Random access message sending method and apparatus, device, and storage medium

Abstract

This application discloses a method, apparatus, device, and storage medium for sending random access messages. The method includes: receiving system information sent by a base station; determining a random access preamble and a target random access timing based on the system information; sending the random access preamble to the base station at the target random access timing; obtaining target random access response information generated by the base station based on the random access preamble; extracting a reference time slot index and a reference time slot structure parameter set from the target random access response information; determining a reference time slot based on the reference time slot index and the reference time slot structure parameter set; determining a target transmission time slot based on the reference time slot; and sending a random access message to the base station at the target transmission time slot. This solution can achieve reliable mapping of random access timing across different standards, stable access capability under complex frame structures, and accurate determination of the timing for sending random access messages on the terminal side.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a method, apparatus, device and storage medium for sending random access messages. Background Technology

[0002] With the rapid development of 5G NR (5G New Radio) air interface technology, broadband satellite communication systems, and converged network architectures for air-space-ground integration, random access mechanisms have become a crucial step for terminal devices to establish initial connections and complete resource requests in multi-standard collaboration, wide-area coverage access, and cross-domain converged communication scenarios. In the standard NR architecture, the random access process relies on the beam scanning mechanism of the synchronization signal block and the mapping relationship between random access timing to achieve uplink resource addressing, enabling terminal devices to complete beam pairing, access timing positioning, and resource matching in multi-beam coverage environments. Simultaneously, the NR system relies on the downlink control channel (PDCCH) to schedule random access responses, carrying uplink authorization and time domain indication in the response message, thus forming a complete access closed loop from Msg1 to Msg4, ensuring access reliability and system resource utilization efficiency in scenarios with multiple terminal devices competing for resources.

[0003] However, in a space-ground converged system that uses DVB-S2 (Digital Video Broadcasting-Satellite-SecondGeneration) to carry downlink broadcast links and 5G NR to carry uplink random access and service signaling, the traditional NR random access procedure is significantly constrained by the heterogeneous air interface structure and timing differences, resulting in key mechanisms that cannot be directly adopted. Because DVB-S2 lacks the PDCCH channel structure of the NR downlink physical layer, the base station cannot schedule random access responses using control information scrambled with RA-RNTI (Random Access Radio Network Temporary Identifier), leading to a missing Msg2 scheduling path. Consequently, the random access procedure cannot establish a downlink control link to complete resource indication in the NR standard format. In the NR system, the Msg3 transmission time slot depends on the time domain resource allocation field in RAR (Random Access Response) and uses the RAR reception time as the reference time base. However, the DVB-S2 frame structure is decoupled from the NR uplink time slot system in the time domain. The terminal device cannot obtain an effective uplink timing base based on RAR, which causes Msg3 timing uncertainty, increased collision probability and increased access failure rate. Summary of the Invention

[0004] This application provides a random access message sending method, apparatus, device, and storage medium. By constructing a collaborative process of cross-system access triggering, response parsing, and time slot reconstruction, it can maintain the stable execution of the random access process in complex access environments with coexisting different standards, significant time delay differences, or dynamically changing frame structures. This improves the access success rate, reduces resource conflicts, and enhances the environmental adaptability of terminals in multi-standard access scenarios. It is suitable for the efficient random access message sending needs in cellular communication systems, satellite-terrestrial converged communication systems, and multi-standard multi-terminal device access scenarios.

[0005] Firstly, this application provides a method for sending random access messages, applied to a terminal device, comprising:

[0006] Receive system information sent by the base station, and determine the random access preamble and the target random access timing based on the system information;

[0007] At the target random access time, the random access preamble is sent to the base station to obtain the target random access response information generated by the base station based on the random access preamble;

[0008] Extract the reference time slot index and reference time slot structure parameter set from the target random access response information, and determine the reference time slot based on the reference time slot index and reference time slot structure parameter set;

[0009] The target transmission time slot is determined based on the reference time slot, and a random access message is sent to the base station in the target transmission time slot.

[0010] Secondly, this application provides a random access message sending device, applied to a terminal device, comprising:

[0011] The access timing module is configured to receive system information sent by the base station and determine the random access preamble and the target random access timing based on the system information.

[0012] The response receiving module is configured to send the random access preamble to the base station at the target random access timing, and obtain the target random access response information generated by the base station based on the random access preamble.

[0013] The reference time slot module is configured to extract a reference time slot index and a reference time slot structure parameter set from the target random access response information, and determine a reference time slot based on the reference time slot index and the reference time slot structure parameter set;

[0014] The random access module is configured to determine a target transmission time slot based on the reference time slot, and send a random access message to the base station in the target transmission time slot.

[0015] Thirdly, this application provides a random access message sending device, comprising:

[0016] One or more processors;

[0017] A memory that stores one or more programs that, when executed by one or more processors, cause the one or more processors to implement the random access message sending method as described in the first aspect.

[0018] Fourthly, this application provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform the random access message sending method as described in the first aspect.

[0019] This application constructs a random access message transmission method for terminal devices, achieving precise determination of cross-frame temporal positioning information and random access uplink transmission location, thus maintaining the stability and predictability of the random access process in complex network environments. The method first receives system information broadcast by the base station, parses the configuration parameters for random access within a unified access configuration framework, and jointly determines the random access preamble and target random access timing based on these parameters, thereby clarifying the access triggering basis and initial transmission conditions of the terminal in the current network temporal structure. Subsequently, the terminal sends a random access preamble to the base station at the target random access timing and receives the target random access response information generated by the base station based on the preamble, completing the initial interactive synchronization of the access process. After receiving the random access response, the target random access response information is structurally parsed to extract the reference time slot index and reference time slot structure parameter set, and based on this, a reference time slot uniquely located within the target radio frame is reconstructed, solving the problem that random access responses under multi-standard, multi-bandwidth parameter, or dynamic frame structures cannot directly indicate precise temporal location. The terminal performs time mapping and resource location based on the reference time slot to determine the target transmission time slot for sending random access messages, ensuring that the uplink transmission timing of the random access messages is consistent with the network-side demodulation window. This solution, through the coordinated use of system information, random access configuration parameters, random access response information, and the reference time slot structure, eliminates access conflicts, time-domain misalignments, or retransmission overhead caused by frame structure differences, propagation delay fluctuations, or time slot location uncertainties in traditional random access. It achieves precise time-domain control and efficient uplink resource integration during the random access message transmission process, significantly improving the success rate, stability, and efficiency of random access. It is suitable for random access message transmission requirements in cellular communication systems, space-ground converged communication systems, and multi-standard collaborative access scenarios. Attached Figure Description

[0020] Figure 1This is a flowchart of a random access message sending method provided in an embodiment of this application;

[0021] Figure 2 This is a flowchart of a method for determining the timing of random access to a target, provided in an embodiment of this application;

[0022] Figure 3 This is a flowchart of a target random access timing selection method provided in an embodiment of this application;

[0023] Figure 4 This is a flowchart of a method for obtaining target random access response information provided in an embodiment of this application;

[0024] Figure 5 This is a flowchart of a reference time slot determination method provided in an embodiment of this application;

[0025] Figure 6 This is a flowchart of a target transmission time slot determination method provided in an embodiment of this application;

[0026] Figure 7 This is a flowchart of a satellite-to-ground propagation delay calculation method provided in an embodiment of this application;

[0027] Figure 8 This is a flowchart illustrating the steps of a random access message sending method provided in an embodiment of this application;

[0028] Figure 9 This is a structural block diagram of a random access message sending device provided in an embodiment of this application;

[0029] Figure 10 This is a schematic diagram of the structure of a random access message sending device provided in an embodiment of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining this application and not for limiting it. It should also be noted that, for ease of description, only the parts relevant to this application are shown in the drawings, not all of them. Before discussing exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as being processed sequentially, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. A process can be terminated when its operation is completed, but it may also have additional steps not included in the drawings. A process can correspond to a method, function, procedure, subroutine, subroutine, etc.

[0031] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0032] Currently, with the rapid development of space-ground converged communication systems, satellite internet, and 5G / 6G network collaboration technologies, communication system architectures are exhibiting characteristics of heterogeneity, multi-standard collaboration, and link decoupling. In the space-ground converged communication scenario of "downlink DVB-S2 + uplink 5G NR," terminal devices need to complete the random access process under asymmetric uplink and downlink physical layer conditions to achieve initial access and link establishment with the ground base station. During the random access process, the accurate acquisition of downlink synchronization reference, access timing reference, and uplink resource indication has become a key factor affecting the success rate of random access, latency performance, and system stability. However, existing random access mechanisms are mainly designed for standard 5G NR networks and are difficult to directly adapt to application scenarios with separated downlink and uplink physical layers and inconsistent frame structures in space-ground converged systems. In standard 5G NR networks, the random access process heavily relies on the mapping relationship between downlink synchronization signal blocks and random access timing to achieve correct beam scanning, beam selection, and association of random access resources; at the same time, random access response messages are usually scheduled through the downlink control channel and carry uplink authorization information to indicate the resources for subsequent random access message transmission. However, in satellite-ground converged communication systems, the random access mechanism based on the unified downlink physical layer faces many technical limitations because the downlink uses the DVB-S2 physical layer and the uplink uses the 5G NR physical layer.

[0033] Regarding downlink synchronization and access resource association, DVB-S2 downlink signals typically employ wide-area beam coverage and lack the multi-beam scanning and identification capabilities of 5G NR synchronization signal blocks. Terminal devices cannot establish a mapping relationship between synchronization signal blocks and random access opportunities through downlink synchronization detection, making it difficult to correctly select random access resources and rendering traditional beam-pair-based random access mechanisms ineffective. In terms of random access response scheduling, since DVB-S2 replaces the downlink physical layer of 5G NR, there is no physical downlink control channel. Base stations cannot schedule random access response messages through control channels that scramble random access identifiers. The lack of a transmission path and reception mechanism for random access responses makes it difficult for terminal devices to obtain target random access response information in a timely and reliable manner, affecting the continuity and determinism of the random access process. Regarding the determination of random access message timing, the time-domain resource allocation information carried in traditional random access responses is usually based on the time the terminal device receives the downlink response. In space-ground converged systems, the downlink DVB frame structure and the uplink 5G NR timeslot structure are independent of each other, and there is a significant space-to-ground propagation delay. Terminal devices cannot directly determine the accurate transmission timeslot of subsequent random access messages based on the relative timing parameters in the random access response, which can easily lead to problems such as timing offsets, resource conflicts, or access failures. Due to the large link delay, heterogeneous frame structure, and complex resource scheduling in space-ground converged communication systems, existing random access methods are insufficient in terms of timing accuracy, access reliability, and system adaptability. They are difficult to implement efficient and stable random access processes in space-ground converged scenarios, thus restricting the deployment and application of related communication systems in practical engineering environments.

[0034] Therefore, this invention aims to propose a random access message sending method that can achieve precise time-domain control and reasonable allocation of uplink resources for random access message sending by jointly utilizing system information, random access parameters and random access response information, effectively improving the success rate, timing stability and resource utilization efficiency of random access, and is suitable for random access scenarios with multiple terminals accessing concurrently and in complex wireless environments.

[0035] Figure 1 This is a flowchart illustrating a random access message sending method provided in an embodiment of this application. (Reference) Figure 1 The random access message sending method specifically includes:

[0036] S110. Receive system information sent by the base station, and determine the random access preamble and the target random access timing based on the system information.

[0037] In some embodiments, system information may be a set of data broadcast by the base station that includes network configuration, access control and other key parameters. The target random access timing may be the specific time point that the terminal device ultimately selects to send an access request to the base station during the random access process, in order to ensure that the access request is sent within the range allowed by network resources. The random access preamble may be a unique code sequence used to identify the terminal access request, in order to distinguish the access attempts of different terminals on the base station side.

[0038] In one embodiment, the method of receiving system information may be: the terminal device listens for and receives system information periodically sent by the base station on a designated broadcast channel.

[0039] In one embodiment, the random access preamble can be determined by selecting a random access preamble associated with the terminal identifier from a set of preambles indicated by the base station or a predefined sequence pool.

[0040] In one embodiment, the target random access opportunity can be determined by selecting the highest priority opportunity from the set of available random access opportunities based on access priority. For example, among multiple candidate random access opportunities, if a certain random access opportunity has a short interval with the current time and a low probability of historical conflict, then the priority of selecting that random access opportunity is increased.

[0041] Through the above steps, the random access preamble and the target random access timing can be accurately determined based on system information, enabling the terminal to obtain clear preamble selection and timing indication during the random access process, thereby achieving a reliable, controllable and low-collision-rate random access initiation process without establishing a connection.

[0042] Optionally, Figure 2 This is a flowchart illustrating a method for determining the timing of random access to a target, as provided in an embodiment of this application. (Reference) Figure 2 The method for determining the timing of random access to the target specifically includes:

[0043] S1101. Parse the target random access parameters from the system information.

[0044] For example, the target random access parameters may be parameters such as preambles, timeslot information, or access resource configurations used by the terminal device to initiate the random access process.

[0045] In one embodiment, the method for parsing the target random access parameters may be: extracting the target random access parameters such as the random access preamble sequence, random access timing, access channel resources, and related timing or power control parameters according to the field structure defined in the protocol.

[0046] Through the above steps, the terminal device can accurately parse and obtain the parameter configuration required for random access based on the information received from the base station broadcast system, providing a reliable parameter basis for subsequent random access timing selection, preamble transmission, and random access channel resource usage.

[0047] S1102. Determine multiple random access opportunities and random access preambles based on the target random access parameters.

[0048] For example, the random access timing can be a time window in which the terminal device can initiate a random access request.

[0049] In one embodiment, the method for determining multiple random access opportunities may be as follows: the terminal device takes the target radio frame corresponding to the current time as the starting point, checks each subframe marked as available in sequence within a predetermined time period, and divides each available subframe into multiple time positions that can be used for random access according to a pre-agreed time slot division method. The terminal device regards each divided time position as a random access opportunity, thereby obtaining multiple different random access opportunities within a time period.

[0050] Through the above steps, the terminal device can determine multiple available random access opportunities and corresponding random access preambles based on the parsed target random access parameters, providing diverse and controlled access options for the subsequent transmission of random access messages.

[0051] S1103. Determine the target random access opportunity from the plurality of said random access opportunities.

[0052] For example, the target random access timing can be the specific time point that the terminal device ultimately selects during the random access process to send an access request to the base station, in order to ensure that the access request is sent within the range allowed by network resources.

[0053] In one embodiment, the target random access opportunity can be determined by selecting the highest priority opportunity from the set of available random access opportunities based on access priority. For example, among multiple candidate random access opportunities, if a certain random access opportunity has a short interval with the current time and a low probability of historical conflict, then the priority of selecting that random access opportunity is increased.

[0054] Through the above steps, the terminal device can adaptively determine the target random access opportunity for actual random access by combining the target random access parameters with its own access conditions among multiple available random access opportunities, thereby reducing the probability of access conflict and improving the success rate of random access.

[0055] Optionally, Figure 3This is a flowchart illustrating a target random access timing selection method provided in an embodiment of this application. (Reference) Figure 3 The specific methods for selecting the timing of random access to the target include:

[0056] S11031. Obtain the local time of the terminal device and calculate the time difference between the local time of the terminal and each of the random access opportunities.

[0057] For example, the terminal's local time can be an internal time base maintained by the terminal device in the current system operating environment, used to characterize the terminal's time reference point in the wireless communication process.

[0058] In one embodiment, the terminal's local time can be obtained by the terminal device reading the current timing value from its internal clock module and using the read current timing value as the terminal's local time.

[0059] In one embodiment, the time difference can be calculated by performing a differential operation between the terminal's local time and the reference time for each random access opportunity to obtain the corresponding time difference.

[0060] Through the above steps, an accurate timing judgment basis can be constructed based on the time difference between the terminal's local time and multiple random access opportunities. This enables the terminal device to more reliably determine random access opportunities, improve the stability and success rate of access scheduling, and provide a calculable and predictable time basis for subsequent preamble transmission and uplink transmission of random access messages.

[0061] S11032. Determine the target random access opportunity based on the time difference corresponding to each of the aforementioned random access opportunities.

[0062] For example, the target random access timing can be the final selected timing for the terminal device to send the random access preamble within the current access period, which is used to ensure that the terminal device initiates an access attempt under the premise of meeting system timing constraints, avoiding access conflicts and improving the preamble hit rate.

[0063] In one embodiment, the target random access opportunity can be determined by sorting all random access opportunities in ascending order of their absolute time differences to obtain an opportunity priority list. In this list, the random access opportunity with the smallest time difference typically represents the reachable transmission window closest to the terminal device's current local time, and this random access opportunity is determined as the target random access opportunity. For example, when the time difference of a certain random access opportunity falls within a preset access tolerance range, the terminal device can immediately prepare a preamble and trigger transmission at that opportunity.

[0064] Through the above steps, the target random access opportunity can be adaptively filtered and dynamically optimized based on the time difference corresponding to multiple random access opportunities. This enables terminal devices to select better access opportunities while meeting time domain constraints and access window reachability, thereby improving the timing consistency, resource matching, and overall access success rate of the random access process.

[0065] S120: When the target random access occurs, send the random access preamble to the base station and obtain the target random access response information generated by the base station based on the random access preamble.

[0066] In some embodiments, the random access preamble may be an identification sequence used by the terminal device to initiate an access request, and the target random access response information may be a feedback message returned by the base station to indicate the access result, allocate access resources, or send scheduling instructions.

[0067] In one embodiment, the random access preamble can be sent by the terminal device according to time slots or subframes, and at a determined target random access time, by sending the selected random access preamble through the physical uplink shared channel.

[0068] In one embodiment, the target random access response information can be obtained by the base station identifying the requesting terminal device based on the received preamble and sending a random access response message on the downlink control channel, which includes access confirmation, allocated temporary identifier, uplink resource allocation or further scheduling instructions, and the terminal device receiving the random access response message sent by the base station through the downlink control channel.

[0069] Through the above steps, the terminal device can send the random access preamble at the target random access time and obtain the target random access response information fed back by the base station, thereby establishing the basis for the interaction between uplink request and downlink response in the random access process.

[0070] Optionally, Figure 4 This is a flowchart illustrating a method for obtaining target random access response information provided in an embodiment of this application. (Reference) Figure 4 The specific methods for obtaining the target random access response information include:

[0071] S1201: Receive the protocol data unit sent by the base station, and extract the associated random access opportunity corresponding to the random access response information from the protocol data unit.

[0072] For example, the protocol data unit can be a link layer or MAC layer data structure that carries random access response information and is sent by the base station in the downlink during the random access process. It is used to carry access assignment content related to the preamble of the terminal device. The associated random access timing can be a time stamp attached by the base station when generating random access response information to indicate the timing of the preamble transmission corresponding to the response information, which is used to indicate which random access attempt the current random access response belongs to.

[0073] In one embodiment, the protocol data unit can be received by receiving downlink data signals sent by the base station through a downlink receiving module, performing radio frequency demodulation, physical layer demodulation, channel decoding and data reassembly operations on the signal, and finally recovering the protocol data unit.

[0074] In one embodiment, the method for extracting the associated random access timing may be as follows: performing structured parsing on the header or control field of the protocol data unit to identify the subfields carrying random access response information, parsing the fields containing random access response number, time offset, indicator field or scheduling preamble information according to the protocol definition, decoding and formatting these information to obtain the associated random access timing used to indicate the timing position corresponding to the random access response.

[0075] Through the above steps, the associated random access timing corresponding to the random access response information can be accurately extracted from the protocol data units sent by the base station. This provides a reliable input basis for subsequent target transmission time slot calculation, uplink message transmission preparation, and timing alignment of the random access process, thereby improving the accuracy and stability of the terminal equipment in executing the random access procedure.

[0076] S1202, If the associated random access timing is consistent with the target random access timing, obtain the target random access response information from the protocol data unit.

[0077] For example, the target random access response information can be a matching response generated by the base station in response to the preamble reported by the terminal device, which is used to indicate key parameters such as uplink resource allocation, timing adjustment amount, and subsequent message sending sequence of the terminal device.

[0078] In one embodiment, the method for determining whether the associated random access timing is consistent with the target random access timing may be: using the target random access timing as the only valid timing identifier of the current access procedure, comparing the identifier with the parsed associated random access timing, and when the two are completely consistent in timing number, time slot offset value or time coordinate, the terminal device determines that the two are successfully matched.

[0079] In one embodiment, the method for extracting target random access response information may be: parsing multiple random access response substructures in the protocol data unit, quickly matching the timing identifier field of each substructure, and extracting the corresponding target random access response information from the successfully matched substructure.

[0080] Through the above steps, under the premise that the associated random access timing is consistent with the target random access timing, the target random access response information can be accurately extracted from the protocol data unit. This ensures that the timing parameters and uplink resource configuration used by the terminal device in the random access process are consistent with those of the base station, providing an accurate input basis for the subsequent calculation of the target transmission time slot and the reliable transmission of random access messages.

[0081] S130. Extract the reference time slot index and reference time slot structure parameter set from the target random access response information, and determine the reference time slot based on the reference time slot index and the reference time slot structure parameter set.

[0082] In some embodiments, the reference slot index can be used to identify the slot location in the target radio frame structure where the target random access response information is located, and the reference slot structure parameter set can be used to describe the resource occupancy of the slot in the frequency domain and time domain.

[0083] In one embodiment, the reference slot index can be extracted by parsing the target random access response information to obtain the reference slot index used to indicate the slot position of the reference slot within the target radio frame.

[0084] In one embodiment, the reference time slot structure parameter set can be extracted by parsing the target random access response information to obtain the reference time slot structure parameter set used to construct the target radio frame corresponding to the reference time slot.

[0085] In one embodiment, the reference time slot can be determined by: reconstructing the target radio frame to which the reference time slot belongs from the reference time slot structure parameter set; when the reference time slot index points to the nth time slot of the radio frame, the nth time slot of the target radio frame is determined as the reference time slot.

[0086] Through the above steps, a reference time slot for scheduling random access messages can be accurately constructed based on the index field and subcarrier structure field in the target random access response information, thereby ensuring the timing consistency, resource alignment, and cross-frame addressing accuracy of the random access process.

[0087] Optionally, Figure 5 This is a flowchart of a reference time slot determination method provided in an embodiment of this application. (Reference) Figure 5 The specific methods for determining the reference time slot include:

[0088] S1301. Determine the number of symbols and symbol duration based on the reference time slot structure parameter set.

[0089] For example, the reference time slot structure parameter set can be a set of configuration parameters used to describe the reference time slot in the frequency and time domains, which helps the terminal device to complete the recovery, positioning, and timing calculation of the reference time slot in subsequent steps. The number of symbols can be a structured parameter describing how many consecutive symbols constitute the reference time slot, and is an important indicator determining the time domain span of the reference time slot and the positioning accuracy of subsequent time slots. The symbol duration can be a core parameter describing the duration occupied by a single symbol in the time domain within the reference time slot, determined by the subcarrier spacing and the cyclic prefix length.

[0090] In one embodiment, the number of symbols can be determined by the terminal device parsing the symbol number field indicated in the subcarrier structure field to directly determine the number of symbols in the reference time slot.

[0091] In one embodiment, the symbol duration can be determined by calculating the symbol duration using the subcarrier spacing and the FFT length, as shown in the following formula:

[0092]

[0093] in, For the duration of the symbol, For subcarrier spacing, This is the duration of the loop prefix.

[0094] Through the above steps, the configuration parameters of the reference time slot can be established based on the reference time slot structure parameter set, enabling the terminal equipment to accurately reconstruct the time and frequency domain characteristics of the reference time slot, thereby providing a stable structural foundation for subsequent reference time slot parameter set generation, time slot alignment, and target transmission time slot determination.

[0095] S1302. Construct a target radio frame based on the number of symbols and the duration of the symbols.

[0096] For example, the target radio frame can be a time-domain structure reconstructed based on the subcarrier spacing, number of symbols, and symbol duration of the reference time slot. This structure is used to establish a radio frame time coordinate system consistent with that of the base station on the terminal side, enabling subsequent reference time slot positioning, target transmission time slot calculation, and uplink message transmission to be performed in a unified time domain. The target radio frame can be regarded as a local radio frame template generated by the terminal according to the reference time slot configuration, used to restore the time-domain organization of the current communication system.

[0097] In one embodiment, the method for constructing a target radio frame may be: the terminal device retrieves the set number of time slots contained in the radio frame from the local configuration table and creates a radio frame containing the set number of time slots; multiplies the number of symbols and the symbol duration to obtain the duration of a single time slot, and sets the time slot duration of each time slot in the radio frame to the calculated duration, thereby obtaining the target radio frame.

[0098] Through the above steps, a target radio frame can be constructed based on the number of symbols and the duration of the symbols, enabling the terminal to have a temporal structure model consistent with that of the base station. This ensures the accuracy of reference time slot positioning, cross-frame mapping, and target transmission time slot calculation, providing a consistent, complete, and computable temporal framework for the uplink transmission of random access messages.

[0099] S1303. Determine the reference time slot based on the target radio frame and the reference time slot index.

[0100] For example, the target radio frame can be used to carry a reference time slot located according to the reference time slot index, thereby enabling precise time-domain addressing in a cross-frame structure.

[0101] In one embodiment, the reference time slot can be determined by selecting the target time slot position corresponding to the reference time slot index from the time slot set of the target radio frame, and determining the target time slot position as the reference time slot.

[0102] Through the above steps, the reference time slot can be accurately located based on the reference time slot index within the structural range of the target radio frame, providing a clear time domain anchor point for the calculation of the target transmission time slot of subsequent random access messages, thereby improving the time domain consistency, resource alignment capability and cross-frame addressing accuracy of the random access process.

[0103] S140. Determine the target transmission time slot according to the reference time slot, and send a random access message to the base station in the target transmission time slot.

[0104] In some embodiments, the target transmission time slot may be a specific time window selected by the terminal device based on the target random access response information returned by the base station for sending a random access message. The random access message may be a data packet containing terminal identifier, capability information or requested resource information, used to complete the uplink message transmission of the random access procedure.

[0105] In one embodiment, the target transmission time slot can be determined by the terminal device parsing the uplink resource allocation field in the target random access response information and calculating the final target transmission time slot based on the time slot number allocated in the uplink resource allocation field.

[0106] In one embodiment, the random access message can be sent by the terminal device sending the random access message through the uplink physical channel in a determined target transmission time slot.

[0107] Through the above steps, the terminal device can accurately determine the target time slot for sending the random access message based on the target random access response information, and complete the uplink transmission of the random access message within that time slot, thereby promoting the evolution of the random access process towards the connection establishment phase.

[0108] Optionally, Figure 6 This is a flowchart illustrating a target transmission time slot determination method provided in an embodiment of this application. (Reference) Figure 6 The method for determining the target transmission time slot specifically includes:

[0109] S1401. Obtain the terminal processing delay of the terminal device and determine the satellite-to-ground propagation delay between the terminal device and the satellite.

[0110] For example, terminal processing latency can be the local processing time generated by the terminal device when executing the random access processing procedure, and satellite-to-ground propagation latency can be the one-way or two-way propagation time of the random access signal between the terminal device and the satellite.

[0111] In one embodiment, the terminal processing latency can be obtained by: the terminal device executing a preset latency measurement program on the local processing module, recording the time difference from receiving the random access response information to completing the corresponding processing operation, and using the time difference as the terminal processing latency.

[0112] In one embodiment, the satellite-to-ground propagation delay can be determined by the terminal device calculating the round-trip time of the signal between the satellite and the terminal based on the time synchronization information broadcast by the satellite, the global time reference, and the time point at which the terminal receives the target random access response information, and then converting this to obtain the satellite-to-ground propagation delay.

[0113] Through the above steps, the terminal processing delay can be accurately obtained, and the satellite-to-ground propagation delay between the terminal device and the satellite can be reliably determined, providing a precise delay parameter basis for the time domain calculation of the target transmission time slot, thereby enhancing the consistency of cross-frame calculation and the time accuracy of scheduling and positioning.

[0114] Optionally, Figure 7 This is a flowchart illustrating a method for calculating satellite-to-ground propagation delay provided in an embodiment of this application. (Reference) Figure 7 The specific methods for calculating satellite-to-ground propagation delay include:

[0115] S14011. Obtain the terminal location of the terminal device and the satellite location of the satellite, and calculate the satellite-to-ground distance based on the terminal location and the satellite location.

[0116] For example, the terminal location can be used to characterize the spatial location of the terminal device in the ground coordinate system, the satellite location can be used to characterize the instantaneous location of the satellite in the orbit coordinate system, and the satellite-to-ground distance can be the actual straight-line distance between the base station and the terminal device in space, used to characterize the physical separation relationship between the two.

[0117] In one embodiment, the terminal location can be obtained by the terminal device performing a location measurement through a local sensing module or positioning module. The terminal location is the coordinate information of the terminal device's current geographical location, such as longitude, latitude, and altitude parameters.

[0118] In one embodiment, the satellite position can be obtained by: the terminal device parsing the ephemeris information broadcast by the satellite, combining it with the system time reference, and calculating the satellite's spatial position in a preset coordinate system using an orbit calculation algorithm, thereby obtaining the satellite position.

[0119] In one embodiment, the satellite-to-ground distance can be determined as follows: the terminal device acquires the spatial location information of the base station and the current location parameters of the terminal device, and performs coordinate mapping between the base station location and the terminal device location based on a unified spatial coordinate system, calculating the geometric distance between them, thereby determining the corresponding satellite-to-ground distance. For example, the formula for calculating the satellite-to-ground distance can be as follows:

[0120]

[0121] in, The distance between the satellite and the Earth is ( ) represents the three-dimensional coordinates of the base station. () represents the three-dimensional coordinates of the terminal device.

[0122] Through the above steps, the terminal device can accurately calculate the satellite-to-ground distance based on the spatial location of the base station and its own device, providing a spatial reference for subsequent propagation delay calculation, timing compensation, and uplink transmission time slot determination.

[0123] S14012. Obtain the set electromagnetic wave velocity, and calculate the satellite-to-ground propagation delay based on the satellite-to-ground distance and the electromagnetic wave velocity.

[0124] For example, the speed of electromagnetic waves can be a preset physical constant or system configuration parameter used to characterize the speed at which wireless signals propagate in space.

[0125] In one embodiment, the electromagnetic wave speed can be obtained by the terminal device reading the corresponding electromagnetic wave propagation speed parameter from the system preset parameter table, communication protocol configuration, or physical layer configuration for subsequent delay calculation.

[0126] In one embodiment, the satellite-to-ground propagation delay can be calculated as follows: Based on the determined satellite-to-ground distance and the acquired electromagnetic wave velocity, the terminal device calculates the satellite-to-ground propagation delay according to the proportional relationship between propagation delay and propagation distance, thereby obtaining the satellite-to-ground propagation delay caused by the wireless signal propagating between the base station and the terminal device. The specific calculation formula is as follows:

[0127]

[0128] in, For satellite-to-ground propagation delay, This is the distance between Earth and space. It represents the speed of electromagnetic waves.

[0129] Through the above steps, the terminal device can accurately calculate the propagation delay of the signal from the base station to the terminal based on the known satellite-to-ground distance and electromagnetic wave speed, providing a reliable time reference for the time domain alignment and transmission timing control of random access messages.

[0130] S1402. Calculate the target transmission time slot based on the terminal processing delay, the satellite-to-ground propagation delay, and the reference time slot.

[0131] For example, terminal processing latency and satellite-to-ground propagation latency can be used together to construct the time compensation amount of the target transmission time slot, and the reference time slot can be used as a time domain reference for executing random access message transmission scheduling.

[0132] In one embodiment, the target transmission time slot can be determined by calculating the target transmission time slot using terminal processing delay, satellite-to-ground propagation delay, and reference time slot, as shown in the following formula:

[0133]

[0134] in, For reference time slot, To reduce terminal processing latency, This is for the time delay of satellite-to-ground propagation.

[0135] Through the above steps, the terminal device can comprehensively consider the time slot, terminal processing delay, and satellite-to-ground propagation delay to accurately determine the target time slot for random access messages, providing a reliable time domain basis for the accurate transmission of uplink messages.

[0136] Optionally, Figure 8 This is a flowchart illustrating the steps of a random access message sending method provided in an embodiment of this application. (Reference) Figure 8 The random access message sending method specifically includes:

[0137] S210, The base station configures the target random access parameters through system information.

[0138] For example, system information can be used to carry a set of key parameters pre-configured by the base station for the random access procedure, and the target random access parameters can be used to guide the terminal device to complete the related operations of preamble selection, timing determination and message sending.

[0139] In one embodiment, the base station can configure target random access parameters through system information by: when generating system information, the base station constructs a random access parameter structure that includes a set of random access preambles, a set of random access timings, a resource interval definition, and parameter fields related to time-domain positioning, and writes the structure into a preset field of the system information.

[0140] In one embodiment, the binding relationship between the Synchronization Signal Block (SSB) and the Physical Random Access Channel (PRACH) in traditional NR is decoupled to construct a random access resource system independent of the SSB. By separating the resource range, frequency domain location, symbol occupancy structure, and transmission timing of the PRACH from the timing of the SSB, the PRACH can be flexibly configured within any preset radio frame structure, thereby improving the scalability and time-domain adaptability of the random access process in large-coverage scenarios.

[0141] S220, The terminal equipment sends a random access preamble on the NR uplink.

[0142] For example, the terminal device sends a random access preamble on the selected NR uplink PRACH resource according to the aforementioned configuration.

[0143] In one embodiment, the terminal device selects an available PRACH opportunity to send Msg1 during the configuration period; resource selection does not rely on the SSB beam index; after Msg1 is sent, the terminal device enters the waiting RAR state. The terminal device can directly use omnidirectional PRACH resources to send the preamble, ensuring that the random access procedure can proceed smoothly when the DVB-S2 downlink in the heterogeneous satellite communication system lacks beam scanning capability.

[0144] S230, the base station sends a random access response via the DVB-S2 downlink.

[0145] For example, after the base station detects the preamble sent by the terminal device, it generates a Random Access Response (RAR) and sends it through the DVB-S2 downlink.

[0146] In one embodiment, the PDU containing the RAR is extended based on the standard 5G format, adding a MAC CE (MAC Control Element) containing the RA-RNTI to the packet header, indicating the PRACH timing resource associated with the RAR to the terminal device. The length of the MAC CE carrying the RA-RNTI can be defined as 2 bytes. The calculation of the RA-RNTI is consistent with the 5G standard and is derived from the parameters of the PRACH timing resource.

[0147] In one embodiment, the RAR message is extended based on the standard 5G format by adding two fields: Number of reference slot (reference slot subcarrier spacing configuration) and Reference slot (reference slot number within the target radio frame).

[0148] In one embodiment, the RAR message is encapsulated in a MAC PDU (Medium Access Control Protocol Data Unit), eliminating the need for the PDCCH to schedule the base station to send the MAC PDU to the terminal device via the DVB-S2 signal. The terminal device receives the DVB-S2 signal, decapsulates the MAC PDU, and obtains the RAR. The terminal device calculates the target transmission time slot based on the reference time slot, terminal processing delay, and satellite-to-ground propagation delay. The specific calculation formula is as follows:

[0149]

[0150] in, For reference time slot; This is to reduce terminal processing latency; This is for the time delay of satellite-to-ground propagation.

[0151] Based on the above embodiments, Figure 9 This is a structural block diagram of a random access message sending device provided in an embodiment of this application. (Reference) Figure 9 The random access message sending device provided in this embodiment specifically includes: an access timing module 11, a response receiving module 12, a reference time slot module 13, and a random access module 14.

[0152] The access timing module 11 is configured to receive system information sent by the base station and determine the random access preamble and the target random access timing based on the system information; the response receiving module 12 is configured to send the random access preamble to the base station at the target random access timing and obtain the target random access response information generated by the base station based on the random access preamble; the reference time slot module 13 is configured to extract the reference time slot index and the reference time slot structure parameter set from the target random access response information and determine the reference time slot based on the reference time slot index and the reference time slot structure parameter set; and the random access module 14 is configured to determine the target transmission time slot based on the reference time slot and send a random access message to the base station at the target transmission time slot.

[0153] Based on the above embodiments, the access timing module 11 includes: an access parameter unit configured to parse target random access parameters from the system information; an access information unit configured to determine multiple random access timings and random access preambles based on the target random access parameters; and a target timing unit configured to determine a target random access timing from the multiple random access timings.

[0154] Based on the above embodiments, the target timing unit includes: a time difference subunit, configured to acquire the local time of the terminal device and calculate the time difference between the local time of the terminal and each of the random access timings; and a target timing subunit, configured to determine a target random access timing based on the time difference between each of the random access timings.

[0155] Based on the above embodiments, the response receiving module 12 includes: an association timing unit configured to receive protocol data units sent by the base station and extract the associated random access timing corresponding to the random access response information from the protocol data units; and a response information unit configured to obtain target random access response information from the protocol data units when the associated random access timing is consistent with the target random access timing.

[0156] Based on the above embodiments, the reference time slot module 13 includes: a symbol information unit configured to determine the number of symbols and the symbol duration according to the reference time slot structure parameter set; a radio frame construction unit configured to construct a target radio frame according to the number of symbols and the symbol duration; and a reference time slot unit configured to determine a reference time slot according to the target radio frame and the reference time slot index.

[0157] Based on the above embodiments, the random access module 14 includes: a delay determination unit, configured to acquire the terminal processing delay of the terminal device and determine the satellite-to-ground propagation delay between the terminal device and the satellite; and a transmission time slot unit, configured to calculate the target transmission time slot based on the terminal processing delay, the satellite-to-ground propagation delay, and the reference time slot.

[0158] Based on the above embodiments, the delay determination unit includes: a satellite-to-ground distance subunit, configured to acquire the terminal position of the terminal device and the satellite position of the satellite, and calculate the satellite-to-ground distance based on the terminal position and the satellite position; and a satellite-to-ground delay subunit, configured to acquire a set electromagnetic wave velocity, and calculate the satellite-to-ground propagation delay based on the satellite-to-ground distance and the electromagnetic wave velocity.

[0159] The random access message sending apparatus provided in this application embodiment, by constructing a multi-level collaborative processing system consisting of an access timing module 11, a response receiving module 12, a reference time slot module 13, and a random access module 14, achieves random access preamble determination, access response parsing, reference time slot derivation, and random access message sending control, thereby improving the timing consistency, resource matching, and transmission reliability of random access in heterogeneous wireless access scenarios. The access timing module 11 undertakes the tasks of system information parsing and access parameter generation, possessing system information receiving capabilities and preamble calculation capabilities. The access timing module 11 receives system information broadcast by the base station, extracts random access-related fields from it, generates a random access preamble set, and determines the target random access timing based on the access configuration broadcast by the system, providing a time reference for subsequent preamble sending and response acquisition. The response receiving module 12 is responsible for uplink sending of access requests and response receiving processing. When the target random access opportunity arrives, the response receiving module 12 sends the selected random access preamble to the base station and receives the target random access response information generated by the base station based on the preamble, thereby triggering access confirmation, resource notification, and subsequent time slot positioning procedures. The reference time slot module 13 undertakes the task of reference time slot derivation, extracting the reference time slot index and reference time slot structure parameter set from the target random access response information. Based on these two key parameters, the reference time slot module 13 restores the actual position of the reference time slot in the current radio frame structure, providing an accurate time anchor point for the uplink transmission of the random access message. The random access module 14 is responsible for the final random access message transmission control. The random access module 14 derives the target transmission time slot based on the reference time slot determined by the reference time slot module 13 and sends the random access message to the base station in the target transmission time slot, completing the uplink data transmission of the random access procedure. By using the system information parsing and preamble generation of the access timing module, the access preamble transmission and response acquisition of the response receiving module, the time slot parsing and location determination of the reference time slot module, and the message scheduling and uplink transmission of the random access module, this device can maintain stable random access performance in complex wireless environments, achieving accurate access timing, efficient uplink feedback, and controllable access process. It is suitable for scenarios with concurrent access from multiple terminals and dynamic graphic adjustment.

[0160] The random access message sending apparatus provided in this application embodiment can be used to execute the random access message sending method provided in the above embodiment, and has corresponding functions and beneficial effects.

[0161] Figure 10 This is a schematic diagram of the structure of a random access message sending device provided in an embodiment of this application, with reference to... Figure 10The random access message sending device includes a processor 21, a memory 22, a communication device 23, an input device 24, and an output device 25. The number of processors 21 and the number of memories 22 in the random access message sending device can be one or more. The processor 21, memory 22, communication device 23, input device 24, and output device 25 of the random access message sending device can be connected via a bus or other means.

[0162] The memory 22, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as program instructions / modules corresponding to the random access message sending method in any embodiment of this application (e.g., access timing module 11, response receiving module 12, reference time slot module 13, and random access module 14 in the random access message sending device). The memory 22 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the device, etc. Furthermore, the memory 22 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0163] The communication device 23 is used for data transmission.

[0164] The processor 21 executes various functional applications and data processing of the device by running software programs, instructions and modules stored in the memory 22, thereby realizing the above-mentioned random access message sending method.

[0165] Input device 24 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 25 may include display devices such as a display screen.

[0166] The random access message sending device provided above can be used to execute the random access message sending method provided in the above embodiments, and has corresponding functions and beneficial effects.

[0167] This application embodiment also provides a storage medium containing computer-executable instructions. When executed by a computer processor, the computer-executable instructions are used to perform a random access message transmission method. The random access message transmission method includes: receiving system information sent by a base station; determining a random access preamble and a target random access timing based on the system information; sending the random access preamble to the base station at the target random access timing; obtaining target random access response information generated by the base station based on the random access preamble; extracting a reference time slot index and a reference time slot structure parameter set from the target random access response information; determining a reference time slot based on the reference time slot index and the reference time slot structure parameter set; determining a target transmission time slot based on the reference time slot; and sending a random access message to the base station at the target transmission time slot.

[0168] Storage medium—any type of memory device or storage device. The term "storage medium" is intended to include: mounting media, such as CD-ROM, floppy disk, or magnetic tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDO RAM, etc.; non-volatile memory, such as flash memory, magnetic media (e.g., hard disk or optical storage); registers or other similar types of memory elements, etc. Storage medium may also include other types of memory or combinations thereof. Furthermore, storage medium may reside in a first computer system in which a program is executed, or it may reside in a different second computer system connected to the first computer system via a network (such as the Internet). The second computer system can provide program instructions to the first computer for execution. The term "storage medium" may include two or more storage media residing in different locations (e.g., in different computer systems connected via a network). Storage medium may store program instructions (e.g., specifically implemented as a computer program) executable by one or more processors.

[0169] Of course, the computer-executable instructions provided in the embodiments of this application are not limited to the random access message sending method described above, but can also execute related operations in the random access message sending method provided in any embodiment of this application.

[0170] The random access message sending apparatus, storage medium, and random access message sending device provided in the above embodiments can execute the random access message sending method provided in any embodiment of this application. For technical details not described in detail in the above embodiments, please refer to the random access message sending method provided in any embodiment of this application.

[0171] The above description is merely a preferred embodiment and the technical principles employed in this application. This application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions that can be made by those skilled in the art will not depart from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of this application. The scope of this application is determined by the scope of the claims.

Claims

1. A method for sending random access messages, applied to a terminal device, characterized in that, include: Receive system information sent by the base station, and determine the random access preamble and the target random access timing based on the system information; At the target random access time, the random access preamble is sent to the base station to obtain the target random access response information generated by the base station based on the random access preamble; Extract the reference time slot index and reference time slot structure parameter set from the target random access response information, and determine the reference time slot based on the reference time slot index and reference time slot structure parameter set; Determine the target transmission time slot based on the reference time slot, and send a random access message to the base station in the target transmission time slot; Determining the reference time slot based on the reference time slot index and the reference time slot structure parameter set includes: The number of symbols and symbol duration are determined based on the reference time slot structure parameter set; Construct a target radio frame based on the number of symbols and the duration of the symbols; The reference time slot is determined based on the target radio frame and the reference time slot index.

2. The random access messaging method of claim 1, wherein, The step of determining the random access preamble and the target random access timing based on the system information includes: Parse the target random access parameters from the system information; Multiple random access opportunities and random access preambles are determined based on the target random access parameters; The target random access opportunity is determined from the plurality of said random access opportunities.

3. The random access messaging method of claim 2, wherein, Determining the target random access opportunity from the plurality of random access opportunities includes: Obtain the local time of the terminal device and calculate the time difference between the local time of the terminal and each of the random access opportunities; The target random access timing is determined based on the time difference corresponding to each of the aforementioned random access timings.

4. The random access messaging method of claim 1, wherein, The step of obtaining the target random access response information generated by the base station based on the random access preamble includes: Receive the protocol data unit sent by the base station, and extract the associated random access opportunity corresponding to the random access response information from the protocol data unit; When the associated random access timing coincides with the target random access timing, the target random access response information is obtained from the protocol data unit.

5. The random access messaging method of claim 1, wherein, Determining the target transmission time slot based on the reference time slot includes: Obtain the terminal processing latency of the terminal device and determine the satellite-to-ground propagation latency between the terminal device and the satellite; The target transmission time slot is calculated based on the terminal processing delay, the satellite-to-ground propagation delay, and the reference time slot.

6. The random access messaging method of claim 5, wherein, The determination of the satellite-to-ground propagation delay between the terminal device and the satellite includes: Obtain the terminal location of the terminal device and the satellite location of the satellite, and calculate the satellite-to-ground distance based on the terminal location and the satellite location; Obtain the set electromagnetic wave velocity, and calculate the satellite-to-ground propagation delay based on the satellite-to-ground distance and the electromagnetic wave velocity.

7. A random access message sending device, applied to a terminal device, characterized in that, include: The access timing module is configured to receive system information sent by the base station and determine the random access preamble and the target random access timing based on the system information. The response receiving module is configured to send the random access preamble to the base station at the target random access timing, and obtain the target random access response information generated by the base station based on the random access preamble. The reference time slot module is configured to extract a reference time slot index and a reference time slot structure parameter set from the target random access response information, and determine a reference time slot based on the reference time slot index and the reference time slot structure parameter set; The random access module is configured to determine a target transmission time slot based on the reference time slot, and send a random access message to the base station in the target transmission time slot; The reference time slot module includes: The symbol information unit is configured to determine the number of symbols and the symbol duration based on the reference time slot structure parameter set; A radio frame construction unit is configured to construct a target radio frame based on the number of symbols and the duration of the symbols. The reference time slot unit is configured to determine a reference time slot based on the target radio frame and the reference time slot index.

8. A random access message transmitting apparatus characterized by comprising: include: One or more processors; A memory that stores one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the random access message sending method as described in any one of claims 1-6.

9. A storage medium containing computer-executable instructions, wherein: The computer-executable instructions, when executed by a computer processor, are used to perform the random access message sending method as described in any one of claims 1-6.

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