Method and terminal device for transmitting a random access preamble

Abstract

Embodiments of the present application relate to a method and a terminal device for transmitting a random access preamble. The method includes: performing the i-th transmission of the random access preamble, where i is a positive integer greater than 1; if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, incrementing the value of the power increase counter for the random access preamble by 1. The method and the terminal device for transmitting a random access preamble according to the embodiments of the present application can enable the terminal device to determine the power increase counter for the random access preamble based on whether the transmission beam changes.

Description

Technical Field

[0001] This application relates to the field of communications, and in particular, to a method and a terminal device for transmitting a random access preamble. Background Art

[0002] In the random access process of a Long Term Evolution (LTE) system, a Media Access Control (MAC) entity in a terminal device only maintains a random access preamble transmission counter (PREAMBLE_TRANSMISSION_COUNTER). This counter is used not only for counting power ramping but also for counting the number of preamble transmissions, thereby limiting the maximum number of transmissions on a random access channel (RACH).

[0003] When a RACH process is initiated, the initial value of the PREAMBLE_TRANSMISSION_COUNTER is set to 1. After transmitting Msg1, if the terminal fails to receive a random access response (RAR) or fails in contention, the PREAMBLE_TRANSMISSION_COUNTER is incremented by one until the PREAMBLE_TRANSMISSION_COUNTER reaches the maximum value. Additionally, the PREAMBLE_TRANSMISSION_COUNTER also determines the transmission power of Msg1 each time the RACH is re-initiated.

[0004] In a New Radio (NR) system, to support beamforming, two counters are introduced. One is the PREAMBLE_TRANSMISSION_COUNTER, and the other is a power ramping counter (PREAMBLE_POWER_RAMPING_COUNTER) set for calculating power ramping. How to maintain these two counters is a problem that needs to be solved. Summary of the Invention

[0005] This application provides a method and a terminal device for transmitting a random access preamble, which can enable the terminal device to determine a power ramping counter for the random access preamble according to whether the transmission beam changes; and set a corresponding maximum number of transmissions of the random access preamble according to whether the transmission resource of the random access preamble belongs to an unlicensed frequency band.

[0006] In a first aspect, a method for transmitting a random access preamble is provided. The method includes: performing an i-th transmission of the random access preamble, where i is a positive integer greater than 1; if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, incrementing the value of a power increment counter for the random access preamble by 1.

[0007] Therefore, in the method for transmitting a random access preamble according to an embodiment of the present application, the terminal device includes a PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. And for a non-first transmission of the random access preamble (hereinafter referred to as the preamble "preamble") performed by the terminal device, if it uses the same beam as the previous transmission, that is, the beam has not changed, then the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to this preamble is incremented by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that power ramping remains unchanged when beam switching occurs during preamble transmission.

[0008] In combination with the first aspect, in one implementation manner of the first aspect, before incrementing the value of the power increment counter for the random access preamble, the method further includes: determining that there is no need to pause the power increment counter.

[0009] In combination with the first aspect and its above implementation manner, in another implementation manner of the first aspect, the method further includes: if the i-th transmission of the random access preamble uses the same synchronization signal block as the (i - 1)-th transmission, determining that the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission.

[0010] In combination with the first aspect and its above implementation manner, in another implementation manner of the first aspect, before performing the i-th transmission of the random access preamble, the method further includes: determining a first preset time-frequency resource in at least one preset time-frequency resource, where the first preset time-frequency resource is used for the i-th transmission of the random access preamble.

[0011] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, determining the first preset time-frequency resource in at least one preset time-frequency resource includes: determining whether a second preset time-frequency resource in the at least one preset time-frequency resource is occupied; if the second preset time-frequency resource is not occupied, determining the second preset time-frequency resource as the first preset time-frequency resource; or, if the second preset time-frequency resource is occupied, determining whether other preset time-frequency resources in the at least one preset time-frequency resource except the second preset time-frequency resource are occupied.

[0012] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, determining whether the second preset time-frequency resource in the at least one preset time-frequency resource is occupied includes: determining an energy value of a signal carried by the second preset time-frequency resource; if the energy value of the signal is less than or equal to a preset energy value, determining that the second preset time-frequency resource is not occupied; or, if the energy value of the signal is greater than the preset energy value, determining that the second preset time-frequency resource is not occupied.

[0013] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, a value of a power increase counter after the i-th transmission of the random access preamble is used to determine a transmission power of the (i + 1)-th transmission of the random access preamble.

[0014] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, after performing the i-th transmission of the random access preamble, the method further includes: if it is determined that the i-th transmission of the random access preamble fails, incrementing a value of a transmission times counter of the random access preamble, where the transmission times counter is used to record the transmission times of the random access preamble.

[0015] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, after incrementing the value of the transmission times counter of the random access preamble, the method further includes: if the value of the transmission times counter is less than or equal to a maximum value of the transmission times of the random access preamble, performing the (i + 1)-th transmission of the random access preamble; or, if the value of the transmission times counter is greater than the maximum value, determining that the random access process fails.

[0016] Combined with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, after determining that the random access process fails, the method further includes: determining a receiving cell of the random access preamble as a primary cell; sending a radio resource control (RRC) signaling to a network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0017] In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the method further includes: determining whether the transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unauthorized frequency band; if the transmission resource belongs to the authorized frequency band, setting the maximum number of transmissions of the random access preamble to a first value; or, if the transmission resource belongs to the unauthorized frequency band, setting the maximum number of transmissions to a second value, where the first value is different from the second value.

[0018] In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the first value is less than the second value.

[0019] In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the method further includes: receiving configuration information sent by a network device, where the configuration information includes the first value and / or the second value.

[0020] Therefore, in the method for transmitting a random access preamble according to the embodiments of the present application, the terminal device includes a PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. Moreover, for a non-first transmission of a preamble performed by the terminal device, if the beam used is the same as that used in the previous transmission, that is, the beam has not changed, the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble is incremented by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that the power ramping remains unchanged when a beam conversion occurs during the preamble transmission.

[0021] In a second aspect, a method for transmitting a random access preamble is provided. The method includes: determining whether the transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unauthorized frequency band; if the transmission resource belongs to the authorized frequency band, setting the maximum number of transmissions of the random access preamble to a first value; or, if the transmission resource belongs to the unauthorized frequency band, setting the maximum number of transmissions to a second value, where the first value is different from the second value.

[0022] Therefore, in the method for transmitting a random access preamble according to the embodiments of the present application, the terminal device may set the maximum number of transmissions of the preamble according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmissions is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmissions is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines the failure of the random access process due to LBT failure.

[0023] Combined with the second aspect, in one implementation manner of the second aspect, the first value is less than the second value.

[0024] Combined with the second aspect and its above implementation manner, in another implementation manner of the second aspect, the method further includes: receiving configuration information sent by a network device, where the configuration information includes the first value and / or the second value.

[0025] Combined with the second aspect and its above implementation manner, in another implementation manner of the second aspect, the method further includes: if the i-th transmission of the random access preamble fails, incrementing the value of the transmission count counter of the random access preamble, where the transmission count counter is used to record the number of transmissions of the random access preamble, and i is a positive integer.

[0026] Combined with the second aspect and its above implementation manner, in another implementation manner of the second aspect, after incrementing the value of the transmission count counter of the random access preamble, the method further includes: if the value of the transmission count counter is less than or equal to the maximum number of transmissions, performing the (i + 1)-th transmission of the random access preamble; or, if the value of the transmission count counter is greater than the maximum number of transmissions, determining that the random access process fails.

[0027] Combined with the second aspect and its above implementation manner, in another implementation manner of the second aspect, after determining that the random access process fails, the method further includes: determining the receiving cell of the random access preamble as the primary cell; sending an RRC signaling to the network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0028] Combined with the second aspect and its above implementation manner, in another implementation manner of the second aspect, the method further includes: determining whether a first resource in the transmission resource is occupied; if the first resource is occupied, determining whether other resources in the transmission resource except the first resource are occupied;

[0029] If the first resource is not occupied, using the first resource to perform the i-th transmission of the random access preamble.

[0030] In combination with the second aspect and its above-mentioned implementation manners, in another implementation manner of the second aspect, after determining whether other resources in the transmission resources except the first resource are occupied when the first resource is occupied, the method further includes: if there is no unoccupied resource in the transmission resources, determining that the i-th transmission of the random access preamble fails.

[0031] Therefore, in the method for transmitting a random access preamble according to an embodiment of the present application, a terminal device can set a maximum number of transmissions of the preamble according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmissions is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmissions is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access process fails due to LBT failure.

[0032] In a third aspect, a terminal device is provided for performing the method in the first aspect or any possible implementation manner of the first aspect. Specifically, the terminal device includes units for performing the method in the first aspect or any possible implementation manner of the first aspect.

[0033] In a fourth aspect, a terminal device is provided for performing the method in the second aspect or any possible implementation manner of the second aspect. Specifically, the terminal device includes units for performing the method in the second aspect or any possible implementation manner of the second aspect.

[0034] In a fifth aspect, a terminal device is provided, including: a memory and a processor. The memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. When the processor executes the instructions stored in the memory, the execution causes the processor to perform the method in the first aspect or any possible implementation manner of the first aspect.

[0035] In a sixth aspect, a terminal device is provided, including: a memory and a processor. The memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. When the processor executes the instructions stored in the memory, the execution causes the processor to perform the method in the second aspect or any possible implementation manner of the second aspect.

[0036] In a seventh aspect, a computer-readable medium is provided for storing a computer program, and the computer program includes instructions for performing the method in the first aspect or any possible implementation manner of the first aspect.

[0037] In an eighth aspect, a computer-readable medium is provided for storing a computer program, the computer program including instructions for performing the method in the second aspect or any possible implementation manner of the second aspect.

[0038] In a ninth aspect, a computer program product including instructions is provided. When a computer runs the instructions of the computer program product, the computer executes the method for transmitting a random access preamble in the first aspect or any possible implementation manner of the first aspect. Specifically, the computer program product can run on the terminal device in the third aspect.

[0039] In a tenth aspect, a computer program product including instructions is provided. When a computer runs the instructions of the computer program product, the computer executes the method for transmitting a random access preamble in the second aspect or any possible implementation manner of the second aspect. Specifically, the computer program product can run on the terminal device in the fourth aspect. Description of the Drawings

[0040] Figure 1 is a schematic flowchart of a method for transmitting a random access preamble according to an embodiment of the present application.

[0041] Figure 2 is a schematic flowchart of a method for transmitting a random access preamble according to another embodiment of the present application.

[0042] Figure 3 is a schematic block diagram of a terminal device according to an embodiment of the present application.

[0043] Figure 4 is a schematic block diagram of a terminal device according to another embodiment of the present application.

[0044] Figure 5 is a schematic block diagram of a terminal device according to still another embodiment of the present application.

[0045] Figure 6 is a schematic block diagram of a terminal device according to still another embodiment of the present application. Detailed Embodiments

[0046] Next, the technical solutions in the embodiments of the present application will be described with reference to the drawings.

[0047] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Global System of Mobile Communication (GSMC) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS) system, Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, future 5th generation (5G) system or New Radio (NR) system, etc.

[0048] The terminal device in the embodiments of the present application may refer to a user equipment, an access terminal, a user unit, a user station, a mobile station, a mobile terminal, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent or a user device. The terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a future 5G network or a terminal device in a future evolved Public Land Mobile Network (PLMN), etc. The embodiments of the present application are not limited thereto.

[0049] The network device in the embodiments of the present application may be a device for communicating with a terminal device. The network device may be a base transceiver station (BTS) in a GSMC system or a CDMA system, or a NodeB (NB) in a WCDMA system, or an evolved NodeB (eNB or eNodeB) in an LTE system, or a radio controller in a cloud radio access network (CRAN) scenario, or the network device may be a relay station, an access point, a vehicle-mounted device, a wearable device, and a network device in a future 5G network or a network device in a future evolved PLMN network, etc. The embodiments of the present application do not limit this.

[0050] Figure 1 FIG. shows a schematic flowchart of a method 100 for transmitting a random access preamble according to an embodiment of the present application. The method 100 may be executed by a terminal device. As Figure 1 shown, the method 100 includes: S110, performing the i-th transmission of the random access preamble, where i is a positive integer greater than 1; S120, if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, incrementing the value of the power increase counter for the random access preamble by 1.

[0051] In the embodiments of the present application, before the terminal device performs the i-th transmission of the random access preamble (hereinafter referred to as the preamble "preamble") in S110, the method 100 further includes: the terminal device determines the transmission resource for performing the preamble. Optionally, the transmission resource for transmitting the preamble may belong to an authorized frequency band or an unauthorized frequency band. If the transmission resource belongs to the authorized frequency band, that is, the terminal device performs the i-th transmission of the preamble according to the resources configured by the network device. If the transmission resource belongs to the unauthorized frequency band, the terminal device may determine a first preset time-frequency resource from at least one preset time-frequency resource according to a preset condition, where the first preset time-frequency resource is used for the i-th transmission of the preamble, and the preset condition may be listen before talk (LBT).

[0052] Optionally, as an embodiment, for the i-th transmission of the preamble using an unlicensed frequency band, the terminal device determines at least one preset time-frequency resource that can be used for transmitting the preamble. The at least one preset time-frequency resource belongs to the unlicensed frequency band, and the terminal device determines a first preset time-frequency resource for the i-th transmission of the preamble from the at least one preset time-frequency resource. Specifically, taking the second preset time-frequency resource in the at least one preset time-frequency resource as an example, the terminal device determines whether the second preset time-frequency resource is occupied. If the second preset time-frequency resource is not occupied, the second preset time-frequency resource is determined as the first preset time-frequency resource for performing the i-th transmission of the preamble; if the second preset time-frequency resource is occupied, the terminal device continues to determine whether other preset time-frequency resources in the at least one preset time-frequency resource are occupied until an unoccupied preset time-frequency resource is found, and the unoccupied preset time-frequency resource is determined as the first preset time-frequency resource, where the other preset time-frequency resources do not include the second preset time-frequency resource.

[0053] It should be understood that if the terminal device does not detect an idle preset time-frequency resource in the at least one preset time-frequency resource, that is, the at least one preset time-frequency resource is currently occupied, the terminal device may consider that the i-th transmission of the preamble fails. Optionally, if the terminal device determines to continue the (i + 1)-th transmission, it may use other resources to perform the transmission, or after a period of time, detect again whether there is an unoccupied preset time-frequency resource in the at least one preset time-frequency resource, and use the unoccupied preset time-frequency resource to perform the (i + 1)-th transmission.

[0054] It should be understood that there are various ways to determine whether any one of the preset time-frequency resources in the at least one preset time-frequency resource is occupied. For example, taking the second preset time-frequency resource as an example here, the terminal device can determine whether the second preset time-frequency resource is occupied by determining the energy value of the signal in the second preset time-frequency resource. Specifically, the terminal device can detect and determine the energy value of the signal carried by the second preset time-frequency resource. If the energy value of the signal is less than or equal to a preset energy value, it is determined that the second preset time-frequency resource is not occupied; if the energy value of the signal is greater than the preset energy value, it is determined that the second preset time-frequency resource is occupied. Optionally, the preset energy value can be set according to actual applications, and the embodiments of this application are not limited thereto.

[0055] In an embodiment of the present application, the terminal device determines the transmission resource for transmitting the preamble and performs the i-th transmission of the preamble through this transmission resource. In S120, if the beam used for the i-th transmission of the preamble is the same as the beam used for the (i - 1)-th transmission, that is, the beams for transmitting the preamble in the previous and subsequent transmissions are the same, then the value of the power increase counter (PREAMBLE_POWER_RAMPING_COUNTER) corresponding to this preamble is incremented by 1. Among them, the i-th transmission of the preamble in the embodiment of the present application is not the first transmission, that is, the value of i is a positive integer greater than 1, and there is an (i - 1)-th transmission of this preamble before this i-th transmission.

[0056] Optionally, the terminal device can determine whether the i-th transmission is not the first transmission through the preamble transmission times counter (PREAMBLE_TRANSMISSION_COUNTER) corresponding to this preamble. The initial value of PREAMBLE_TRANSMISSION_COUNTER is set to 1, and then each time a preamble transmission fails, the value of this PREAMBLE_TRANSMISSION_COUNTER is incremented by 1. Therefore, when the value of PREAMBLE_TRANSMISSION_COUNTER is greater than 1, it indicates that the i-th transmission is not the first transmission.

[0057] It should be understood that the terminal device determines that the beam used for the i-th transmission of the preamble is the same as the beam used for the (i - 1)-th transmission, which may include: if the i-th transmission and the (i - 1)-th transmission of the preamble use the same synchronous signal block (SS block), that is, this SS block has not changed, then it can be determined that the beam used for the i-th transmission of the preamble is the same as the beam used for the (i - 1)-th transmission. That is, the transmission beam used by the terminal device to send the preamble in the i-th transmission is the same as the transmission beam used by the terminal device to send the preamble in the (i - 1)-th transmission, and there is no beam switching. Then, after the i-th transmission of this preamble, the terminal device can increment the value of the corresponding PREAMBLE_POWER_RAMPING_COUNTER by 1.

[0058] Correspondingly, if the beam used for the i-th transmission of the preamble is different from the beam used for the (i - 1)-th transmission, that is, the transmission beam used by the terminal device to send the preamble in the i-th transmission is different from the transmission beam used by the terminal device to send the preamble in the (i - 1)-th transmission, then the value of PREAMBLE_POWER_RAMPING_COUNTER corresponding to the i-th transmission of the preamble remains unchanged.

[0059] In the embodiment of the present application, in S120, if the terminal device determines that the beam used for the i-th transmission of the preamble is the same as the beam used for the (i - 1)-th transmission, then the value of the corresponding PREAMBLE_POWER_RAMPING_COUNTER is incremented by 1. Further, it may further include: if the terminal device determines that the beam used for the i-th transmission of the preamble is the same as the beam used for the (i - 1)-th transmission, and the terminal device determines that there is no need to pause the PREAMBLE_POWER_RAMPING_COUNTER, then the value of the PREAMBLE_POWER_RAMPING_COUNTER is incremented by 1, otherwise it remains unchanged. Specifically, the MAC entity of the terminal device may pause the PREAMBLE_POWER_RAMPING_COUNTER according to the indication of the lower layer, so that the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged; if after the i-th transmission of the preamble, the terminal device does not receive the indication, or receives an indication not to pause the PREAMBLE_POWER_RAMPING_COUNTER, then when the beam used for the i-th transmission of the preamble by the terminal device is the same as the beam used for the (i - 1)-th transmission, the value of PREAMBLE_POWER_RAMPING_COUNTER corresponding to the i-th transmission of the preamble is incremented by 1.

[0060] In the embodiment of the present application, the value of the PREAMBLE_POWER_RAMPING_COUNTER can be used to determine the transmission power of the terminal device to send the preamble. Specifically, after the terminal device performs the i-th transmission of the preamble, if the i-th transmission fails, the terminal device can determine whether to perform the (i + 1)-th transmission of the preamble. If it is to be performed, then at the (i + 1)-th transmission, the power of the terminal device to send the preamble can be determined according to the value of the corresponding PREAMBLE_POWER_RAMPING_COUNTER determined after performing the (i + 1)-th transmission of the preamble.

[0061] Optionally, when performing the (i + 1)-th transmission, the power PREAMBLE_RECEIVED_TARGET_POWER at which the terminal device sends the preamble can be determined by the following formula:

[0062] PREAMBLE_RECEIVED_TARGET_POWER

[0063] = ra - Preamble Initial Received Target Power + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER – 1) * power Ramping Step

[0064] where ra - Preamble Initial Received Target Power, DELTA_PREAMBLE, and power Ramping Step are all pre-configured parameters, and PREAMBLE_POWER_RAMPING_COUNTER represents the value of the corresponding PREAMBLE_POWER_RAMPING_COUNTER determined by the terminal device after performing the (i + 1)-th transmission of the preamble.

[0065] In the embodiments of this application, after the terminal device performs the i-th transmission of the preamble, it can determine whether the i-th transmission fails according to whether the terminal device successfully receives the RAR and according to whether the competition is successful. Specifically, when the terminal device performs the i-th transmission of the preamble, it sends the preamble, that is, msg1, to the network device. The preamble can be determined by random selection. The network device sends the RAR, that is, msg2, to the terminal device according to the received preamble. If the terminal device fails to successfully receive the RAR within the RAR window, it is determined that the i-th transmission of the preamble fails. For example, if the terminal device fails to send the preamble to the network device, or the network device fails to send the RAR to the terminal device, etc., it will cause the terminal device to fail to receive the RAR within the RAR window.

[0066] For another example, when performing the i-th transmission of the preamble using unlicensed transmission resources, if the network device has been unable to determine the resources available for transmitting msg2, for example, if the network device performs LBT multiple times and the detected transmission resources are all occupied, it may also cause the terminal device to be unable to receive msg2 within the RAR window, thereby causing the terminal device to determine that the i-th transmission of the preamble fails.

[0067] It should be understood that the duration of the RAR window can be set according to actual applications, and the embodiments of this application do not limit this.

[0068] Optionally, if the terminal device fails in competition, the i-th transmission of the preamble of the terminal device fails. Specifically, when the terminal device receives msg2 sent by the network device, it sends msg3 to the network device, and sends an RRC connection request (Connection Request) through this msg3. Among them, this msg3 includes the identifier of the terminal device. The network device sends msg4 to the terminal device according to this msg3, and this msg4 also includes the identifier of the terminal device. When multiple terminal devices send the same preamble to the network device at the same time, the network device receives the msg3 sent by these multiple terminal devices. Each msg3 includes the identifier of the corresponding terminal device. The network device determines a terminal device among these multiple terminal devices and sends msg4 to this terminal device. This msg4 includes the identifier of this terminal device, so that multiple terminal devices can determine whether they succeed in competition according to the received msg4. If the terminal device determines its own identifier information in msg4, it succeeds in competition. If the terminal device does not determine its own identifier in msg4, the terminal device fails in competition.

[0069] In the embodiments of this application, if the i-th transmission of the preamble by the terminal device fails, it can be determined whether to perform the (i + 1)-th transmission of the preamble according to the value of PREAMBLE_TRANSMISSION_COUNTER corresponding to this preamble. Specifically, the terminal device can record the number of times of transmitting the preamble through this PREAMBLE_TRANSMISSION_COUNTER, and when the value of this PREAMBLE_TRANSMISSION_COUNTER reaches the maximum value of the number of transmissions, it is determined that the random access process fails.

[0070] Specifically, when the i-th transmission of the preamble by the terminal device fails, the value of PREAMBLE_TRANSMISSION_COUNTER corresponding to this preamble is incremented by 1. At this time, if the corresponding value of PREAMBLE_TRANSMISSION_COUNTER is less than or equal to the maximum value of the number of transmissions, the terminal device continues to perform the (i + 1)-th preamble transmission; if the corresponding value of PREAMBLE_TRANSMISSION_COUNTER is greater than the maximum value of the number of transmissions, the terminal device determines that the random access process fails.

[0071] In an embodiment of the present application, after the random access process of the terminal device fails, the terminal device can determine whether the cell where the preamble is transmitted is the primary cell. If it is the primary cell, the terminal device sends an RRC signaling to the network device corresponding to the primary cell, and the RRC signaling is used to indicate a radio link failure; if it is not the primary cell but a secondary cell, there is no need to send the RRC signaling. Optionally, the primary cell may include the primary cell of the primary base station connected by the terminal device, or the primary cell of the secondary base station connected by the terminal device; the secondary cell may include the secondary cell of the primary base station connected by the terminal device, or the secondary cell of the secondary base station connected by the terminal device, and the embodiments of the present application are not limited thereto.

[0072] In an embodiment of the present application, the maximum value of the transmission times of the preamble can be set according to actual applications. For example, it can be set to a certain fixed value, or the maximum value of the transmission times can be determined according to the configuration of the network device. Optionally, the terminal device can set the maximum value of the transmission times according to whether the frequency band where the resource for transmitting the preamble is located is an authorized frequency band.

[0073] Specifically, if the resource for transmitting the preamble belongs to an authorized frequency band, the terminal device sets the maximum value of the transmission times of the preamble to a first value; if the resource for transmitting the preamble belongs to an unauthorized frequency band, the terminal device sets the maximum value of the transmission times of the preamble to a second value, and the first value is different from the second value.

[0074] Optionally, considering that for an unauthorized frequency band, the terminal device needs to perform LBT on the corresponding preset time-frequency resource to determine an unoccupied resource to perform the transmission of the preamble; correspondingly, the network device also needs to perform LBT on the corresponding preset time-frequency resource to determine an unoccupied resource to perform the transmission of the RAR corresponding to the preamble. Therefore, this will increase the probability that the terminal device cannot receive the RAR within the RAR window. However, the terminal device can set the maximum value of the transmission times of the preamble according to whether the resource for transmitting the preamble belongs to an unauthorized frequency band, and set the second value corresponding to the unauthorized frequency band to be greater than the first value corresponding to the authorized frequency band, so as to reduce the probability that the terminal device determines that the random access process fails due to LBT failure.

[0075] Optionally, the terminal device determines the first value and the second value, including: the terminal device receives the configuration information sent by the network device, and the configuration information includes the first value and / or the second value, but the embodiments of the present application are not limited thereto.

[0076] Therefore, in the method for transmitting a random access preamble according to an embodiment of the present application, the terminal device includes a PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. Moreover, for a non-first transmission of a preamble performed by the terminal device, if the beam used is the same as that used in the previous transmission, i.e., the beam has not changed, the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble is incremented by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that power ramping remains unchanged when a beam conversion occurs during preamble transmission.

[0077] Figure 2 FIG. 4 shows a schematic flowchart of a method 200 for transmitting a random access preamble according to another embodiment of the present application. The method 200 may be executed by a terminal device. As Figure 2 shown, the method 200 includes: S210, determining whether the transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unlicensed frequency band; S220, if the transmission resource belongs to the authorized frequency band, setting the maximum number of transmissions of the random access preamble to a first value; S230, if the transmission resource belongs to the unlicensed frequency band, setting the maximum number of transmissions to a second value, where the first value is different from the second value.

[0078] In an embodiment of the present application, considering that when a terminal device uses resources in an unlicensed frequency band to transmit a preamble, the terminal device needs to perform LBT on the corresponding transmission resources to determine unoccupied resources for preamble transmission; correspondingly, the network device also needs to perform LBT on the corresponding transmission resources to determine unoccupied resources for transmitting the RAR corresponding to the preamble. Therefore, the LBT of the terminal device and the network device increases the transmission duration, thereby increasing the probability that the terminal device cannot receive the RAR within the RAR window.

[0079] Therefore, in the method for transmitting a random access preamble according to an embodiment of the present application, the terminal device may set the maximum number of transmissions of the preamble according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmissions is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmissions is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access process fails due to an LBT failure.

[0080] In an embodiment of the present application, the terminal device includes a transmission times counter (PREAMBLE_TRANSMISSION_COUNTER) for recording the transmission times of the preamble. Specifically, the terminal device sets the initial value of the PREAMBLE_TRANSMISSION_COUNTER to 1. After that, when the terminal device fails in the i-th transmission of the preamble, the value of the PREAMBLE_TRANSMISSION_COUNTER is incremented by 1, where i is a positive integer.

[0081] In an embodiment of the present application, if the terminal device fails in the i-th transmission of the preamble, it can determine whether to perform the (i + 1)-th transmission of the preamble according to the value of the PREAMBLE_TRANSMISSION_COUNTER corresponding to the preamble. Specifically, the terminal device can record the number of times of transmitting the preamble through the PREAMBLE_TRANSMISSION_COUNTER. When the value of the PREAMBLE_TRANSMISSION_COUNTER reaches the maximum value of the transmission times, it is determined that the random access process fails, where the maximum value of the transmission times can be a first value or a second value.

[0082] Specifically, when the terminal device fails in the i-th transmission of the preamble, the value of the PREAMBLE_TRANSMISSION_COUNTER corresponding to the preamble is incremented by 1. At this time, if the value of the corresponding PREAMBLE_TRANSMISSION_COUNTER is less than or equal to the maximum value of the transmission times, the terminal device continues to perform the (i + 1)-th preamble transmission; if the value of the corresponding PREAMBLE_TRANSMISSION_COUNTER is greater than the maximum value of the transmission times, the terminal device determines that the random access process fails.

[0083] In an embodiment of the present application, the terminal device can determine that the maximum value of the transmission times of the preamble is a first value or a second value according to whether the transmitted preamble belongs to an unlicensed frequency band. Specifically, the first value and the second value can be set according to actual applications, or the terminal device can receive configuration information sent by the network device, where the configuration information includes the first value and / or the second value, and then the terminal device determines the first value and the second value according to the configuration information. The embodiments of the present application are not limited thereto.

[0084] It should be understood that before the terminal device performs the i-th transmission of the preamble, the method 200 further includes: determining the resources for performing the i-th transmission in the transmission resources for transmitting the preamble. Specifically, for authorized resources, the terminal device uses the authorized resources to perform the i-th preamble transmission.

[0085] Optionally, for unauthorized transmission resources, the terminal device determines, through LBT in the unauthorized transmission resources, the resources that can be used to perform the i-th transmission of the preamble. Specifically, the terminal device determines whether the first resource in the unauthorized transmission resources is occupied. If the first resource is not occupied, the first resource is used to perform the i-th transmission of the preamble; if the first resource is occupied, the terminal device continues to determine whether other resources except the first resource in the unauthorized resources are occupied until an unoccupied resource is determined, and the unoccupied resource is used to perform the i-th transmission of the preamble.

[0086] It should be understood that if the terminal device does not detect idle resources in all unauthorized transmission resources, that is, all the unauthorized transmission resources are currently occupied, the terminal device may consider that the i-th transmission of the preamble fails. Optionally, if the terminal device determines to continue performing the (i + 1)-th transmission, it can be performed using other resources, or, after a period of time, the terminal device detects again whether there are unoccupied time-frequency resources in the unauthorized transmission resources, and uses the unoccupied time-frequency resources to perform the (i + 1)-th transmission.

[0087] It should be understood that there are various ways to determine whether any time-frequency resource in the unauthorized transmission resources is occupied. For example, taking the first resource as an example here, it can be determined whether the first resource is occupied by determining the energy value of the signal in the first resource. Specifically, the terminal device can detect and determine the energy value of the signal carried by the first resource. If the energy value of the signal is less than or equal to a preset energy value, it is determined that the first resource is not occupied; if the energy value of the signal is greater than the preset energy value, it is determined that the first resource is occupied. Optionally, the preset energy value can be set according to actual applications, and the embodiments of the present application are not limited thereto.

[0088] In an embodiment of the present application, after the terminal device performs the i-th transmission of the preamble, it can also determine whether the i-th transmission fails according to whether the terminal device successfully receives the RAR and whether the competition is successful. Specifically, when the terminal device performs the i-th transmission of the preamble, it sends the preamble, that is, msg1, to the network device. The preamble can be determined by random selection. The network device sends the RAR, that is, msg2, to the terminal device according to the received preamble. If the terminal device fails to successfully receive the RAR within the RAR window, it is determined that the i-th transmission of the preamble fails. For example, if the terminal device fails to send the preamble to the network device, or the network device fails to send the RAR to the terminal device, etc., it will cause the terminal device to fail to receive the RAR within the RAR window.

[0089] For another example, for the i-th transmission of the preamble using unlicensed transmission resources, if the network device has been unable to determine the resources available for transmitting msg2, for example, if the network device performs LBT multiple times and the detected transmission resources are all occupied, it may also cause the terminal device to be unable to receive msg2 within the RAR window, thereby causing the terminal device to determine that the i-th transmission of the preamble fails.

[0090] It should be understood that the duration of the RAR window can be set according to actual applications, and the embodiments of the present application do not limit this.

[0091] Optionally, for the terminal device that fails in the competition, the terminal device can also determine that the i-th transmission of the preamble fails. Specifically, when the terminal device receives msg2 sent by the network device, it sends msg3 to the network device and sends an RRC connection request (Connection Request) through this msg3. The msg3 includes the identifier of the terminal device. The network device sends msg4 to the terminal device according to this msg3, and the msg4 also includes the identifier of the terminal device. When multiple terminal devices send the same preamble to the network device at the same time, the network device receives the msg3 sent by these multiple terminal devices. Each msg3 includes the identifier of the corresponding terminal device. The network device determines one terminal device among these multiple terminal devices and sends msg4 to this terminal device. The msg4 includes the identifier of this terminal device, so that multiple terminal devices can determine whether the competition is successful according to the received msg4. If the terminal device determines its own identifier information in msg4, the competition is successful. If the terminal device does not determine its own identifier in msg4, the terminal device fails in the competition.

[0092] In summary, for preamble transmission on unlicensed transmission resources, the terminal device determines that the probability of the preamble transmission failing is greater than that of the preamble transmission on licensed resources. Therefore, when transmitting the preamble on unlicensed transmission resources, the maximum number of preamble transmission times corresponding thereto can be set to a larger second value, while when transmitting the preamble on licensed transmission resources, the maximum number of preamble transmission times corresponding thereto can be set to a smaller first value.

[0093] In an embodiment of the present application, after the terminal device determines that the random access process fails according to the value of PREAMBLE_TRANSMISSION_COUNTER, the terminal device can determine whether the cell where the preamble transmission is located is the primary cell. If it is the primary cell, the terminal device sends an RRC signaling to the network device corresponding to the primary cell, and the RRC signaling is used to indicate radio link failure; if it is not the primary cell but the secondary cell, there is no need to send the RRC signaling. Optionally, the primary cell may include the primary cell of the primary base station to which the terminal device is connected, or the primary cell of the secondary base station to which the terminal device is connected; the secondary cell may include the secondary cell of the primary base station to which the terminal device is connected, or the secondary cell of the secondary base station to which the terminal device is connected. The embodiments of the present application are not limited thereto.

[0094] Therefore, in the method for transmitting a random access preamble according to the embodiment of the present application, the terminal device can set the maximum number of preamble transmission times according to whether the resource for transmitting the preamble belongs to the unlicensed frequency band. If it belongs to the licensed resource, the maximum number of transmission times is correspondingly set to the first value; if it belongs to the unlicensed frequency band, the maximum number of transmission times is correspondingly set to the second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access process fails due to LBT failure.

[0095] It should be understood that in various embodiments of the present application, the magnitudes of the sequence numbers of the above processes do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0096] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0097] As described above in combination with Figures 1 to 2, which details a method for transmitting a random access preamble according to an embodiment of the present application. Below, it will be combined with Figures 3 to 6 , to describe a terminal device according to an embodiment of the present application.

[0098] As Figure 3 shown, the terminal device 300 according to an embodiment of the present application includes: a transceiver unit 310 and a processing unit 320. Optionally, it may further include a determination unit 330.

[0099] Specifically, the transceiver unit 310 is used to: perform the i-th transmission of the random access preamble, where i is a positive integer greater than 1; the processing unit 320 is used to: if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, increment the value of the power increment counter for the random access preamble by 1.

[0100] Therefore, the terminal device according to an embodiment of the present application includes PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. And for a non-first transmission of the preamble performed by the terminal device, if it uses the same beam as the previous transmission, that is, the beam has not changed, then increment the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that power ramping remains unchanged when beam switching occurs during preamble transmission.

[0101] Optionally, the determination unit 330 is used to: before the processing unit 320 increments the value of the power increment counter for the random access preamble by 1, determine that there is no need to pause the power increment counter.

[0102] Optionally, the determination unit 330 is used to: if the i-th transmission of the random access preamble uses the same synchronization signal block as the (i - 1)-th transmission, determine that the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission.

[0103] Optionally, the determination unit 330 is used to: before the transceiver unit 310 performs the i-th transmission of the random access preamble, determine a first preset time-frequency resource in at least one preset time-frequency resource, and the first preset time-frequency resource is used for the i-th transmission of the random access preamble.

[0104] Optionally, the determining unit 330 is specifically configured to: determine whether a second preset time-frequency resource among the at least one preset time-frequency resource is occupied; if the second preset time-frequency resource is not occupied, determine the second preset time-frequency resource as the first preset time-frequency resource; or, if the second preset time-frequency resource is occupied, determine whether other preset time-frequency resources among the at least one preset time-frequency resource except the second preset time-frequency resource are occupied.

[0105] Optionally, the determining unit 330 is specifically configured to: determine an energy value of a signal carried by the second preset time-frequency resource; if the energy value of the signal is less than or equal to a preset energy value, determine that the second preset time-frequency resource is not occupied; or, if the energy value of the signal is greater than the preset energy value, determine that the second preset time-frequency resource is occupied.

[0106] Optionally, a value of a power increase counter after an i-th transmission of the random access preamble is used to determine a transmission power of an (i + 1)-th transmission of the random access preamble.

[0107] Optionally, the processing unit 320 is specifically configured to: after the transceiver unit 310 performs an i-th transmission of the random access preamble, if it is determined that the i-th transmission of the random access preamble fails, increment a value of a transmission times counter of the random access preamble, where the transmission times counter is used to record a transmission times of the random access preamble.

[0108] Optionally, the transceiver unit 310 is specifically configured to: after the processing unit 320 increments a value of the transmission times counter of the random access preamble, if the value of the transmission times counter is less than or equal to a maximum value of the transmission times of the random access preamble, perform an (i + 1)-th transmission of the random access preamble; or, if the value of the transmission times counter is greater than the maximum value of the transmission times, determine that the random access procedure fails.

[0109] Optionally, the determining unit 330 is configured to: after the determining unit 330 determines that the random access procedure fails, determine a cell that receives the random access preamble as a primary cell; the transceiver unit 310 is specifically configured to: send an RRC signaling to a network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0110] Optionally, the determining unit 330 is configured to: determine whether a transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unauthorized frequency band; the processing unit 320 is specifically configured to: if the transmission resource belongs to the authorized frequency band, set the maximum value of the transmission times of the random access preamble to a first value; or, if the transmission resource belongs to the unauthorized frequency band, set the maximum value of the transmission times to a second value, where the first value is different from the second value.

[0111] Optionally, the first value is less than the second value.

[0112] Optionally, the transceiver unit 310 is specifically configured to: receive configuration information sent by a network device, where the configuration information includes the first value and / or the second value.

[0113] It should be understood that the terminal device 300 according to the embodiments of the present application may correspond to the execution of the method 100 in the embodiments of the present application, and the above and other operations and / or functions of each unit in the terminal device 300 are respectively for implementing Figure 1 the corresponding processes of the terminal device for the methods in, for the sake of brevity, will not be elaborated herein.

[0114] Therefore, the terminal device in the embodiments of the present application includes a PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. Moreover, for a non-first transmission of a preamble performed by the terminal device, if the beam used is the same as that in the previous transmission, that is, the beam has not changed, the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble is incremented by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that power ramping remains unchanged when beam switching occurs during preamble transmission.

[0115] As Figure 4 shown, the terminal device 400 according to the embodiments of the present application includes: a determination unit 410 and a processing unit 420. Optionally, it may further include a transceiver unit 430.

[0116] Specifically, the determination unit 410 is configured to: determine whether the transmission resource for transmitting a random access preamble belongs to an authorized frequency band or an unlicensed frequency band; the processing unit 420 is configured to: if the transmission resource belongs to an authorized frequency band, set the maximum number of transmission times of the random access preamble to a first value; the processing unit 420 is further configured to: if the transmission resource belongs to an unlicensed frequency band, set the maximum number of transmission times to a second value, where the first value is different from the second value.

[0117] Therefore, the terminal device in the embodiments of the present application sets the maximum number of transmission times of the preamble according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmission times is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmission times is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines the failure of the random access process due to LBT failure.

[0118] Optionally, the first value is less than the second value.

[0119] Optionally, the transceiver unit 430 is configured to: receive configuration information sent by a network device, where the configuration information includes the first value and / or the second value.

[0120] Optionally, the processing unit 420 is specifically configured to: if the i-th transmission of the random access preamble fails, increment the value of the transmission count counter of the random access preamble, where the transmission count counter is used to record the transmission count of the random access preamble, and i is a positive integer.

[0121] Optionally, the processing unit 420 is specifically configured to: after incrementing the value of the transmission count counter of the random access preamble, if the value of the transmission count counter is less than or equal to the maximum number of transmissions, perform the (i + 1)-th transmission of the random access preamble; or, if the value of the transmission count counter is greater than the maximum number of transmissions, determine that the random access procedure fails.

[0122] Optionally, the determining unit 410 is specifically configured to: after determining that the random access procedure fails, determine the cell where the random access preamble is received as the primary cell; the transceiver unit 430 is configured to: send an RRC signaling to the network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0123] Optionally, the determining unit 410 is specifically configured to: determine whether a first resource in the transmission resource is occupied; if the first resource is occupied, determine whether other resources in the transmission resource except the first resource are occupied; or, if the first resource is not occupied, use the first resource to perform the i-th transmission of the random access preamble.

[0124] Optionally, the determining unit 410 is specifically configured to: after determining whether other resources in the transmission resource except the first resource are occupied if the first resource is occupied, if there is no unoccupied resource in the transmission resource, determine that the i-th transmission of the random access preamble fails.

[0125] It should be understood that the terminal device 400 according to the embodiment of the present application may correspond to the execution of the method 200 in the embodiment of the present application, and the above and other operations and / or functions of each unit in the terminal device 400 respectively implement Figure 2 the corresponding processes of the terminal device for the method in, for the sake of brevity, will not be described in detail here.

[0126] Optionally, the terminal device 400 may be the terminal device 300 of the embodiment of the present application, but the embodiment of the present application is not limited thereto.

[0127] Therefore, for the terminal device according to the embodiments of the present application, the maximum number of preamble transmissions is set according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmissions is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmissions is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access process fails due to LBT failure.

[0128] Figure 5 FIG. shows a schematic block diagram of a terminal device 500 according to an embodiment of the present application, as Figure 5 shown, the terminal device 500 includes: a processor 510 and a transceiver 520, the processor 510 and the transceiver 520 are connected. Optionally, the terminal device 500 further includes a memory 530, and the memory 530 is connected to the processor 510. Among them, the processor 510, the memory 530, and the transceiver 520 communicate with each other through an internal connection path to transmit and / or control data signals. The memory 530 can be used to store instructions, and the processor 510 is used to execute the instructions stored in the memory 530 to control the transceiver 520 to send information or signals. The transceiver 520 is used for: performing the i-th transmission of the random access preamble, where i is a positive integer greater than 1; the processor 510 is used for: if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, increment the value of the power increase counter of the random access preamble by 1.

[0129] Therefore, the terminal device according to the embodiments of the present application includes a PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping. Moreover, for a non-first transmission of the preamble performed by the terminal device, if it uses the same beam as the previous transmission, that is, the beam has not changed, the value of the PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble is incremented by 1; if the beam changes, the value of the PREAMBLE_POWER_RAMPING_COUNTER remains unchanged. That is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that the power ramping remains unchanged when a beam conversion occurs during the preamble transmission.

[0130] Optionally, as an embodiment, the processor 510 is used for: before incrementing the value of the power increase counter of the random access preamble by 1, determining that there is no need to pause the power increase counter.

[0131] Optionally, as an embodiment, the processor 510 is configured to: if the i-th transmission of the random access preamble uses the same synchronization signal block as the (i-1)-th transmission, determine that the beam used for the i-th transmission of the random access preamble is the same as that of the (i-1)-th transmission.

[0132] Optionally, as an embodiment, the processor 510 is configured to: before the transceiver 520 performs the i-th transmission of the random access preamble, determine a first preset time-frequency resource in at least one preset time-frequency resource, where the first preset time-frequency resource is used for the i-th transmission of the random access preamble.

[0133] Optionally, as an embodiment, the processor 510 is configured to: determine whether a second preset time-frequency resource in the at least one preset time-frequency resource is occupied; if the second preset time-frequency resource is not occupied, determine the second preset time-frequency resource as the first preset time-frequency resource; or, if the second preset time-frequency resource is occupied, determine whether other preset time-frequency resources in the at least one preset time-frequency resource except the second preset time-frequency resource are occupied.

[0134] Optionally, as an embodiment, the processor 510 is configured to: determine the energy value of the signal carried by the second preset time-frequency resource; if the energy value of the signal is less than or equal to a preset energy value, determine that the second preset time-frequency resource is not occupied; or, if the energy value of the signal is greater than the preset energy value, determine that the second preset time-frequency resource is occupied.

[0135] Optionally, as an embodiment, the value of the power increase counter after the i-th transmission of the random access preamble is used to determine the transmission power of the (i+1)-th transmission of the random access preamble.

[0136] Optionally, as an embodiment, the processor 510 is configured to: after the transceiver 520 performs the i-th transmission of the random access preamble, if it is determined that the i-th transmission of the random access preamble fails, increment the value of the transmission times counter of the random access preamble by 1, where the transmission times counter is used to record the transmission times of the random access preamble.

[0137] Optionally, as an embodiment, the transceiver 520 is specifically configured to: after the processor 510 increments the value of the transmission times counter of the random access preamble by 1, if the value of the transmission times counter is less than or equal to the maximum value of the transmission times of the random access preamble, perform the (i+1)-th transmission of the random access preamble; or, if the value of the transmission times counter is greater than the maximum value of the transmission times, determine that the random access process fails.

[0138] Optionally, as an embodiment, the processor 510 is configured to: after determining that the random access procedure fails, determine the cell where the random access preamble is received as the primary cell; the transceiver 520 is configured to: send RRC signaling to the network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0139] Optionally, as an embodiment, the processor 510 is configured to: determine whether the transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unauthorized frequency band; if the transmission resource belongs to the authorized frequency band, set the maximum number of transmissions of the random access preamble to a first value; or, if the transmission resource belongs to the unauthorized frequency band, set the maximum number of transmissions to a second value, where the first value is different from the second value.

[0140] Optionally, as an embodiment, the first value is less than the second value.

[0141] Optionally, as an embodiment, the transceiver 520 is specifically configured to: receive configuration information sent by a network device, where the configuration information includes the first value and / or the second value.

[0142] It should be understood that the terminal device 500 according to the embodiment of the present application may correspond to the terminal device 300 in the embodiment of the present application, and may correspond to the corresponding entity that executes the method 100 according to the embodiment of the present application, and the above and other operations and / or functions of each unit in the terminal device 500 are respectively for implementing Figure 1 the corresponding processes of the terminal device in each method in, for the sake of brevity, will not be described in detail here.

[0143] Therefore, the terminal device in the embodiment of the present application includes PREAMBLE_POWER_RAMPING_COUNTER for recording power ramping, and for a non-first transmission of a preamble executed by the terminal device, if the beam used is the same as the beam used in the previous transmission, that is, the beam has not changed, then the value of PREAMBLE_POWER_RAMPING_COUNTER corresponding to the preamble is incremented by 1; if the beam changes, the value of PREAMBLE_POWER_RAMPING_COUNTER remains unchanged, that is, the PREAMBLE_POWER_RAMPING_COUNTER of the terminal device supports ensuring that power ramping remains unchanged when beam switching occurs during preamble transmission.

[0144] Figure 6 FIG. shows a schematic block diagram of a terminal device 600 according to an embodiment of the present application, as Figure 6As shown in the figure, the terminal device 600 includes: a processor 610 and a transceiver 620. The processor 610 is connected to the transceiver 620. Optionally, the terminal device 600 further includes a memory 630, and the memory 630 is connected to the processor 610. Among them, the processor 610, the memory 630, and the transceiver 620 communicate with each other through an internal connection path to transmit and / or control data signals. The memory 630 can be used to store instructions, and the processor 610 is used to execute the instructions stored in the memory 630 to control the transceiver 620 to send information or signals. The processor 610 is used to: determine whether the transmission resource for transmitting the random access preamble belongs to an authorized frequency band or an unlicensed frequency band; if the transmission resource belongs to the authorized frequency band, set the maximum number of transmissions of the random access preamble to a first value; if the transmission resource belongs to the unlicensed frequency band, set the maximum number of transmissions to a second value, and the first value is different from the second value.

[0145] Therefore, for the terminal device in the embodiment of the present application, according to whether the resource for transmitting the preamble belongs to the unlicensed frequency band, the maximum number of transmissions of the preamble is set. If it belongs to the authorized resource, the maximum number of transmissions is correspondingly set to the first value; if it belongs to the unlicensed frequency band, the maximum number of transmissions is correspondingly set to the second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access process fails due to LBT failure.

[0146] Optionally, as an embodiment, the first value is less than the second value.

[0147] Optionally, as an embodiment, the transceiver 620 is used to: receive configuration information sent by a network device, and the configuration information includes the first value and / or the second value.

[0148] Optionally, as an embodiment, the processor 610 is used to: if the i-th transmission of the random access preamble fails, increment the value of the transmission count counter of the random access preamble. The transmission count counter is used to record the number of transmissions of the random access preamble, and i is a positive integer.

[0149] Optionally, as an embodiment, the processor 610 is used to: after incrementing the value of the transmission count counter of the random access preamble, if the value of the transmission count counter is less than or equal to the maximum number of transmissions, perform the (i + 1)-th transmission of the random access preamble; or, if the value of the transmission count counter is greater than the maximum number of transmissions, determine that the random access process fails.

[0150] Optionally, as an embodiment, the processor 610 is configured to: after determining that the random access procedure fails, determine the cell that receives the random access preamble as the primary cell; the transceiver 620 is configured to: send RRC signaling to the network device corresponding to the primary cell, where the RRC signaling is used to indicate a radio link failure.

[0151] Optionally, as an embodiment, the processor 610 is configured to: determine whether a first resource in the transmission resource is occupied; if the first resource is occupied, determine whether other resources in the transmission resource except the first resource are occupied; or, if the first resource is not occupied, use the first resource to perform the i-th transmission of the random access preamble.

[0152] Optionally, as an embodiment, after determining whether other resources in the transmission resource except the first resource are occupied when the first resource is occupied, if there is no unoccupied resource in the transmission resource, the processor 610 is configured to determine that the i-th transmission of the random access preamble fails.

[0153] It should be understood that the terminal device 600 according to the embodiments of the present application may correspond to the terminal device 400 in the embodiments of the present application, and may correspond to the corresponding entity that executes the method 200 according to the embodiments of the present application, and the above and other operations and / or functions of each unit in the terminal device 600 are respectively for implementing Figure 2 the corresponding processes of the terminal device in each method in, for the sake of brevity, will not be described in detail here.

[0154] Therefore, for the terminal device according to the embodiments of the present application, the maximum number of transmissions of the preamble is set according to whether the resource for transmitting the preamble belongs to an unlicensed frequency band. If it belongs to an authorized resource, the maximum number of transmissions is correspondingly set to a first value; if it belongs to an unlicensed frequency band, the maximum number of transmissions is correspondingly set to a second value, and the first value is different from the second value. For example, the second value is set to be greater than the first value to reduce the probability that the terminal device determines that the random access procedure fails due to LBT failure.

[0155] It should be noted that the above method embodiments of the present application can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method embodiments can be completed by the integrated logic circuit in the hardware of the processor or by instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0156] It can be understood that the memory in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0157] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of the present application.

[0158] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0159] In several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0160] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0161] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0162] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0163] As described above, the above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method for transmitting a random access preamble, characterized in that including: The terminal device performs the i-th transmission of the random access preamble, where i is a positive integer greater than 1; If the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, the terminal device increments the value of the power increase counter for the random access preamble by 1. Before incrementing the value of the power increase counter for the random access preamble, the method further includes: Determining that there is no need to pause the power increase counter; The method further includes: If the i-th transmission of the random access preamble uses the same synchronization signal block as the (i - 1)-th transmission, determining that the beam used for the i-th transmission of the random access preamble is the same as that of the (i - 1)-th transmission; Wherein, before performing the i-th transmission of the random access preamble, the method further includes: The terminal device determines a first preset time-frequency resource in at least one preset time-frequency resource, and the first preset time-frequency resource is used for the i-th transmission of the random access preamble. The terminal device determining a first preset time-frequency resource in at least one preset time-frequency resource includes: the terminal device determining whether a second preset time-frequency resource in the at least one preset time-frequency resource is occupied; If the second preset time-frequency resource in the at least one preset time-frequency resource is not occupied, then the second preset time-frequency resource is the first preset time-frequency resource; If the second preset time-frequency resource is occupied, the other unoccupied preset time-frequency resources in the at least one preset time-frequency resource except the second preset time-frequency resource are the first preset time-frequency resource. The first preset time-frequency resource and the second preset time-frequency resource belong to the unlicensed band and do not belong to the licensed band. The maximum number of transmissions of the random access preamble corresponding to the licensed band is a first value; the maximum number of transmissions of the random access preamble corresponding to the unlicensed band is a second value, and the second value is greater than the first value.

2. The method according to claim 1, characterized in that, The value of the power increase counter after the i-th transmission of the random access preamble is used to determine the transmission power of the (i + 1)-th transmission of the random access preamble.

3. The method according to claim 1, characterized in that, After performing the i-th transmission of the random access preamble, the method further includes: If it is determined that the i-th transmission of the random access preamble fails, increment the value of the transmission count counter for the random access preamble by 1, and the transmission count counter is used to record the number of transmissions of the random access preamble.

4. The method according to claim 3, wherein After incrementing the value of the transmission count counter for the random access preamble by 1, the method further includes: If the value of the transmission count counter is less than or equal to the maximum number of transmissions of the random access preamble, perform the (i + 1)-th transmission of the random access preamble; or If the value of the transmission count counter is greater than the maximum number of transmissions, determine that the random access process fails.

5. The method according to claim 4, wherein After determining that the random access process fails, the method further includes: Determining that the receiving cell of the random access preamble is the primary cell; Sending a radio resource control (RRC) signaling to the network device corresponding to the primary cell, and the RRC signaling is used to indicate a radio link failure.

6. The method according to claim 1, characterized in that The method further includes: Receive the configuration information sent by the network device, where the configuration information includes the first value and / or the second value.

7. A terminal device, characterized in that, Comprises: A transceiver unit for performing the i-th transmission of the random access preamble, where i is a positive integer greater than 1; A processing unit for incrementing the value of the power increase counter of the random access preamble by 1 if the i-th transmission of the random access preamble uses the same beam as the (i - 1)-th transmission, and a first determination unit for determining a first preset time-frequency resource in at least one preset time-frequency resource before the transceiver unit performs the i-th transmission of the random access preamble, where the first preset time-frequency resource is used for the i-th transmission of the random access preamble. Wherein, the first determination unit determines whether a second preset time-frequency resource in the at least one preset time-frequency resource is occupied; Wherein, the terminal device further comprises: A second determination unit for determining that there is no need to pause the power increase counter before the processing unit increments the value of the power increase counter of the random access preamble by 1; A third determination unit for determining that the beam used for the i-th transmission of the random access preamble is the same as that used for the (i - 1)-th transmission if the i-th transmission of the random access preamble uses the same synchronization signal block as the (i - 1)-th transmission; If the second preset time-frequency resource in the at least one preset time-frequency resource is not occupied, then the second preset time-frequency resource is the first preset time-frequency resource; if the second preset time-frequency resource is occupied, the other unoccupied preset time-frequency resources in the at least one preset time-frequency resource except the second preset time-frequency resource are the first preset time-frequency resources. Wherein, the first preset time-frequency resource and the second preset time-frequency resource belong to the unlicensed band and do not belong to the licensed band. The maximum number of transmissions of the random access preamble corresponding to the licensed band is the first value; the maximum number of transmissions of the random access preamble corresponding to the unlicensed band is the second value, and the second value is greater than the first value.

8. The terminal device according to claim 7, wherein The value of the power increase counter after the i-th transmission of the random access preamble is used to determine the transmission power of the (i + 1)-th transmission of the random access preamble.

9. The terminal device according to claim 7, characterized in that, The processing unit is specifically used for: After the transceiver unit performs the i-th transmission of the random access preamble, if it is determined that the i-th transmission of the random access preamble fails, increment the value of the transmission times counter of the random access preamble by 1, and the transmission times counter is used to record the number of transmissions of the random access preamble.

10. The terminal device according to claim 9, wherein The transceiver unit is specifically used for: After the processing unit increments the value of the transmission times counter of the random access preamble by 1, if the value of the transmission times counter is less than or equal to the maximum number of transmissions of the random access preamble, perform the (i + 1)-th transmission of the random access preamble; or If the value of the transmission times counter is greater than the maximum number of transmissions, determine that the random access process fails.

11. The terminal device according to claim 10, characterized in that, The terminal device further comprises: A determination unit for determining that the receiving cell of the random access preamble is the primary cell after the determination unit determines that the random access process fails; The transceiver unit is specifically used for: Send radio resource control (RRC) signaling to the network device corresponding to the primary cell, where the RRC signaling is used to indicate radio link failure.

12. The terminal device according to claim 7, wherein Specifically, the transceiver unit is configured to: Receive configuration information sent by the network device, where the configuration information includes the first value and / or the second value.

13. A terminal device, characterized in that Comprising: A memory and a processor, where the memory is used to store instructions, and the processor is used to execute the instructions stored in the memory. When the processor executes the instructions stored in the memory, the processor is caused to execute the method according to any one of claims 1-6.

14. A computer-readable medium, characterized in that, The computer-readable medium is used to store a computer program, where the computer program includes instructions for executing the method according to any one of claims 1-6.

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