Communication method, electronic device, and storage medium

Abstract

The application provides a communication method, an electronic device and a storage medium. The method comprises the following steps: a base station sends a system information block containing configuration information to a user equipment, wherein the configuration information is used for indicating the user equipment to determine whether a Msg4 retransmission process needs to be triggered in a current signal coverage range; if the user equipment determines that the Msg4 retransmission process needs to be triggered in the current signal coverage range, the user equipment sends retransmission request information for the Msg4 to the base station through a Msg3; the base station verifies whether the retransmission is really needed according to the retransmission request information; if the retransmission is really needed, the base station sends the Msg4 to the user equipment for multiple times; and after the user equipment receives and decodes the Msg4, the user equipment sends response information to the base station, so that the connection between the user equipment and the base station is established. Through the technical scheme of the application, the purpose is to improve the receiving reliability of the Msg4, and then improve the success rate of the user equipment accessing the network.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a communication method, an electronic device, and a storage medium. Background Technology

[0002] With the rapid development of 5G and NTN (Non-Terrestrial Networks), such as satellite communication, IoT and vehicle-to-everything (V2X) technologies, the success rate of user equipment (UE) with wireless communication capabilities accessing NTN has always been a research focus. In particular, the process of random access via RACH (Random Access Channel) is a key step in establishing a connection between UE and base station (usually called gNB).

[0003] The random access process via RACH typically involves the exchange of four messages (Msg1 to Msg4) between the user equipment and the base station. Among them, Msg4 is the contention resolution message sent by the base station to the user equipment, and its reliable transmission directly affects the success rate of the user equipment accessing the NTN.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] This application aims to provide a communication method, electronic device, and storage medium, with the purpose of improving the reception reliability of Msg4 and thereby increasing the success rate of user equipment accessing the network.

[0006] In a first aspect, embodiments of this application provide a communication method applied to a user equipment, comprising:

[0007] In response to receiving a system information block sent by a base station, configuration information is determined from the system information block;

[0008] Based on the configuration information, determine whether the Msg4 retransmission process needs to be triggered within the current signal coverage area;

[0009] In response to the determination that the Msg4 retransmission process needs to be triggered within the current signal coverage area, the retransmission request information for Msg4 is sent to the base station via Msg3;

[0010] Receive Msg4 sent by the base station according to the retransmission request information, and establish a connection with the base station according to Msg4.

[0011] Secondly, embodiments of this application also provide a communication method applied to a base station, comprising:

[0012] Send system information blocks to user equipment;

[0013] Receive Msg3 sent by the user equipment, determine the retransmission policy information of Msg4, and send the retransmission policy information of Msg4 to the user equipment.

[0014] In addition, Msg4 is sent to the user equipment according to the retransmission strategy information, and a connection is established with the user equipment upon receiving a response message from the user equipment indicating that Msg4 has been successfully decoded.

[0015] Thirdly, embodiments of this application also provide an electronic device, the electronic device comprising:

[0016] Processor and memory;

[0017] The processor executes the steps of the communication method as described in any embodiment by invoking programs or instructions stored in the memory.

[0018] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a program or instructions that cause a computer to perform the steps of the communication method as described in any embodiment.

[0019] In summary, this application proposes a communication method in which a base station sends configuration information to a user equipment (UE). The UE determines, based on the configuration information, whether a Msg4 retransmission process needs to be triggered within the current signal coverage area. When it is determined that a Msg4 retransmission process needs to be triggered within the current signal coverage area, the UE sends a retransmission request for Msg4 to the base station via Msg3, and receives the Msg4 sent by the base station based on the retransmission request. This achieves dynamic setting and execution of Msg4 retransmission, improves the reliability of Msg4 reception, and thus increases the success rate of UE network access. It also solves the problems of potential loss of Msg4 transmissions due to extremely long path loss caused by NTN over long distances, the easy loss of Msg4 at cell edges due to weak signals, and communication channel abnormalities caused by interference signals. Attached Figure Description

[0020] Figure 1 This is a flowchart of a communication method provided in an embodiment of this application. Figure 1 ;

[0021] Figure 2 This is a schematic diagram of the interaction between a user equipment and a base station provided in an embodiment of this application. Figure 1 ;

[0022] Figure 3 This is a flowchart of a communication method provided in an embodiment of this application. Figure 2 ;

[0023] Figure 4 This is a schematic diagram illustrating the logic of deciding whether a retransmission is truly necessary, provided in an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the interaction between a user equipment and a base station provided in an embodiment of this application. Figure 2 ;

[0025] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0026] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] As described in the background section, the random access process via the Random Access Channel (RACH) is a crucial step in establishing a connection between a user equipment (UE) and a base station (usually referred to as a gNB). Typically, the random access procedure is triggered when a UE first powers on and attempts to register with the network, or when the UE moves from the network coverage area of ​​one base station to the network coverage area of ​​another (i.e., network handover).

[0029] According to communication protocol standards, the random access process via RACH typically involves the exchange of four messages (Msg1, Msg2, Msg3, and Msg4) between the user equipment and the base station, such as... Figure 1 As shown. Msg1 is sent by the user equipment to the base station; it is a random access preamble, a predefined sequence designed to help the base station recognize the user equipment's access request. Msg2 is sent by the base station to the user equipment; it is the random access response the base station sends back to the user equipment upon receiving Msg1, used to allocate temporary resources to the user equipment. Msg3 is an RRC (Radio Resource Control) connection request sent by the user equipment to the base station, equivalent to a formal network access application. In this step, the user equipment uses the temporary resources indicated in Msg2 to send Msg3 to the base station. Msg4 is sent by the base station to the user equipment, containing confirmation of "agreement to establish connection" and parameters to be used after network connection (such as frequency band, power control, etc.).

[0030] In general, Msg4 is an RRC connection establishment message (such as RRCSetup) sent by the base station to the user equipment through PDSCH (Physical Downlink Shared Channel, a type of communication channel) during the random access procedure.

[0031] In particular, such as Figure 1 As shown, before the user equipment (UE) sends Msg1 to the base station, it achieves time synchronization and cell identification by detecting the base station's SSB (Synchronization Signal Block). The SSB includes the PBCH (Physical Broadcast Channel), which carries the MIB (Master Information Block). Decoding the MIB yields basic system information such as cell bandwidth, subcarrier spacing, and system frame number, enabling the UE to initially adapt to the base station environment. Afterward, the base station sends System Information Block Type 1 (SIB1), which includes PRACH (Physical Random Access Channel) resources. Subsequently, the UE sends Msg1 via the PRACH.

[0032] Based on the above background, the embodiments of this application aim to solve the problems that the path loss caused by the ultra-long distance of NTN is extremely large, and a single Msg4 transmission may not be received and correctly decoded by the user equipment, as well as the problem that Msg4 is easily lost at the cell edge due to weak signal, and the problem that communication channel is abnormal due to interference signals. Ultimately, the reliability of Msg4 reception is improved, thereby increasing the success rate of user equipment accessing the network.

[0033] Figure 2 This is a flowchart illustrating a communication method provided in an embodiment of this application. This communication method is applied to user equipment, specifically to scenarios where the user equipment accesses a network, including initial network registration upon power-on, or network handover scenarios where the user equipment moves from the network coverage area of ​​one base station to the network coverage area of ​​another base station. The user equipment refers to a terminal with wireless communication capabilities, including but not limited to: smartphones, smart tablets, smartwatches, and connected vehicles.

[0034] See Figure 2 The communication method specifically includes the following steps:

[0035] S210. In response to receiving a system information block sent by the base station, determine configuration information from the system information block.

[0036] The system information block refers to System Information Block Type 1 (SIB1), which includes PRACH (Physical Random Access Channel) resources. Subsequently, the user equipment transmits Msg1 via PRACH.

[0037] In this embodiment, configuration information is added to SIB1. This configuration information assists the user equipment in deciding whether to trigger the Msg4 retransmission process within the current signal coverage area. When the user equipment receives SIB1, it parses it to obtain the configuration information. The current signal coverage area includes the cell range of a cellular network or the beam range of a satellite network.

[0038] The core objectives of repeatedly sending Msg4 include: enhancing downlink coverage; improving the decoding success rate of user equipment in weak signal scenarios (such as cell edge and NTN satellite communication) by repeatedly sending Msg4 multiple times, thereby improving the success rate of user equipment accessing the network; ensuring the reliability of critical signaling, avoiding the random access process from falling back to the Msg1 sending step due to a single transmission failure, thereby reducing access latency.

[0039] In some implementations, the configuration information includes one or more of the following: a reference signal received power threshold; a signal-to-interference-plus-noise ratio (SINNR) threshold; a timing advance threshold; and a Doppler frequency shift threshold. Further, the configuration information may also include: retransmission policy indication information, specifically one or more of the following: maximum number of retransmissions, retransmission interval (the time interval between two adjacent transmissions of Msg4), and a switch state indicating whether retransmission requests are allowed in Msg3. If the switch state is "true," it indicates that retransmission requests for Msg4 are allowed in Msg3; if the switch state is "false," it indicates that retransmission requests for Msg4 are not allowed in Msg3. Typically, the switch state defaults to "true."

[0040] For example, configuration information can be obtained by parsing the "msg4RepetitionConfig" field in SIB1.

[0041] Here is an example of the “msg4RepetitionConfig” field:

[0042] msg4RepetitionConfig::=SEQUENCE{

[0043] rsrpThresholdINTEGER (-140..-80),

[0044] sinrThresholdINTEGER (-10..30),

[0045] taThresholdINTEGER (0..2000000),

[0046] dopplerThresholdINTEGER(0..20000),

[0047] maxRepetitionsINTEGER (1..4),

[0048] repetitionIntervalINTEGER (1..10),

[0049] enableDynamicRequestBOOLEAN(true),

[0050] } Here, rsrpThreshold represents the reference signal received power threshold, which can be determined through network signal testing. For example, in LEO communication scenarios, rsrpThreshold = -105 dBm; in high-speed mobile communication scenarios, rsrpThreshold = -95 dBm.

[0051] sinrThreshold represents the signal-to-interference-plus-noise ratio (SIR) threshold, which can be determined through testing or can be set to sinrThreshold=3dB by default.

[0052] taThreshold represents the timing advance threshold, which can be determined through testing or a default value can be used. In terrestrial network communication scenarios, taThreshold = 500μs; in GEO communication scenarios, taThreshold = 100000μs.

[0053] dopplerThreshold represents the Doppler frequency shift threshold, which can be determined through testing or by using the default value. In LEO communication scenarios, dopplerThreshold = 10000Hz; in high-speed movement scenarios, dopplerThreshold = 5000Hz.

[0054] `maxRepetitions` represents the maximum number of retransmissions, which defaults to 2 and is usually not allowed to exceed 4 to ensure real-time performance.

[0055] repetitionInterval represents the retransmission interval, which defaults to 4 time slots.

[0056] enableDynamicRequest indicates the Msg4 retransmission switch status, which is "true" by default.

[0057] In some implementations, the configuration information further includes the current communication scenario category, and one or more of the following: retransmission policy indication information, reference signal received power threshold; signal-to-interference-plus-noise ratio threshold; timing advance threshold; and Doppler frequency shift threshold. An example of the corresponding "msg4RepetitionConfig" field is as follows:

[0058] msg4RepetitionConfig::=SEQUENCE{

[0059] rsrpThresholdINTEGER (-140..-80),

[0060] sinrThresholdINTEGER (-10..30),

[0061] taThresholdINTEGER (0..2000000),

[0062] dopplerThresholdINTEGER(0..20000),

[0063] maxRepetitionsINTEGER (1..4),

[0064] repetitionIntervalINTEGER (1..10),

[0065] enableDynamicRequestBOOLEAN(true),

[0066] scenario ENUMERATED {

[0067] terrestrial (0),

[0068] leoSatellite (1),

[0069] geoSatellite (2),

[0070] OPTIONAL

[0071] }

[0072] Wherein, "0" indicates that the current communication scenario category is "terrestrial network communication scenario"; "1" indicates that the current communication scenario category is "LEO communication scenario"; and "2" indicates that the current communication scenario category is "GEO communication scenario".

[0073] S220. Determine whether the Msg4 retransmission process needs to be triggered within the current signal coverage area based on the configuration information.

[0074] In some implementations, the parameter categories corresponding to at least two thresholds included in the configuration information are determined; parameter values ​​matching the parameter categories are measured in real time; and based on the parameter values ​​and the corresponding thresholds, it is determined whether the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0075] In some implementations, the configuration information includes a reference signal received power threshold and a Doppler frequency shift threshold, with the parameter categories corresponding to these two thresholds being reference signal received power and Doppler frequency shift, respectively. The user equipment measures the reference signal received power and Doppler frequency shift values ​​in real time. If the reference signal received power value is less than the reference signal received power threshold and the Doppler frequency shift value is greater than the Doppler frequency shift threshold, then it is determined that a Msg4 retransmission procedure needs to be triggered within the current signal coverage area.

[0076] The Received Reference Signal Power (RSRP) is used to evaluate the received power and signal strength of the reference signal received from the base station, and is used to measure the signal coverage strength (or to determine the quality of the underlying link). The range of the Received Reference Signal Power is between -44dBm and -140dBm, with higher values ​​indicating stronger signals. For example, -54dBm indicates a stronger signal than -64dBm.

[0077] Doppler shift is a frequency change caused by the relative motion between user equipment and base station. In wireless communication, when user equipment moves, the signal frequency changes due to the Doppler effect, resulting in Doppler shift. Doppler shift leads to signal distortion and increased bit error rate, affecting decoding success rate. Adjusting the Doppler shift can reduce these problems and improve communication quality.

[0078] In some implementations, the configuration information includes a signal-to-interference-plus-noise ratio (SINR) threshold and a timing advance threshold; these two thresholds correspond to the parameter categories of SINR and timing advance, respectively. The user equipment measures the SINR and timing advance values ​​in real time; if the SINR value is less than the SINR threshold and the timing advance value is greater than the timing advance threshold, it is determined that a Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0079] The signal-to-interference-plus-noise ratio (SINR) is the ratio of the received useful signal power to the sum of the interference signal power and the noise power. It is used to measure the quality of the received signal (or to assess the impact of interference and noise). The value ranges from -23dB to -40dB. A higher value indicates better signal quality. For example, -23dB indicates better signal quality than -29dB.

[0080] Timing advance (TA), derived from Msg2's RAR, refers to the time user equipment (UE) needs to send signals in advance to compensate for the propagation delay experienced during transmission. Propagation delay is caused by the time it takes for a signal to travel from the UE to the base station in the wireless channel. By adjusting the timing advance, it can be ensured that all UE signals arrive at the base station at the correct time, thereby avoiding signal collisions and interference.

[0081] The above embodiments illustrate that when determining whether to trigger the Msg4 retransmission procedure, a decision is made based on a combination of the reference signal received power and the Doppler frequency shift, or based on a combination of the signal-to-interference-plus-noise ratio (SINR) and the timing advance. In general, if the RSRP is less than a threshold (e.g., -100 dBm) and the Doppler frequency shift is greater than a threshold (e.g., 5 kHz), then the Msg4 retransmission is triggered. Alternatively, if the SINR is less than a threshold (e.g., -3 dB) and the TA is greater than a threshold (e.g., 500 μs), then the Msg4 retransmission is triggered.

[0082] In other implementations, a parameter category corresponding to a threshold included in the configuration information is determined; parameter values ​​matching the parameter category are measured in real time; and based on the parameter values ​​and the corresponding threshold, it is determined whether a Msg4 retransmission process needs to be triggered within the current signal coverage area. For example, if the threshold included in the configuration information is a reference signal received power threshold, and the corresponding parameter category is reference signal received power, the value of the reference signal received power in the current network environment is measured in real time. If this value is less than the reference signal received power threshold, it is determined that a Msg4 retransmission process needs to be triggered. As another example, if the threshold included in the configuration information is a signal-to-interference-plus-noise ratio (SINR) threshold, and the corresponding parameter category is SINR, the value of the SINR in the current network environment is measured in real time. If this value is less than the SINR threshold, it is determined that a Msg4 retransmission process needs to be triggered. As yet another example, if the threshold included in the configuration information is a timing advance threshold, and the corresponding parameter category is timing advance, the value of the timing advance in the current network environment is measured in real time. If this value is greater than the timing advance threshold, it is determined that a Msg4 retransmission process needs to be triggered. For example, one of the thresholds included in the configuration information is the Doppler frequency shift threshold, and the corresponding parameter category is Doppler frequency shift. The value of Doppler frequency shift in the current network environment is measured in real time. If the value is greater than the Doppler frequency shift threshold, it is determined that the Msg4 retransmission process needs to be triggered.

[0083] In general, the determination can be made based on any one or a combination of two of the following: received reference signal power, signal-to-interference-plus-noise ratio (SIR), timing advance, and Doppler shift. Alternatively, it can be made based on any three or four of these factors.

[0084] For example, if the value of the reference signal received power is less than the reference signal received power threshold and the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, then the Msg4 retransmission process is triggered.

[0085] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0086] Alternatively, if the Doppler frequency shift value is greater than the Doppler frequency shift threshold and the signal-to-interference-plus-noise ratio (SINR) value is less than the SINR threshold, then the Msg4 retransmission process is triggered.

[0087] Alternatively, if the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0088] Alternatively, if the signal-to-interference-plus-noise ratio (SIR) is less than the SIR threshold and the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0089] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, and the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, then the Msg4 retransmission process is triggered.

[0090] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0091] Alternatively, if the Doppler frequency shift value is greater than the Doppler frequency shift threshold, the signal-to-interference-plus-noise ratio (SIR) value is less than the SIR threshold, and the timing advance value is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0092] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0093] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0094] Furthermore, in some implementations, it can be determined whether the Msg4 retransmission process needs to be triggered within the current signal coverage area based on the current communication scenario category.

[0095] For example, based on the current communication scenario category, a matching target parameter is determined (specifically, a target parameter matching the current communication scenario category can be determined through a preset mapping relationship); the value of the target parameter is measured in real time; and based on the value of the target parameter and the corresponding threshold, it is determined whether the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0096] For example, if the current communication scenario is a LEO satellite communication scenario, the target parameters to be matched include Doppler frequency shift. The Doppler frequency shift value is then measured in real time. If the Doppler frequency shift value is greater than the Doppler frequency shift threshold, it is determined that a Msg4 retransmission process needs to be triggered within the current signal coverage area. That is, if the current communication scenario is a LEO satellite communication scenario, then Doppler frequency shift is the dominant condition (Doppler frequency shift > 10kHz), and the requirements for the Reference Signal Received Power (RSRP) are relaxed.

[0097] If the current communication scenario is a GEO satellite communication scenario, the matched target parameters include timing advance; the timing advance value is measured in real time, and if the timing advance value is greater than the timing advance threshold, it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area. In particular, if the current communication scenario is a GEO satellite communication scenario, a higher timing advance TA threshold (e.g., 100ms) is set separately.

[0098] If the current communication scenario is a terrestrial network communication scenario, the matching target parameters include reference signal received power and Doppler shift. The values ​​of reference signal received power and Doppler shift are measured in real time. If the value of reference signal received power is less than the reference signal received power threshold, and the value of Doppler shift is greater than the Doppler shift threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area. Alternatively, if the current communication scenario is a terrestrial network communication scenario, the matching target parameters include signal-to-interference-plus-noise ratio (SIR) and timing advance. The values ​​of SIR and timing advance are measured in real time. If the value of SIR is less than the SIR threshold, and the value of timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

[0099] In general, for the current communication scenario category of terrestrial network communication, the Doppler frequency shift threshold is reduced to 5kHz, and the reference signal received power (RSRP) threshold is increased to -95dBm. Alternatively, if the signal-to-interference-plus-noise ratio (SINR) is below a certain threshold (e.g., -3dB) and the timing advance (TA) is greater than a certain threshold (e.g., 500μs), it is determined that the Msg4 retransmission process needs to be triggered.

[0100] In summary, the threshold used to determine whether to trigger the Msg4 retransmission process based on the current communication scenario category is different from the threshold used in the determination scheme that does not consider the current communication scenario category. The specific value of the threshold can be determined through actual testing or calibration.

[0101] S230. In response to determining that a Msg4 retransmission procedure needs to be triggered within the current signal coverage area, a retransmission request information for Msg4 is sent to the base station via Msg3.

[0102] The retransmission request information of Msg4 is encapsulated into Msg3 and sent to the base station together with Msg3. The base station is requested to perform the operation of retransmitting Msg4 when sending Msg4, that is, to send Msg4 multiple times, so as to increase the probability that Msg4 is received and successfully decoded by the user equipment, thereby improving the success rate of user equipment accessing the network.

[0103] In some implementations, the communication method further includes: determining whether to add a Doppler frequency shift compensation value to Msg3 based on the current communication scenario category; if it is determined that a Doppler frequency shift compensation value should be added to Msg3, then calculating the Doppler frequency shift compensation value and adding the Doppler frequency shift compensation value to Msg3.

[0104] Specifically, when deciding whether to add a Doppler shift compensation value to Msg3, the decision can be made as follows: If the current communication scenario is LEO satellite communication or the relative speed between the user equipment and the communication satellite reaches a speed threshold, then it is determined that a Doppler shift compensation value should be added to Msg3. If the base station pre-corrects the Doppler shift through beamforming or satellite ephemeris, then the user equipment does not need to report an additional compensation value.

[0105] In some implementations, if Msg4 is retransmitted due to a high Doppler frequency shift, then Msg3 needs to carry a further Doppler frequency shift compensation value. If Msg4 is retransmitted due to a large timing advance and a low reference signal reception power, then Msg3 does not need to carry a further Doppler frequency shift compensation value.

[0106] For example, when the current communication scenario is LEO communication, if the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold and the value of the timing advance is greater than the timing advance threshold, then it is determined that Msg3 needs to carry a further Doppler frequency shift compensation value.

[0107] When the current communication scenario is GEO communication, if the value of Doppler frequency shift is less than the Doppler frequency shift threshold and the value of timing advance is greater than the timing advance threshold, then Msg3 does not need to carry the Doppler frequency shift compensation value.

[0108] In summary, in some implementations, Msg3 includes retransmission request information for Msg4, which includes whether to request retransmission; when the retransmission request information includes the request for retransmission, the retransmission request information also includes the number of retransmissions, which is custom or the maximum number of retransmissions indicated in the configuration information, and the Doppler frequency shift compensation value.

[0109] For example, add the following fields to Msg3:

[0110] RRCSetupRequest ::= SEQUENCE {

[0111] ueIdentityBIT STRING,

[0112] msg4RepetitionRequest ENUMERATED {

[0113] noRequest(0), -- No retransmission requested

[0114] defaultRepetition (1), -- Number of retransmissions indicated by SIB1

[0115] customRepetition(2), -- Custom repetition count

[0116] },

[0117] requestedRepetitionsINTEGER (1..4) OPTIONAL,-- Custom number of repetitions (only carried in customRepetition)

[0118] dopplerCompensationINTEGER (-10000..10000) OPTIONAL, -- Doppler frequency shift compensation value (Hz)

[0119] }

[0120] Here, requestedRepetitions represents the suggested number of retransmissions, and dopplerCompensation represents the compensation value of the Doppler frequency shift measured by the user equipment.

[0121] S240: Receive Msg4 sent by the base station according to the retransmission request information, and establish a connection with the base station according to Msg4.

[0122] In some implementations, before receiving the Msg4 sent by the base station according to the retransmission request information, the process further includes receiving Msg4 retransmission policy information sent by the base station. When the base station receives the Msg4 retransmission request information, it checks whether the Msg4 retransmission process needs to be triggered and feeds back the Msg4 retransmission policy information to the user equipment based on the verification result. The Msg4 retransmission policy information includes the number of retransmissions. In some implementations, in addition to the number of retransmissions, the Msg4 retransmission policy information may also include a Doppler frequency shift compensation value to assist the user equipment in correctly decoding the Msg4. Subsequently, the user equipment receives the Msg4 sent by the base station according to the Msg4 retransmission policy information.

[0123] Optionally, Msg4 retransmission policy information can be sent to the user equipment by reusing existing fields or using reserved fields.

[0124] For example, the base station stores Msg4 retransmission policy information in existing or reserved fields of DCIFormat1_0 to achieve the purpose of sending Msg4 retransmission policy information to user equipment.

[0125] An example of DCI Format 1_0 is as follows:

[0126] DCI Format 1_0 (TC-RNTI) := {

[0127] Existing fields (frequency domain / time domain resource allocation, MCS, etc.)

[0128] msg4RepetitionControlBIT STRING (SIZE(2)),

[0129] dopplerPreCompensationINTEGER (-10000..10000),

[0130] }

[0131] Among them, msg4RepetitionControl is used to explicitly indicate the number of retransmissions. dopplerPreCompensation is used to represent the Doppler frequency shift compensation value.

[0132] According to the retransmission policy, the user equipment receives the retransmitted Msg4 copy. In some implementations, in response to receiving the first Msg4 sent by the base station and successfully decoding it, the user equipment sends an acknowledgment message to the base station, or sends an acknowledgment message along with the identifier of the communication beam when the Msg4 was received, to inform the base station that the Msg4 has been successfully decoded and there is no need to retransmit it, thus enabling the base station to establish a connection with the user equipment. Alternatively, in response to receiving the first Msg4 sent by the base station and successfully decoding it, no acknowledgment message is sent to the base station, and subsequent repeatedly received Msg4s are discarded directly. This configuration aims to avoid wasting network resources and conserve network resources.

[0133] Alternatively, in response to receiving all Msg4 messages from the base station, all Msg4 messages are decoded, and upon successful decoding, a response message is sent back to the base station. Alternatively, a response message along with the identifier of the communication beam at the time of receiving the Msg4 message is sent back to the base station. This configuration aims to ensure reliable reception and decoding of Msg4 messages, adapting to scenarios with unstable communication, such as high frequency shifts or high latency.

[0134] If Msg4 decoding fails, no message is sent back to the base station, and the base station triggers a new round of access procedures through a timeout mechanism.

[0135] Based on the above embodiments, refer to as follows Figure 3 The diagram illustrates a communication method applied to a base station and executed in conjunction with user equipment. Figure 3 As shown, it includes the following steps:

[0136] S310, Send system information block to user equipment.

[0137] S320. Receive Msg3 sent by the user equipment, determine the retransmission policy information of Msg4 according to the network environment where the user equipment is located, and send the retransmission policy information of Msg4 to the user equipment.

[0138] In some implementations, if the user equipment (UE) does not request a retransmission, the base station proactively determines whether to retransmit Msg4 based on the network environment in which the UE is located, and determines the retransmission strategy information for Msg4.

[0139] For example, the base station detects one or more of the following values: the received power of the reference signal, the signal-to-interference-plus-noise ratio, the timing advance, and the Doppler shift, and compares the detected values ​​with the corresponding thresholds to determine whether to retransmit Msg4.

[0140] For example, the base station detects whether the value of the reference signal received power is less than the reference signal received power threshold. If so, it forces a retransmission and sends retransmission policy information to the user equipment according to the retransmission parameters configured in SIB1, and performs the retransmission operation according to the retransmission parameters configured in SIB1.

[0141] In some implementations, the system information block includes configuration information, which is used by the user equipment to determine whether the Msg4 retransmission process needs to be triggered within the current signal coverage area. If the user equipment determines that the Msg4 retransmission process needs to be triggered within the current signal coverage area, the user equipment sends a retransmission request for Msg4 to the base station via Msg3 sent to the base station.

[0142] Correspondingly, the base station determines the retransmission strategy information of Msg4 based on the network environment where the user equipment is located and the retransmission request information carried in Msg3.

[0143] Msg3 includes a retransmission request for Msg4, which includes whether a retransmission is requested. If the retransmission request includes a request for retransmission, it also includes the number of retransmissions, which is either custom or the maximum number of retransmissions indicated in the configuration information, as well as the Doppler frequency shift compensation value.

[0144] When the base station receives Msg3 from the user equipment, it determines the final retransmission strategy information based on the retransmission request information carried in Msg3. The retransmission strategy information includes one or more of the following: Doppler frequency shift compensation value, the number of retransmissions for Msg4, and the retransmission interval. The base station then sends the retransmission strategy information for Msg4 to the user equipment, enabling the user equipment to receive and decode Msg4 according to the retransmission strategy information.

[0145] In some implementations, the base station parses Msg3 to obtain the retransmission request information carried by Msg3. If the retransmission request information includes the number of retransmissions, the base station verifies whether this number of retransmissions is user-defined or the number indicated in the configuration information. If it is user-defined, the base station verifies whether the user-defined number is reasonable (usually not allowed to exceed 4). If it is unreasonable, it will be forcibly changed to avoid excessive retransmission requests from the user equipment. If it is reasonable, the base station will further detect the quality of the current communication channel to determine whether it is really necessary to retransmit Msg4.

[0146] Specifically, the base station measures the uplink reference signal received power, timing advance, Doppler shift, and signal-to-interference-plus-noise ratio in real time, and combines these measurements with the reference signal received power threshold, timing advance threshold, Doppler shift threshold, and signal-to-interference-plus-noise ratio threshold indicated in the configuration information to determine whether Msg4 really needs to be retransmitted. If Msg4 really needs to be retransmitted, the base station further sends the number of retransmissions, retransmission interval, and Doppler shift compensation value to the user equipment.

[0147] In some implementations, as shown in Table 1, the base station refers to the specific value of the msg4RepetitionRequest field of Msg3. If msg4RepetitionRequest=0, it indicates that the user equipment does not request retransmission; if msg4RepetitionRequest=1, it indicates that the user equipment requests retransmission and uses the retransmission count indicated by SIB1; if msg4RepetitionRequest=2, it indicates that the user equipment requests retransmission and customizes the retransmission count. The customized count is determined by the value of the requestedRepetitions field.

[0148] Meanwhile, the base station refers to the maxRepetitions field in SIB1 to determine the maximum number of allowed retransmissions, and refers to the rsrpThreshold field in SIB1 to determine the reference signal received power threshold, the sinrThreshold field in SIB1 to determine the signal-to-interference-plus-noise ratio threshold, the taThreshold field to determine the timing advance threshold, and the dopplerThreshold field to determine the Doppler frequency shift threshold. These thresholds are used to verify whether a retransmission is really necessary.

[0149] Table 1

[0150]

[0151] Where RSRP represents the real-time measured value of the received reference signal power, rsrpThreshold represents the received reference signal power threshold, dopplerThreshold represents the Doppler frequency shift threshold, sinrThreshold represents the signal-to-interference-plus-noise ratio threshold, taThreshold represents the timing advance threshold, Doppler represents the real-time measured value of the Doppler frequency shift, TA represents the real-time measured value of the timing advance, and SINR represents the real-time measured value of the signal-to-interference-plus-noise ratio.

[0152] For example, see references to Figure 4The diagram illustrates a logic for determining whether a retransmission is truly necessary. Specifically, it includes: when the User Equipment (UE) does not request a retransmission, determining whether the reference signal received power is less than a reference signal received power threshold; if so, forcing a retransmission, sending a retransmission policy to the UE according to the retransmission parameters configured in SIB1, and executing the retransmission operation according to the SIB1 configuration parameters. When the UE requests a retransmission according to the SIB1 configuration parameters (i.e., the UE requests a default retransmission), if the reference signal received power is less than the reference signal received power threshold and the Doppler shift is greater than the Doppler shift threshold, then agreeing to the retransmission, sending a retransmission policy to the UE according to the SIB1 configuration parameters, and executing the retransmission operation according to the SIB1 configuration parameters. In the case of a user equipment requesting retransmission using custom retransmission parameters (i.e., the UE requests custom retransmission), it is determined whether the requested number of retransmissions (requestedRepe represents the number of requested retransmissions) is less than the maximum number of retransmissions max. If so, the retransmission is approved, and a retransmission policy is sent to the user equipment according to the retransmission parameters configured in SIB1 or the user equipment's custom retransmission parameters, and the retransmission operation is performed according to the retransmission parameters configured in SIB1 or the user equipment's custom retransmission parameters.

[0153] The above implementation is only an example. When determining whether a retransmission is really necessary, the base station can still make a determination based on any one, any two, any three, or any combination of four of the following: reference signal received power, signal-to-interference-plus-noise ratio, timing advance, and Doppler frequency shift.

[0154] For example, if the value of the reference signal received power is less than the reference signal received power threshold, and the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, then it is determined that retransmission is required.

[0155] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that a retransmission is required.

[0156] Alternatively, if the Doppler shift value is greater than the Doppler shift threshold and the signal-to-interference-plus-noise ratio (SINR) value is less than the SINR threshold, then retransmission is required.

[0157] Alternatively, if the Doppler shift value is greater than the Doppler shift threshold and the timing advance value is greater than the timing advance threshold, then it is determined that a retransmission is required.

[0158] Alternatively, if the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold and the timing advance is greater than the timing advance threshold, then a retransmission is required.

[0159] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, and the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, then it is determined that retransmission is required.

[0160] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that retransmission is required.

[0161] Alternatively, if the Doppler shift value is greater than the Doppler shift threshold, the signal-to-interference-plus-noise ratio (SIR) value is less than the SIR threshold, and the timing advance value is greater than the timing advance threshold, then it is determined that retransmission is required.

[0162] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that retransmission is required.

[0163] Alternatively, if the value of the reference signal received power is less than the reference signal received power threshold, the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, the value of the signal-to-interference-plus-noise ratio (SINR) is less than the SINR threshold, and the value of the timing advance is greater than the timing advance threshold, then it is determined that retransmission is required.

[0164] In summary, the retransmission strategy information for Msg4 is determined, including:

[0165] If Msg3 includes the retransmission request information of Msg4, the retransmission request information is verified, and the retransmission strategy information of Msg4 is determined based on the verification result. If Msg3 does not include the retransmission request information of Msg4, the retransmission process of Msg4 needs to be triggered based on the real-time measured parameter values ​​and configuration information. If so, the retransmission interval and retransmission number indicated by the configuration information are determined as the retransmission strategy information of Msg4.

[0166] The retransmission request information is verified, and the retransmission strategy information of Msg4 is determined based on the verification result. This includes: if the retransmission request information is determined based on the configuration information, then the retransmission process of Msg4 needs to be triggered based on the real-time measured parameter values ​​and the configuration information. If so, the retransmission interval and retransmission number indicated by the configuration information are determined as the retransmission strategy information of Msg4. If the retransmission request information is not determined based on the configuration information, then it is determined whether the number of retransmissions requested in the retransmission request information is less than the maximum number indicated by the configuration information. If so, the retransmission interval indicated by the configuration information and the number of retransmissions requested by the retransmission request information are determined as the retransmission strategy information of Msg4.

[0167] The process of determining whether to trigger the Msg4 retransmission procedure based on real-time measured parameter values ​​and configuration information includes: determining the parameter category corresponding to at least one threshold included in the configuration information; measuring parameter values ​​matching the parameter category in real time; and determining whether to trigger the Msg4 retransmission procedure based on the parameter values ​​and corresponding thresholds. Parameter values ​​include one or more of the following: reference signal received power, Doppler frequency shift, timing advance, and signal-to-interference-plus-noise ratio.

[0168] For example, if the user equipment does not request a retransmission, and the base station determines through detection that the reference signal received power is less than the reference signal received power threshold indicated in the configuration information, it can force a retransmission to cover weak network scenarios and improve the success rate of user equipment accessing the network. Alternatively, if the Doppler shift value is greater than the Doppler shift threshold, a retransmission can be forced to cover LEO satellite high-frequency shift scenarios. Or, if the timing advance is greater than the timing advance threshold, a retransmission can be forced to cover high-latency scenarios.

[0169] S330. Send Msg4 to the user equipment according to the retransmission strategy information, and establish a connection with the user equipment when receiving a response message from the user equipment indicating that Msg4 has been successfully decoded.

[0170] Specifically, the purpose of Doppler shift adjustment is to compensate for frequency shifts caused by the Doppler effect and other factors (such as clock skew) to ensure the stability and reliability of communication. Specific objectives include: improving communication quality: Doppler shift can lead to signal distortion and increased bit error rate; adjusting the Doppler shift can reduce these problems and improve communication quality. Maintaining synchronization: In wireless communication systems, the transmitting and receiving ends need to maintain frequency synchronization; otherwise, demodulation and data recovery will be affected. Doppler shift adjustment helps maintain this synchronization. Reducing interference: Doppler shift can cause interference between adjacent channels; adjustment can reduce this interference and optimize spectrum usage. Supporting high-speed movement: In high-speed movement scenarios (such as on vehicles or trains), Doppler shift is more pronounced; Doppler shift adjustment can ensure stable communication in such situations.

[0171] As shown in Table 2, Doppler frequency shift compensation is required in LEO satellite communication scenarios and scenarios where user equipment is moving at high speeds. This is because the frequency shift amount far exceeds the capability of the physical layer's Automatic Frequency Control (AFC) (which can typically correct Doppler frequency shifts within ±1kHz), and without compensation, Msg4 PDSCH demodulation will fail, and even retransmission may not be able to recover.

[0172] Table 2

[0173]

[0174] Referring to Table 3, scenarios requiring Msg4 retransmission but not Doppler shift compensation include GEO satellite communication scenarios where the timing advance is greater than the timing advance threshold; scenarios where the signal-to-interference-plus-noise ratio (SIR) is less than the SIR threshold, such as high-interference scenarios like dense urban areas; and scenarios where the reference signal received power is less than the threshold, such as scenarios with shadow obstruction.

[0175] Table 3

[0176]

[0177] Doppler frequency shift compensation can solve the problem of signal waveform distortion, and Msg4 retransmission can solve the problem of decoding failure.

[0178] General, Reference Figure 5 The diagram illustrates an interaction between a User Equipment (UE) and a base station. Specifically, when the base station sends SIB1 to the UE, it adds configuration information to SIB1, including: a reference signal received power threshold, a signal-to-interference-plus-noise ratio (SINR) threshold, a timing advance threshold, and a Doppler shift threshold, providing the UE with a basis for deciding whether to initiate a Msg4 retransmission; and, when necessary, adding a Doppler shift compensation value. The configuration information may also include retransmission policy indication information, which includes the maximum number of retransmissions, the retransmission interval, and a switch state indicating whether retransmission requests in Msg3 are allowed.

[0179] The user equipment parses SIB1 to obtain configuration information and determines whether the current network environment requires initiating Msg4 retransmission, as well as whether Doppler shift compensation values ​​need to be reported. If it is determined that retransmission is required, the retransmission request information and Doppler shift compensation values ​​are added to Msg3 and sent to the base station.

[0180] The base station parses Msg3 to obtain the retransmission request information, verifies whether retransmission is really necessary, and sends the final retransmission strategy information to the user equipment through DCI Format1_0, as well as sending Doppler frequency shift compensation values ​​when needed.

[0181] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Figure 6 As shown, the electronic device 500 includes one or more processors 501 and memory 502.

[0182] The processor 501 may be a central processing unit (CPU) or other form of processing unit with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device 500 to perform desired functions.

[0183] The memory 502 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, random access memory (RAM) and / or cache memory. The non-volatile memory may include, for example, read-only memory (ROM), hard disk, flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 501 may execute the program instructions to implement the communication methods and / or other desired functions described in any embodiment of this application above. Various contents such as initial extrinsic parameters and thresholds may also be stored in the computer-readable storage medium.

[0184] In one example, the electronic device 500 may further include an input device 503 and an output device 504, these components being interconnected via a bus system and / or other forms of connection mechanisms (not shown). The input device 503 may include, for example, a keyboard, a mouse, etc. The output device 504 may output various information to the outside, including warning messages, braking force, etc. The output device 504 may include, for example, a display, a speaker, a printer, and a communication network and its connected remote output devices, etc.

[0185] Of course, for the sake of simplicity, Figure 6 Only some of the components of the electronic device 500 relevant to this application are shown in this illustration; components such as buses, input / output interfaces, etc., are omitted. In addition, the electronic device 500 may include any other suitable components depending on the specific application.

[0186] In addition to the methods and devices described above, embodiments of this application may also be computer program products, which include computer program instructions that, when executed by a processor, cause the processor to perform the steps of the communication method provided in any embodiment of this application.

[0187] The computer program product can be written in any combination of one or more programming languages ​​to perform the operations of the embodiments of this application. The programming languages ​​include object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0188] Furthermore, embodiments of this application may also be computer-readable storage media storing computer program instructions thereon, which, when executed by a processor, cause the processor to perform the steps of the communication method provided in any embodiment of this application.

[0189] The computer-readable storage medium may be any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof.

[0190] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in the specification and claims of this application, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0191] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0192] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this invention, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A communication method applied to a user equipment, characterized in that, include: In response to receiving a system information block sent by a base station, configuration information is determined from the system information block; The configuration information includes the current communication scenario category; Determining whether the Msg4 retransmission process needs to be triggered within the current signal coverage area based on the configuration information includes: determining the matching target parameters based on the current communication scenario category; The values ​​of the target parameters are measured in real time; Determine whether the Msg4 retransmission process needs to be triggered within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information. In response to the determination that the Msg4 retransmission process needs to be triggered within the current signal coverage area, the retransmission request information for Msg4 is sent to the base station via Msg3; Receive Msg4 sent by the base station according to the retransmission request information, and establish a connection with the base station according to Msg4; The configuration information includes one or more of the following: Reference signal received power threshold; Signal-to-interference-plus-noise ratio threshold; Timing lead time threshold; Doppler frequency shift threshold; The current communication scenario category includes LEO satellite communication scenarios, and the target matching parameter includes Doppler frequency shift; The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information includes: If the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

2. The method according to claim 1, characterized in that, The step of determining whether the Msg4 retransmission process needs to be triggered within the current signal coverage area based on the configuration information includes: Determine the parameter categories corresponding to at least two thresholds included in the configuration information; Measure parameter values ​​that match the parameter category in real time; Based on the parameter values ​​and the corresponding thresholds in the configuration information, it is determined whether the Msg4 retransmission process needs to be triggered within the current signal coverage area.

3. The method according to claim 2, characterized in that, The configuration information includes a reference signal received power threshold and a Doppler frequency shift threshold; The parameter values ​​include the reference signal received power and the Doppler frequency shift. The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the parameter value and the corresponding threshold in the configuration information includes: If the value of the reference signal received power is less than the reference signal received power threshold, and the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

4. The method according to claim 2, characterized in that, The configuration information includes the signal-to-interference-plus-noise ratio threshold and the timing advance threshold; The parameter values ​​include the signal-to-interference-plus-noise ratio (SINR) and the timing advance. The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the parameter value and the corresponding threshold in the configuration information includes: If the signal-to-interference-plus-noise ratio (SIR) is less than the SIR threshold and the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

5. The method according to claim 1, characterized in that, The current communication scenario category includes GEO satellite communication scenarios, and the matching target parameters include timing advance. The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information includes: If the value of the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

6. The method according to claim 1, characterized in that, The current communication scenario category includes terrestrial network communication scenarios, and the target parameters for matching include reference signal received power and Doppler frequency shift; The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information includes: If the value of the reference signal received power is less than the reference signal received power threshold, and the value of the Doppler frequency shift is greater than the Doppler frequency shift threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

7. The method according to claim 1, characterized in that, The current communication scenario category includes terrestrial network communication scenarios, and the target parameters for matching include signal-to-interference-plus-noise ratio and timing advance. The step of determining whether to trigger the Msg4 retransmission process within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information includes: If the signal-to-interference-plus-noise ratio (SIR) is less than the SIR threshold and the timing advance is greater than the timing advance threshold, then it is determined that the Msg4 retransmission process needs to be triggered within the current signal coverage area.

8. The method according to claim 1, characterized in that, Also includes: Based on the current communication scenario category, determine whether to add a Doppler frequency shift compensation value to Msg3; If it is determined that a Doppler frequency shift compensation value should be added to Msg3, then a Doppler frequency shift compensation value should be added to Msg3.

9. The method according to claim 8, characterized in that, The step of determining whether to add a Doppler frequency shift compensation value to Msg3 based on the current communication scenario category includes: If the current communication scenario category is LEO satellite communication or the relative speed between the user equipment and the communication satellite reaches a speed threshold, then it is determined to add a Doppler frequency shift compensation value to Msg3.

10. The method according to claim 1, characterized in that, The configuration information also includes retransmission policy indication information, which includes one or more of the following: maximum number of retransmissions, retransmission interval, and whether retransmission requests are allowed in Msg3.

11. The method according to claim 1, characterized in that, Msg3 includes a retransmission request message for Msg4, which includes whether a retransmission is requested. If the retransmission request information includes a request for retransmission, the retransmission request information also includes the number of retransmissions, which is either custom or the maximum number of retransmissions indicated in the configuration information.

12. The method according to claim 1, characterized in that, The step of receiving Msg4 sent by the base station according to the retransmission request information, and establishing a connection with the base station according to Msg4, includes: In response to receiving the first Msg4 sent by the base station and successfully decoding it, the system sends an acknowledgment message back to the base station, or sends an acknowledgment message back to the base station along with the identifier of the communication beam when the Msg4 was received, to inform the base station that the Msg4 has been successfully decoded and there is no need to retransmit the Msg4, so that the base station can establish a connection with the user equipment. Alternatively, in response to receiving all Msg4s sent by the base station, all Msg4s are decoded, and upon successful decoding, the response message is sent back to the base station; or, the response message and the identifier of the communication beam when the Msg4s were received are sent back to the base station.

13. The method according to claim 1, characterized in that, Before receiving Msg4 sent by the base station according to the retransmission request information, and establishing a connection with the base station according to Msg4, the method further includes: The base station receives Msg4 retransmission policy information from the base station. When the base station receives the Msg4 retransmission request information, it checks whether the Msg4 retransmission process needs to be triggered and feeds back the Msg4 retransmission policy information to the user equipment based on the verification result.

14. A communication method applied to a base station, characterized in that, include: Send system information blocks to user equipment; The system information block includes configuration information, which includes the current communication scenario category; Receive Msg3 sent by the user equipment, determine the retransmission policy information for Msg4 based on the network environment where the user equipment is located, and send the retransmission policy information for Msg4 to the user equipment; including: If Msg3 includes retransmission request information of Msg4, the retransmission request information is verified, and the retransmission strategy information of Msg4 is determined based on the verification result. If Msg3 does not include the retransmission request information of Msg4, check whether the retransmission process of Msg4 needs to be triggered based on the real-time measured parameter values ​​and configuration information. If so, the retransmission interval and retransmission number indicated by the configuration information are determined as the retransmission strategy information of Msg4. The process of determining whether to trigger the Msg4 retransmission procedure based on real-time measured parameter values ​​and configuration information includes: determining the matching target parameter according to the current communication scenario category; measuring the value of the target parameter in real time; and determining whether to trigger the Msg4 retransmission procedure within the current signal coverage area based on the value of the target parameter and the corresponding threshold in the configuration information. In addition, Msg4 is sent to the user equipment according to the retransmission strategy information, and a connection is established with the user equipment upon receiving a response message from the user equipment indicating that Msg4 has been successfully decoded.

15. The method according to claim 14, characterized in that, The configuration information is used by the user equipment to determine whether the Msg4 retransmission process needs to be triggered within the current signal coverage area. If the user equipment determines that the Msg4 retransmission process needs to be triggered within the current signal coverage area, the user equipment sends the retransmission request information for Msg4 to the base station through Msg3 sent to the base station. Correspondingly, determining the retransmission policy information for Msg4 based on the network environment of the user equipment includes: The retransmission strategy information of Msg4 is determined based on the network environment where the user equipment is located and the retransmission request information carried in Msg3.

16. The method according to claim 15, characterized in that, The step of verifying the retransmission request information and determining the retransmission strategy information of Msg4 based on the verification result includes: If the retransmission request information is determined based on the configuration information, then the retransmission process of Msg4 needs to be triggered based on the real-time measured parameter values ​​and the configuration information. If so, the retransmission interval and retransmission number indicated by the configuration information are determined as the retransmission strategy information of Msg4. If the retransmission request information is not determined based on the configuration information, determine whether the number of retransmissions requested in the retransmission request information is less than the maximum number indicated by the configuration information. If so, determine the retransmission interval indicated by the configuration information and the number of retransmissions requested by the retransmission request information as the retransmission strategy information of Msg4.

17. The method according to claim 15 or 16, characterized in that, The step of checking whether to trigger the Msg4 retransmission process based on the real-time measured parameter values ​​and the configuration information includes: Determine the parameter categories corresponding to at least two thresholds included in the configuration information; Measure parameter values ​​that match the parameter category in real time; Based on the parameter values ​​and the corresponding thresholds, it is determined whether the Msg4 retransmission process needs to be triggered.

18. The method according to claim 17, characterized in that, The parameter values ​​include one or more of the following: reference signal received power, Doppler frequency shift, timing advance, and signal-to-interference-plus-noise ratio.

19. The method according to claim 14, characterized in that, The retransmission strategy information includes one or more of the following: Doppler frequency shift compensation value, number of retransmissions of Msg4, and retransmission interval.

20. The method according to claim 14, characterized in that, The step of sending Msg4 retransmission policy information to the user equipment includes: The retransmission policy information for Msg4 is sent to the user equipment by reusing existing fields or using reserved fields.

21. An electronic device, characterized in that, The electronic device includes: Processor and memory; The processor executes the steps of the communication method as described in any one of claims 1 to 20 by invoking programs or instructions stored in the memory.

22. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program or instructions that cause a computer to perform the steps of the communication method as described in any one of claims 1 to 20.

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