WO2018227602A1

WO2018227602A1 - Method for transmitting random access preamble, and terminal device

Info

Publication number: WO2018227602A1
Application number: PCT/CN2017/088753
Authority: WO
Inventors: 张治�
Original assignee: Oppo广东移动通信有限公司
Priority date: 2017-06-16
Filing date: 2017-06-16
Publication date: 2018-12-20
Also published as: CN109565886A; TW201906361A; CN109565886B; TWI676381B

Abstract

The embodiments of the present application relate to a method for transmitting a random access preamble, and a terminal device. The method comprises: a terminal device transmitting, through a first transmission beam, a first random access preamble to a network device; and where the terminal device determines that the transmission of the first random access preamble has failed, the terminal device sending a second random access preamble to the network device through a second transmission beam, the first transmission beam being different from the second transmission beam. With regard to the method for transmitting a random access preamble and the terminal device according to the embodiments of the present application, in the case of the transmission of a first random access preamble through a first transmission beam failing, the terminal device can switch a transmission beam to retransmit a random access preamble, i.e. retransmitting using a second transmission beam different from the first transmission beam, thus reducing the probability of random access preamble collision, and thus reducing transmission delay.

Description

Method and terminal device for transmitting random access preamble

Technical field

The present application relates to the field of communications, and in particular, to a method and a terminal device for transmitting a random access preamble.

Background technique

In the multi-beam system currently discussed by 5G/NR, different beams correspond to different directions and different coverage areas. User equipment (UE) measures the signals carried on different beams (such as synchronization signals, or Channel State Information (CSI)-measurement (RS) signals). A preferred downlink transmission beam (DL Tx Beam), when the UE performs random access, needs to inform the network device of its selected DL Tx Beam.

In the existing 3rd Generation Partnership Project (3GPP) system, different DL Tx Beams may indicate different physical random access channel (PRACH) resources and for the random access procedure. The sequence, that is, the PRACH resources and/or sequences are grouped, and the different groups correspond to different DL Tx Beams. If the UE selects the best DL Tx beam according to the measurement result of some signals in the synchronous signal block (SS block), select a PRACH preamble for transmission from the corresponding group, and the network device The best DL Tx Beam selected by the UE can be determined according to the time-frequency resources and/or sequences of the received PRACH preamble.

When the UE does not receive a valid corresponding Random Access Response (RAR) sent by the network device in the corresponding time window, for example, the network device does not receive the preamble, or the network device sends the RAR, and the terminal device If not received, the UE reselects a preamble according to a preset rule to perform transmission again until a valid corresponding RAR is received, or the maximum number of transmissions specified by the system is reached. When the corresponding RAR is not successfully received when the maximum number of transmissions is reached, the UE notifies the upper layer.

However, in the multi-beam system of 5G/NR, the UE may include multiple uplink transmit beams (UL Tx Beam), so when preamble retransmission, there may be a problem of how to select the beam, so the retransmission of the existing preamble The mechanism will not be applicable to the needs of this type of UE.

Summary of the invention

The present application provides a method and a terminal device for transmitting a random access preamble, which can reduce the probability of occurrence of a preamble collision and reduce the transmission delay.

In a first aspect, a method for transmitting a random access preamble is provided, the method includes: the terminal device sends a first random access preamble to a network device by using a first transmit beam; and determining, by the terminal device, the first random access preamble In the case that the transmission fails, the terminal device sends a second random access preamble to the network device by using the second transmit beam, where the first transmit beam is different from the second transmit beam.

Therefore, in the method for transmitting a random access preamble in the embodiment of the present application, when the first random access preamble fails to be sent by the first transmit beam, the terminal device may switch the transmit beam to resend the random access preamble, that is, adopt and A second transmit beam with different transmit beams is transmitted again, thereby reducing the probability of collision of random access preambles, thereby reducing transmission delay.

It should be understood that in the case where the first random access preamble transmission fails, the terminal device may determine to switch or not to switch the transmission beam to retransmit the random access preamble. Specifically, the terminal device may determine that the second broadcast access preamble is still sent by using the first transmit beam, and the second random access preamble may be determined by the terminal device according to a preset condition; The second transmission access preamble may be sent to the network device by using the second transmit beam, where the first transmit beam and the second transmit beam are different.

With reference to the first aspect, in an implementation manner of the first aspect, before the terminal device sends the second random access preamble to the network device by using the second sending beam, the method further includes: the terminal device receiving the network device The third indication information is sent, where the third indication information is used to indicate that the terminal device switches the first transmit beam when the first random access preamble transmission fails.

It should be understood that, according to the third indication information sent by the network device, the terminal device determines that the first transmit beam is switched when the first random access preamble transmission fails.

Optionally, the third indication information may further indicate that the terminal device does not switch the first transmit beam when the first random access preamble transmission fails.

Optionally, the third indication information may further indicate that the terminal device determines whether to switch the first transmit beam when the first random access preamble transmission fails.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the first random access preamble is the same as the second random access preamble.

Optionally, the terminal device may further determine whether to switch the random access preamble if the transmit beam is switched. Specifically, when the terminal device determines that the random access preamble is not switched, the first random access preamble may be directly used, that is, the second random access preamble is the same as the first random access preamble.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, before the terminal device sends the second random access preamble to the network device by using the second transmit beam, the method further includes: The terminal device receives the first indication information sent by the network device, where the first indication information is used to indicate that the terminal device does not switch the first random access preamble when the first random access preamble transmission fails.

It should be understood that the terminal device may determine not to switch the first random access preamble according to the first indication information sent by the network device.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, before the terminal device sends the second random access preamble to the network device by using the second transmit beam, the method further includes: The terminal device determines that the second random access preamble has not been sent by the second transmit beam.

It should be understood that the terminal device may determine whether the second transmit beam has sent the first random access preamble, and if not, may not switch the random access preamble, that is, the second random transmission sent by the second transmit beam. The access preamble is the same as the first random access preamble.

Optionally, if the terminal device determines that the second transmit beam does not send the first random access preamble, the terminal may also select to switch the random access preamble, that is, the second random access preamble sent by the second transmit beam is the terminal device. Determined according to preset conditions.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, before the terminal device sends the second random access preamble to the network device by using the second transmit beam, the method further includes: The terminal device determines the second random access preamble according to a preset condition.

Optionally, the terminal device may further determine whether to switch the random access preamble if the transmit beam is switched. Specifically, when the terminal device determines to switch the random access preamble, the second random access preamble sent by the terminal device by using the second beam may be determined by the terminal device according to the preset condition.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, before the determining, by the terminal device, the second random access preamble according to the preset condition, the method further includes: the terminal device receiving the The second indication information that is sent by the network device, where the second indication information is used to indicate that the terminal device switches the first random access preamble when the first random access preamble fails to be sent.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, before the determining, by the terminal device, the second random access preamble according to the preset condition, the method further includes: determining, by the terminal device The second transmit beam has been transmitted through the first random access preamble.

In combination with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, The preset condition is: randomly selecting a random access preamble in a pre-configured random preamble subset.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the first random access preamble and the second random access preamble belong to the same random preamble subset.

Optionally, the first random access preamble and the second random access preamble may be located in the same or different random preamble subsets, and the random preamble subset may be configured for the network device in advance for the network device. Specifically, the network device may configure one or more random preamble subsets for the terminal device, and the random preamble subset may correspond to the transmit beam of the network device.

With the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the terminal device sends the second random access preamble to the network device by using the second sending beam, where the terminal device determines to send the When the first transmit power of the first random access preamble meets the power preset condition, the second random access preamble is sent to the network device by using the second transmit beam.

It should be understood that, when the terminal device sends the first random access preamble through the first transmit beam, the first transmit power may be used. When the first random access preamble transmission fails, the terminal device sends the random access preamble again, for example, through the second. When the transmit beam sends the second random access preamble, the second transmit power may be used, the second transmit power is greater than or equal to the first transmit power, and the second transmit power is less than or equal to the maximum transmit power.

It should be understood that the terminal device may determine whether to switch the transmit beam according to the transmit power, and may also determine whether to switch the random access preamble. For example, the power preset condition and the corresponding rule may be determined according to the transmit power, and the terminal device determines the corresponding rule according to whether the power preset condition is met when the random access preamble fails to be sent.

With reference to the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the power preset condition includes: the first transmit power is less than a preset maximum power, and/or the first transmit power is equal to The preset maximum power.

In combination with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the rule corresponding to the power preset condition may include whether to switch the transmit beam, or may include whether to switch the random access preamble, or The method includes determining whether to switch the transmit beam and whether to switch the random access preamble according to the beam correspondence of the terminal device.

For example, the power preset condition may be set to: the transmit power is equal to the maximum transmit power, and the corresponding rule may be set to: switch the transmit beam and the random access preamble. Specifically, the terminal device sends the first random access preamble through the first transmit beam, and uses the first transmit power. When the first random access preamble fails to transmit, if the first transmit power is equal to the maximum transmit power, the terminal device Indeed The second random access preamble is sent by the second transmit beam, and the second transmit beam is different from the first transmit beam, and the second random access preamble is the terminal device according to the corresponding rule. The preset conditions are determined.

For example, the power preset condition may be set to: the transmit power is equal to the maximum transmit power, and the corresponding rule may be set to: if the beam correspondence of the terminal device is not established, the transmit beam is switched. Specifically, the terminal device sends the first random access preamble through the first transmit beam, and uses the first transmit power. When the first random access preamble transmission fails, the terminal device determines that the first transmit power is equal to the maximum transmit power. The terminal device determines whether the terminal device is a correspondingly established terminal device, and if the correspondence is not established, the transmission beam and the random access preamble are switched, that is, the second random access preamble, the second transmit beam, and the first transmit beam are sent by using the second transmit beam. Differently, the second random access preamble is determined by the terminal device according to a preset condition.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the method further includes: the terminal device does not receive the random corresponding to the first random access preamble within a preset time When the access response RAR is determined, it is determined that the first random access preamble transmission fails.

In conjunction with the first aspect and the foregoing implementation manner, in another implementation manner of the first aspect, the correspondence of the beam of the terminal device does not hold.

In a second aspect, a terminal device is provided for performing the method of any of the above first aspect or any of the possible implementations of the first aspect. In particular, the terminal device comprises means for performing the method of any of the above-described first aspect or any of the possible implementations of the first aspect.

In a third aspect, a terminal device is provided, comprising: a storage unit for storing instructions for executing instructions stored in the memory, and a processor, and when the processor executes the instructions stored by the memory The execution causes the processor to perform the method of the first aspect or any possible implementation of the first aspect.

In a fourth aspect, a computer readable medium is provided for storing a computer program comprising instructions for performing the method of the first aspect or any of the possible implementations of the first aspect.

In a fifth aspect, a computer program product comprising instructions for operating when the computer is The computer program implements the method of transmitting a random access preamble in any of the possible implementations of the first aspect or the first aspect described above. Specifically, the computer program product can be run on the terminal device of the first aspect described above.

DRAWINGS

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

FIG. 2 is a schematic block diagram of a terminal device according to an embodiment of the present application.

FIG. 3 is another schematic block diagram of a terminal device according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as a Global System of Mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, and a wideband code. Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) System, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), or Worldwide Interoperability for Microwave Access (WiMAX) communication system.

In the embodiment of the present application, the terminal device may include, but is not limited to, a mobile station (MS), a mobile terminal, a mobile phone, a UE, a handset, and a portable device. , a vehicle, etc., the terminal device can communicate with one or more core networks via a Radio Access Network (RAN), for example, the terminal device can be a mobile phone (or "cellular" phone) The computer with wireless communication function, etc., the terminal device can also be a mobile device that is portable, pocket-sized, handheld, built-in or on-board.

The network device involved in the embodiment of the present application is a device deployed in a radio access network to provide a wireless communication function for a terminal device. The network device may be a base station, and the base station may include various forms of macro base stations, micro base stations, relay stations, access points, and the like. In systems with different radio access technologies, the names of devices with base station functionality may vary. For example in In an LTE network, an Evolved NodeB (eNB or eNodeB) is called a Node B or the like in a 3rd Generation (3G) network.

FIG. 1 shows a schematic flowchart of a method 100 of transmitting a random access preamble, which may be performed by a terminal device, according to an embodiment of the present application. As shown in FIG. 1, the method 100 includes:

S110. The terminal device sends a first random access preamble to the network device by using the first sending beam.

S120. If the terminal device determines that the first random access preamble transmission fails, the terminal device sends a second random access preamble, the first transmit beam, and the second send to the network device by using a second transmit beam. The beams are different.

In the embodiment of the present application, the terminal device sends a random access preamble, that is, a preamble in the PRACH, to the network device, and after the network device successfully receives, returns the RAR to the terminal device. If the terminal device does not receive a valid RAR in the corresponding time window, for example, the RAR is not received, or the identifiers in the received RAR do not match, the terminal device may resend the random access preamble to the network device. And the number of times the terminal device sends the preamble is incremented once. When the number of times the terminal device transmits the preamble reaches the maximum number of transmissions and the corresponding valid RAR is not received, the upper layer is notified.

In this embodiment, the terminal device may include multiple transmit beams. For example, the multiple transmit beams may include a first transmit beam and a second transmit beam. When the first random access preamble fails to be sent by the first transmit beam, the terminal device may switch the transmit beam, for example, from the first transmit beam to the second transmit beam, and then send the second random access by using the second transmit beam. The preamble, wherein the first random access preamble and the second random access preamble may be the same random access preamble, or may be different random access preambles.

It should be understood that, in the embodiment of the present application, the terminal device sends a random access preamble to the network device, for example, sends a first random access preamble to the network device by using the first sending beam, and after the network device successfully receives, returns the RAR to the terminal device. If the terminal device does not receive a valid RAR within a preset time, for example, within a corresponding time window, for example, the terminal device sends the first random access preamble without receiving the RAR, or the received RAR. The identifiers do not match, that is, the received RAR is not the RAR corresponding to the first random access preamble, and the terminal device can determine the randomness of the transmission. The access preamble failed to be sent.

It should be understood that, in the case that the first random access preamble transmission fails, the terminal device may determine to switch or not to switch the transmission beam to retransmit the random access preamble. Specifically, the terminal device may determine whether to switch the transmit beam, or may receive the indication information sent by the network device, and determine whether to switch the transmit beam according to the indication information. For example, the terminal device may receive the third indication information sent by the network device, and determine, according to the third indication information, whether to switch the transmit beam.

Specifically, if the first random access preamble transmission sent by the first transmission beam fails, the terminal device may determine that the transmission beam is not switched, for example, the terminal device determines that the transmission beam is not to be switched; or the terminal device receives the network device to send. The third indication information indicates that the terminal device does not switch the transmission beam; or the third indication information indicates that the terminal device determines whether to switch by itself, and the terminal device determines to not switch the transmission beam. After the terminal device determines that the transmit beam is not to be switched, the second random access preamble is still sent by using the first transmit beam, where the second random access preamble may be determined by the terminal device according to the preset condition.

Optionally, the terminal device may also determine to switch the transmit beam if the first random access preamble transmission sent by the first transmit beam fails, for example, the terminal device determines the handover transmit beam by itself; or the terminal device receives the network device to send. The third indication information indicates that the terminal device switches the transmission beam; or the third indication information indicates that the terminal device determines whether to switch, and the terminal device determines to switch the transmission beam. The terminal device determines to switch the transmit beam, and the terminal device may send the second random access preamble to the network device by using the second transmit beam, where the first transmit beam and the second transmit beam are different.

In addition, the terminal device may also determine whether to switch the random access preamble if the transmit beam is switched. Specifically, the terminal device may determine whether to switch the random access preamble, or may receive the indication information sent by the network device, and determine whether to switch the random access preamble according to the indication information. For example, the terminal device may receive the first indication information sent by the network device, and determine, according to the first indication information, that the random access preamble is not switched. For example, the terminal device may receive the second indication information sent by the network device, and determine, according to the second indication information, the handover random access preamble. For example, the terminal device may further receive the fourth indication information sent by the network device, and according to the fourth indication information, the terminal device determines whether to switch the random access preamble.

Specifically, the terminal device may determine whether to switch the random access preamble, for example, when the terminal device determines that the first random access preamble transmission sent by the first transmit beam fails, the terminal device determines that the transmit beam needs to be switched, that is, uses the first Two transmit beams, the terminal device can determine the second Whether the transmit beam has sent the first random access preamble.

When the terminal device has sent the first random access preamble through the second transmit beam, the terminal device determines to switch the first random access preamble, that is, sends the second random access preamble through the second transmit beam, and the second The random access preamble is determined by the terminal device according to a preset condition.

When the terminal device does not send the first random access preamble through the second transmit beam, the terminal device may choose not to switch the random access preamble, and continue to use the first random access preamble, that is, send the second through the second transmit beam. The second random access preamble is the first random access preamble; or the terminal device may also choose to switch the random access preamble, and the second random access preamble is determined by the terminal device according to the preset condition. of.

Optionally, the terminal device may also receive the indication information sent by the network device, for example, the terminal device receives the first indication information sent by the network device, where the first indication information indicates that the terminal device does not switch the random access preamble, and the terminal device determines When the first random access preamble transmission of the first transmission beam fails, the first random access preamble can be directly used according to the first indication information, that is, the second random access preamble is the same as the first random access preamble.

For example, the terminal device receives the second indication information that is sent by the network device, where the second indication information indicates that the terminal device switches the random access preamble, and the terminal device determines that the first random access preamble transmission sent by the first transmit beam fails. According to the second indication information, the terminal device sends the second random access preamble through the second beam, and the second random access preamble is determined by the terminal device according to the preset condition.

For example, the terminal device receives the fourth indication information sent by the network device, where the fourth indication information indicates that the terminal device determines whether to switch the random access preamble, and the terminal device determines to send the first random access preamble sent by the first sending beam. Upon failure, according to the fourth indication information, it is determined by itself whether to switch the random access preamble.

It should be understood that the terminal device determines the second random access preamble according to the preset condition, and the preset condition may include the terminal device randomly selecting one random access preamble as the second random access preamble in the pre-configured random preamble subset.

Optionally, the first random access preamble and the second random access preamble may be located in the same or different random preamble subsets, and the random preamble subset may be configured for the network device in advance for the network device. Specifically, the network device may configure one or more random preamble subsets for the terminal device, and the random preamble subset may correspond to the transmit beam of the network device. After the terminal device determines the optimal DL Tx Beam, the random preamble subset corresponding to the DL Tx Beam can be determined, and the first random The access preamble and the second random access preamble may be randomly selected in the random preamble subset, that is, the first random access preamble and the second random access preamble may be located in the same random preamble subset, but the embodiment of the present application is Not limited to this.

In the embodiment of the present application, in a case that the first random access preamble transmission sent by the first sending beam fails, the terminal device may receive the third indication information sent by the network device, where the third indication is used. If the information indicates that the terminal device does not switch the transmit beam, the terminal device sends the second random access preamble through the first transmit beam if the first random access preamble transmission sent by the first transmit beam fails. The access preamble is determined by the terminal device according to a preset condition.

It should be understood that the terminal device in the embodiment of the present application may include multiple beams, and the correspondence of the beams of the terminal device may or may not be established, and the terminal device may determine whether to switch the transmit beam according to the beam correspondence.

For example, when the beam correspondence of the terminal device is established, the uplink transmission beam of the terminal device corresponds to the downlink reception beam, and when the terminal device sends the first random access preamble through the first transmission beam, the first transmission beam may be the terminal device. According to the best DL Tx Beam, and when the first random access preamble transmission of the terminal device fails, the transmission beam can be selected not to be switched, and the second random access preamble is still transmitted through the first transmission beam.

For example, when the beam correspondence of the terminal device is not established, the uplink transmission beam of the terminal device does not correspond to the downlink reception beam, and the terminal device may select to switch the transmission beam when the first random access preamble fails to be sent by using the first transmission beam. The second transmit beam transmits a second random access preamble.

In the embodiment of the present application, when the terminal device sends a random access preamble to the network device by using the transmit beam, the transmit power is increased every time until the maximum transmit power is reached. For example, when the terminal device sends the first random access preamble through the first transmit beam, the first transmit power may be used. When the first random access preamble transmission fails, the terminal device sends the random access preamble again, for example, through the second sending. When the second random access preamble is sent by the beam, the second transmit power may be used, the second transmit power is greater than or equal to the first transmit power, and the second transmit power is less than or equal to the maximum transmit power.

It should be understood that the terminal device may determine whether to switch the transmit beam according to the transmit power, and may also determine whether to switch the random access preamble. For example, the power preset condition and the corresponding rule may be determined according to the transmit power, and the terminal device determines the corresponding rule according to whether the power preset condition is met when the random access preamble fails to be sent. For example, the power preset condition may be that the transmission power is less than the maximum transmission. The power is transmitted, or is equal to the maximum transmit power; the rule may include whether to switch the transmit beam, or may include whether to switch the random access preamble, and may further include determining whether to switch the transmit beam and whether to switch the random access according to the beam correspondence of the terminal device. The preamble, but the embodiment of the present application is not limited thereto.

For example, the power preset condition may be set to: the transmit power is equal to the maximum transmit power, and the corresponding rule may be set to: switch the transmit beam and the random access preamble. Specifically, the terminal device sends the first random access preamble through the first transmit beam, and uses the first transmit power. When the first random access preamble fails to be sent, the terminal device determines whether the first transmit power meets the power preset condition. That is, whether the first transmission power is equal to the maximum transmission power. If not, the terminal device may determine whether to switch the transmission beam and the random access preamble, or determine by other means; if equal, the terminal device determines to execute the corresponding rule. Transmitting the transmit beam and the random access preamble, that is, sending the second random access preamble through the second transmit beam, the second transmit beam is different from the first transmit beam, and the second random access preamble is determined by the terminal device according to the preset condition. .

For example, the power preset condition may be set to: the transmit power is equal to the maximum transmit power, and the corresponding rule may be set to: if the beam correspondence of the terminal device is not established, the transmit beam is switched. Specifically, the terminal device sends the first random access preamble through the first transmit beam, and uses the first transmit power. When the first random access preamble fails to be sent, the terminal device determines whether the first transmit power meets the power preset condition. That is, whether the first transmission power is equal to the maximum transmission power. If not, the terminal device may determine whether to switch the transmission beam and the random access preamble, or determine by other means; if equal, the terminal device determines to execute the corresponding rule. The terminal device determines whether it is a terminal device whose correspondence is established. If the correspondence is established, it is still possible to determine whether to switch the transmit beam and the random access preamble, or determine by other means; if the correspondence is not established, switch the transmit beam and the random connection. The second random access preamble is sent by the second transmit beam, and the second transmit beam is different from the first transmit beam, and the second random access preamble is determined by the terminal device according to the preset condition.

It should be understood that the terminal device may formulate different power preset conditions according to the transmission power, and corresponding rules, and is not limited to the above embodiments, and will not be enumerated one by one.

It should be understood that, in the various embodiments of the present application, the size of the sequence numbers of the foregoing processes does not mean the order of execution sequence, and the order of execution of each process should be determined by its function and internal logic, and should not be applied to the embodiment of the present application. The implementation process constitutes any limitation.

A method for transmitting a random access preamble according to an embodiment of the present application is described in detail above with reference to FIG. 1 . A terminal device that transmits a random access preamble according to an embodiment of the present application will be described below with reference to FIG. 2 to FIG. 3 .

As shown in FIG. 2, the terminal device 200 according to the embodiment of the present application includes:

The sending unit 210 is configured to send, by using the first sending beam, a first random access preamble to the network device;

The sending unit 210 is further configured to: when the terminal device determines that the first random access preamble transmission fails, the terminal device sends a second random access preamble to the network device by using the second sending beam, the first sending The beam is different from the second transmit beam.

Therefore, in the case that the first random access preamble fails to be transmitted through the first transmit beam, the terminal device of the embodiment of the present application may switch the transmit beam to retransmit the random access preamble, that is, adopt a second different from the first transmit beam. The transmit beam is transmitted again, thereby reducing the probability of collision of the random access preamble, thereby reducing the transmission delay.

Optionally, the first random access preamble is the same as the second random access preamble.

Optionally, the terminal device further includes: a receiving unit 220, configured to receive the first indication information sent by the network device, before the sending unit 210 sends the second random access preamble to the network device by using the second sending beam, The first indication information is used to indicate that the terminal device does not switch the first random access preamble when the first random access preamble transmission fails.

Optionally, the terminal device further includes: a determining unit 230, configured to: before the terminal device sends the second random access preamble to the network device by using the second transmit beam, determining that the second transmit beam is not sent by the first Random access preamble.

Optionally, the determining unit 230 is further configured to: before the sending unit 210 sends the second random access preamble to the network device by using the second sending beam, the terminal device determines the second random access preamble according to the preset condition. .

Optionally, the receiving unit is further configured to: before the determining unit 230 determines the second random access preamble according to the preset condition, receive second indication information that is sent by the network device, where the second indication information is used to indicate the The terminal device switches the first random access preamble when the first random access preamble transmission fails.

Optionally, the determining unit 230 is specifically configured to: before determining the second random access preamble according to the preset condition, determining that the second transmit beam has sent the first random access preamble.

Optionally, the preset condition is: randomly selecting a random access preamble in the pre-configured random preamble subset.

Optionally, the first random access preamble and the second random access preamble belong to the same random preamble subset.

Optionally, the sending unit 210 is specifically configured to: when the first transmit power when the first random access preamble is sent meets a power preset condition, send the second to the network device by using the second transmit beam Random access preamble.

Optionally, the power preset condition includes: the first transmit power is less than a preset maximum power, and/or the first transmit power is equal to the preset maximum power.

Optionally, the determining unit 230 is further configured to: when the random access response RAR corresponding to the first random access preamble is not received, determine that the first random access preamble transmission fails.

Optionally, the correspondence of the beams of the terminal device does not hold.

Optionally, the receiving unit 220 is further configured to: before the sending unit 210 sends the second random access preamble to the network device by using the second sending beam, receive the third indication information sent by the network device, where the third indication is received. The information is used to indicate that the terminal device switches the first transmit beam when the first random access preamble transmission fails.

It should be understood that the terminal device 200 according to the embodiment of the present application may correspond to the method 100 in the embodiment of the present application, and the foregoing and other operations and/or functions of the respective units in the terminal device 200 are respectively implemented in FIG. The corresponding process of the terminal device in the method is not described here for brevity.

FIG. 3 shows a schematic block diagram of a network device 300 according to an embodiment of the present application. As shown in FIG. 3, the network device 300 includes a processor 310 and a transceiver 320. The processor 310 is connected to the transceiver 320. The network device 300 also includes a memory 330 that is coupled to the processor 310. Wherein, the processor 310, the memory 330 and the transceiver 320 are connected internally. The access paths communicate with one another to communicate control and/or data signals. The memory 330 can be used to store instructions for executing instructions stored by the memory 330 to control the transceiver 320 to transmit information or signals. The transceiver 320 The method is: sending, by using a first transmit beam, a first random access preamble to a network device; and when the terminal device determines that the first random access preamble transmission fails, the terminal device sends the second random transmit beam to the network device a second random access preamble, the first transmit beam being different from the second transmit beam.

Optionally, the transceiver 320 is configured to: before sending the second random access preamble to the network device by using the second transmit beam, receive the first indication information sent by the network device, where the first indication information is used to indicate the The terminal device does not switch the first random access preamble when the first random access preamble transmission fails.

Optionally, the processor 310 is configured to: before the terminal device sends the second random access preamble to the network device by using the second transmit beam, determining that the second transmit beam has not sent the first random access preamble.

Optionally, the processor 310 is configured to: before the transceiver 320 sends the second random access preamble to the network device by using the second transmit beam, the terminal device determines the second random access preamble according to the preset condition.

Optionally, the transceiver 320 is configured to: before the determining, by the processor 310, the second random access preamble according to the preset condition, receive the second indication information sent by the network device, where the second indication information is used to indicate the The terminal device switches the first random access preamble when the first random access preamble transmission fails.

Optionally, the processor 310 is configured to: before determining the second random access preamble according to the preset condition, determining that the second transmit beam has sent the first random access preamble.

Optionally, the transceiver 320 is configured to: when the first transmit power when the first random access preamble is sent meets a power preset condition, send the second random to the network device by using the second transmit beam Access the preamble.

Optionally, the processor 310 is configured to determine that the first random access preamble transmission fails when the random access response RAR corresponding to the first random access preamble is not received within a preset time.

Optionally, the transceiver 320 is configured to: before sending the second random access preamble to the network device by using the second transmit beam, receive third indication information sent by the network device, where the third indication information is used to indicate the The terminal device switches the first transmit beam when the first random access preamble transmission fails.

It should be understood that the terminal device 300 according to the embodiment of the present application may correspond to the terminal device 200 in the embodiment of the present application, and may correspond to the corresponding body in the method 100 according to the embodiment of the present application, and each of the terminal devices 300 The foregoing and other operations and/or functions of the unit are respectively implemented in order to implement the corresponding processes of the terminal devices in the respective methods in FIG. 1. For brevity, no further details are provided herein.

It should be noted that the above method embodiments of the present application may 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 foregoing method embodiment may be completed by an integrated logic circuit of hardware in a processor or an instruction in a form of software. The 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 the like. Programming logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. Software module can It is located in a random storage medium, such as a flash memory, a read only memory, a programmable read only memory or an electrically erasable programmable memory, a register, and the like. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method.

It is to be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (Erasable PROM, EPROM), or an electric Erase programmable read only memory (EEPROM) or flash memory. The volatile memory can be a Random Access Memory (RAM) that acts as an external cache. By way of example and 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 (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the term "and/or" herein is merely an association relationship describing an associated object, indicating that there may be three relationships, for example, A and/or B, which may indicate that A exists separately, and A and B exist simultaneously. There are three cases of B alone. In addition, the character "/" in this article generally indicates that the contextual object is an "or" relationship.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods to implement the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present application.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and The method can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

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

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present application, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including The instructions are used to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The foregoing is only a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present application. It should be covered by the scope of protection of this application. Therefore, the scope of protection of the present application should be determined by the scope of the claims.

Claims

A method for transmitting a random access preamble, comprising:

Transmitting, by the first sending beam, the first random access preamble to the network device by using the first sending beam;

When the terminal device determines that the first random access preamble transmission fails, the terminal device sends a second random access preamble to the network device by using a second transmit beam, where the first transmit beam and the The second transmit beam is different.
The method of claim 1, wherein the first random access preamble is the same as the second random access preamble.
The method according to claim 2, wherein before the sending, by the terminal device, the second random access preamble to the network device by using the second transmit beam, the method further includes:

The terminal device receives the first indication information that is sent by the network device, where the first indication information is used to indicate that the terminal device does not switch the first random connection when the first random access preamble transmission fails. Enter the lead.
The method according to claim 2, wherein before the sending, by the terminal device, the second random access preamble to the network device by using the second transmit beam, the method further includes:

The terminal device determines that the second transmit beam has not sent the first random access preamble.
The method according to claim 1, wherein before the sending, by the terminal device, the second random access preamble to the network device by using the second transmit beam, the method further includes:

The terminal device determines the second random access preamble according to a preset condition.
The method according to claim 5, wherein before the determining, by the terminal device, the second random access preamble according to a preset condition, the method further includes:

The terminal device receives the second indication information that is sent by the network device, where the second indication information is used to indicate that the terminal device switches the first random access when the first random access preamble fails to be sent. Leading.
The method according to claim 5, wherein before the determining, by the terminal device, the second random access preamble according to a preset condition, the method further includes:

The terminal device determines that the second transmit beam has been sent by the first random access preamble.
The method according to any one of claims 5 to 7, wherein the preset condition is: randomly selecting a random access preamble in a pre-configured random preamble subset.
The method of claim 8 wherein said first random access preamble And the second random access preamble belongs to the same random preamble subset.
The method according to any one of claims 1 to 9, wherein the terminal device sends a second random access preamble to the network device by using a second transmit beam, including:

When the terminal device determines that the first transmit power when the first random access preamble is sent to meet the power preset condition, the second random access preamble is sent to the network device by using the second transmit beam. .
The method according to claim 10, wherein the power preset condition comprises: the first transmit power is less than a preset maximum power, and/or the first transmit power is equal to the preset maximum power .
The method according to any one of claims 1 to 11, wherein the method further comprises:

When the terminal device does not receive the random access response (RAR) corresponding to the first random access preamble, the terminal device determines that the first random access preamble transmission fails.
The method according to any one of claims 1 to 12, characterized in that the correspondence of the beams of the terminal device is not established.
The method according to any one of claims 1 to 13, wherein before the terminal device sends the second random access preamble to the network device by using the second transmit beam, the method further includes:

The terminal device receives the third indication information that is sent by the network device, where the third indication information is used to indicate that the terminal device switches the first transmit beam when the first random access preamble fails to be sent.
A terminal device, comprising:

a sending unit, configured to send, by using the first sending beam, a first random access preamble to the network device;

The sending unit is further configured to: when the terminal device determines that the first random access preamble transmission fails, the terminal device sends a second random access preamble to the network device by using a second sending beam, The first transmit beam and the second transmit beam are different.
The terminal device according to claim 15, wherein the first random access preamble is the same as the second random access preamble.
The terminal device according to claim 16, wherein the terminal device further comprises:

a receiving unit, configured to send, by the sending unit, the second sending beam to the network device Before the second random access preamble, the first indication information that is sent by the network device is received, where the first indication information is used to indicate that the terminal device does not switch when the first random access preamble fails to be sent. The first random access preamble.
The terminal device according to claim 16, wherein the terminal device further comprises:

And a determining unit, configured to determine that the second transmit beam has not sent the first random access preamble before the terminal device sends the second random access preamble to the network device by using the second transmit beam.
The terminal device according to claim 15, wherein the terminal device further comprises:

And a determining unit, configured to determine, according to a preset condition, the second random access preamble, before the sending unit sends the second random access preamble to the network device by using the second sending beam.
The terminal device according to claim 19, wherein the terminal device further comprises:

a receiving unit, configured to receive, according to the preset condition, the second random access preamble, the second indication information that is sent by the network device, where the second indication information is used to indicate the terminal device And when the first random access preamble transmission fails, the first random access preamble is switched.
The terminal device according to claim 19, wherein the determining unit is specifically configured to:

Before determining the second random access preamble according to the preset condition, determining that the second transmit beam has sent the first random access preamble.
The terminal device according to any one of claims 19 to 21, wherein the preset condition is: randomly selecting a random access preamble in a pre-configured random preamble subset.
The terminal device according to claim 22, wherein the first random access preamble and the second random access preamble belong to the same random preamble subset.
The terminal device according to any one of claims 15 to 23, wherein the transmitting unit is specifically configured to:

And sending, before the second random access, to the network device by using the second transmit beam, when the first transmit power when the first random access preamble is sent meets a power preset condition guide.
The terminal device according to claim 24, wherein the power preset condition comprises: the first transmit power is less than a preset maximum power, and/or the first transmit power is equal to the preset maximum power.
The terminal device according to any one of claims 15 to 25, wherein the terminal device further comprises:

The determining unit is configured to determine that the first random access preamble transmission fails when the random access response RAR corresponding to the first random access preamble is not received within a preset time.
The terminal device according to any one of claims 15 to 26, characterized in that the correspondence of the beams of the terminal device is not established.
The terminal device according to any one of claims 15 to 27, wherein the terminal device further comprises:

a receiving unit, configured to receive third indication information that is sent by the network device, where the sending unit sends the second random access preamble to the network device by using the second sending beam, where the third indication information is used to indicate The terminal device switches the first transmit beam when the first random access preamble transmission fails.