Physical random access channel repetition transmission method and apparatus

Abstract

The present disclosure relates to the technical field of mobile communication, and in particular to a physical random access channel repeated transmission method and device, a storage medium and an electronic device. The method comprises: when it is determined that a network device currently allows repeated transmission of a physical random access channel (PRACH), determining a current PRACH repeated transmission strategy, and performing PRACH repeated transmission according to the PRACH repeated transmission strategy; wherein the PRACH repeated transmission strategy comprises a number of times of repeated transmission of the PRACH. The method of the present disclosure can enable a terminal device to determine a PRACH repeated transmission strategy according to an indication of a network device, and thus implement PRACH repeated transmission.

Description

[0001] This application is a divisional application of the invention patent application with the application date of December 17, 2021, the invention name of Physical Random Access Channel Repeated Transmission Method and Device, and the application number of 202111555496.5. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of mobile communication, in particular to a physical random access channel repeated transmission method, a physical random access channel repeated transmission device, a storage medium and an electronic device. BACKGROUND

[0003] The 3GPP NR Realease-16 protocol does not support the repeated transmission of the physical random access channel PRACH (Physical Random Access Channel). According to the current protocol version, the user sends a preamble Preamble once at the PRACH transmission occasion indicated by the base station. According to the time-frequency position of the PRACH transmission occasion, the user can calculate the corresponding RA-RNTI value, and then the user listens to the physical downlink control channel PDCCH (Physical Downlink Control Channel) in the random access response RAR (Random Access Response) time window. If the user successfully descrambles and detects DCI 1_0 using the RA-RNTI, and can identify the RAPID number in the RAR information scheduled by the DCI, the user considers that the PRACH transmission is successful, otherwise the user needs to resend a new PRACH, which will bring additional delay. Especially for high frequency bands, PRACH is a potential coverage limited channel. Therefore, it is necessary to consider enhancing the coverage performance of PRACH.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] The purpose of the present disclosure is to provide a physical random access channel repeated transmission method, a physical random access channel repeated transmission device, a storage medium and a terminal device, which can effectively manage the repeated transmission of PRACH, and further at least partially overcome the defects caused by the limitations and defects of the related art.

[0006] Other characteristics and advantages of the present disclosure will become apparent from the following detailed description, or will be learned by practice of the present disclosure.

[0007] According to a first aspect of the present disclosure, a physical random access channel (PRACH) repetition transmission method is provided, comprising: determining a current PRACH repetition transmission strategy when it is determined that a network device currently allows repeated transmission of a PRACH, and performing PRACH repetition transmission according to the PRACH repetition transmission strategy; wherein the PRACH repetition transmission strategy comprises determining a number of repetitions of the PRACH.

[0008] In an example embodiment of the present disclosure, the determination that the network device currently allows repeated transmission of a PRACH comprises reading PRACH repetition transmission flag information to determine, according to the repetition transmission flag information, that the network device currently supports repeated transmission of a PRACH.

[0009] In an example embodiment of the present disclosure, the reading of the PRACH repetition transmission flag information comprises parsing target signaling issued by the network device to read the PRACH repetition transmission flag information.

[0010] In an example embodiment of the present disclosure, the target signaling is a radio resource control (RRC) message or a SIB1 message; and the reading of the repetition transmission flag information comprises determining that the network device currently supports repeated transmission of a PRACH when a repetition transmission flag bit is read as 1, or determining that the network device currently does not support repeated transmission of a PRACH when the repetition transmission flag bit is read as 0.

[0011] In an example embodiment of the present disclosure, when it is determined that the network device currently allows repeated transmission of a PRACH, the method further comprises determining, by a terminal device, a current PRACH repetition transmission strategy according to a PRACH repetition transmission capability supported by the terminal device.

[0012] In an example embodiment of the present disclosure, before the determination of the current PRACH repetition transmission strategy, the method further comprises determining, by the terminal device, the current PRACH repetition transmission strategy when it is identified that a current channel quality is lower than a preset indicator and there are multiple available PRACH transmission occasions.

[0013] In an example embodiment of the present disclosure, the identification, by the terminal device, that the current channel quality is lower than the preset indicator comprises obtaining a current target signal received power, and determining that the current channel quality of the terminal device is lower than the preset indicator when the target signal received power is lower than a preset first threshold value.

[0014] In an example embodiment of the present disclosure, the target signal received power comprises a received power of a downlink signal.

[0015] In an example embodiment of the present disclosure, the downlink signal comprises a synchronization signal block (SSB) and / or a synchronization signal (SS).

[0016] In an example embodiment of the present disclosure, the terminal device identifies that the current channel quality is lower than the preset index, comprising: when the terminal device measures and / or calculates a signal received power of a downlink path loss reference lower than a preset second threshold value, the terminal device determines that the current channel quality of the terminal device is lower than the preset index.

[0017] In an example embodiment of the present disclosure, the number of PRACH repeated transmissions in the current PRACH repeated transmission strategy is determined according to a combination of one or more of the following conditions: the number of PRACH repeated transmissions supported by the network device contained in the target signaling issued by the network device, the number of PRACH repeated transmissions supported by the terminal device, the number of PRACH repeated transmissions calculated based on the current channel quality information of the terminal device.

[0018] In an example embodiment of the present disclosure, the target signaling further comprises a combination of any one or any multiple of the following: a PRACH transmission occasion, a number of preambles used for PRACH repeated transmission, a number of PRACH repeated transmissions supported by the network device, and a PRACH repeated transmission manner.

[0019] In an example embodiment of the present disclosure, the PRACH repeated transmission strategy further comprises: a number of preambles used for PRACH repeated transmission, a PRACH repeated transmission manner, and a PRACH transmission occasion.

[0020] In an example embodiment of the present disclosure, determining the number of preambles used for PRACH repeated transmission in the PRACH repeated transmission strategy comprises: determining the number of preambles used for PRACH repeated transmission in the PRACH repeated transmission strategy according to the number of preambles used for PRACH repeated transmission contained in the target signaling issued by the network device, and / or according to the currently available preambles identified by the terminal device.

[0021] In an example embodiment of the present disclosure, the PRACH repeated transmission manner comprises: transmitting the same preamble at multiple PRACH transmission occasions, or transmitting different preambles at multiple PRACH transmission occasions.

[0022] In an example embodiment of the present disclosure, determining the PRACH repeated transmission manner in the PRACH repeated transmission strategy comprises:

[0023] The PRACH repeat transmission method in the PRACH repeat transmission strategy is determined based on the PRACH repeat transmission method contained in the target signaling issued by the network device, and / or based on the number of currently available preambles identified by the terminal device.

[0024] In one exemplary embodiment of this disclosure, the method further includes: determining the preamble in the PRACH repetition strategy based on a set of preamble sequences pre-configured by the network device for PRACH repetition.

[0025] In an exemplary embodiment of this disclosure, when a terminal device transmits the same preamble for repeated PRACH transmission at multiple PRACH transmission times, the method further includes: listening to the Physical Downlink Control Channel (PDCCH) and attempting to decode the Downlink Control Information (DCI) using the RA-RNTI; wherein the RA-RNTI is determined based on a rule pre-agreed between the terminal device and the network device; the rule includes: selecting one RA-RNTI from multiple RA-RNTIs corresponding to the multiple PRACH transmission times.

[0026] In an exemplary embodiment of this disclosure, when a terminal device transmits different preambles for repeated PRACH transmission at multiple PRACH transmission times, the method further includes: listening to the Physical Downlink Control Channel (PDCCH) and attempting to decode the DCI using RA-RNTI; wherein the RA-RNTI is determined based on rules pre-agreed between the terminal device and the network device; the rules include: attempting to decode the DCI using multiple RA-RNTIs corresponding to the multiple PRACH transmission times respectively.

[0027] In one exemplary embodiment of this disclosure, determining the PRACH retransmission timing in the PRACH retransmission strategy includes: determining the currently available PRACH retransmission timing based on the correspondence between the SSB index number decoded by the terminal device and the PRACH transmission timing.

[0028] According to a second aspect of this disclosure, a method for repeated transmission of a Physical Random Access Channel (PRACH) is provided. The method includes: when a network device determines that repeated transmission of a PRACH is currently permitted, it notifies a terminal device so that the terminal device can determine the current PRACH repeated transmission strategy and perform PRACH repeated transmission; wherein the PRACH repeated transmission strategy includes: determining the number of times the PRACH will be repeated.

[0029] In one exemplary embodiment of this disclosure, the network device notifies the terminal device that repeated transmission of the Physical Random Access Channel (PRACH) is currently permitted by configuring PRACH retransmission flag information.

[0030] In one exemplary embodiment of this disclosure, the PRACH retransmission flag information is carried using target signaling; the method includes: a network device notifying a terminal device via broadcast target signaling that retransmission of the Physical Random Access Channel (PRACH) is currently permitted.

[0031] In one exemplary embodiment of this disclosure, the method further includes: when receiving multiple preambles repeatedly transmitted by the terminal device, calculating the corresponding RA-RNTI according to a preset rule, and using the RA-RNTI to scramble the scheduling DCI of the random access response message; wherein the multiple preambles repeatedly transmitted by the terminal device are the same multiple preambles or different multiple preambles.

[0032] In an exemplary embodiment of this disclosure, when multiple different preambles are detected being repeatedly transmitted by the terminal device, the step of calculating the corresponding RA-RNTI according to a preset rule includes: selecting one of the multiple preambles and calculating the RA-RNTI of the PRACH transmission timing corresponding to the preamble; or calculating the RA-RNTI of the PRACH transmission timing corresponding to each preamble respectively.

[0033] In an exemplary embodiment of this disclosure, when multiple identical preambles are detected being repeatedly transmitted by a terminal device, the step of calculating the RA-RNTI value for the multiple preambles according to a preset rule includes: detecting the same preamble at multiple PRACH transmission times, merging the multiple identical preambles, and when the power of the merged preamble sequence is greater than a preset third threshold value, selecting one PRACH transmission time from the multiple PRACH transmission times based on a rule pre-agreed with the terminal device to calculate the corresponding RA-RNTI.

[0034] In one exemplary embodiment of this disclosure, the method further includes: configuring a first preamble sequence set and a second preamble sequence set for a first type of terminal device with PRACH retransmission capability and a second type of terminal device without PRACH retransmission capability, respectively.

[0035] In one exemplary embodiment of this disclosure, the target signaling further includes: PRACH transmission timing, the number of preambles used for PRACH retransmission, the number of PRACH retransmissions supported by the network device, and any one or any combination of PRACH retransmission methods.

[0036] According to a third aspect of this disclosure, a physical random access channel (PRACH) retransmission apparatus is provided, comprising: a terminal-side retransmission management module, configured to determine a current PRACH retransmission policy when it is determined that the network device currently allows retransmission of the physical random access channel (PRACH), and to perform PRACH retransmission according to the PRACH retransmission policy; wherein the PRACH retransmission policy includes: determining the number of times the PRACH is retransmitted.

[0037] According to a fourth aspect of this disclosure, a physical random access channel (PRACH) retransmission apparatus is provided, comprising: a network device retransmission management module, configured to notify a terminal device when the network device determines that retransmission of the physical random access channel (PRACH) is currently permitted, so that the terminal device can determine the current PRACH retransmission strategy and perform PRACH retransmission; wherein the PRACH retransmission strategy includes: determining the number of PRACH retransmissions.

[0038] According to a fifth aspect of this disclosure, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described physical random access channel repeated transmission method.

[0039] According to a sixth aspect of this disclosure, an electronic device is provided, comprising:

[0040] Processor; and

[0041] Memory for storing the executable instructions of the processor;

[0042] The processor is configured to execute the physical random access channel retransmission method described in the first or second aspect of the above embodiments by executing the executable instructions.

[0043] In one embodiment of the Physical Random Access Channel (PRC) repeat transmission method provided in this disclosure, when the terminal device determines that the network device currently has the PRACH repeat transmission function enabled and allows PRACH repeat transmission, it can proactively construct the PRACH repeat transmission strategy of the terminal device and perform PRACH repeat transmission. This achieves the PRACH repeat transmission function.

[0044] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0046] Figure 1 This schematic diagram illustrates a system architecture according to an exemplary embodiment of the present disclosure.

[0047] Figure 2 This illustration schematically depicts a physical random access channel retransmission method performed by a network device according to an exemplary embodiment of the present disclosure;

[0048] Figure 3 This illustration schematically depicts a physical random access channel retransmission method performed by a user-side terminal device according to an exemplary embodiment of this disclosure;

[0049] Figure 4 This diagram illustrates the correspondence between PRACH transmission timing and SSB index number in an exemplary embodiment of this disclosure.

[0050] Figure 5 This illustration schematically shows a physical random access channel retransmission method according to an exemplary embodiment of the present disclosure;

[0051] Figure 6 This illustration schematically shows a physical random access channel retransmission method according to an exemplary embodiment of the present disclosure;

[0052] Figure 7 This schematic diagram illustrates a physical random access channel retransmission apparatus according to an exemplary embodiment of the present disclosure;

[0053] Figure 8 This schematic diagram illustrates a physical random access channel retransmission apparatus according to an exemplary embodiment of the present disclosure;

[0054] Figure 9 This schematic diagram illustrates the composition of a terminal device in an exemplary embodiment of the present disclosure.

[0055] Figure 10 The schematic diagram illustrates a storage medium according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0056] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0057] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0058] In related technologies, the 3GPP NR Realease-16 protocol does not yet support repeated transmissions of PRACH (Physical Random Access Channel). After performing the cell search procedure, the UE (User Equipment) has achieved downlink synchronization with the cell, and therefore the UE can receive downlink data. However, the UE can only perform uplink transmissions after achieving uplink synchronization with the cell. The UE establishes a connection with the cell and achieves uplink synchronization through the Random Access Procedure.

[0059] According to the current protocol version, the user sends a preamble once at the PRACH transmission timing indicated by the base station. Based on the time-frequency position of this PRACH transmission timing, the user can calculate the corresponding RA-RNTI value. Then, the terminal device listens to the PDCCH (Physical Downlink Control Channel) within the Random Access Response (RAR) time window. If the terminal device successfully descrambles the PRACH using the RA-RNTI and detects DCI 1_0, and can identify the RAPID number in the RAR information scheduled by the DCI, the terminal device considers its PRACH transmission successful. Otherwise, the terminal device needs to retransmit a new PRACH, which will introduce additional latency. Especially for high-frequency bands, PRACH is a potentially coverage-limited channel.

[0060] For the above-mentioned application scenarios, this example embodiment provides a method for repeated transmission of the Physical Random Access Channel (PRACH), which can be applied to control the repeated transmission of PRACH during the random access process of a UE. The following will describe in more detail each step of the physical random access channel repeated transmission method in this example embodiment with reference to the accompanying drawings and embodiments.

[0061] Generally, physical channels carry data information from higher layers. Physical channels can be physical downlink channels or physical uplink channels; among them, physical downlink channels include Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ Indicator Channel (PHICH), Enhanced-Physical Downlink Control Channel (EPDCCH), Physical Broadcast Channel (PBCH), and Physical Multicast Channel (PMCH), etc. Physical uplink channels can include the Physical Uplink Shared Channel (PUSCH), the Physical Uplink Control Channel (PUCCH), and the Physical Random Access Channel (PRACH), or channels newly introduced in the standard with the same function but different names. Combinations of these channels are also possible.

[0062] refer to Figure 1The illustrated application scenario provides an application scenario for the above method, including network device 101, network device 102 adjacent to network device 101, and user-side terminal device 103. Terminal device 103 is located within a coverage area smaller than base station 101 and communicates with network device 101. Network device 101 and terminal device 103 are communication devices that support communication on unlicensed spectrum resources. Network device 102 supports the same frequency band as network device 101, and network device 102 can be the same type of communication device as network device 101, or it can be a different type of communication device. For example, network device 101 can be a base station for an LTE system, such as a cell base station; correspondingly, terminal device 103 is a user equipment for an LTE system, and network device 102 can be a base station for an LTE system, or it can be a wireless router, wireless repeater, or user equipment for a Wireless Fidelity (Wi-Fi) system.

[0063] This example embodiment first provides a method for repeated transmission of physical random access channels, which can be applied to and executed by network devices. For example, the network device can be a 4G base station, a 5G base station, a base station of a later version, or a base station in other communication systems, or referred to as a Node B, an evolved Node B, a Transmission Reception Point (TRP), an Access Point (AP), or other terms in the field, as long as the same technical effect is achieved, the network device is not limited to specific technical terms.

[0064] refer to Figure 2 As shown, the physical random access channel retransmission method may include:

[0065] Step S21: When the network device determines that repeated transmission of the Physical Random Access Channel (PRACH) is currently allowed, it notifies the terminal device so that the terminal device can determine the current PRACH repeated transmission strategy and perform PRACH repeated transmission; wherein, the PRACH repeated transmission strategy includes: determining the number of times PRACH is repeated.

[0066] In this example implementation, the network device can control the enabling / disabling of the PRACH repeat transmission function; it can also determine whether the PRACH repeat transmission function can be enabled based on preset rules. When the network device determines that the PRACH repeat transmission function is enabled, it can notify the terminal device in a certain way to ensure that the terminal device can perform PRACH repeat transmission during random access and access the network. Specifically, the PRACH repeat transmission function means that the terminal device can perform multiple preamble transmissions at multiple available PRACH transmission opportunities; wherein, one preamble transmission is completed at each PRACH transmission opportunity. The preambles transmitted multiple times can be the same or different.

[0067] For example, the rules for determining whether to enable the PRACH retransmission function in the network device can be pre-configured rules for enabling the PRACH retransmission function within a specified time period; or, it can be activated when the base station detects interference signals that persist for a certain duration and whose strength exceeds a certain threshold; or, based on other conditions, when it is determined that there is an adverse impact on the uplink synchronization of the terminal device; in these cases, the PRACH retransmission function can be activated. Of course, in other exemplary embodiments of this disclosure, other features can also be used on the network device side as the basis for determining whether to activate the PRACH retransmission function; for example, based on the received power of the reference signal, channel quality, etc.

[0068] In this example implementation, the network device notifies the terminal device that repeated transmission of the Physical Random Access Channel (PRACH) is currently permitted by configuring the PRACH retransmission flag information.

[0069] For example, a network device can configure the PRACH repeat transmission flag to "1", which means that PRACH repeat transmission is allowed under the current PRACH configuration, that is, the network device currently enables the PRACH repeat transmission function; and it can also configure the PRACH repeat transmission flag to "0", which means that PRACH repeat transmission is not allowed under the current PRACH configuration, that is, the network device currently disables the PRACH repeat transmission function.

[0070] In this example implementation, the network device notifies the terminal device via broadcast target signaling that repeated transmissions of the Physical Random Access Channel (PRACH) are currently permitted.

[0071] Specifically, the aforementioned target signaling can be an RRC (Radio Resource Control) message. Specifically, the network device can configure a 1-bit PRACH retransmission flag in the RRC system message; the network device uses the value of this retransmission flag to indicate whether the terminal device can currently perform the PRACH retransmission function. The RRC system message can include a Master Information Block (MIB) and multiple System Information Blocks (SIBs).

[0072] Alternatively, in this example implementation, the target signaling described above can be an SIB (System Information Block) message. Specifically, for example, an SIB1 message.

[0073] Specifically, a 1-bit PRACH repeat transmission flag can be configured in the SIB1 message. For example, when the PRACH repeat transmission flag is "1" in the SIB1 message, it indicates that PRACH repeat transmission is allowed under the current PRACH configuration. That is, terminal devices with PRACH repeat transmission capability can perform PRACH repeat transmission under the current configuration, meaning the network device has enabled the PRACH repeat transmission function. When the PRACH repeat transmission flag is "0" in the SIB1 message, it indicates that PRACH repeat transmission is not allowed under the current PRACH configuration, regardless of whether the terminal device has PRACH repeat transmission capability. That is, the network device currently disables the PRACH repeat transmission function.

[0074] Alternatively, in some exemplary embodiments, the network device may also carry the PRACH repeat transmission flag via the SIB2 message.

[0075] In some exemplary embodiments, the network device can also notify the terminal devices that PRACH retransmission is currently possible by configuring different PRACH resources for terminal devices that have PRACH retransmission capability and those that do not. Specifically, the network device can pre-allocate different Preamble sequence sets for terminal devices that support PRACH retransmission and those that do not. For example, a first Preamble sequence set can be configured for terminal devices that support PRACH retransmission, and a second Preamble sequence set can be configured for terminal devices that do not support PRACH retransmission.

[0076] For example, PRACH configuration information can be indicated by the SIB1 prach-Configuration Index, which is an index value from 0 to 255, corresponding to the row index in the random access configuration table. Alternatively, the indexes within the PRACH configuration table can be grouped, dividing the PRACH configurations corresponding to some table indexes into groups that can be repeatedly transmitted, and dividing the PRACH configurations corresponding to other table indexes into groups that cannot be repeatedly transmitted. For example, grouping the 0 to 255 indexes can be achieved by adding a column to the index table to indicate whether the PRACH resources in each row are available for repeated transmission. Alternatively, pre-configured rules can be used to define the row indexes that can be repeatedly transmitted; for example, PRACHs with odd-numbered row indexes can be repeatedly transmitted, while PRACHs with even-numbered row indexes cannot be repeatedly transmitted.

[0077] Based on this, when parsing SIB1 messages, the terminal device can determine whether the current network device supports PRACH retransmission by using the currently distinguished preamble; without needing the PRACH retransmission flag. When the terminal device needs to perform PRACH retransmission, it can use the first preamble sequence set; and when the terminal device does not need to perform PRACH retransmission, even if it has PRACH retransmission capability, it uses the second preamble sequence set.

[0078] For example, preambles can be directly grouped in the protocol, with the preamble in one group used for PRACH retransmission and the preamble in another group not used for PRACH retransmission. Alternatively, PRACH resources can be pre-allocated, allowing network devices and terminal devices to predetermine the specific PRACH transmission timings and / or PRACH preambles that can be used by first-type terminal devices with PRACH retransmission capabilities; while second-type terminal devices without PRACH retransmission capabilities use the second part, i.e., the remaining PRACH transmission timings and / or PRACH preambles.

[0079] In some exemplary embodiments, when a network device notifies a terminal device via a broadcast message that it currently supports PRACH repeat transmission, it may also add additional PRACH repeat transmission configuration information to the target signaling. For example, the SIB1 message carries the PRACH repeat transmission configuration information. Additionally, in some exemplary embodiments, the signaling transmitting the PRACH repeat transmission configuration information may be other signaling distinct from the aforementioned signaling containing the PRACH repeat transmission flag information. For example, the PRACH repeat transmission configuration information may be broadcast via a MIB message.

[0080] Specifically, the configuration information for PRACH repeat transmission may also include: the number of PRACH repeat transmissions supported by the network device, the timing of PRACH transmission, the number of preambles used in PRACH repeat transmission, and any one or any combination of PRACH repeat transmission methods. The network device can decide whether to specify specific PRACH repeat transmission configuration parameters to the terminal device based on the current actual situation.

[0081] For example, the number of PRACH retransmissions supported by the network device mentioned above can be configurable as 2, 4, 6, or 8, and this value can be added to the target signaling. This allows the terminal device to perform PRACH retransmissions according to the number of retransmissions specified by the network device.

[0082] The aforementioned PRACH repetition transmission methods can include method 1 or method 2; wherein, PRACH repetition transmission method 1 can transmit completely different preambles at multiple PRACH transmission times; PRACH repetition transmission method 2 can transmit the exact same preamble at multiple PRACH transmission times. Network devices can add the PRACH repetition transmission method to the target signaling, thereby enabling terminal devices to perform PRACH repetition transmission in a specified manner.

[0083] Corresponding to the PRACH repetition transmission mode, the number of preambles used for the corresponding PRACH repetition transmission can also be configured. For example, when using mode 1, the number of preambles can be configured to be multiple; when using mode 2, the number of preambles can be configured to be 1.

[0084] Furthermore, in some exemplary embodiments, the terminal device can customize the PRACH retransmission configuration information that is not actively limited by the network device, according to the actual situation.

[0085] In this example implementation, the method described above may further include:

[0086] Step S22: When receiving multiple preambles repeatedly transmitted by the terminal device, calculate the corresponding RA-RNTI according to a preset rule, and use the RA-RNTI to scramble the scheduling DCI of the random access response message; wherein, the multiple preambles repeatedly transmitted by the terminal device are the same multiple preambles or different multiple preambles.

[0087] Specifically, in this example implementation, step S22 may include: when multiple different preambles are detected being repeatedly transmitted by the terminal device:

[0088] Select one of the plurality of preambles, and calculate the RA-RNTI of the PRACH transmission timing corresponding to that preamble; or

[0089] Each preamble is calculated separately to obtain multiple RA-RNTIs corresponding to each PRACH transmission timing.

[0090] Specifically, for network devices, when receiving multiple different preambles uploaded by terminal devices at different PRACH transmission times, the multiple PRACH transmissions of each terminal device can be treated as single PRACH transmissions of different users; that is, for n preambles uploaded by the terminal device, n corresponding RAR (Random Access Response) messages are fed back; where n is a positive integer. Specifically, for each preamble, based on the time-frequency resource location and preamble number of the corresponding PRACH transmission time, the RA-RNTI value used for scrambling DCI (Downlink Control Information) is calculated, and the corresponding RAPID (Random Access Preamble Identifier) ​​is added to the RAR (Random Access Response), i.e., Msg2.

[0091] At this point, the complexity of the network equipment remains the same, while the complexity of the user-side terminal equipment increases, with the gain source being diversity gain. In this scenario, the network equipment does not need to determine whether multiple different preambles originate from the same terminal device.

[0092] Alternatively, for network devices, when determining that multiple different preambles originate from the same terminal device, one preamble can be selected from the multiple different preambles, and the RA-RNTI of the PRACH transmission timing corresponding to that preamble can be calculated; thus saving resources and avoiding the terminal device processing multiple RARs. When selecting one of the multiple different preambles, the selection can be based on a pre-agreed selection method between the network device and the terminal device; for example, random selection, or specifying the PRACH transmission timing.

[0093] Specifically, in this example embodiment, step S22 may further include: when multiple identical preambles are detected being repeatedly transmitted by the terminal device:

[0094] If the same preamble is detected at multiple PRACH transmission times, the multiple identical preambles are merged. If the power of the merged preamble sequence is greater than a preset third threshold, a PRACH transmission time is selected from the multiple PRACH transmission times based on a rule pre-agreed with the terminal device to calculate the corresponding RA-RNTI.

[0095] Specifically, when a network device receives multiple identical preambles, it can determine whether there is a correlation between the multiple identical preambles based on the association between the SSB index and the PRACH transmission timing. If it is determined that the multiple identical preambles correspond to different PRACH transmission timings and share the same SSB index, then joint detection of the multiple preambles can be performed.

[0096] For example, refer to Figure 4 As shown, during PRACH transmission times #0 and #3, candidate Preamble sequences are detected at the corresponding index SSB #0. If the same Preamble sequence is detected, they are merged. If the sequence energy (signal power) of the merged Preamble reaches a given threshold, it is considered that a terminal device has sent the Preamble. At this time, since the network device may detect the Preamble at multiple PRACH transmission times, there will be multiple RA-RNTIs. Therefore, the network device needs to select a specified preamble according to the predetermined rules agreed upon with the terminal device, calculate the RA-RNTI used by the DCI1_0 scrambling code based on the time-frequency position of the specified preamble, and put the corresponding RAPID number into the RAR information.

[0097] At this point, the complexity of network devices increases, while the complexity of terminal devices remains unchanged, and the gain comes from the combined gain of multiple repeated transmissions.

[0098] Furthermore, in some exemplary embodiments, when the network device is pre-configured to configure a first Preamble sequence set for terminal devices that support PRACH repetition transmission and a second Preamble sequence set for terminal devices that do not support PRACH repetition transmission, the network device can determine whether the current preamble is a PRACH repetition transmission of the terminal device based on the judgment result that the received preamble sequence belongs to the first Preamble sequence set or the second Preamble sequence set. When it is determined to be a PRACH repetition transmission of the terminal device, RA-RNTI is calculated according to the method in the above embodiments, and the corresponding RAPID number is placed in the RAR information.

[0099] In some practical scenarios, two terminal devices that do not support PRACH retransmission might send the same preamble at PRACH transmission time #0 and PRACH transmission time #3 respectively. The base station might mistakenly interpret this as two PRACH messages being sent repeatedly by a single terminal device that supports PRACH retransmission, leading to a misunderstanding on the base station's side. However, by configuring separate preamble sequence sets for the first type of terminal devices that support PRACH retransmission and the second type of terminal devices that do not support PRACH retransmission, the misjudgment of multiple terminal devices uploading the same preamble can be eliminated.

[0100] This disclosure provides an exemplary embodiment of a physical random access channel retransmission method, executed and implemented by a user-side terminal equipment (UE). Specifically, refer to... Figure 3 As shown, the above-mentioned physical random access channel repeated transmission method may include:

[0101] In step S31, when it is determined that the network device currently allows repeated transmission of the Physical Random Access Channel (PRACH), the current PRACH repeated transmission strategy is determined, and PRACH repeated transmission is performed according to the PRACH repeated transmission strategy; wherein, the PRACH repeated transmission strategy includes: the number of times PRACH is repeated.

[0102] In this example implementation, after the UE powers on, it enters the cell search and access process. The UE performs cell downlink synchronization through the Physical Broadcast Channel (PBCH), demodulates the MIB information, and then demodulates the PDCCH (Physical Downlink Control Channel) content using the relevant information in the MIB. The UE then locates the SIB1 message using the PDCCH content. The SIB1 message is carried through the PDSCH (Physical Downlink Shared Channel). Generally, the SIB1 message needs to contain PRACH-related configuration information. The UE generates a Preamble signal at the relevant time-frequency location based on the PRACH configuration in the SIB1 message, initiating the random access procedure. Specifically, the PRACH configuration information in the SIB1 message may also include a PRACH retransmission flag. After decoding the SIB1 message, the UE obtains all uplink synchronization information and can then enter the random access procedure.

[0103] In this example implementation, determining that the network device currently allows repeated transmissions of the Physical Random Access Channel (PRACH) includes:

[0104] Read the PRACH repeat transmission flag information to determine whether the network device currently supports repeat transmission PRACH based on the repeat transmission flag information.

[0105] In this example implementation, reading the PRACH repeat transmission flag information includes:

[0106] Parse the target signaling sent by the network device to read the PRACH repeat transmission flag information.

[0107] In this example implementation, the target signaling is a radio resource control message or a SIB1 message;

[0108] The reading of the duplicate transmission flag information includes:

[0109] When the repeat transmission flag is read as 1, it is determined that the network device currently supports repeat transmission PRACH; or

[0110] If the repeat transmission flag is 0, it is determined that the network device does not currently support repeat transmission PRACH.

[0111] Specifically, when network devices carry target signaling via RRC system messages, terminal devices parse the RRC system messages. If the repeat transmission flag is "1", the terminal device determines that PRACH can be repeated; if the repeat transmission flag is "0", the terminal device determines that PRACH cannot be repeated. For example, an RRC system message can also be a MIB message. For instance, an MIB message can carry system bandwidth, PHICH (Physical Hybrid ARQ Indicator Channel) configuration information, system frame number, and PRICH repeat transmission flag information.

[0112] Alternatively, in some exemplary embodiments, when the network device configures the PRACH repeat transmission flag in the SIB1 message, the terminal device, when parsing the SIB1 message, determines that PRACH can be repeated when it identifies that the PRACH repeat transmission flag information is 1, that is, the network device starts the PRACH repeat transmission function; or, when it identifies that the PRACH repeat transmission flag information is 0, it determines that PRACH cannot be repeated, that is, the network device currently disables the PRACH repeat transmission function.

[0113] In some exemplary embodiments, the SIB1 message may also include PRICH repeat transmission configuration information. For example, this may include: PRACH transmission timing, the number of PRACH repeat transmissions supported by the network device, the number of preambles used for PRACH repeat transmissions, and any one or a combination of multiple PRACH repeat transmission methods. For example, the PRICH repeat transmission configuration information may include a preamble count of 1 and a preamble transmission method of method 2, i.e., uploading the same preamble at multiple transmission timings; or, the PRICH repeat transmission configuration information may include a network device repeat transmission limit of 6 and a preamble transmission method of method 1, i.e., uploading different preambles at multiple transmission timings; or, the PRICH repeat transmission configuration information may only include a network device repeat transmission limit of 9; and so on. This disclosure does not specifically limit the specific parameters of the PRACH repeat transmission configuration information issued by the network device.

[0114] For terminal devices, when a network device uses a SIB1 message to carry PRACH repeat transmission configuration information, the terminal device can obtain all the configuration information about PRACH repeat transmission when parsing the SIB1 message.

[0115] Based on the above, in some exemplary embodiments, when determining that the network device is currently allowed to repeatedly transmit the Physical Random Access Channel (PRACH), the method further includes:

[0116] The terminal device determines the current PRACH retransmission strategy based on its supported PRACH retransmission capabilities.

[0117] Specifically, after determining that the network device currently has the PRACH retransmission function enabled, the terminal device can first identify its own capabilities to determine whether it possesses the PRACH retransmission capability. If the terminal device identifies that it has the PRACH retransmission capability, it can then determine whether it needs to perform PRACH retransmission. If the terminal device identifies that it does not have the PRACH retransmission capability, it can terminate this determination process.

[0118] In this example implementation, before determining the current PRACH retransmission strategy, the method further includes: when the terminal device identifies that the current channel quality is lower than a preset index and there are multiple available PRACH transmission opportunities, it determines the current PRACH retransmission strategy.

[0119] Specifically, after determining that the network device currently supports PRACH retransmission and confirming that the terminal device itself has the capability for PRACH retransmission, the terminal device can determine whether it needs to perform PRACH retransmission. For example, if the calculation results based on channel quality and available PRACH transmission opportunities indicate that the terminal device needs to perform PRACH retransmission, then the PRACH retransmission policy content is formulated. Conversely, if the terminal device determines, based on the above conditions, that it does not need to perform PRACH retransmission or does not have the conditions for PRACH retransmission, then the current cycle's judgment process is terminated, and the PRACH retransmission policy content is not formulated.

[0120] In this example implementation, the terminal device identifies that the current channel quality is lower than a preset indicator, including:

[0121] The system acquires the current target signal received power, and when the target signal received power is lower than a preset first threshold, determines that the current channel quality of the terminal device is lower than a preset indicator. The target signal received power includes the received power of the downlink signal. The downlink signal includes a synchronization signal block (SSB) and / or a synchronization signal (SS).

[0122] In this example implementation, the terminal device identifies that the current channel quality is lower than a preset index, including: when the signal received power of the downlink path loss reference measured and / or calculated by the terminal device is lower than a preset second threshold, it determines that the current channel quality of the terminal device is lower than the preset index.

[0123] Specifically, after determining that the network device has enabled the PRACH retransmission function, the terminal device can use some characteristic parameters of its own to judge the current state and determine whether the terminal device needs to perform PRACH retransmission. Specifically, the terminal device can judge the current channel quality; if the current channel quality is poor, PRACH retransmission is required to improve its transmission performance, thereby enabling faster access to the current cell.

[0124] Specifically, the terminal device can acquire the current target signal power, and when the target signal power is lower than a preset first threshold, determine that the current channel quality of the terminal device is lower than a preset indicator. For example, the target signal power includes the power value of the reference signal received power of the downlink signal. For example, the downlink signal can be an SSB (Synchronization Signal Block) signal and / or an SS signal (Synchronization Signal).

[0125] Alternatively, if the terminal device calculates that the downlink path loss is higher than a preset second threshold, it determines that the current channel quality of the terminal device is lower than a preset indicator. For example, if the RSRP (Reference Signal Received Power) value of the downlink path loss measured or calculated by the terminal device is lower than a preset threshold; that is, if the downlink path loss is higher than a preset threshold, it can also be determined that the channel quality of the terminal device is lower than a threshold indicator.

[0126] That is, if the terminal device determines that the current channel quality is higher than the preset index, it does not need to perform PRACH retransmission; or, if it determines that the current channel quality is lower than the preset index, it needs to perform PRACH retransmission.

[0127] In this example implementation, when the terminal device determines that the current channel quality is lower than a preset indicator, it also needs to determine whether the terminal device has multiple PRACH transmission opportunities available for transmitting the preamble under the current PRACH configuration, for repeated PRACH transmission. If multiple available PRACH transmission opportunities exist, repeated PRACH transmission can be performed; if only one PRACH transmission opportunity exists, or no available PRACH transmission opportunities exist (i.e., no multiple available PRACH transmission opportunities), repeated PRACH transmission cannot be performed. This determination process can be restarted in the next cycle.

[0128] Specifically, when the terminal device determines that the current channel quality is lower than a preset indicator and there are multiple available PRACH transmission opportunities, it determines that the terminal device needs to perform PRACH retransmission and has the conditions to execute PRACH retransmission. At this point, the terminal device can determine the current PRACH retransmission strategy. Alternatively, if the terminal device determines that the current channel quality is lower than the preset indicator but there are no multiple available PRACH transmission opportunities, it indicates that the terminal device needs to perform PRACH retransmission but does not have the conditions to execute it, and the determination process for this cycle terminates. Or, if the terminal device determines that the current channel quality is higher than the preset indicator, it indicates that the terminal device does not need to perform PRACH retransmission.

[0129] Alternatively, in some exemplary embodiments, when the terminal device determines that the network device currently supports PRACH retransmission, the terminal device may first use channel quality information to determine whether PRACH retransmission is currently necessary; if it determines that PRACH retransmission is necessary, it then identifies whether the terminal device has PRACH retransmission capability; if it identifies that the terminal device has PRACH retransmission capability, it then determines whether there are multiple available PRACH transmission opportunities. Alternatively, the terminal device may simultaneously judge any two or three of the above conditions, and determine whether to formulate a PRACH retransmission strategy based on the judgment results of at least two conditions.

[0130] Alternatively, in some exemplary embodiments, when the terminal device recognizes that the network device described in the above embodiments has configured different sets of Preamble sequences or divided PRACH resources for a first type of terminal device that supports PRACH repetition and a second type of terminal device that does not support PRACH repetition, the terminal device can determine whether it has the capability to perform PRACH repetition and whether it needs to perform PRACH repetition.

[0131] In this exemplary embodiment, generally, during initial random access, the relevant PRACH configuration information of the terminal device is indicated by the PRACH-Configuration Index of SIB1. This parameter has a value of 0 to 255, corresponding to a row index in the random access configuration table, specifically indicating the following information: Preamble format, system frame number of PRACH transmission, subframe number, starting OFDM symbol position, number of time slots used for PRACH transmission within a subframe, number of PRACH time-domain transmission opportunities within a PRACH time slot, and number of PRACH duration symbols. The number of PRACH frequency-domain transmission opportunities is indicated by the parameter msg1-FDM of SIB1, which can be configured as {1, 2, 4, 8}. The total number of PRACH transmission opportunities within a time slot is determined by both the number of time-domain transmission opportunities and the number of frequency-domain transmission opportunities. The parameter ssb-perRACH-Occasion And CB-Preambles in the SIB1 message indicates the number of PRACH transmissions associated with each SSB (Synchronization Signalblock) index.

[0132] When determining whether multiple PRACH transmission opportunities exist, the terminal device uses the SSB index number decoded from the SIB1 message. Because the PRACH transmission opportunities available for the terminal device to transmit the preamble are related to the SSB index decoded by the user, not all PRACH transmission opportunities are available for that user to transmit the preamble. (Reference) Figure 4 As shown, this schematically illustrates the association between the SSB index number and the PRACH transmission timing under a certain configuration. If the SSB index number decoded by the user is 1, then the user can only send the Preamble on PRACH transmission timing #1 and PRACH transmission timing #4.

[0133] In this example implementation, when the terminal device determines that the network device has started the PRACH retransmission function, has the capability to retransmit PRACH, the current channel quality is lower than the preset index, and there are multiple available PRACH transmission opportunities, it can combine the PRACH retransmission configuration information broadcast by the network device to determine the PRACH retransmission strategy for the current period.

[0134] Specifically, the PRACH retransmission strategy determined by the terminal device may include the number of PRACH retransmissions, the number of preambles used for PRACH retransmissions, the PRACH retransmission method, and the PRACH transmission timing.

[0135] In this example implementation, the number of PRACH retransmissions in the RACH retransmission strategy can be determined using one or more of the following conditions: the number of PRACH retransmissions supported by the network device contained in the target signaling issued by the network device, the number of PRACH retransmissions supported by the terminal device, and the number of PRACH retransmissions calculated based on the current channel quality information of the terminal device.

[0136] Specifically, when the PRACH retransmission configuration information issued by the network device includes the number of PRACH retransmissions supported by the network device, that is, when the network device specifies the number of PRACH retransmissions, the terminal device can use this value as the number of PRACH retransmissions in the PRACH retransmission policy.

[0137] Alternatively, when the network device does not specify the number of PRACH retransmissions, the terminal device can determine the number of PRACH retransmissions in the PRACH retransmission strategy based on the number of PRACH retransmissions supported by the terminal device and / or based on the current channel quality information of the terminal device.

[0138] For example, the number of PRACH retransmissions can be set based solely on the number of PRACH retransmissions supported by the terminal device, ensuring that the total number of PRACH retransmissions is less than or equal to the number of PRACH retransmissions supported by the terminal device. The terminal device can pre-configure its maximum supported number of PRACH retransmissions based on its own device characteristics. For instance, if the network device has not specified a number of PRACH retransmissions, and the number of currently available PRACH transmission opportunities exceeds the number of PRACH retransmissions supported by the terminal device, then the terminal-side retransmission limit can be configured to the maximum number of retransmissions supported.

[0139] Alternatively, the PRACH retransmission strategy can be determined based on the current channel quality information of the terminal device.

[0140] For example, if the network device does not specify the number of PRACH retransmissions, the number of retransmissions can be determined based on the difference between the current channel quality and a preset threshold. For instance, if the difference between the current SSB signal reference received power and the preset threshold is less than 3dB, the number of retransmissions can be configured as 2; or, if the difference is greater than 3dB but less than 5dB, the number of retransmissions can be configured as 5; and so on. In other words, the worse the current channel quality, the more retransmissions can be configured. However, this number must be less than the retransmission limit set by the terminal.

[0141] Alternatively, in this example implementation, the PRACH retransmission strategy can be determined by combining the number of PRACH retransmissions supported by the network device in the target signaling, the number of PRACH retransmissions supported by the terminal device pre-configured by the terminal device, and the number of PRACH retransmissions calculated by the terminal device based on the current channel quality information.

[0142] For example, if the network device limits the number of PRACH retransmissions it supports (this number represents the upper limit of the number of retransmissions supported by the network device), the terminal device pre-configures the number of PRACH retransmissions it supports (this number represents the upper limit of the number of retransmissions supported by the terminal device), and a retransmission count is calculated based on the current channel quality, we can first compare any two or three of these factors and select the minimum value; then compare this minimum value with the number of currently available PRACH transmission opportunities to determine the final retransmission count. For instance, if the network device supports 5 PRACH retransmissions, the terminal device supports 6 PRACH retransmissions, and a retransmission count of 3 is calculated based on the current channel quality, then the minimum value of 3 is selected; and the number of currently available PRACH transmission opportunities is 4, so the final determined PRACH retransmission count is 3. Alternatively, we can consider only the network device supporting 5 PRACH retransmissions, the terminal device supporting 6 PRACH retransmissions, and the number of currently available PRACH transmission opportunities is 8, then the final determined PRACH retransmission count is 5.

[0143] In this example implementation, the above-mentioned PRACH retransmission strategy may further include PRACH retransmission methods; wherein, method 1 is to transmit completely different Preambles at multiple PRACH transmission times; and method 2 is to transmit completely identical Preambles at multiple PRACH transmission times.

[0144] Specifically, if the network device indicates a specific PRACH repetition transmission method and / or the number of preambles used for PRACH repetition transmission in the SIB1 information, the terminal device can execute the corresponding transmission method according to the indication information. For example, the network device can determine the transmission method based on the number of currently connected terminal devices; or, based on the current load of the network device. For example, the network device indicates the use of method 1 and / or indicates that the number of preambles is multiple; or, the network device indicates the use of method 2 and / or indicates that the number of preambles is 1.

[0145] Alternatively, if the network device does not specify a particular transmission method, the terminal device can determine the PRACH repetition transmission method using a random selection method; or, it can determine the transmission method based on the number of currently available preambles, or select the PRACH repetition transmission method based on the number of currently available PRACH transmission opportunities. For example, if the number of currently available preambles is 1, then method 2 is used. Alternatively, the terminal device can determine the transmission method based on a comparison between the current channel quality and a preset threshold; for example, if the current channel quality is extremely poor, method 2 can be selected, or if the current channel quality is relatively poor, method 1 can be selected.

[0146] Alternatively, in this example implementation, the terminal device may select the PRACH transmission timing and preamble from the PRACH resources allocated by the network device for the first type of terminal device with PRACH repetition capability.

[0147] In this example implementation, after determining the various aspects of the PRACH retransmission strategy, the terminal device can execute the PRACH retransmission strategy. When using mode 1, the terminal device transmits completely different preambles at multiple PRACH transmission times. When using mode 2, the terminal device transmits the exact same preamble at multiple PRACH transmission times.

[0148] In this example implementation, the method described above may further include:

[0149] Step S32-1: When the terminal device transmits the same preamble for repeated PRACH transmission at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH) and attempts to decode the Downlink Control Information (DCI) using the RA-RNTI. The RA-RNTI is determined based on a rule pre-agreed between the terminal device and the network device. The rule includes selecting one RA-RNTI from the multiple RA-RNTIs corresponding to the multiple PRACH transmission times.

[0150] Step S32-2: When the terminal device transmits different preambles for repeated PRACH transmission at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH) and attempts to decode the DCI using RA-RNTI. The RA-RNTI is determined based on a pre-agreed rule between the terminal device and the network device. The rule includes: using multiple RA-RNTIs corresponding to the multiple PRACH transmission times to attempt to decode the DCI respectively.

[0151] Specifically, when a terminal device repeatedly transmits PRACH in Mode 1, the base station treats the multiple PRACH transmissions of the terminal device as single PRACH transmissions from different terminal devices and uses the original Preamble detection method. Based on the reception of the Preamble, it calculates the RA-RNTI number used for DCI scrambling and puts the corresponding RAPID number into the RAR information. Within the RAR time window, the terminal device attempts to descramble and obtain DCI 1_0 using multiple RA-RNTIs. If the terminal device successfully descrambles DCI 1_0 and can identify the RAPID number in the RAR information scheduled for the DCI, the terminal device considers the PRACH transmission successful; otherwise, the terminal device needs to retransmit a new PRACH. The multiple RA-RNTIs are calculated by the terminal device based on the time-frequency position of the previous PRACH transmissions during Preamble transmission. Since the terminal device performs multiple repeated PRACH transmissions and does not know which PRACH transmission the base station has successfully decoded, it is necessary to use multiple RA-RNTIs to attempt to descramble the DCI separately.

[0152] In this example implementation, when the terminal device repeatedly transmits in mode 2, the base station receives multiple identical preambles sent by the terminal device and performs joint detection of the preamble. If the signal power of the merged preamble reaches a given threshold, it is considered that a terminal device has sent the preamble. At this time, since the base station may detect the preamble at multiple PRACH transmission times, there will be multiple RA-RNTIs. Therefore, the base station needs to determine the RA-RNTI used by the DCI 1_0 scrambling code according to the predetermined rules agreed upon with the terminal device and put the corresponding RAPID number into the RAR information. Within the RAR time window, the terminal device attempts to descramble and obtain DCI 1_0 using the corresponding RA-RNTI selected according to the predetermined rules. If the terminal device successfully descrambles DCI 1_0 and can identify the RAPID number in the RAR information of the DCI scheduling, the user considers its PRACH transmission successful; otherwise, the user needs to retransmit a new PRACH.

[0153] In some exemplary embodiments, reference Figure 5As shown, in step S51, the base station can configure the flag for PRACH retransmission; in step S52, when PRACH retransmission is enabled, terminal devices supporting retransmission will perform PRACH retransmission under certain conditions; otherwise, all users cannot perform PRACH retransmission; in step S53, the terminal device transmits completely different preambles at multiple PRACH transmission times; in step S54, the base station treats the multiple PRACH transmissions of the terminal device as single PRACH transmissions of different users and uses the original preamble detection method, and calculates the RA-RNTI number used for DCI scrambling based on the preamble reception, and puts the corresponding RAPID number into the RAR information; and can generate a RAR message to feed back to the terminal device; in step S55, within the RAR time window, the terminal device attempts to descramble and obtain DCI 1_0 using multiple RA-RNTIs, and if the terminal device successfully descrambles the DCI... If the terminal device can identify the RAPID number in the RAR information of the DCI scheduler, it considers its PRACH transmission successful; otherwise, the terminal device needs to resend a new PRACH.

[0154] In some exemplary embodiments, reference Figure 6 As shown, in step S61, the base station configures the flag bit for PRACH retransmission; in step S62, when PRACH retransmission is enabled, terminal devices that support retransmission perform PRACH retransmission when certain conditions are met; otherwise, all users cannot perform PRACH retransmission; in step S63, the terminal device transmits the exact same Preamble at multiple PRACH transmission times; in step S64, the base station performs joint detection of the Preamble at multiple PRACH transmission times associated with the same SSB index. If the sequence energy of the merged Preamble reaches a given threshold, it is considered that a terminal device has sent the Preamble; therefore, the base station needs to determine the RA-RNTI used by the DCI 1_0 scrambling code according to the predetermined rules agreed upon with the terminal side, and put the corresponding RAPID number into the RAR information. In step S65, within the RAR time window, the terminal device attempts to descramble DCI 1_0 using the corresponding RA-RNTI. If the terminal device successfully descrambles DCI 1_0 and can identify the RAPID number in the RAR information scheduled by the DCI, the terminal device considers its PRACH transmission successful; otherwise, the terminal device needs to resend a new PRACH.

[0155] Specifically, the aforementioned multiple PRACH transmission opportunities can be all available PRACH transmission opportunities, or they can be some PRACH transmission opportunities selected by the terminal device.

[0156] The physical random access channel (PRC) retransmission method disclosed herein configures a retransmission flag in the broadcast messages of the network device. This allows the network device and user-side terminal devices to more flexibly control PRACH retransmission based on different service scenarios and requirements. It enables PRACH retransmission to be disabled in some cases and enabled in others, ensuring that the introduced PRACH retransmission feature is controllable. Furthermore, the network device can add PRACH retransmission configuration information to the broadcast messages, allowing terminal devices to perform PRACH retransmission according to a specified method, achieving precise control over PRACH retransmission. Moreover, terminal devices can determine whether PRACH retransmission is necessary based on actual needs.

[0157] It should be noted that the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may, for example, be executed synchronously or asynchronously in multiple modules.

[0158] Further reference Figure 7 As shown, this example embodiment also provides a physical random access channel repeat transmission device 70, which can be applied to user-side terminal equipment; including: a terminal-side repeat transmission management module 701.

[0159] The terminal-side retransmission management module 701 can be used to determine the current PRACH retransmission policy when it is determined that the network device is currently allowed to retransmit the Physical Random Access Channel (PRACH), and to perform PRACH retransmission according to the PRACH retransmission policy; wherein, the PRACH retransmission policy includes: the number of times PRACH is retransmitted.

[0160] Further reference Figure 8 As shown, this example embodiment also provides a physical random access channel repeat transmission device 80, which can be applied to network devices on the network side; including: network device repeat transmission management module 801.

[0161] The network device repeat transmission management module 801 can be used to notify the terminal device when the network device determines that the physical random access channel (PRACH) is currently allowed to be repeated, so that the terminal device can determine the current PRACH repeat transmission strategy and perform PRACH repeat transmission; wherein, the PRACH repeat transmission strategy includes: determining the number of times PRACH is repeated.

[0162] The specific details of each module in the aforementioned physical random access channel repeat transmission device have been described in detail in the corresponding physical random access channel repeat transmission method, so they will not be repeated here.

[0163] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0164] In an exemplary embodiment of this disclosure, a computer system capable of implementing the above-described method is also provided.

[0165] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: entirely hardware implementations, entirely software implementations (including firmware, microcode, etc.), or implementations combining hardware and software aspects, collectively referred to herein as “circuits,” “modules,” or “systems.”

[0166] The following reference Figure 9 To describe a terminal device 900 according to this embodiment of the present invention. Figure 9 The electronic device 900 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0167] like Figure 9 As shown, the electronic device 900 is manifested in the form of a general-purpose computing device. The components of the electronic device 600 may include, but are not limited to: at least one processing unit 610, at least one storage unit 620, and a bus 630 connecting different system components (including storage unit 620 and processing unit 610).

[0168] The storage unit stores program code that can be executed by the processing unit 610, causing the processing unit 610 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of the present invention. For example, the processing unit 610 can perform actions such as... Figure 2 or Figure 3 The steps are shown in the figure.

[0169] Storage unit 620 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 6201 and / or cache memory 6202, and may further include a read-only memory (ROM) 6203.

[0170] Storage unit 620 may also include a program / utility 6204 having a set (at least one) program module 6205, such program module 6205 including but not limited to: operating system, one or more application programs, other program modules and program data, each or some combination of these examples may include an implementation of a network environment.

[0171] Bus 630 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0172] Computer system 600 can also communicate with one or more external devices 700 (e.g., keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with computer system 600, and / or any device that enables computer system 600 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 650. Display unit 640 is connected via input / output (I / O) interface 650. Furthermore, computer system 600 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 660. As shown, network adapter 660 communicates with other modules of computer system 600 via bus 630. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with computer system 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0173] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0174] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the invention described in the "Exemplary Methods" section of this specification.

[0175] refer to Figure 10 As shown, a program product 100 for implementing the above-described method according to an embodiment of the present invention is described. It may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited thereto. In this document, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0176] The program product may employ 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, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0177] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0178] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0179] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's 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. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0180] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0181] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0182] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for repeated transmission in a physical random access channel, characterized in that, The method includes: When determining that the network device is currently allowed to repeatedly transmit the Physical Random Access Channel (PRACH), if the terminal device itself has the capability to repeatedly transmit PRACH, it determines the current PRACH repeated transmission strategy and performs PRACH repeated transmission according to the PRACH repeated transmission strategy. The process of determining the current PRACH retransmission strategy includes: Determine the timing of PRACH transmission; Determine the number of preambles used for repeated PRACH transmissions; When the terminal device identifies that the current channel quality is lower than the preset index and there are multiple available PRACH transmission opportunities, the number of PRACH retransmissions is determined. After the terminal device performs repeated PRACH transmissions at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH) and attempts to detect Downlink Control Information (DCI) using RA-RNTI. The RA-RNTI is calculated by selecting one PRACH transmission time from among the multiple PRACH transmission times.

2. The physical random access channel repeated transmission method according to claim 1, characterized in that, The determination of whether the network device is currently allowed to repeatedly transmit the Physical Random Access Channel (PRACH) includes: Read the PRACH repeat transmission flag information to determine whether the network device currently supports repeat transmission PRACH based on the repeat transmission flag information.

3. The physical random access channel repeated transmission method according to claim 2, characterized in that, The step of reading the PRACH repeat transmission flag information includes: Parse the target signaling sent by the network device to read the PRACH repeat transmission flag information.

4. The physical random access channel repeated transmission method according to claim 3, characterized in that, The target signaling is a radio resource control message or a SIB1 message; The step of reading the PRACH repeat transmission flag information includes: When the repeat transmission flag is read as 1, it is determined that the network device currently supports repeat transmission PRACH; or If the repeat transmission flag is 0, it is determined that the network device does not currently support repeat transmission PRACH.

5. The physical random access channel repeated transmission method according to claim 1, characterized in that, When determining that the network device is currently allowed to repeatedly transmit the Physical Random Access Channel (PRACH), the method further includes: The terminal device determines the current PRACH retransmission strategy based on its supported PRACH retransmission capabilities.

6. The physical random access channel repeated transmission method according to claim 1, characterized in that, The terminal device identifies that the current channel quality is lower than a preset indicator, including: The current target signal received power is obtained, and when the target signal received power is lower than a preset first threshold, the current channel quality of the terminal device is determined to be lower than a preset index.

7. The physical random access channel repeated transmission method according to claim 6, characterized in that, The target signal receiving power includes the downlink signal receiving power.

8. The physical random access channel repeated transmission method according to claim 7, characterized in that, The downlink signal includes a synchronization signal block SSB and / or a synchronization signal SS.

9. The physical random access channel repeated transmission method according to claim 5, characterized in that, The terminal device identifies that the current channel quality is lower than a preset indicator, including: When the signal received power of the downlink path loss reference measured and / or calculated by the terminal device is lower than a preset second threshold, it is determined that the current channel quality of the terminal device is lower than a preset index.

10. The physical random access channel repeated transmission method according to claim 1 or 3, characterized in that, Determine the number of PRACH retransmissions in the current PRACH retransmission policy based on any one or a combination of the following conditions: The target signaling issued by the network device includes the number of PRACH retransmissions supported by the network device, the number of PRACH retransmissions supported by the terminal device, and the number of PRACH retransmissions calculated based on the current channel quality information of the terminal device.

11. The physical random access channel repeated transmission method according to claim 3, characterized in that, The target signaling also includes: The timing of PRACH transmission, the number of preambles used in PRACH retransmission, the number of PRACH retransmissions supported by the network device, and any one or any combination of PRACH retransmission methods.

12. The physical random access channel repeated transmission method according to claim 1 or 11, characterized in that, The PRACH repeat transmission strategy also includes: PRACH repeat transmission mode.

13. The physical random access channel repeated transmission method according to claim 1, characterized in that, Determine the number of preambles used for repeated PRACH transmissions, including: The number of preambles used for PRACH retransmission in the PRACH retransmission strategy is determined based on the number of preambles used for PRACH retransmission contained in the target signaling sent by the network device, and / or based on the currently available preambles identified by the terminal device.

14. The physical random access channel repeated transmission method according to claim 12, characterized in that, The PRACH repetition transmission method includes: transmitting the same preamble at multiple PRACH transmission times, or transmitting different preambles at multiple PRACH transmission times.

15. The physical random access channel repeated transmission method according to claim 14, characterized in that, Determining the PRACH retransmission mode in the PRACH retransmission strategy includes: The PRACH repeat transmission method in the PRACH repeat transmission strategy is determined based on the PRACH repeat transmission method contained in the target signaling issued by the network device, and / or based on the number of currently available preambles identified by the terminal device.

16. The physical random access channel repeated transmission method according to claim 2 or 14, characterized in that, The method further includes: The preamble in the PRACH repetition strategy is determined based on a set of preamble sequences pre-configured by the network device for PRACH repetition.

17. The physical random access channel repeated transmission method according to claim 14, characterized in that, When a terminal device transmits the same preamble at multiple PRACH transmission times for repeated PRACH transmission, the method further includes: The device listens to the Physical Downlink Control Channel (PDCCH) and uses RA-RNTI to attempt to decode and detect Downlink Control Information (DCI). The RA-RNTI is determined based on a pre-agreed rule between the terminal device and the network device. The rule includes selecting one RA-RNTI from multiple PRACH transmission times.

18. The physical random access channel repeated transmission method according to claim 14, characterized in that, When a terminal device transmits different preambles for repeated PRACH transmission at multiple PRACH transmission times, the method further includes: Listen to the Physical Downlink Control Channel (PDCCH) and attempt to decode the DCI using RA-RNTI; wherein, the RA-RNTI is determined based on rules pre-agreed between the terminal device and the network device; the rules include: using multiple RA-RNTIs corresponding to the multiple PRACH transmission times to attempt to decode and detect the DCI respectively.

19. The physical random access channel repeated transmission method according to claim 12, characterized in that, Determining the PRACH retransmission timing in the PRACH retransmission strategy includes: Based on the correspondence between the SSB index number decoded by the terminal device and the PRACH transmission timing, the currently available PRACH retransmission timing is determined.

20. A method for repeated transmission in a physical random access channel, characterized in that, The method includes: When a network device determines that repeated transmission of the Physical Random Access Channel (PRACH) is currently allowed, it notifies the terminal device. For terminal devices that have the capability to repeat PRACH transmission, when the terminal device identifies that the current channel quality is lower than a preset index and there are multiple available PRACH transmission opportunities, it determines the current PRACH repeat transmission strategy and performs PRACH repeat transmission. The process of determining the current PRACH retransmission strategy includes: Determine the timing of PRACH transmission; Determine the number of preambles used for repeated PRACH transmissions; When the terminal device identifies that the current channel quality is lower than the preset index and there are multiple available PRACH transmission opportunities, the number of PRACH retransmissions is determined. After the terminal device performs repeated PRACH transmissions at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH), selects one PRACH transmission time from the multiple PRACH transmission times to calculate the RA-RNTI, and attempts to detect the Downlink Control Information (DCI) using the RA-RNTI.

21. The physical random access channel repeated transmission method according to claim 20, characterized in that, Network devices notify terminal devices of the current permission to repeatedly transmit the Physical Random Access Channel (PRACH) by configuring the PRACH repeat transmission flag information.

22. The physical random access channel repeated transmission method according to claim 21, characterized in that, The PRACH retransmission flag information is carried using target signaling; the method includes: Network devices notify terminal devices of the current permission to repeatedly transmit the Physical Random Access Channel (PRACH) by broadcasting target signaling.

23. The physical random access channel repeated transmission method according to claim 20, characterized in that, The method further includes: When receiving multiple preambles repeatedly transmitted by the terminal device, the corresponding RA-RNTI is calculated according to a preset rule, and the scheduling DCI of the random access response message is detected using the RA-RNTI; wherein, the multiple preambles repeatedly transmitted by the terminal device are either the same multiple preambles or different multiple preambles.

24. The physical random access channel repeated transmission method according to claim 23, characterized in that, When multiple different preambles are detected being repeatedly transmitted by the terminal device, the calculation of the corresponding RA-RNTI according to preset rules includes: Select one of the plurality of preambles, and calculate the RA-RNTI of the PRACH transmission timing corresponding to that preamble; or Calculate the RA-RNTI of the PRACH transmission timing corresponding to each of the preambles.

25. The physical random access channel repeated transmission method according to claim 23, characterized in that, When multiple identical preambles are detected being repeatedly transmitted by a terminal device, the step of calculating the RA-RNTI value for the multiple preambles according to a preset rule includes: If the same preamble is detected at multiple PRACH transmission times, the multiple identical preambles are merged. If the power of the merged preamble sequence is greater than a preset third threshold, a PRACH transmission time is selected from the multiple PRACH transmission times based on a rule pre-agreed with the terminal device to calculate the corresponding RA-RNTI.

26. The physical random access channel repeated transmission method according to claim 20, 21 or 23, characterized in that, The method further includes: A first preamble sequence set and a second preamble sequence set are configured for a first type of terminal device with PRACH retransmission capability and a second type of terminal device without PRACH retransmission capability, respectively.

27. The physical random access channel repeated transmission method according to claim 22, characterized in that, The target signaling also includes: The timing of PRACH transmission, the number of preambles used in PRACH retransmission, the number of PRACH retransmissions supported by the network device, and any one or any combination of PRACH retransmission methods.

28. A physical random access channel retransmission apparatus, characterized in that, The device includes: The terminal-side retransmission management module is used to determine the current PRACH retransmission policy when it is determined that the network device is currently allowed to retransmit the Physical Random Access Channel (PRACH). If the terminal device itself has the PRACH retransmission capability, it will then perform PRACH retransmission according to the PRACH retransmission policy. The process of determining the current PRACH retransmission strategy includes: Determine the timing of PRACH transmission; Determine the number of preambles used for repeated PRACH transmissions; When the terminal device identifies that the current channel quality is lower than the preset index and there are multiple available PRACH transmission opportunities, the number of PRACH retransmissions is determined. After the terminal device performs repeated PRACH transmissions at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH) and attempts to detect Downlink Control Information (DCI) using RA-RNTI. The RA-RNTI is calculated by selecting one PRACH transmission time from among the multiple PRACH transmission times.

29. A physical random access channel retransmission apparatus, characterized in that, The device includes: The network device repeat transmission management module is used to notify the terminal device when the network device determines that the physical random access channel (PRACH) is allowed to be repeated. For terminal devices that have PRACH repeat transmission capabilities, when the terminal device identifies that the current channel quality is lower than the preset index and there are multiple available PRACH transmission opportunities, the module determines the current PRACH repeat transmission strategy and performs PRACH repeat transmission. The process of determining the current PRACH retransmission strategy includes: Determine the timing of PRACH transmission; Determine the number of preambles used for repeated PRACH transmissions; When the terminal device identifies that the current channel quality is lower than the preset index and there are multiple available PRACH transmission opportunities, the number of PRACH retransmissions is determined. After the terminal device performs repeated PRACH transmissions at multiple PRACH transmission times, it listens to the Physical Downlink Control Channel (PDCCH), selects one PRACH transmission time from the multiple PRACH transmission times to calculate the RA-RNTI, and attempts to detect the Downlink Control Information (DCI) using the RA-RNTI.

30. A storage medium having a computer program stored thereon, which, when executed by a processor, implements the physical random access channel repetitive transmission method according to any one of claims 1 to 19, or 20 to 27.

31. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the physical random access channel retransmission method of any one of claims 1 to 19, or 20 to 27, by executing the executable instructions.

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