A wireless communication system and method based on TDD relay and digital optical fiber

Abstract

This invention relates to the field of wireless communication and automated port private network technology, specifically to a wireless communication system and method based on TDD relay and digital optical fiber, comprising: TDD relay nodes collecting uplink and downlink medium transmission status and network jitter dynamic data of the digital optical fiber link between the baseband processing unit; calculating the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters based on these data; if the misalignment parameters are higher than a preset timing offset threshold, calculating the timing pre-compensation value and the guard interval adjustment amount based on the tolerance; if they are not higher, retaining the current guard interval and setting the above two parameters to zero; generating a TDD frame reconstruction instruction based on the above two parameters; and performing transmit and receive timing pre-adjustment and adaptive scaling of the guard interval at the node according to the instruction, outputting the compensated radio frequency transmission signal. This invention achieves high-precision observation of the real link status of digital optical fiber.

Description

Technical Field

[0001] This invention relates to the field of wireless communication and automated port private network technology, specifically to a wireless communication system and method based on TDD relay and digital optical fiber. Background Technology

[0002] In current wireless communication private networks for scenarios such as automated ports, the baseband processing unit and time-division duplex relay nodes are usually connected through digital fiber optic links to carry high-frequency scheduling instructions and service return data.

[0003] To ensure transmission and reception synchronization, existing solutions generally rely on fixed physical layer clock precision and rigid frame structure, i.e., using preset fixed guard intervals to absorb transmission delay. However, due to photoelectric conversion, switching forwarding, and temporary detours in different routing segments of digital optical fiber, uplink and downlink propagation exhibit significant asymmetry, and network jitter increases sharply during peak traffic periods. This mechanism, which relies on rigid timing configuration, cannot detect and dynamically absorb asymmetric delay fluctuations caused by cross-media transmission, nor does it take into account the baseband RF conversion processing overhead within the node. When cross-media timing misalignment occurs, it is very easy for the transmit and receive windows of relay nodes to overlap in the time domain at the switching edge, causing severe air interface collisions and a sharp drop in system throughput.

[0004] Therefore, how to overcome the limitations of fixed physical clock precision, construct a timing adaptive mechanism that senses link status, and realize pre-adjustment of transmit and receive timing and dynamic scaling of guard interval under asymmetric delay and dynamic jitter conditions has become an urgent technical problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a wireless communication system and method based on TDD relay and digital optical fiber, solving the following technical problems:

[0006] To avoid relay node transmit / receive window compression and air interface collision caused by asymmetric uplink and downlink transmission and network dynamic jitter in digital optical fiber, and to reduce the risk of air interface overlap and sudden drop in throughput by sensing link status and performing system-level time elastic compensation, thereby achieving stable transmit / receive switching under asymmetric latency and dynamic jitter conditions.

[0007] The objective of this invention can be achieved through the following technical solutions:

[0008] A wireless communication method based on TDD relay and digital optical fiber is applied to a communication system including a time-division duplex relay node, a baseband processing unit, and a digital optical fiber link. The method includes:

[0009] The time-division duplex relay node establishes a clock synchronization reference with the baseband processing unit and periodically triggers the acquisition process based on this reference. The time-division duplex relay node acquires uplink and downlink media transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through the photoelectric conversion interface configured on it.

[0010] Based on the uplink and downlink medium transmission status data and the network jitter dynamic data, the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters are calculated.

[0011] Obtain the current protection interval currently configured for the time-division duplex relay node;

[0012] Based on the comparison between the cross-medium timing misalignment parameter and the pre-stored preset timing offset threshold, a determination is made: if the cross-medium timing misalignment parameter is higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in conjunction with the asymmetric delay fluctuation tolerance; if the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero.

[0013] Based on the timing pre-compensation value and the protection interval adjustment amount, a time-division duplex frame reconstruction instruction is generated.

[0014] Based on the time-division duplex frame reconstruction instruction, the transmit and receive timing pre-adjustment and guard interval adaptive scaling are performed at the time-division duplex relay node, and the compensated radio frequency transmission signal is output.

[0015] Optionally, collect uplink and downlink media transmission status data and network jitter dynamic data of the digital fiber optic link, including:

[0016] Obtain the time-division duplex scheduled message timestamp in the digital fiber optic link;

[0017] Based on the time-division duplex scheduled message timestamp, the downlink transmission delay and uplink transmission delay of the digital optical fiber link are calculated;

[0018] The difference between the downlink transmission delay and the uplink transmission delay is defined as the uplink and downlink medium transmission status data.

[0019] Extract the set of historical transmission delay deviations within a preset sampling period as the network jitter dynamic data.

[0020] Optionally, based on the uplink and downlink medium transmission status data and the network jitter dynamic data, the asymmetric delay fluctuation tolerance is calculated, including:

[0021] In response to the time-division duplex relay node having a packet loss rate lower than a preset packet loss threshold within a preset monitoring period, the maximum deviation peak value in the network jitter dynamic data is extracted.

[0022] The uplink and downlink medium transmission status data are added to the maximum deviation peak value to obtain the safety buffer boundary;

[0023] The safety buffer boundary is defined as the asymmetric delay fluctuation tolerance, wherein the asymmetric delay fluctuation tolerance characterizes the maximum tolerance parameter before an air interface signal collision occurs in cross-medium communication. In response to the packet loss rate of the time division duplex relay node being higher than or equal to the preset packet loss threshold in the preset monitoring period, the tolerance result of the previous monitoring period or the preset device safety upper limit value is used as the asymmetric delay fluctuation tolerance.

[0024] Optionally, the calculation process for cross-medium timing misalignment parameters includes:

[0025] Obtain the baseband RF conversion processing cycle at the time-division duplex relay node;

[0026] Extract the currently active preset initial protection interval time parameter;

[0027] The baseband radio frequency conversion processing cycle, the currently active preset initial protection interval time parameter, and the uplink and downlink medium transmission status data are summed to obtain the radio frequency signal transmission and reception overlap characteristic value associated with the uplink and downlink switching edge.

[0028] The radio frequency signal transmission and reception overlap characteristic value is set as the cross-medium timing misalignment parameter.

[0029] Optionally, the timing pre-compensation value is calculated by combining the aforementioned asymmetric delay fluctuation tolerance, including:

[0030] Initialize the reference timing offset parameters;

[0031] Subtract the reference timing offset parameter from the cross-medium timing misalignment parameter to generate the error signal feedback quantity;

[0032] Read the preset adaptive pre-compensation convergence rate parameter based on the dynamic mapping of the service quality requirements of the current service being carried;

[0033] The error signal feedback quantity is multiplied by the adaptive pre-compensation convergence rate parameter to obtain the compensation step size, and the compensation step size is accumulated to the reference time offset parameter to obtain the target convergence compensation bias.

[0034] The target convergence compensation bias is determined as the timing pre-compensation value.

[0035] Optionally, the protection interval adjustment amount is calculated, including:

[0036] Compare the asymmetric delay fluctuation tolerance with the currently configured maximum protection interval margin parameter;

[0037] If the asymmetric time delay fluctuation tolerance is greater than the currently configured maximum protection interval margin parameter, the asymmetric time delay fluctuation tolerance is subtracted from the currently configured maximum protection interval margin parameter to obtain the excess amplitude;

[0038] The excess amplitude is multiplied by a preset expansion coefficient configured based on the historical stability of the link and the service fault tolerance rate to output the protection interval adjustment amount;

[0039] If the asymmetric delay fluctuation tolerance is lower than or equal to the currently configured maximum protection interval margin parameter, the protection interval adjustment amount is configured to zero to maintain the stability of the current frame structure.

[0040] Optionally, transmit / receive timing pre-adjustment and guard interval adaptive scaling are performed at the time-division duplex relay node, including:

[0041] The time-division duplex frame reconstruction instruction is parsed, and the timing pre-compensation value and the guard interval adjustment amount embedded in the instruction are extracted.

[0042] The protection interval of the time-division duplex relay node is reconfigured using the protection interval adjustment amount.

[0043] Using the aforementioned timing pre-compensation value, the downlink signal transmission time of the time-division duplex relay node is pre-adjusted to compensate for the asymmetric delay deviation introduced by digital fiber optic transmission.

[0044] Optionally, after outputting the compensated RF transmit signal, the following are included:

[0045] The cross-medium timing misalignment collision probability parameter associated with the compensated radio frequency transmission signal is continuously monitored through the radio frequency eavesdropping channel configured in the time division duplex relay node.

[0046] If the cross-medium timing misalignment collision probability parameter is greater than zero, a timing failure alarm signal is triggered, and the step of collecting uplink and downlink medium transmission status data and network jitter dynamic data of the digital optical fiber link is re-executed in a loop.

[0047] If the cross-medium timing misalignment collision probability parameter is equal to zero, the timing pre-compensation value is extracted and encapsulated into the baseline configuration repository of the time-division duplex relay node.

[0048] A wireless communication system based on TDD relay and digital optical fiber is applied to a communication system including a time-division duplex relay node, a baseband processing unit, and a digital optical fiber link. The system includes:

[0049] The status awareness module is used to enable the time-division duplex relay node to collect uplink and downlink media transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through the photoelectric conversion interface configured on it.

[0050] The timing state calculation module is used to calculate the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters based on the uplink and downlink medium transmission state data and the network jitter dynamic data.

[0051] The current protection interval acquisition module is used to acquire the current protection interval currently configured in the time-division duplex relay node;

[0052] The compensation decision module is used to perform a determination based on the comparison result between the cross-medium timing misalignment parameter and the pre-stored preset timing offset threshold: if the cross-medium timing misalignment parameter is higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in combination with the asymmetric delay fluctuation tolerance; if the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero.

[0053] The instruction generation module is used to generate a time-division duplex frame reconstruction instruction based on the timing pre-compensation value and the protection interval adjustment amount;

[0054] The adaptive reconstruction module is used to perform pre-adjustment of transmit and receive timing and adaptive scaling of guard interval at the time division duplex relay node according to the time division duplex frame reconstruction instruction, and output the compensated radio frequency transmission signal.

[0055] Optional, also includes:

[0056] The baseband processing computing resource pool is used to generate time-domain symmetric raw business data streams;

[0057] An asymmetric transmit / receive equalization network device located near the time-division duplex relay node is used to receive the compensated radio frequency transmit signal to complete the air interface mapping operation without changing the physical layer clock synchronization accuracy.

[0058] The beneficial effects of this invention are:

[0059] 1. This invention collects uplink and downlink transmission status and network jitter data of optical fiber links, calculates error parameters and fluctuation tolerance, and adaptively issues frame reconstruction commands when the error exceeds the limit. This mechanism breaks the rigid frame structure that relies on fixed physical clock precision in the traditional way, effectively solves the problem of transmit and receive window squeezing caused by asymmetric delay and jitter, and reduces the risk of air interface collision.

[0060] 2. This invention prioritizes extracting time-division duplex scheduled message timestamps from the link to calculate the uplink and downlink delay difference, and retains the historical delay deviation set as network jitter data; this mechanism avoids interference from ordinary service load fluctuations on the basic delay assessment, establishes a two-dimensional input of static asymmetric quantity and dynamic jitter quantity, and realizes high-precision observation of the real link status of digital optical fiber;

[0061] 3. This invention introduces a packet loss rate screening mechanism, which extracts the maximum deviation peak value when the packet loss rate is compliant, and superimposes it with the medium transmission status data to form a tolerance boundary. This combination of difference and peak value reflects the inherent asymmetric trend of the link and covers short-term impact situations, providing the system with a quantitative safety tolerance and transforming passive collision repair into risk absorption in advance.

[0062] 4. In solving the cross-medium timing misalignment parameters, this invention innovatively incorporates the baseband RF conversion processing cycle and the initial protection interval parameter inside the node into the summation calculation. This mechanism maps the uncertainty of the optical fiber link with the processing delay inside the relay node that fluctuates with the load, thus achieving a more complete and realistic characterization of the actual air interface switching edge overlap and collision risk.

[0063] 5. This invention calculates the error feedback caused by timing misalignment and combines the adaptive pre-compensation convergence rate and the reference offset parameter to generate the timing pre-compensation value in an asymptotic manner. This strategy effectively avoids single adjustment overshoot or frequent configuration pullback caused by transient network fluctuations, achieves smooth convergence of compensation actions, and greatly improves the engineering stability of dynamic reconstruction.

[0064] 6. This invention compares the latency fluctuation tolerance with the current maximum protection interval margin. When the fluctuation exceeds the limit, the protection interval adjustment amount is generated by combining the expansion coefficient. This mechanism makes up for the defect that simple pre-compensation cannot cope with the significant increase in overall network jitter. By adaptively retaining an extra time buffer at the handover boundary, it effectively prevents the transmission and reception windows from seriously overlapping under sudden spikes.

[0065] 7. After outputting the compensation signal, this invention uses the radio frequency listening channel to continuously monitor the cross-medium collision probability. If there is no collision, it is fixed as the baseline configuration. If there is a collision, an alarm is triggered and the calculation process is restarted. This closed-loop verification mechanism overcomes the technical defect of lacking a posteriori feedback in unidirectional feedforward compensation, enabling the system to form a self-updating loop under complex networking conditions, ensuring long-term reliable operation. Attached Figure Description

[0066] The invention will now be further described with reference to the accompanying drawings.

[0067] Figure 1A flowchart illustrating a wireless communication method based on TDD relay and digital optical fiber provided in this application embodiment;

[0068] Figure 2 This is a schematic diagram of a wireless communication system based on TDD relay and digital optical fiber provided in an embodiment of this application. Detailed Implementation

[0069] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0070] Please see Figure 1 A wireless communication method based on TDD relay and digital optical fiber is applied to a communication system including a time-division duplex relay node, a baseband processing unit, and a digital optical fiber link. The method includes: the time-division duplex relay node establishing a clock synchronization reference with the baseband processing unit and periodically triggering a data acquisition process based on the reference; the time-division duplex relay node acquiring uplink and downlink media transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through a photoelectric conversion interface configured on it.

[0071] Based on the uplink and downlink medium transmission status data and the network jitter dynamic data, the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters are calculated; the current protection interval configured by the time-division duplex relay node is obtained; based on the comparison result between the cross-medium timing misalignment parameters and the pre-stored preset timing offset threshold, a determination is made: if the cross-medium timing misalignment parameters are higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in combination with the asymmetric delay fluctuation tolerance;

[0072] If the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero. Based on the timing pre-compensation value and the protection interval adjustment amount, a time-division duplex frame reconstruction instruction is generated. According to the time-division duplex frame reconstruction instruction, transmit and receive timing pre-adjustment and adaptive scaling of the protection interval are performed at the time-division duplex relay node, and the compensated radio frequency transmission signal is output.

[0073] This embodiment provides a cross-media timing adaptive mechanism for wireless private networks in automated container terminals. Specifically, a baseband processing unit is set up in the central computer room of the port, and multiple time-division duplex relay nodes are deployed on the top of the quay crane and the edge of the yard. Each relay node is connected to the central computer room through a digital fiber optic link to carry automated guided vehicle scheduling instructions, spreader status feedback, and high-definition video inspection data.

[0074] Because the optical fiber in the port area undergoes switching, forwarding, photoelectric conversion, and temporary detours in different routing segments, the uplink and downlink propagation is not always symmetrical, and jitter increases during peak loading and unloading periods, causing the transmission and reception windows of relay nodes to overlap in the time domain at the switching edge.

[0075] Furthermore, the relay node first continuously reads the link operation information through the local optoelectronic conversion interface, forming two types of input data: one type reflects the uplink and downlink medium transmission status, and the other type reflects the network jitter dynamics within a short period. The control logic uses these two types of data to calculate the system's tolerable delay fluctuation boundary and the current degree of cross-medium timing misalignment. Here, the tolerable boundary can be understood as the time margin that can still be absorbed before an air interface collision occurs, while the degree of misalignment indicates whether the uplink and downlink switching edge has approached the collision critical zone.

[0076] For ease of explanation, a quantitative deduction is made: Assuming a relay node measures an average downlink delay of 120 microseconds and an average uplink delay of 108 microseconds over three consecutive sampling periods, the uplink and downlink transmission state can be taken as 12 microseconds; within the same time period, the historical transmission delay deviation set can be simplified to... If the value is in microseconds, then the jitter peak value of 5 microseconds can be extracted from it.

[0077] The preset timing offset threshold is a system empirical boundary value configured based on the cyclic prefix length or maximum tolerable delay spread parameter specified in the air interface standard protocol of the communication system. If the calculated asymmetric delay fluctuation tolerance is 17 microseconds, and combined with the processing cycle of the baseband to the radio frequency of this node and the initial guard interval, the cross-medium timing misalignment parameter is 20 microseconds, and the preset timing offset threshold is set to 15 microseconds, it indicates that the current misalignment degree has exceeded the safety threshold. At this time, the system no longer uses the fixed frame structure, but further calculates the timing pre-compensation value and the guard interval adjustment amount. Assuming that the timing pre-compensation value is 6 microseconds and the guard interval adjustment amount is 4 microseconds, a frame reconstruction instruction is generated to advance the downlink transmission time by 6 microseconds, that is, to execute the transmit / receive timing pre-adjustment, and to adjust the guard interval from the original 10 microseconds to 14 microseconds. After receiving the instruction, the relay node rearranges the transmit / receive boundaries and finally outputs the compensated radio frequency transmission signal.

[0078] If the comparison results show that the degree of misalignment is not higher than the threshold, the system will keep the current protection interval unchanged and set the pre-compensation value and adjustment amount to zero to avoid over-adjustment when the link is stable and introduce new timing fluctuations; if the collected data is missing, the timestamp is incomplete, or the calculation result exceeds the allowable range of the device, a conservative strategy will be adopted for this cycle, the stable configuration of the previous cycle will continue to be used, and an anomaly marker will be recorded for the next round of detection and verification.

[0079] For example, when a sudden fog occurs at the port at night and the video backhaul traffic increases, the digital fiber optic link corresponding to the relay node on the north side of the yard passes through a temporary aggregation and switching device, resulting in the uplink backhaul path having one more buffer queue than the downlink.

[0080] The system thus detected a sudden increase in the uplink and downlink time delay difference, indicating that the original fixed protection interval was insufficient. After the aforementioned calculation and reconstruction, the downlink transmission time was appropriately advanced, and the protection interval was widened synchronously, so that the automatic guided vehicle control signal and the tower crane feedback signal could still switch without collision within the predetermined TDD frame.

[0081] The purpose of this step is to transform the control approach that relies on the extreme precision of a fixed physical clock into a system-level time elastic compensation based on the perception of the link status, thereby achieving stable transmission and reception switching under the conditions of asymmetric delay and dynamic jitter in digital optical fiber, and reducing the risk of air interface overlap and sudden drop in throughput.

[0082] In a preferred embodiment of the present invention, the step of collecting uplink and downlink medium transmission status data and network jitter dynamic data of a digital optical fiber link includes: obtaining the time-division duplex timed message timestamp in the digital optical fiber link; and calculating the downlink transmission delay and uplink transmission delay of the digital optical fiber link based on the time-division duplex timed message timestamp.

[0083] The difference between the downlink transmission delay and the uplink transmission delay is defined as the uplink and downlink medium transmission status data; the set of historical transmission delay deviations within a preset sampling period is extracted as the network jitter dynamic data.

[0084] This embodiment provides a link status acquisition step for the aforementioned port private network; specifically, the relay node does not directly use service packets as the measurement basis, but instead prioritizes extracting time-division duplex timed message timestamps specifically for timed measurement from the digital optical fiber link, so as to avoid ordinary service load fluctuations directly interfering with the basic latency assessment.

[0085] Specifically, the time-division duplex timed message is generated based on the Precision Time Protocol or the Synchronous Ethernet Protocol, and the timestamp it carries contains nanosecond-level high-precision physical layer marking information.

[0086] Furthermore, within each sampling window, the baseband processing unit sends downlink timed messages to the relay node, and the relay node records the reception time; the relay node then returns uplink timed messages to the baseband processing unit, and the equipment room records the reception time; by combining the sending timestamp and the receiving timestamp, the downlink transmission delay and the uplink transmission delay can be obtained respectively.

[0087] To keep the explanation concise, let's assume that within a certain sampling window, the time it takes for a downlink message to travel from the equipment room to the node is 120 microseconds, and the time it takes for an uplink message to travel from the node to the equipment room is 108 microseconds. The difference of 12 microseconds is defined as the uplink and downlink media transmission status data. If the delay deviations measured in five consecutive sampling windows are 2 microseconds, 4 microseconds, 3 microseconds, 5 microseconds, and 1 microsecond, respectively, then the set... This serves as the input of dynamic network jitter data for that period into the subsequent calculation module;

[0088] It should be noted that a single difference is insufficient to characterize link stability; therefore, this embodiment retains the set of historical deviations over a short period.

[0089] This approach can distinguish between long-term stable conditions with fixed asymmetries and conditions where the average difference is small but the instantaneous jitter peak exceeds the preset fluctuation threshold. For example, if the average difference between uplink and downlink on a certain link is only 3 microseconds, but there is an 11-microsecond peak in the historical deviation set, then there may still be risks at the edge of TDD switching.

[0090] Regarding the system's fault tolerance mechanism, if only downlink scheduled messages are received within a certain window but no uplink feedback is received, or if timestamps are rolled back, missing, or out of order, then the data in that window will not be used in the current set statistics, but will be marked as invalid sampling.

[0091] If the number of consecutive invalid samples exceeds the preset limit, the relay node will suspend updating the compensation parameters and report the link status abnormality. If the difference between the uplink and downlink delays is negative, the symbol information can be retained and input into subsequent modules to indicate that the uplink is slower than the downlink, rather than forcibly taking the absolute value, so that the subsequent compensation direction can be correctly determined.

[0092] For example, during the morning peak operation period at an automated terminal, the downlink control signal from the central computer room to the quay crane relay node needs to pass through two levels of aggregation equipment, while the uplink status return is carried out along another path with a shorter transmission path than the downlink route; the system detects through regular time messages that the average downlink delay is 126 microseconds and the average uplink delay is 114 microseconds, with a difference of 12 microseconds; within a 10-millisecond sampling period, it extracts... The historical deviation set in microseconds provides the original basis for subsequent judgment on whether the protection interval needs to be expanded;

[0093] The purpose of this step is to establish a two-dimensional input of static asymmetric quantity and dynamic jitter quantity that can be directly called by subsequent compensation logic, so as to realize the observability of the real time-varying characteristics of digital fiber optic links.

[0094] In a preferred embodiment of the present invention, the step of calculating the asymmetric delay fluctuation tolerance based on the uplink and downlink medium transmission status data and the network jitter dynamic data includes: in response to the packet loss rate of the time division duplex relay node being lower than a preset packet loss threshold within a preset monitoring period, extracting the maximum deviation peak value in the network jitter dynamic data;

[0095] The uplink and downlink medium transmission status data are added to the maximum deviation peak value to obtain the safety buffer boundary; the safety buffer boundary is defined as the asymmetric delay fluctuation tolerance, wherein the asymmetric delay fluctuation tolerance characterizes the maximum tolerance parameter before the cross-medium communication air interface signal collision occurs. In response to the packet loss rate of the time division duplex relay node being higher than or equal to the preset packet loss threshold in the preset monitoring period, the tolerance result of the previous monitoring period or the preset device safety upper limit value is used as the asymmetric delay fluctuation tolerance.

[0096] This embodiment provides a mechanism for calculating the tolerance of asymmetric latency fluctuations. Specifically, the link latency difference alone is insufficient to directly guide frame structure adjustment because when service quality deteriorates significantly, jitter peaks may have already been mixed with the effects of abnormal packet loss. If used directly, it is easy to amplify misjudgments. Therefore, this embodiment first introduces packet loss rate screening and then extracts the maximum deviation peak.

[0097] Furthermore, the system calculates the packet loss rate of the relay node within a preset monitoring period; the preset packet loss threshold is a parameter dynamically configured according to the service quality requirements or service level protocol of the current carried service, and different preset packet loss thresholds correspond to services with different latency sensitivity priorities.

[0098] If the packet loss rate is lower than the preset threshold, it means that the delay deviation in the current sampling period mainly reflects normal network fluctuations. At this time, the maximum deviation peak value is taken from the network jitter dynamic data and added to the uplink and downlink medium transmission status data to obtain the safety buffer boundary.

[0099] This boundary is defined as the tolerance for asymmetric time delay fluctuations; based on the aforementioned quantitative data, if the uplink and downlink medium transmission time is 12 microseconds, the historical deviation set is... If the packet loss rate within the monitoring period is 0.02%, which is lower than the preset threshold of 0.1%, then the maximum deviation peak value is 5 microseconds. After adding them together, we get 17 microseconds. This 17 microseconds is the time elasticity space that the current system can reserve first.

[0100] The reason for using a combination of difference and peak values ​​is that the difference reflects the inherent asymmetric trend of the cross-medium path, while the peak value reflects short-term impacts; the combination of the two is closer to the worst-case scenario that actually needs to be defended; if only the average difference is used, instantaneous high jitter may be ignored; if only the peak value is used, the long-term asymmetric baseline cannot be reflected.

[0101] Regarding the system's fault tolerance mechanism, if the packet loss rate is higher than the preset threshold, it indicates that the current network may be in an abnormal state. Simply using the peak value for estimation is easily affected by abnormal data. At this time, one of the two conservative strategies can be adopted: First, use the tolerance result of the previous monitoring period.

[0102] Secondly, the tolerance is directly raised to the safety limit of the device configuration and the link anomaly flag is triggered; if the historical deviation set is empty, the maximum deviation peak is regarded as zero, and only the uplink and downlink difference is used to form a temporary tolerance; if the difference itself is negative, its amplitude value can be taken before summation or converted into an effective time margin according to the system's preset direction rules to avoid confusion in the direction of the compensation amount.

[0103] Specifically, to avoid positive deviation errors in the calculated safety buffer boundary value due to isolated extreme outliers when extracting the maximum deviation peak, the system can perform a rapid outlier removal of the historical deviation set using box plots or the three sigma criterion before extracting the maximum deviation peak, retaining only the network jitter dynamic data within the confidence interval for the final summation calculation; in this way, the tolerance calculation results can be effectively prevented from being overly sensitive to transient noise;

[0104] For example, when a short-term high-concurrency video transmission occurs in the storage yard on the south side of the port, the deviation set of a certain relay node within 10 milliseconds changes from the original... microseconds rise to The data transmission speed is microseconds, but the packet loss rate remains at 0.03%.

[0105] Based on this, the system determined that although the link jitter had increased, it was still within a controllable range. The maximum deviation peak value of 7 microseconds was extracted and superimposed with the existing uplink-downlink difference of 10 microseconds to obtain a tolerance of 17 microseconds, which was used for the next step of protection boundary estimation.

[0106] The purpose of this step is to provide a quantifiable safety boundary for subsequent compensation and protection interval adjustments, thereby enabling the early absorption of air interface collision risks rather than passive repairs after a collision occurs.

[0107] In a preferred embodiment of the present invention, the calculation process of the cross-medium timing misalignment parameter includes: obtaining the baseband radio frequency conversion processing cycle at the time division duplex relay node; extracting the currently active preset initial guard interval time parameter; summing the baseband radio frequency conversion processing cycle, the currently active preset initial guard interval time parameter, and the uplink and downlink medium transmission status data to obtain the radio frequency signal transmission and reception overlap characteristic value associated with the uplink and downlink switching edge; and setting the radio frequency signal transmission and reception overlap characteristic value as the cross-medium timing misalignment parameter.

[0108] This embodiment provides a method for constructing cross-medium timing misalignment parameters. Specifically, in the aforementioned scenario, it is not enough to know that the fiber optic link has asymmetry and jitter, because the relay node itself also has a processing cycle from baseband to radio frequency, which will further transmit the time deviation on the fiber side to the wireless interface. Therefore, this embodiment also incorporates the internal processing overhead of the node into the misalignment estimation.

[0109] Furthermore, the system reads the current baseband RF conversion processing cycle from the relay node, such as the total time occupied by RF modulation, digital upconversion, and power amplifier enable preparation; then extracts the currently activated initial protection interval time parameter; sums these two items with the uplink and downlink medium transmission status data to obtain an RF signal transmit / receive overlap characteristic value that characterizes the risk of uplink / downlink handover edge, and uses it as a cross-medium timing misalignment parameter;

[0110] In the quantitative simulation, if the baseband RF conversion processing cycle is 5 microseconds, the initial protection interval is 3 microseconds, and the uplink and downlink medium transmission state is 12 microseconds, then the sum of the three is 20 microseconds. This 20 microseconds is not simply the link delay, but the switching edge pressure exhibited at the air interface after the combined effects of link asymmetry, node internal processing, and the original protection buffer.

[0111] This setup exposes a bottleneck in the previous layer solution: if compensation is only determined based on link difference and jitter, the variation of internal processing latency under different loads may be ignored; especially during peak port operations, relay nodes need to simultaneously carry multiple services such as video, control, and alarms, and the internal processing cycle will fluctuate with the load, thus causing the actual air interface misalignment to deviate from the link measurement results.

[0112] Regarding the system's fault tolerance mechanism, if a node is temporarily unable to read the real-time processing cycle, the most recent stable sample value can be used as a substitute; if the protection interval parameter has not been initialized, the device's factory default value will be used.

[0113] If the summation result exceeds the maximum adjustable range allowed by the system, extreme compensation will not be issued directly. Instead, the system will enter protection mode, prioritizing the increase of the protection interval and the reduction of the transmission duty cycle to avoid more serious self-interference that exceeds the system's physical tolerance. If the summation result is an abnormally small value or even a negative value below the preset lower limit, it indicates that one of the data items may have been collected incorrectly, and it is necessary to roll back to the previous version configuration and resample.

[0114] For example, when the lifting of the quay crane spreader and the transmission of high-definition video are carried out simultaneously, the internal processing cycle of the relay node on the top of the quay crane increases from the usual 4 microseconds to 6 microseconds, while the original protection interval remains at 3 microseconds. However, the measured uplink and downlink difference is 11 microseconds, so the misalignment parameter reaches 20 microseconds. Based on this, the system recognizes that the transmission and reception edge of the node is approaching the danger zone and no longer continues to use the original rigid frame arrangement.

[0115] The purpose of this step is to map the fiber-side uncertainty and the intra-node processing delay into a directly comparable timing misalignment, thereby achieving a more complete characterization of the actual air interface overlap risk.

[0116] In a preferred embodiment of the present invention, the timing pre-compensation value is calculated in conjunction with the asymmetric delay fluctuation tolerance, including: initializing a reference timing offset parameter; subtracting the reference timing offset parameter from the cross-medium timing misalignment parameter to generate an error signal feedback quantity; reading a preset adaptive pre-compensation convergence rate parameter dynamically mapped based on the service quality requirements of the current service; multiplying the error signal feedback quantity by the adaptive pre-compensation convergence rate parameter to obtain a compensation step size, and accumulating the compensation step size to the reference timing offset parameter to obtain a target convergence compensation bias; and determining the target convergence compensation bias as the timing pre-compensation value.

[0117] This embodiment provides an asymptotic convergence solution mechanism for timing pre-compensation values. Specifically, the aforementioned scheme can identify misalignment risks, but if all misalignment amounts are directly sent as compensation values ​​at once, overshoot can easily occur due to link transient fluctuations, causing the transmission time to be moved too far forward. Therefore, this embodiment introduces a reference timing offset parameter and an adaptive pre-compensation convergence rate parameter to approximate the target compensation amount in a gradual manner.

[0118] Furthermore, the system first initializes a reference timing offset parameter. It can take the compensation value currently enabled by the device, or it can take zero value when it is first enabled; the cross-medium timing misalignment parameter is compared with the reference timing offset parameter. The difference is calculated to obtain the error signal feedback quantity. ;

[0119] Then read the preset adaptive pre-compensation convergence rate parameter, which is dynamically mapped based on the service quality requirements of the current service being carried. Feedback quantity of error signal Multiply by the adaptive pre-compensation convergence rate parameter Forming a compensation step size and the compensation step size Accumulated to the reference timing offset parameter Above, the target convergence compensation bias is obtained. This serves as the pre-compensation value for the current time series; the specific calculation process can be expressed by the following quantitative derivation formula:

[0120] in, Multiplication operator; step size compensation Feedback quantity from error signal With adaptive pre-compensation convergence rate parameter The objective convergence compensation bias is jointly determined. The calculation formula is:

[0121] Among them, the target convergence compensation bias From the reference timing offset parameter With compensation step size The sum is obtained by accumulation. This is the addition operator;

[0122] Based on the quantitative simulation data, assuming the misalignment parameter is 20 microseconds and the current reference time offset parameter is 8 microseconds, the error signal feedback is 12 microseconds; if the convergence rate parameter is set to 0.5, the compensation step size is 6 microseconds, and after accumulation, a target convergence compensation bias of 14 microseconds is obtained.

[0123] In this round, the entire 20 microseconds are not used for pre-launch. Instead, the launch time is advanced by 14 microseconds to allow for further verification during subsequent monitoring to determine if it is necessary to move closer to the target. If the next round of monitoring finds that the misalignment parameter has dropped to 15 microseconds, the iteration will continue with a new benchmark to achieve a smoother compensation process.

[0124] The reason for this gradual strategy is that although the previous layer solution can achieve the degree of misalignment, it does not solve the problem of how to avoid compensation oscillations. Especially when the network jitter in the port area changes in a pulse-like manner, if the compensation step size is too large, it may overshoot in one round and pull back in the next round, causing frequent configuration fluctuations of the TDD boundary. The convergence rate parameter essentially provides a smooth adjustment mechanism.

[0125] Regarding the fault tolerance mechanism, if the error signal feedback is too small, such as less than the minimum adjustment resolution, the compensation step size can be set to zero to maintain the existing compensation state in order to avoid meaningless frequent write configuration operations; if the convergence rate parameter is abnormally greater than 1, it can be automatically truncated to 1.

[0126] If it is less than 0, it will fall back to the default value; if the calculated target convergence compensation bias exceeds the hardware-allowed upper limit, it will not be used directly, but will be clamped to the upper limit and the subsequent mechanism will be notified to expand the protection interval first; if the reference parameter fails, the most recently effective value will be used as the replacement reference.

[0127] For example, in the relay node on the east side of the yard, the system detected timing misalignment parameters of 20 microseconds and 18 microseconds in two consecutive rounds; the first time, a compensation value of 14 microseconds was obtained with a baseline of 8 microseconds and a convergence rate of 0.5.

[0128] The second time, 14 microseconds was used as the new benchmark, the error became 4 microseconds, the step size was reduced to 2 microseconds, and the compensation value was updated to 16 microseconds. It can be seen that the compensation process gradually approximates rather than jumps, which is beneficial to maintaining the stability of the air interface boundary during the continuous operation of the automated guided vehicle.

[0129] In actual systems, the adaptive pre-compensation convergence rate parameter is not a fixed value, but can be dynamically mapped according to the service level: for example, for automated guided vehicle scheduling signaling links that are highly sensitive to latency and have high retransmission resource overhead, the convergence rate parameter can be preset to 0.8 to achieve fast approximation.

[0130] For high-definition video inspection and other service flows with built-in fault-tolerant buffering mechanisms, the convergence rate parameter can be preset to 0.3 to obtain a smoother adjustment process, thereby further meeting the real timing requirements of various services in cross-media communication.

[0131] The purpose of this step is to achieve smooth convergence of pre-compensation through a controllable step size, thereby reducing overcompensation and oscillations and improving the system stability of dynamic time slot reconstruction.

[0132] In a preferred embodiment of the present invention, calculating the protection interval adjustment amount includes: comparing the asymmetric delay fluctuation tolerance with the currently configured maximum protection interval margin parameter; if the asymmetric delay fluctuation tolerance is greater than the currently configured maximum protection interval margin parameter, subtracting the currently configured maximum protection interval margin parameter from the asymmetric delay fluctuation tolerance to obtain the excess amplitude;

[0133] The excess amplitude is multiplied by a preset extension coefficient configured based on the link's historical stability and service fault tolerance, and the protection interval adjustment amount is output. If the asymmetric delay fluctuation tolerance is lower than or equal to the currently configured maximum protection interval margin parameter, the protection interval adjustment amount is configured to zero to maintain the stability of the current frame structure.

[0134] This embodiment provides a solution step for the protection interval adjustment amount; specifically, in the previous embodiment, relying solely on pre-compensation can handle a considerable portion of the misalignment, but under the condition of a sudden increase in jitter, simply advancing the launch time is still insufficient to cover all risks, and at this time it is necessary to simultaneously assess whether to expand the protection interval.

[0135] Furthermore, the system will use the currently calculated asymmetric time delay fluctuation tolerance. Maximum protection margin parameter in the existing equipment configuration Compare; if the tolerance for asymmetric time delay fluctuations... Not exceeding the maximum protection interval margin parameter This indicates that the existing protection interval still has room for absorption, and no additional adjustments are needed in this round. The adjustment amount for the protection interval is... Set to zero;

[0136] If the tolerance for asymmetric time delay fluctuations Exceeding the maximum protection interval margin parameter First, calculate the difference to obtain the value exceeding the amplitude. Then, exceed the amplitude. Multiplied by a preset expansion factor Output the final protection interval adjustment amount The preset expansion coefficient β is a weighting factor based on a combination of link historical stability and service fault tolerance, used to adjust the system's conservative response to network jitter envelope expansion. The specific calculation rule can be expressed using the following quantitative formula:

[0137] in, This is the subtraction operator; it exceeds the range. Tolerance for asymmetric time delay fluctuations Relative to the maximum protection interval margin parameter The excess portion constitutes the protection interval adjustment amount. The calculation formula is:

[0138] in, Protect the interval adjustment for the multiplication operator. From exceeding the amplitude Combined with preset expansion coefficient Calculated;

[0139] The quantitative deduction is as follows: If the current tolerance is 17 microseconds and the existing maximum protection interval margin is 13 microseconds, then the excess amplitude is 4 microseconds; assuming the expansion coefficient is 1, then the protection interval adjustment is 4 microseconds.

[0140] If the expansion factor is 0.5, the adjustment amount is 2 microseconds, which is used for conservative relaxation; or if the tolerance is 11 microseconds and the maximum protection interval margin is 13 microseconds, it means that the existing protection capability is still sufficient, and the adjustment amount in this round is directly taken as zero, without making unnecessary changes to the existing frame structure.

[0141] This demonstrates the complementary relationship with the previous layer: the pre-compensation mainly solves the time offset problem, but it cannot handle the situation where the jitter envelope is expanded as a whole; the guard interval adjustment is equivalent to leaving an extra buffer for the TDD handover boundary, which can avoid the time slot overlap interference between the transmit and receive windows when link spike jitter occurs;

[0142] Regarding the system's fault tolerance mechanism, if the excess value is positive but less than the device's minimum adjustable granularity, it can be treated as a zero value; if the expansion coefficient is configured too large, causing the adjustment amount to exceed the device's allowable upper limit, the upper limit value will be used and a configuration alarm will be recorded.

[0143] If the existing maximum protection interval margin parameter fails to be read, the factory default margin will be used; if the adjusted total protection interval will occupy too many service time slots, causing the system throughput to fall below the minimum service threshold, the degradation mode can be entered, retaining the relaxed protection interval only for critical control services, while implementing rate limiting for non-critical high-traffic services.

[0144] For example, after a temporary bypass fiber optic cable was connected to the port, the tolerance of a certain relay node suddenly increased from 12 microseconds to 18 microseconds, while the node originally only had a maximum protection interval margin of 14 microseconds. Based on this, the system calculated that the excess was 4 microseconds and increased the protection interval by 4 microseconds from the original configuration, so that the quay crane control link could still operate smoothly during the temporary network reconstruction.

[0145] The purpose of this step is to provide an additional time buffer for scenarios involving increased jitter envelope, thereby enabling adaptive expansion of the air interface collision boundary.

[0146] In a preferred embodiment of the present invention, performing transmit / receive timing pre-adjustment and adaptive scaling of the guard interval at the time-division duplex relay node includes: parsing the time-division duplex frame reconstruction instruction, extracting the timing pre-compensation value and the guard interval adjustment amount embedded in the instruction; reconstructing the guard interval of the time-division duplex relay node using the guard interval adjustment amount; and triggering the downlink signal transmission time advance adjustment operation of the time-division duplex relay node using the timing pre-compensation value to compensate for the asymmetric delay deviation introduced by digital optical fiber transmission.

[0147] This embodiment provides a process for executing frame reconstruction on the relay node side. Specifically, the calculation logic for compensation values ​​and adjustment amounts has been given in the aforementioned implementation methods. However, if the relay node execution layer lacks a clear parsing and reassembly process, the parameters cannot be stably mapped to the actual sending and receiving actions. Therefore, this embodiment further refines the instruction landing process.

[0148] Furthermore, the relay node parses the received time-division duplex frame reconstruction command and extracts the timing pre-compensation value and the protection interval adjustment amount from it; the node's frame scheduling unit first recalculates the uplink and downlink switching boundaries based on the protection interval adjustment amount, and then calls the transmission control unit to advance the downlink transmission time according to the pre-compensation value.

[0149] In the quantitative simulation, if the instruction specifies a pre-compensation value of 6 microseconds and a protection interval adjustment of 4 microseconds, and the current protection interval of the node is 10 microseconds, the execution layer first reorganizes the protection interval to 14 microseconds, and then advances the downlink transmission start point by 6 microseconds. In this way, even if the digital optical fiber introduces an additional delay of several microseconds in the downlink direction, the actual transmission on the radio frequency side can be realigned with the expected TDD boundary.

[0150] Compared with the previous calculation scheme, this embodiment solves the problem of how parameters become actual actions. If the node-side execution of transaction splitting is lacking, there may be a situation where the parameters have been calculated but the transmission control and frame boundary update are not synchronized, which may cause new timing disorder. Therefore, this embodiment prefers to update the protection interval first and then trigger the transmission pre-set to ensure that the switching boundary is stable first and the transmission action is followed by the action.

[0151] Regarding the system's fault tolerance mechanism, if the reconstruction instruction verification fails, the fields are incomplete, or the version number does not match, the node will reject the update, retain the original configuration, and report the execution error; if the extracted protection interval adjustment amount is zero, only the transmission time adjustment will be performed; if the pre-compensation value is zero, only the protection interval will be reassembled.

[0152] If both are zero, the node only records once without adjusting its state and does not trigger any hardware register rewriting, thus reducing control plane overhead. If the node is in an uninterruptible service window, the new configuration can be postponed to the next frame boundary to avoid half-frame switching.

[0153] For example, when the quay crane completes a heavy lifting operation, the control link requires the continuity index to be higher than the preset safety and stability threshold. After the reconfiguration command issued by the central computer room arrives, the relay node on the top of the quay crane first adjusts the protection interval from 10 microseconds to 14 microseconds on the new TDD frame that is about to start, and advances the downlink control signal transmission time by 6 microseconds.

[0154] In this way, even if there is still asymmetric delay in the fiber optic link, the spreader position command and status feedback will not compete with each other at the switching edge.

[0155] The purpose of this step is to stably and atomically map the upper-layer calculation results to the actual transmission and reception control of the relay node, thereby ensuring the reliable effectiveness of the compensation strategy.

[0156] In a preferred embodiment of the present invention, after outputting the compensated radio frequency transmission signal, the method includes: continuously monitoring the cross-medium timing misalignment collision probability parameter associated with the compensated radio frequency transmission signal through the radio frequency eavesdropping channel configured in the time division duplex relay node; if the cross-medium timing misalignment collision probability parameter is greater than zero, triggering a timing failure alarm signaling, and re-executing the step of collecting uplink and downlink medium transmission status data and network jitter dynamic data of the digital optical fiber link;

[0157] If the cross-medium timing misalignment collision probability parameter is equal to zero, the timing pre-compensation value is extracted and encapsulated into the baseline configuration repository of the time-division duplex relay node.

[0158] This embodiment provides a closed-loop verification and parameter update mechanism after compensation. Specifically, the aforementioned scheme can complete state awareness, parameter calculation and frame reconstruction. However, if the compensation effect is not verified a posteriori during long-term operation, the system will find it difficult to determine whether the current parameters have truly eliminated the collision risk. Therefore, this embodiment introduces a radio frequency eavesdropping channel for continuous monitoring after transmission compensation.

[0159] Furthermore, after outputting the compensated radio frequency transmission signal, the relay node uses its own configured radio frequency eavesdropping channel, which includes an independently configured radio frequency receiving antenna or a baseband energy eavesdropping module time-division multiplexed with the main transceiver channel, to sample the overlap signs of the transmission window edge and the receiving window edge, and converts the sampling results into cross-medium timing misalignment collision probability parameters.

[0160] This can be explained using basic statistical methods: Assuming that two transmission leaks are detected entering the receiving window in 100 consecutive TDD frames, the collision probability parameter can be recorded as 0.02; if no overlap is detected within 100 frames, the parameter is recorded as 0; the system processes accordingly: when the parameter is greater than zero, it indicates that the current compensation is still insufficient or the link state has changed again, a timing failure alarm should be triggered, and the entire loop should restart from the front-end sampling step; when the parameter is equal to zero, it indicates that the current compensation value has matched the field state, and the compensation value can be written into the relay node's baseline configuration repository as the initialization basis for the next round of calculation;

[0161] This closed-loop mechanism overcomes the technical deficiency of the previous layer scheme, which only performs feedforward compensation and lacks after-feedback feedback. In actual engineering environments, digital fiber optic links may experience new routing detours or queuing fluctuations after compensation takes effect. Without after-feedback verification, the system can only passively wait for the service to expose problems. By listening for verification, the compensation logic can form an adaptive update loop.

[0162] Regarding the fault tolerance mechanism, if the listening channel itself is abnormal and cannot provide reliable collision probability parameters, the system will not rashly solidify the new compensation value, but will continue to run in a temporary manner and require re-verification in the next monitoring cycle; if the collision probability parameter is greater than zero but lower than the minimum threshold, such as 0.001, it can be decided whether to recalculate immediately according to the business level.

[0163] For high-reliability control services, immediate recalculation is prioritized. For ordinary video backhaul services, observation can be conducted for several consecutive cycles before a decision is made. If the repository write fails, the current running compensation is retained but not set as a new baseline value.

[0164] For example, after completing a pre-compensation and protection interval relaxation at the relay node in the western area of ​​the yard, the system continuously monitors 200 TDD frames. If no overlap between the transmit window and the receive window is found, the pre-compensation value of 16 microseconds for this round is recorded in the local baseline configuration repository.

[0165] A few hours later, due to the temporary rerouting, the collision probability parameter rose to 0.015, and the node immediately triggered a timing failure alarm and re-entered the link state sampling and calculation process;

[0166] It should be added that, in addition to simple binary statistics, the system can also extract the intensity envelope area of ​​the transmitted leakage signal for quantification based on the sampling results obtained from the continuous monitoring of the radio frequency eavesdropping channel: if the intensity of the overlapping leakage signal is lower than the threshold of the background noise of the receiving channel plus 3 dB, it indicates that even if the leakage exists, it does not constitute a substantial interference to the effective reception. At this time, the event can be downgraded in statistics or its weighting coefficient for the cross-medium timing misalignment collision probability parameter can be reduced to 0.1, thereby avoiding the misjudgment of harmless slight signal overlap as a hard collision, and further reducing the cost of invalid cycle recalculation caused by false triggering of the system;

[0167] The purpose of this step is to form a closed-loop control, thereby achieving adaptive stability during long-term operation.

[0168] Please see Figure 2 A wireless communication system based on TDD relay and digital optical fiber is applied to a communication system including a time-division duplex relay node, a baseband processing unit and a digital optical fiber link. The system includes: a status awareness module, which enables the time-division duplex relay node to collect uplink and downlink medium transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through a photoelectric conversion interface configured on it.

[0169] The timing state calculation module is used to calculate the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters based on the uplink and downlink medium transmission state data and the network jitter dynamic data; the current protection interval acquisition module is used to acquire the current protection interval currently configured by the time division duplex relay node.

[0170] The compensation decision module is used to make a determination based on the comparison result between the cross-medium timing misalignment parameter and the pre-stored preset timing offset threshold: if the cross-medium timing misalignment parameter is higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in combination with the asymmetric delay fluctuation tolerance.

[0171] If the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero.

[0172] The instruction generation module is used to generate a time-division duplex frame reconstruction instruction based on the timing pre-compensation value and the protection interval adjustment amount; the adaptive reconstruction module is used to perform transmit and receive timing pre-adjustment and adaptive scaling of the protection interval at the time-division duplex relay node according to the time-division duplex frame reconstruction instruction, and output the compensated radio frequency transmission signal.

[0173] This embodiment provides a system structure corresponding to the aforementioned method; specifically, when deployed in an automated container terminal, the system can be composed of central computer room side equipment and relay node side equipment working together, which can be implemented in a centralized manner or have some functions distributed and pushed down to the local processing board of the relay node.

[0174] Furthermore, the status awareness module is responsible for extracting uplink and downlink medium transmission status data and network jitter dynamic data from the photoelectric conversion interface and link measurement messages; the timing status calculation module is responsible for obtaining the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters based on the input data; and the current protection interval acquisition module reads the protection interval configuration currently being used by the device.

[0175] The compensation decision module determines whether to enter the compensation and expansion process based on the comparison result between the misalignment parameter and the preset timing offset threshold; the instruction generation module is responsible for encapsulating the pre-compensation value and the protection interval adjustment amount into a standardized frame reconstruction instruction; the adaptive reconstruction module performs specific timing adjustments and protection interval scaling at the relay node.

[0176] To illustrate module collaboration, a set of micro-process simulations can be performed: the state-aware module outputs a difference of 12 microseconds, and the deviation set... The timing state calculation module outputs a tolerance of 17 microseconds and a misalignment parameter of 20 microseconds. The current protection interval acquisition module returns the current protection interval of 10 microseconds. The compensation decision module then combines this with a threshold of 15 microseconds to derive a pre-compensation value of 6 microseconds and an adjustment amount of 4 microseconds. The instruction generation module encodes this into a reconstruction instruction. Based on this, the adaptive reconstruction module rewrites the node parameters to shift the launch time forward by 6 microseconds and change the protection interval to 14 microseconds. The results can be transmitted between modules through shared memory, message bus, or high-speed control plane link, as long as the temporal order and field consistency are guaranteed.

[0177] Regarding the system's fault tolerance mechanism, if the state awareness module outputs abnormal data, subsequent modules can directly refuse to process it; if the timing state calculation module fails to complete the calculation within the specified time, the compensation decision module will prioritize maintaining the status quo to avoid destroying frame boundaries due to late instructions; if the instruction generation module fails to encode, the adaptive reconstruction module will not execute the incomplete configuration.

[0178] If a module goes offline temporarily, the system can choose to degrade its operation based on the module's importance, for example, retaining only monitoring and alarms while suspending proactive reconstruction;

[0179] For example, in the central computer room of the port area, status awareness and timing status calculation can be completed by the computing server, while the current protection interval acquisition and adaptive reconfiguration are carried out on the local control board of the quay crane relay node; when a new queuing jitter occurs in the link of the south yard, the system modules are executed in a predetermined order to complete the complete closed loop from awareness, calculation to effectiveness.

[0180] The purpose of this step is to break down the aforementioned method into engineering-featured functional modules, thereby achieving a clear division of labor and deployability between software algorithms and relay node hardware control.

[0181] In a preferred embodiment of the present invention, the system further includes: a baseband processing computing resource pool for generating a time-domain symmetrical original service data stream; and an asymmetric transmit / receive equalization network device located near the time-division duplex relay node for receiving the compensated radio frequency transmit signal to complete the air interface mapping operation without changing the physical layer clock synchronization accuracy.

[0182] This embodiment provides a further improved system deployment form; specifically, in large port scenarios, in addition to a single relay node, there are often multiple nodes and multiple services running concurrently. Compensation only at the node side is sometimes insufficient to take into account the overall scheduling performance. Therefore, this embodiment further introduces a baseband processing computing resource pool and a near-end asymmetric transmit / receive balancing network device into the system.

[0183] Furthermore, the baseband processing computing resource pool is deployed in the central computer room and is responsible for generating the original business data stream that is symmetrical in the time domain. The symmetrical time domain here does not deny that asymmetry will be introduced in subsequent links, but rather means that the business follows a unified frame reference when it is generated, which makes it easier to clearly attribute the imbalance factors to the fiber optic transmission and node execution links in the future.

[0184] The near-end asymmetric transmit / receive equalization network device is located near the relay node to receive the compensated RF transmit signal and complete the air interface mapping without changing the synchronization accuracy of the underlying physical clock. In other words, this device does not redefine the system synchronization reference, but acts as a transmit / receive equalization and interface buffering device to make the compensated timing relationship fall more smoothly on the air interface transmit side. In terms of hardware structure, the asymmetric transmit / receive equalization network device includes at least an RF interface buffer module and a mapping logic array. The RF interface buffer module absorbs the transient timing jitter at the underlying interface level, and the mapping logic array outputs the reconstructed timing boundary to the physical antenna.

[0185] The collaborative relationship between the two can be explained by simplifying the process: The resource pool in the central computer room first generates a data stream with a unified rhythm, such as the control data block and the return data block within a certain frame arranged according to a predetermined boundary; after passing through the digital fiber optic link and the aforementioned compensation mechanism, the relay node has obtained the effective result of moving forward by 6 microseconds and extending by 4 microseconds;

[0186] The near-end equalization network device receives the compensated RF transmit signal and completes the final air interface mapping, so that the RF side transmit and receive window is output according to the new boundary. The advantage of doing this is that it does not require extreme improvement of physical clock accuracy to offset all link uncertainties, but introduces a layer of engineering buffer for transmit and receive asymmetry while maintaining the basic stability of the original synchronization system.

[0187] Compared to the aforementioned system architecture, this embodiment addresses two bottlenecks in large-scale deployment: First, when multiple relay nodes run in parallel, if there is no unified computing resource pool to form the original time domain reference, subsequent compensation will lack a consistent reference; Second, if the relay nodes directly map the compensation results to the air interface without a near-end equalization device, some interface jitter and instantaneous load changes may still cause the calculation results to fail.

[0188] Regarding the system's fault tolerance mechanism, if the resource pool is busy and some service flows fail to be generated on time, priority will be given to ensuring control and alarm services, while high-bandwidth non-critical services will be postponed.

[0189] If the near-end load balancer fails, the system can switch to pass-through mode, but at the same time tighten the service level and maintain only the critical control link to prevent air interface mapping from becoming unstable when the load balancer is missing. If the device is detected to be attempting to modify the physical layer synchronization reference, it will be prohibited from performing related operations and only the forwarding and mapping functions will be retained to maintain the consistency of the system clock architecture.

[0190] For example, after two new quay cranes were added to the East Operation Area of ​​the port, the central computer room uniformly generated multiple time-domain symmetrical business flows through the baseband processing computing resource pool, and then sent them to each relay node respectively.

[0191] The asymmetric transmit / receive equalization network equipment deployed near the quay bridge relay node receives the compensated radio frequency output and completes the final air interface mapping; even if one of the digital optical fibers experiences asymmetric delay due to temporary detour for construction, the overall system can still maintain stable communication without disrupting the original synchronous architecture.

[0192] The purpose of this step is to further improve the engineering stability and scalability in multi-node, complex link environments through the synergy of centralized baseband reference and near-end equalization mapping.

[0193] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A wireless communication method based on TDD relay and digital optical fiber, applied to a communication system including a time-division duplex relay node, a baseband processing unit, and a digital optical fiber link, characterized in that, The method includes: The time-division duplex relay node establishes a clock synchronization reference with the baseband processing unit and periodically triggers the acquisition process based on this reference. The time-division duplex relay node acquires uplink and downlink media transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through the photoelectric conversion interface configured on it. Based on the uplink and downlink medium transmission status data and the network jitter dynamic data, the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters are calculated. Obtain the current protection interval currently configured for the time-division duplex relay node; Based on the comparison between the cross-medium timing misalignment parameter and the pre-stored preset timing offset threshold, a determination is made: if the cross-medium timing misalignment parameter is higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in conjunction with the asymmetric delay fluctuation tolerance; if the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero. Based on the timing pre-compensation value and the protection interval adjustment amount, a time-division duplex frame reconstruction instruction is generated. Based on the time-division duplex frame reconstruction instruction, the transmit and receive timing pre-adjustment and guard interval adaptive scaling are performed at the time-division duplex relay node, and the compensated radio frequency transmission signal is output.

2. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The steps of collecting uplink and downlink medium transmission status data and network jitter dynamic data of the digital optical fiber link include: obtaining the time division duplex timed message timestamp in the digital optical fiber link; Based on the time-division duplex scheduled message timestamp, the downlink transmission delay and uplink transmission delay of the digital optical fiber link are calculated; The difference between the downlink transmission delay and the uplink transmission delay is defined as the uplink and downlink medium transmission status data. Extract the set of historical transmission delay deviations within a preset sampling period as the network jitter dynamic data.

3. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The calculation of asymmetric delay fluctuation tolerance based on the uplink and downlink medium transmission status data and the network jitter dynamic data includes: In response to the time-division duplex relay node having a packet loss rate lower than a preset packet loss threshold within a preset monitoring period, the maximum deviation peak value in the network jitter dynamic data is extracted. The uplink and downlink medium transmission status data are added to the maximum deviation peak value to obtain the safety buffer boundary; The safety buffer boundary is defined as the asymmetric delay fluctuation tolerance, wherein the asymmetric delay fluctuation tolerance characterizes the maximum tolerance parameter before an air interface signal collision occurs in cross-medium communication. In response to the packet loss rate of the time division duplex relay node being higher than or equal to the preset packet loss threshold in the preset monitoring period, the tolerance result of the previous monitoring period or the preset device safety upper limit value is used as the asymmetric delay fluctuation tolerance.

4. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The calculation process for the cross-medium timing misalignment parameter includes: Obtain the baseband RF conversion processing cycle at the time-division duplex relay node; Extract the currently active preset initial protection interval time parameter; The baseband radio frequency conversion processing cycle, the currently active preset initial protection interval time parameter, and the uplink and downlink medium transmission status data are summed to obtain the radio frequency signal transmission and reception overlap characteristic value associated with the uplink and downlink switching edge. The radio frequency signal transmission and reception overlap characteristic value is set as the cross-medium timing misalignment parameter.

5. A wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The calculation of the timing pre-compensation value, based on the asymmetric time delay fluctuation tolerance, includes: Initialize the reference timing offset parameters; Subtract the reference timing offset parameter from the cross-medium timing misalignment parameter to generate the error signal feedback quantity; Read the preset adaptive pre-compensation convergence rate parameter based on the dynamic mapping of the service quality requirements of the current service being carried; The error signal feedback quantity is multiplied by the adaptive pre-compensation convergence rate parameter to obtain the compensation step size, and the compensation step size is accumulated to the reference time offset parameter to obtain the target convergence compensation bias. The target convergence compensation bias is determined as the timing pre-compensation value.

6. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The calculation of the protection interval adjustment includes: Compare the asymmetric delay fluctuation tolerance with the currently configured maximum protection interval margin parameter; If the asymmetric time delay fluctuation tolerance is greater than the currently configured maximum protection interval margin parameter, the asymmetric time delay fluctuation tolerance is subtracted from the currently configured maximum protection interval margin parameter to obtain the excess amplitude; The excess amplitude is multiplied by a preset expansion coefficient configured based on the historical stability of the link and the service fault tolerance rate to output the protection interval adjustment amount; If the asymmetric delay fluctuation tolerance is lower than or equal to the currently configured maximum protection interval margin parameter, the protection interval adjustment amount is configured to zero to maintain the stability of the current frame structure.

7. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, The step of performing transmit / receive timing pre-adjustment and guard interval adaptive scaling at the time-division duplex relay node includes: The time-division duplex frame reconstruction instruction is parsed, and the timing pre-compensation value and the guard interval adjustment amount embedded in the instruction are extracted. The protection interval of the time-division duplex relay node is reconfigured using the protection interval adjustment amount. Using the aforementioned timing pre-compensation value, the downlink signal transmission time of the time-division duplex relay node is pre-adjusted to compensate for the asymmetric delay deviation introduced by digital fiber optic transmission.

8. The wireless communication method based on TDD relay and digital optical fiber according to claim 1, characterized in that, After the output compensated radio frequency transmission signal, the following is included: The cross-medium timing misalignment collision probability parameter associated with the compensated radio frequency transmission signal is continuously monitored through the radio frequency eavesdropping channel configured in the time division duplex relay node. If the cross-medium timing misalignment collision probability parameter is greater than zero, a timing failure alarm signal is triggered, and the step of collecting uplink and downlink medium transmission status data and network jitter dynamic data of the digital optical fiber link is re-executed in a loop. If the cross-medium timing misalignment collision probability parameter is equal to zero, the timing pre-compensation value is extracted and encapsulated into the baseline configuration repository of the time-division duplex relay node.

9. A wireless communication system based on TDD relay and digital optical fiber, applied in a communication system including a time-division duplex relay node, a baseband processing unit, and a digital optical fiber link, characterized in that, The system includes: The status awareness module is used to enable the time-division duplex relay node to collect uplink and downlink media transmission status data and network jitter dynamic data of the digital optical fiber link between itself and the baseband processing unit through the photoelectric conversion interface configured on it. The timing state calculation module is used to calculate the asymmetric delay fluctuation tolerance and cross-medium timing misalignment parameters based on the uplink and downlink medium transmission state data and the network jitter dynamic data. The current protection interval acquisition module is used to acquire the current protection interval currently configured in the time-division duplex relay node; The compensation decision module is used to perform a determination based on the comparison result between the cross-medium timing misalignment parameter and the pre-stored preset timing offset threshold: if the cross-medium timing misalignment parameter is higher than the preset timing offset threshold, the timing pre-compensation value and the protection interval adjustment amount are calculated in combination with the asymmetric delay fluctuation tolerance; if the cross-medium timing misalignment parameter is lower than or equal to the preset timing offset threshold, the current protection interval is retained, and the timing pre-compensation value and the protection interval adjustment amount are configured to zero. The instruction generation module is used to generate a time-division duplex frame reconstruction instruction based on the timing pre-compensation value and the protection interval adjustment amount; The adaptive reconstruction module is used to perform pre-adjustment of transmit and receive timing and adaptive scaling of guard interval at the time division duplex relay node according to the time division duplex frame reconstruction instruction, and output the compensated radio frequency transmission signal.

10. A wireless communication system based on TDD relay and digital optical fiber according to claim 9, characterized in that, The baseband processing unit is used to generate a time-domain symmetric raw service data stream; The time-division duplex relay node is used to receive the compensated radio frequency transmission signal to complete the air interface mapping operation without changing the physical layer clock synchronization accuracy.

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