected to be no greater than 1ms (preferably configured as 1ms or 0.5ms) to ensure that the calibration response speed matches the low-latency requirements of the service; for eMBB (Enhanced Mobile Broadband) high-bandwidth services (timing scheduling period can be flexibly adjusted to 1ms to 5ms), the second time period can be selected as 1ms or 5ms to balance calibration accuracy and resource overhead.

[0071] Step 2062: Based on the clock synchronization signal, perform a calibration operation on the local clock of the base station equipment.

[0072] This step can be referred to as step 2042 above, and will not be repeated here.

[0073] The method further includes: Step 207: Start the initialization of the base station equipment.

[0074] In this embodiment, the initialization of the base station equipment can be initiated. This initialization includes hardware power-on initialization, core module self-test, loading of underlying parameters, communication link initialization, and system calibration. By providing initial power or a reset power supply to the base station equipment, the various hardware modules can be controlled to power on according to a preset timing sequence, prioritizing the L1 layer core modules such as the sniffer channel, local clock module, and DPLL. After the core modules' power supply stabilizes, other auxiliary modules are then powered on to avoid hardware damage caused by disordered power-on timing. Initialization configuration parameters, including initial operating parameters of the clock module, basic attributes of the sniffer channel, and initial rules for core resource allocation, can be read from the base station equipment's non-volatile storage medium. Then, internal communication links between the L1 layer core modules are established, and communication links between L1 layer and L2, L3 layers, and the base station equipment core network are established simultaneously to ensure smooth command transmission and data interaction between modules. Transmission delay is verified after link initialization.

[0075] Step 208: After the initialization of the base station equipment is completed, the local clock of the base station equipment is aligned with the reference clock and locked by starting the initial clock synchronization task.

[0076] In this embodiment, after starting the initial clock synchronization task, the local clock of the base station device can be aligned with and locked to the reference clock through the initial clock synchronization task, laying the foundation for the subsequent creation of the first clock calibration task and the second clock calibration task.

[0077] The initial clock synchronization sniffing task can be used. This sniffing task is a core pre-processor for base station clock synchronization, deployed at the L1 physical layer. It shares sniffer channel hardware resources with the first and second clock calibration tasks but executes independently. Its core purpose is to collect macro-site synchronization signals through the sniffer channel, achieving coarse synchronization alignment and locking between the local clock and the macro-site reference clock. For example, the extracted initial parameters of the macro-site reference clock (e.g., frequency, time, and phase) are sent to the DPLL. The DPLL, in conjunction with the local OCXO clock module, performs coarse synchronization adjustments on the local clock. The adjustment step size is 10 times the high-frequency calibration step size (0.01Hz / step for frequency, 1ns / step for time, and 0.01 rad / step for phase) until the deviation between the local clock and the macro-site reference clock is locked within a preset initial threshold (e.g., frequency deviation ≤ 0.1Hz, time deviation ≤ 10ns, and phase deviation ≤ 0.1rad).

[0078] Figure 3 A flowchart of another clock calibration method provided in an embodiment of this application.

[0079] Reference Figure 3 This application provides another clock calibration method, the method comprising: Step 301: Initialize the system kernel of the base station equipment.

[0080] In this embodiment, the real-time operating system of the mobile communication system's base station equipment performs kernel initialization and enables the task management module, process scheduling module, and kernel binding module. It also initializes the clock calibration management module, synchronizing the base station equipment's local clock with the reference clocks of surrounding macrocells to complete the initial clock synchronization and locking of the base station equipment. This initial clock synchronization and locking is a coarse synchronization process of the base station equipment's local clock, ensuring that the base station equipment has a local clock.

[0081] Step 302: Create the first clock calibration task and the second clock calibration task.

[0082] In this embodiment, the task can be initiated by the task management module of the base station device and completed by calling the standardized task creation API or kernel interface provided by the real-time operating system. The first clock calibration task and the second clock calibration task are immediately created in the clock synchronization domain of the L1 physical layer through atomic operations. The creation process of the first clock calibration task needs to be bound to the target core in the multi-core processor of the base station device and enter the standby state. The second clock calibration task can be pre-created and then enter the dormant state, waiting for the handover operation to activate it directly.

[0083] Step 303: Perform the first clock calibration task.

[0084] In this embodiment, a first clock calibration task can be executed based on the periodic sniffer request issued by the upper layer service. The first clock calibration task is a permanently online periodic sniffer task. At this time, the flavor cell state is not ready, and there is no service execution in the L1 physical layer. There is no need for strict timing requirements. Therefore, a processor core that is not executing core services can be selected to run the permanently online periodic sniffer task with a more relaxed time period, such as 10ms.

[0085] Step 304: In response to cell establishment, perform the second clock calibration task.

[0086] In this embodiment, when the base station cellular service management module initiates a clock calibration request based on the cell establishment requirements, it can terminate the currently running first clock calibration task and load a temporarily online second clock calibration task. This is because the second clock calibration task has a second time period that meets the service timing requirements. The second time period can be dynamically configured based on the service timing requirements of the cell, for example, from 0.5ms to 5ms. It can obtain the clock synchronization signals of surrounding macro stations, such as SSB signals, by performing scanning and sniffing within its own frequency band range. Then, by parsing the reference clock in the clock synchronization signal, and when the deviation between the local clock and the reference clock is greater than the deviation threshold in each dimension, synchronization and calibration operations are performed, such as frequency, time, and phase.

[0087] Step 305: In response to a cellular malfunction, switch to performing the first clock calibration task.

[0088] In this embodiment, if an abnormal cell operation is detected during the execution of the second clock calibration task, the system immediately switches to executing the first clock calibration task. The L1 layer control module of the base station equipment can monitor the cell's operating status in real time, focusing on service timing stability, data transmission and reception success rate, signal interference intensity, and local clock synchronization status, for example, collecting abnormal monitoring data every 500μs. If the cell service timing offset is ≥5ns, the data transmission and reception success rate is <99.9%, strong interference signals continuously appear (interference intensity >-90dBm), or the local clock deviation rebounds to twice or more of the initial threshold, an abnormal cell operation can be determined. An emergency soft termination command is immediately issued to the second clock calibration task, triggering a rapid sleep for the second clock calibration task. Then, the first clock calibration task can be activated, and the resources occupied by the second clock calibration task can be released. Based on the issued activation command for the first clock calibration task, the preset configuration parameters of the first clock calibration task can be loaded, the sniffer channel can be activated, and the first clock calibration task can be started to perform clock calibration at a first time period, such as 5ms, ensuring the basic operating clock requirements of the cell.

[0089] In the embodiments of this application, a temporary online second clock calibration task can be switched to calibrate the local clock of the base station equipment while ensuring that the service timing requirements are met. This solves the problem that the periodic clock reference calibration task depends on higher-layer service requests, which causes clock deviation and leads to communication service instability. It decouples the clock calibration task of the base station equipment from higher-layer services. By creating two logically independent and fully functional periodic clock calibration tasks, it is ensured that at least one periodic clock calibration task runs during the operation of the base station equipment, so as to ensure clock accuracy and improve the stability and reliability of the communication system.

[0090] Figure 4 This is a structural block diagram of a clock calibration device provided in an embodiment of this application.

[0091] like Figure 4 As shown, the device 400 includes: Module 401 is used to create a first clock calibration task and a second clock calibration task, wherein the first clock calibration task and the second clock calibration task perform clock calibration with different clock cycles.

[0092] The binding module 402 is used to assign the first clock calibration task to a target core in the multi-core processor of the base station device and execute the first clock calibration task; the first clock calibration task is to calibrate the local clock of the base station device at a first time period.

[0093] The switching module 403 is used to switch the first clock calibration task to the second clock calibration task in response to a clock calibration request initiated by the cellular service of the base station equipment.

[0094] The execution module 404 is used to execute the second clock calibration task, which calibrates the local clock of the base station device at a second time period.

[0095] In the embodiments of this application, a permanently online first clock calibration task and a temporarily online second clock calibration task can be created. When there is no service demand, the first clock calibration task is activated, and when cellular services are in operation, the second clock calibration task is switched to. This allows for periodic calibration of the local clock of the base station equipment while meeting the service timing requirements of the base station equipment. This solves the problem that the clock reference calibration task depends on higher-layer service requests, which can cause communication service instability due to accumulated clock deviations when no core services are being executed. This decouples the clock calibration task of the base station equipment from higher-layer services. By creating two logically independent and fully functional periodic clock calibration tasks, it is ensured that at least one periodic clock calibration task runs during the operation of the base station equipment to provide accurate clock signals, thereby improving the stability and reliability of the communication system.

[0096] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0097] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0098] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A clock calibration method, applied to base station equipment in a mobile communication system, characterized in that, include: Create a first clock calibration task and a second clock calibration task respectively; The first clock calibration task is assigned to the target core in the multi-core processor of the base station device, and the first clock calibration task is executed. The first clock calibration task is to calibrate the local clock of the base station equipment using a first time period; In response to a clock calibration request initiated by the cellular service of the base station equipment, the first clock calibration task is switched to the second clock calibration task; Perform the second clock calibration task; The second clock calibration task is to calibrate the local clock of the base station equipment using a second time period.

2. The method as described in claim 1, characterized in that, The execution of the first clock calibration task includes: The base station equipment obtains clock synchronization signals from surrounding macro stations at the first time period through the sniffer channel of the base station equipment. Based on the clock synchronization signal, a calibration operation is performed on the local clock of the base station equipment.

3. The method as described in claim 1, characterized in that, The execution of the second clock calibration task includes: The base station equipment obtains clock synchronization signals from surrounding macro stations through the sniffer channel of the base station equipment at the second time period; the second time period satisfies the service timing of the base station equipment. Based on the clock synchronization signal, a calibration operation is performed on the local clock of the base station equipment.

4. The method as described in claim 2 or 3, characterized in that, The calibration operation performed on the local clock of the base station equipment based on the clock synchronization signal includes: Extract the reference clock from the clock synchronization signal; The reference clock is compared with the local clock of the base station equipment to obtain the clock deviation value; When the clock deviation value is less than the clock threshold, a clock calibration command is executed to synchronize the local clock as the reference clock.

5. The method as described in claim 2 or 3, characterized in that, The process of obtaining clock synchronization signals from surrounding macro stations includes: Based on the frequency band scanning capability of the base station equipment, the synchronization signal block signal of the surrounding macro stations is scanned. Valid synchronization signal block signals that meet the signal quality conditions are selected from multiple synchronization signal block signals, wherein the signal quality condition is that the reference signal reception quality of the synchronization signal block signal is greater than a quality threshold. The effective synchronization signal block signal is used as the clock synchronization signal.

6. The method as described in claim 1, characterized in that, Switching the first clock calibration task to the second clock calibration task includes: Terminate the first clock calibration task to stop data acquisition from the sniffer channel; Load the configuration parameters for the second clock calibration task; The sniffer channel is configured based on the configuration parameters.

7. The method as described in claim 1, characterized in that, The step of assigning the first clock calibration task to the target core in the multi-core processor of the base station device includes: From the multiple cores of the multi-core processor of the base station device, select the core whose load rate meets the load threshold condition as the target core; Configure core binding parameters for the first clock calibration task and establish a binding relationship with the target core through the binding interface.

8. The method as described in claim 1, characterized in that, Before creating the first clock calibration task and the second clock calibration task, the method further includes: Initiate the initialization of the base station equipment; After the base station equipment initialization is completed, the local clock of the base station equipment is aligned with the reference clock and locked by starting the initial clock synchronization task.

9. The method as described in claim 1, characterized in that, The cellular services of the base station equipment include at least one of the following: cell establishment, cell operation, and cell fault recovery.

10. A clock calibration device, applied to base station equipment in a mobile communication system, characterized in that, The device includes: A creation module is used to create a first clock calibration task and a second clock calibration task, wherein the first clock calibration task and the second clock calibration task perform clock calibration with different clock cycles; A binding module is used to assign the first clock calibration task to a target core in the multi-core processor of the base station device and execute the first clock calibration task; the first clock calibration task calibrates the local clock of the base station device at a first time period. The switching module is used to switch the first clock calibration task to the second clock calibration task in response to a clock calibration request initiated by the cellular service of the base station equipment. An execution module is used to execute the second clock calibration task, which calibrates the local clock of the base station device at a second time period.

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