Preamble repeated sending method, device, system and medium

Abstract

The embodiment of the invention provides a lead code repeated sending method, device and system and a medium, and relates to the technical field of communication. In the scheme of the application, a network device configures a PRACH resource used for repeated transmission for a terminal device, and the terminal device generates a preamble used for repeated transmission according to the configured PRACH resource, and determines an RO used for repeated transmission of the preamble. And then, the terminal equipment repeatedly transmits the PRACH on the same wave beam for multiple times, or repeatedly transmits the PRACH on different wave beams for multiple times. In the embodiment of the invention, whether the PRACH is repeatedly transmitted on the same beam for multiple times or on different beams for multiple times, each PRACH carries the same preamble, so that a plurality of PRACHs are combined to generate gain, the coverage enhancement of the PRACHs is realized, and the success rate of random access is further improved.

Description

Method, device, system and medium for repeated transmission of preamble code

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on September 26, 2022, with application number 202211173349.6 and application name “Preamble Code Repeated Transmission Method, Device, System and Medium”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a method, device, system and medium for repeatedly sending a preamble code. Background Art

[0003] Random access (RA) is a process in which a user equipment (UE) requests access from a network device, receives a response message from the network device, and is allocated an access channel.

[0004] As shown in Figure 1, in the new radio (NR) system of the fifth generation (5G) mobile communication, the random access process can include the following four steps: S1. The UE selects a physical random access channel (PRACH) resource based on the random access configuration information and downlink measurement results, and sends a random access preamble to the network device on the PRACH resource. S2. The network device returns a random access response message to the UE. S3. The UE sends a scheduled transmission request to the network device, such as a radio resource control (RRC) connection request message. S4. The network device returns a contention resolution message to the UE.

[0005] For the random access process, since the base station's transmit power is usually large, the probability of weak signal strength when transmitting downlink (DL) data is low. However, since the UE's transmit power is usually limited, weak signal strength is likely to occur when transmitting uplink (UL) data, especially when sending a preamble to a network device on a PRACH resource, resulting in random access failure.

[0006] Summary of the Invention

[0007] The present application provides a method, device, system and medium for repeatedly transmitting a preamble to solve the technical problem of random access failure due to weak signal strength when sending a preamble to a network device on a PRACH resource.

[0008] To achieve the above objectives, this application adopts the following technical solutions:

[0009] In a first aspect, an embodiment of the present application provides a method for repeatedly transmitting a preamble. The method may include:

[0010] The terminal device receives configuration information from the network device, which indicates PRACH resources for repeated transmission on the same beam or different beams. The PRACH resources include: a preamble for repeated transmission and a RO for repeated transmission of the preamble. Based on the configuration information, the terminal device repeatedly transmits the same preamble on multiple ROs in a beam or on the same ROs corresponding to multiple beams.

[0011] Through the above solution, when the network device is configured with PRACH resources for repeated transmission on the same beam, the terminal device can repeatedly transmit PRACH multiple times on the same beam; alternatively, when the network device is configured with PRACH resources for repeated transmission on different beams, the terminal device can repeatedly transmit PRACH multiple times on different beams. Whether repeatedly transmitting PRACH multiple times on the same beam or multiple times on different beams, each PRACH carries the same preamble, so that multiple PRACHs are combined to generate gain, achieving PRACH coverage enhancement and thereby improving the success rate of random access.

[0012] In some embodiments, the configuration information may include preamble configuration parameters. Accordingly, the method may further include: the terminal device generates a first resource pool according to the preamble configuration parameters. The first resource pool includes one or more preambles for repeated transmission. It can be understood that the preambles in the existing resource pool have not been used for repeated transmission. By generating a preamble resource pool specifically for repeated transmission, the terminal device can randomly select a preamble from it as the preamble to be repeatedly transmitted on multiple ROs of a beam or on the corresponding same ROs of multiple beams.

[0013] In some embodiments, the preamble configuration parameters may include: the number of preambles for repeated transmission, the number of bits of the root sequence of the preamble for repeated transmission each time, and the root index of the preamble for repeated transmission. Accordingly, the terminal device generates a first resource pool based on the preamble configuration parameters, including: the terminal device generates the first resource pool based on the number of preambles for repeated transmission, the number of bits of the root sequence of the preamble for repeated transmission each time, and the root index of the preamble for repeated transmission. It can be understood that the network device configures a new set of parameters for the terminal device so that the terminal device can generate a new resource pool based on the new set of parameters.

[0014] In some embodiments, the preamble configuration parameters may include: a starting index of a preamble for repeated transmission, and the number of preambles for repeated transmission. Accordingly, the terminal device generates a first resource pool according to the preamble configuration parameters, including: the terminal device divides the first resource pool from the second resource pool according to the starting index of the preamble for repeated transmission, and the number of preambles for repeated transmission. The second resource pool can be generated according to the following parameters: the number of preambles for non-repeated transmission, the number of bits of the root sequence of the preamble for non-repeated transmission each shift, and the root index of the preamble for non-repeated transmission. It can be understood that the network device configures the starting index of the preamble for repeated transmission and the number of preambles for repeated transmission for the terminal device, so that the code resource pool for repeated transmission can reuse the existing code resources, that is, a preamble resource pool specifically for repeated transmission is separately divided from the existing resource pool.

[0015] In some embodiments, the configuration information may further include: a first parameter and a second parameter, the first parameter is used to indicate the number of times N that the preamble is repeatedly sent on the same beam, and the second parameter is used to indicate the RO interval for repeatedly sending the preamble on the same beam, where N is an integer greater than or equal to 2. Accordingly, the terminal device repeatedly sends the same preamble on multiple ROs of a beam according to the configuration information, including: the terminal device determines N ROs in a beam according to the first parameter and the second parameter, and repeatedly sends the same preamble on the N ROs. It can be understood that the network device configures the first parameter and the second parameter for the terminal device so that the terminal device can calculate the group used to repeatedly send the same preamble on the same beam according to the first parameter and the second parameter.

[0016] In some embodiments, the N ROs belong to the same group, which is a group randomly selected by the terminal device from the groups included in a beam. Accordingly, before determining the N ROs in a beam, the method may further include: the terminal device determining a total number M of ROs included in the same beam within a preset time; and the terminal device determining the groups in the same beam for repeatedly transmitting the preamble using the following formula:

[0017] {(s+nk)modM};

[0018] Wherein, s represents the first RO mapped in each group of the same beam, n = (0, 1, ..., N-1), k represents the RO interval for repeatedly sending the preamble on the same beam, mod is the modulo operator, s ≤ M.

[0019] In some embodiments, the preset time may be a mapping period or a mapping pattern period.

[0020] In some embodiments, within a preset time period, ROs within the same beam can be sorted by frequency domain first and time domain second, or by time domain first and frequency domain second. The frequency domain first and time domain second rule is specified by the protocol, while the time domain first and frequency domain second rule is configured by the network device.

[0021] In some embodiments, when the configuration information further includes a preset rule, the ROs included in the same beam within the preset time period are sorted according to the rule of first sorting the time domain and then the frequency domain; or, when the configuration information does not include a preset rule, the ROs included in the same beam within the preset time period are sorted according to the rule of first sorting the frequency domain and then the time domain. The preset rule is that the ROs within the same beam within the preset time period are sorted according to the rule of first sorting the time domain and then the frequency domain.

[0022] In some embodiments, the time domain resources of each RO in a group are the same but the frequency domain resources are different; or, the time domain resources of each RO in a group are different but the frequency domain resources are the same; or, there are ROs in a group with different time domain resources and different frequency domain resources.

[0023] In some embodiments, the beam used to repeatedly transmit the same preamble is the strongest beam. This strongest beam is the beam with the strongest signal strength received by the terminal device among all beams transmitted by the network device. It is understood that by selecting to repeatedly transmit the same preamble on multiple ROs of the strongest beam, the terminal device implicitly informs the network device of the initial downlink beam.

[0024] In some embodiments, the configuration information may further include a third parameter indicating whether to enable repeated transmission of the same preamble on the same beam. It is understood that the third parameter is equivalent to an enable switch, and setting this parameter triggers the terminal device to perform multiple PRACH retransmissions on the same beam.

[0025] In some embodiments, the configuration information may further include: a fourth parameter, the fourth parameter is used to indicate the number K of beams on which the multi-beam preamble is repeatedly transmitted, where K is an integer greater than or equal to 2. The preamble configuration parameter includes: the number of preambles for repeated transmission. Accordingly, the terminal device repeatedly transmits the same preamble on the corresponding same ROs of multiple beams according to the configuration information, including: the terminal device determines the preamble corresponding to each beam in the K beams according to the fourth parameter, the first resource pool, and the number of preambles for repeated transmission; the terminal device repeatedly transmits the same preamble on the corresponding same ROs of the K beams. The K beams include the strongest beam, which is the beam with the strongest signal strength received by the terminal device among all beams transmitted by the network device, and the same preamble is a preamble randomly selected by the terminal device from the preamble corresponding to the strongest beam. It can be understood that the network device configures the fourth parameter for the terminal device so that the terminal device can calculate the corresponding same RO for repeatedly transmitting the same preamble on different beams according to the fourth parameter.

[0026] In some embodiments, the number of preambles corresponding to each of the K beams is equal to: the number of preambles for repeated transmission divided by the number K. It can be understood that by determining the preamble corresponding to each beam, the preamble corresponding to the strongest beam can be sent on the same RO corresponding to the K beams, implicitly notifying the network device of the beam information where the terminal device is located.

[0027] In some embodiments, the fourth parameter may also be used to indicate that the same preamble is reused every K beams. It is understood that the preamble used for repeated transmission may be reused every K beams.

[0028] In some embodiments, the signal strength of the K beams is greater than the signal strength of other beams transmitted by the network device. It can be understood that by selecting the K beams with the strongest signal strength, a stronger gain can be generated, thereby improving the success rate of random access.

[0029] In some embodiments, the K beams include: the strongest beam, beams broadcast before the strongest beam, and beams broadcast after the strongest beam. Alternatively, the K beams include: the strongest beam, and beams broadcast before the strongest beam. Alternatively, the K beams include: the strongest beam, and beams broadcast after the strongest beam.

[0030] In some embodiments, the configuration information may further include a fifth parameter, which is used to indicate whether to enable repeated transmission of the same preamble on different beams. It is understood that the fifth parameter is equivalent to an enable switch, and by setting this parameter, the terminal device can be triggered to perform multiple PRACH retransmissions on different beams.

[0031] In some embodiments, the corresponding identical ROs of the K beams are: identically numbered ROs in each beam of the plurality of beams.

[0032] In a second aspect, an embodiment of the present application provides a method for repeatedly transmitting a preamble. The method may include:

[0033] The network device sends configuration information to the terminal device, indicating PRACH resources for repeated transmission on the same beam or different beams. The PRACH resources include: a preamble for repeated transmission and an RO for repeated transmission of the preamble. The network device receives multiple PRACHs from multiple ROs in a beam, or multiple PRACHs from ROs in multiple beams, from the terminal device. Each of the multiple PRACHs carries the same preamble.

[0034] Through the above solution, the network device configures PRACH resources for the UE to be repeatedly transmitted on the same beam or different beams, so that the UE can repeatedly transmit PRACH multiple times on the same beam or different beams. Since each PRACH carries the same preamble, the network device generates gain by combining multiple PRACHs, thereby achieving PRACH coverage enhancement and improving the success rate of random access.

[0035] In some embodiments, the configuration information may include preamble configuration parameters, which are used to generate a preamble resource pool for repeated transmission, namely, a first resource pool. The first resource pool includes one or more preambles for repeated transmission. It is understood that the preambles in the existing resource pool have not yet been used for repeated transmission. By generating a preamble resource pool specifically for repeated transmission, a terminal device can randomly select a preamble from the preamble as the same preamble to be repeatedly transmitted on multiple ROs of a beam or on the same ROs corresponding to multiple beams.

[0036] In some embodiments, the preamble configuration parameters may include: the number of preambles for repeated transmission, the number of bits of each shift of the root sequence of the repeatedly transmitted preamble, and the root index of the repeatedly transmitted preamble. It is understood that by configuring a new set of parameters for the terminal device, the network device enables the terminal device to generate a new resource pool based on the new set of parameters.

[0037] In some embodiments, the preamble configuration parameters may include: a starting index of a preamble for repeated transmission, and the number of preambles for repeated transmission. It is understood that by configuring the starting index of the preamble for repeated transmission and the number of preambles for repeated transmission for the terminal device, the network device enables the code resource pool for repeated transmission to reuse existing code resources, that is, to separately divide a preamble resource pool specifically for repeated transmission from the existing resource pool.

[0038] In some embodiments, the configuration information may include: a first parameter and a second parameter, where the first parameter is used to indicate the number of times N that a preamble is repeatedly transmitted on the same beam, and the second parameter is used to indicate an RO interval for repeatedly transmitting the preamble on the same beam. It will be understood that by configuring the first and second parameters for the terminal device, the network device can calculate, based on the first and second parameters, a group for repeatedly transmitting the same preamble on the same beam.

[0039] In some embodiments, the configuration information may further include a preset rule, where the preset rule is that the ROs included in the same beam within a preset time are sorted according to the rule of firstly in the time domain and then in the frequency domain.

[0040] In some embodiments, the preset time may be a mapping period or a mapping pattern period.

[0041] In some embodiments, the configuration information may further include a third parameter indicating whether to enable repeated transmission of the same preamble on the same beam. It is understood that the third parameter is equivalent to an enable switch. By setting this parameter, the network device can trigger the terminal device to perform multiple PRACH retransmissions on the same beam.

[0042] In some embodiments, the configuration information may further include: a fourth parameter, which is used to indicate the number K of beams in which the multi-beam system repeatedly transmits the preamble. It is understood that by configuring the fourth parameter for the terminal device, the network device enables the terminal device to calculate, based on the fourth parameter, the corresponding identical RO for repeatedly transmitting the same preamble on different beams.

[0043] In some embodiments, the fourth parameter may also be used to indicate that the same preamble is reused every K beams. It is understood that the preamble used for repeated transmission may be reused every K beams.

[0044] In some embodiments, the configuration information may further include a fifth parameter, which is used to indicate whether to enable repeated transmission of the same preamble on different beams. It is understood that the fifth parameter is equivalent to an enable switch, and by setting this parameter, the terminal device is triggered to perform multiple PRACH retransmissions on different beams.

[0045] In some embodiments, one beam is the strongest beam, or multiple beams include the strongest beam. The strongest beam is the beam with the strongest signal strength received by the terminal device among all beams sent by the network device. Accordingly, the method may also include: the network device sends downlink data to the terminal device on the strongest beam. It is understood that when the network device receives a PRACH signal from the strongest beam, or from multiple beams including the strongest beam, it can determine the strongest beam of the terminal device based on the mapping relationship between the PRACH and the beam, and send downlink data to the terminal device on the strongest beam.

[0046] In a third aspect, embodiments of the present application provide a communication device, which may include a processor, a communication interface, and a memory coupled to the processor and the communication interface. The memory stores instructions that, when executed by the processor, cause the communication device to perform the preamble retransmission method described in any one of the first aspects, or the preamble retransmission method described in any one of the second aspects.

[0047] In a fourth aspect, an embodiment of the present application provides a communication system, which may include a terminal device and a network device. The terminal device is configured to execute the preamble retransmission method described in any one of the first aspects, and the network device is configured to execute the preamble retransmission method described in any one of the second aspects.

[0048] In a fifth aspect, embodiments of the present application provide a computer-readable storage medium storing a computer program. When the computer program is executed on a terminal device, the terminal device executes the preamble retransmission method described in any one of the first aspects; or, when the computer program is executed on a network device, the network device executes the preamble retransmission method described in any one of the second aspects.

[0049] In a sixth aspect, an embodiment of the present application provides a chip, which is coupled to a memory and is used to read and execute a computer program stored in the memory to implement a method for repeatedly sending a preamble code as described in any one of the first aspect or the second aspect.

[0050] In a seventh aspect, a computer program product is provided. When the computer program product is run on a computer, the computer is caused to execute the method for repeatedly sending a preamble code as described in any one of the first aspect or the second aspect.

[0051] It can be understood that the beneficial effects of the third to seventh aspects mentioned above can be found in the relevant descriptions of the first and second aspects mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG1 is a schematic diagram of a four-step random access process according to an embodiment of the present application;

[0053] FIG2 is a mapping diagram of RO and SSB provided in an embodiment of the present application;

[0054] FIG3 is another RO and SSB mapping diagram provided in an embodiment of the present application;

[0055] FIG4 is a schematic diagram of a scenario in which a UE selects an SSB according to an embodiment of the present application;

[0056] FIG5 is a schematic diagram of a communication system provided in an embodiment of the present application;

[0057] FIG6 is a schematic diagram of the hardware structure of a communication device provided in an embodiment of the present application;

[0058] FIG7 is a schematic diagram of a flow chart of a method for repeatedly transmitting a preamble provided in an embodiment of the present application;

[0059] FIG8 is a schematic diagram of an existing preamble resource pool and a new preamble resource pool provided in an embodiment of the present application;

[0060] FIG9 is a schematic diagram of a multiplexed resource pool provided in an embodiment of the present application;

[0061] FIG10 is a schematic diagram of repeatedly sending a preamble on multiple ROs of the same SSB according to an embodiment of the present application;

[0062] FIG11 is a schematic diagram of repeatedly sending a preamble on multiple ROs of different SSBs according to an embodiment of the present application;

[0063] FIG12 is a schematic diagram of a method for repeatedly transmitting PRACH on the same beam multiple times according to an embodiment of the present application;

[0064] FIG13 is a schematic diagram of RO grouping in the same SSB provided by an embodiment of the present application;

[0065] FIG14 is a schematic diagram of another RO grouping in the same SSB provided by an embodiment of the present application;

[0066] FIG15 is a schematic diagram of another RO grouping in the same SSB provided by an embodiment of the present application;

[0067] FIG16 is a schematic diagram of another RO grouping in the same SSB provided by an embodiment of the present application;

[0068] FIG17 is a schematic diagram of sending a preamble on a group of ROs on the same SSB according to an embodiment of the present application;

[0069] FIG18 is a schematic diagram of a scenario in which the strongest beam changes due to UE movement according to an embodiment of the present application;

[0070] FIG19 is a schematic diagram of a method for repeatedly transmitting PRACH on different beams according to an embodiment of the present application;

[0071] FIG20 is a schematic diagram of a preamble resource pool for multi-beam repeated transmission provided in an embodiment of the present application;

[0072] FIG21 is a schematic diagram of a scenario in which the same preamble is repeatedly transmitted on N beams according to an embodiment of the present application;

[0073] FIG22 is a schematic diagram of a scenario in which two UEs respectively repeatedly send preambles on multiple SSBs according to an embodiment of the present application;

[0074] FIG23 is a schematic diagram of a scenario in which a preamble is repeatedly transmitted on multiple ROs of multiple beams according to an embodiment of the present application;

[0075] FIG24 is a schematic diagram showing that ROs of all SSBs are arranged in ascending order within a preset time period according to an embodiment of the present application;

[0076] FIG25 is a schematic structural diagram of a device provided in an embodiment of the present application;

[0077] FIG26 is a schematic structural diagram of another device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0078] In order to facilitate understanding of the method provided in the embodiments of the present application, the technical terms involved in the embodiments of the present application are described.

[0079] 1. PRACH

[0080] The PRACH is the access channel used by a UE to initiate a call. After receiving a random access response message from a network device, the UE sends an RRC connection request message on the PRACH, based on the network device's instructions, to establish an RRC connection. Typically, a PRACH contains a preamble.

[0081] 2. Random access preamble

[0082] The preamble is a string of length L. RA Zadd Off Chu (ZC) sequence: {x(0), x(1), ..., x(L RA -1)}. Preambles can be divided into two categories: long preambles and short preambles. Long preambles have four formats: format0, format1, format2, and format3; short preambles have nine formats: A1, A2, A3, B1, B2, B3, B4, C0, and C2. In the time domain, a preamble consists of a cyclic prefix (CP), a preamble sequence, and a guard period.

[0083] Currently, there are two methods for generating ZC sequences: one is to generate them based on different root sequence numbers, that is, using the following formula 1; the other is to generate them based on the same root sequence number by performing cyclic shift, that is, using the following formula 2. x u，v (n) = x u ((n+c v )modL RA ) (Formula 2)

[0084] Among them, L RA is the length of the root sequence, u is the root sequence number, and v is the number of cyclic shifts using a root sequence number.

[0085] Usually, the total number of preambles to be generated and the number of bits N of each shift of the root sequence are configured by the network device. csThe UE generates a preamble based on the preamble parameters and the root index value. Furthermore, the network device configures the time-frequency domain resources used to send the preamble, such as the random access signal occasion (RACH occasion, RO). RO is also called a transmission opportunity. The UE can find the RO corresponding to each synchronization signal block (SSB) based on the network configuration. Furthermore, the network device configures the mapping between the preamble, RO, and SSB.

[0086] The following three parts introduce how to configure preamble on network devices.

[0087] Part 1: Generation of preamble

[0088] Network devices can use the parameter msgA-TotalNumberofRA-Preambles-r16 to configure the total number of preambles for the UE. The default number of preambles is 64. The 3GPP protocol specifies that a cyclic shift is performed on a root sequence. If insufficient preambles are generated, the next root sequence is used until all 64 preambles are generated.

[0089] The network device can use the parameter zeroCorrelationZoneConfig to configure the number of bits N of each shift of the root sequence for the UE. cs , that is, the network device sends a parameter zeroCorrelationZoneConfig to the UE, and the UE uses a table lookup to determine the N corresponding to this parameter cs .

[0090] The network device can use the parameter msgA-PRACH-RootSequenceIndex-r16 to configure the length of the root sequence L for the UE. RA And root index. Usually, the parameter msgA-PRACH-RootSequenceIndex-r16 contains two parameters: length L RA and a numerical value i. L RA =839 or L RA = 139. The value i corresponds to the root sequence number u (i.e., the root index), that is, the network device indicates a value i to the UE, and the UE can determine the root sequence number u corresponding to the value i by looking up the table, where i = 0, 1, ..., 15.

[0091] Assume zeroCorrelationZoneConfig = 6, LRA =839, i=20, then the preamble is generated as follows:

[0092] For example, Table 1 shows the N values ​​of the unrestricted set, restricted set type A, and restricted set type B corresponding to each value when zeroCorrelationZoneConfig takes different values. cs value.

[0093] Table 1

[0094] The UE can obtain the following by referring to Table 1: When zeroCorrelationZoneConfig=6, the non-restricted set N cs =32.

[0095] UE can Round down to get v = 0, 1, ..., 25, Cv = V·N cs =0,32,64,……,832.

[0096] Exemplarily, Table 2 shows a partial correspondence between the root sequence number u and the value i.

[0097] Table 2

[0098] The UE can obtain by referring to Table 2 that: when i=20, u=2.

[0099] Then, the UE can use the above formula 2 to cyclically shift the root sequence, shifting the root sequence by 32 each time, and finally generate 64 preamble sequences. The specific method is as follows:

[0100] When u=2,v=0,x 20 (n) = x2(n);

[0101] When u=2,v=1,

[0102] …

[0103] When u = 2, v = 25, ...

[0104] So far, the UE has generated 26 preamble sequences using the root sequence u=2.

[0105] The UE continues to refer to Table 2 and obtains that when i=21, u=837. Referring to the above method, the UE generates 26 preamble sequences using the root sequence of u=837.

[0106] The UE continues to consult Table 2 and finds that when i = 22, u = 1. Referring to the above method, the UE generates 12 preamble sequences using the root sequence with u = 1. Ultimately, a total of 64 preamble sequences are generated.

[0107] The second part: Determine RO

[0108] The RO of an SSB includes the time domain resources of the transmission opportunity (time domain RO) and the frequency domain resources of the transmission opportunity (frequency domain RO).

[0109] When the network device configures the time domain RO of the PRACH, the network device may configure the parameter prach-ConfigurationIndex. The UE may determine the time domain transmission timing of the PRACH by looking up the table based on the parameter prach-ConfigurationIndex.

[0110] For example, as shown in Table 3, when prach-ConfigurationIndex=103, PRACH time domain RO is in all frames with frame number n f In subframe #2 (subframe numbered 2) and subframe #7 (subframe numbered 7) of the radio frame with modx=y, starting from symbol 0, there are 2 PRACH time slots in one subframe, each PRACH time slot has 6 consecutive time domain ROs, and each time domain RO occupies 2 symbols.

[0111] Wherein, x represents the PRACH time domain resource configuration period, y represents the radio frame in which the PRACH time domain resource is configured in the PRACH time domain resource configuration period, is the number of continuous ROs in the time domain in a PRACH time slot, It should be noted that Table 1, Table 2 and Table 3 are all specified by the 3GPP protocol. In addition, Table 2 and Table 3 only show part of the information specified by the 3GPP protocol.

[0112] Table 3

[0113] When the network device configures the frequency domain RO of PRACH, the network device can configure the parameters msg-FrequencyStart and msg-FDM. The UE can determine the starting position of the PRACH frequency domain resource according to the parameter msg-FrequencyStart. In addition, the UE can determine the number of resource blocks (RBs) occupied in the frequency domain according to the parameter msg-FDM. The total number of RBs occupied in the frequency domain depends on how many ROs are mapped in the frequency domain at a certain point in time and how many RBs each RO occupies. The number of ROs mapped in the frequency domain can be determined according to the parameter msg-FDM. For example, if msg-FDM=4, there can be 4 ROs in the frequency domain. The number of RBs occupied by each RO can be determined by looking up the table.

[0114] The third part: mapping relationship between RO and SSB

[0115] The 3GPP protocol associates RO resources in different time and frequency domains with SSB indices. Network devices can use the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB to configure the mapping between RO resources and SSBs. This parameter consists of two parts: ssb-perRACH-Occasion, which indicates the number of SSBs associated with one RO; and CB-PreamblesPerSSB, which indicates the number of contention-based preambles mapped to each SSB.

[0116] Assume that one RO corresponds to N SSBs, and each SSB corresponds to R contention-based preambles in each RO. If N<1, then one SSB corresponds to 1 / N consecutive ROs, and each RO corresponds to R contention-based preambles, and the preamble index starts from 0. If N≥1, then one RO maps N SSBs, and the SSBs in each RO map R contention-based preambles. For SSB n (0≤n≤N-1), the corresponding preamble index starts from n*N_total_preamble / N. It should be noted that when N<1, that is, when one SSB corresponds to multiple ROs, the ROs are selected in ascending order of frequency domain first and then time domain.

[0117] Take ssb-perRACH-OccasionAndCB-PreamblesPerSSB = (1 / 2, 64) as an example. As shown in Figure 2, taking a mapping period of 20 milliseconds (ms) as an example, for the same subframe in the time domain, there are 4 ROs in the frequency domain. One SSB corresponds to two ROs, and the number of contention-based preambles that can be used by each SSB in an RO is 64. For example, SSB1 corresponds to RO1 and RO2. RO1 can use contention-based preambles 0-63, and RO2 can use contention-based preambles 0-63.

[0118] Take ssb-perRACH-OccasionAndCB-PreamblesPerSSB=(4, 13) as an example. As shown in Figure 3, a cell transmits a total of 4 SSBs, and 1 RO corresponds to 4 SSBs. Each SSB corresponds to 13 contention-based preambles. The network device can determine the index of the SSB by detecting the range of the preamble index, and the mapping relationship is {SSB0: preamble0-12, SSB1: preamble16-28, SSB2: preamble32-44, SSB3: preamble48-60}. In addition, according to this mapping relationship, the preamble index for non-contention-based can also be calculated, that is, the 12 preambles remaining after the contention-based preamble is removed from the 64 preambles {13-15, 29-31, 45-47, 61-63}.

[0119] Currently, after a UE generates a preamble based on the configuration parameters of a network device, it selects the SSB beam with the strongest signal from multiple SSB beams broadcast by the network device. Based on the mapping relationship between RO and SSB index, it selects an RO within this strongest SSB beam to send the generated preamble. After receiving the preamble from the UE, the network device infers that the SSB beam is the best downlink beam for the UE based on this mapping relationship and sends downlink data to the UE on this SSB beam.

[0120] For example, as shown in (a) of FIG4 , the base station can sequentially send four directional beams (beams), namely SSB1, SSB2, SSB3 and SSB4, in different spatial directions in chronological order. The UE measures the signal strength of the four SSB beams. For example, the UE measures that the signal of SSB2 is the strongest. Afterwards, as shown in (b) of FIG4 , the UE can select an RO from multiple ROs of SSB2 according to the mapping relationship between RO and SSB index, and send UL data to the base station on this RO, such as sending a preamble on PRACH2. Based on the mapping relationship between RACH2 and SSB2, the base station infers that SSB2 is the best downlink beam for the UE and sends DL data to the UE on SSB2.

[0121] In the 4-step random access (RACH) procedure shown in Figure 1, since the base station's transmit power is usually large, the probability of weak signal strength when transmitting DL data is low. However, since the UE's transmit power is limited, when the UE transmits UL data to the network device, especially when sending a preamble to the network device on the PRACH resource, weak signal strength is likely to occur, resulting in random access failure.

[0122] In order to solve the above technical problems, an embodiment of the present application provides a method for repeated transmission of a preamble. The method may include: a network device configures PRACH resources for repeated transmission for a terminal device, such as code domain resources, time domain resources, and frequency domain resources, and the terminal device generates a preamble for repeated transmission according to the configuration parameters, and determines the RO for sending the preamble. Then, the terminal device repeatedly transmits the PRACH multiple times on the same beam, or repeatedly transmits the PRACH multiple times on different beams. Regardless of whether the PRACH is repeatedly transmitted on the same beam or repeatedly transmitted on different beams, each PRACH carries the same preamble, so that multiple PRACHs are combined to generate gain, thereby achieving coverage enhancement of the PRACH, thereby improving the reliability of the communication link and the success rate of random access.

[0123] The technical solutions in the embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0124] The preamble code repetition transmission method provided in the embodiment of the present application can be applied to the communication system 00 shown in Figure 5. The communication system 00 can be a cellular communication system, a universal mobile telecommunication system terrestrial radio access network (UTRAN) system, an evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) system, a long term evolution (LTE) system, etc. It can also be a new radio (NR) system, or other mobile communication systems, such as future mobile communication systems, etc. The embodiment of the present application is not limited to this.

[0125] As shown in Figure 5 , the communication system 00 may include a network device 01 and one or more terminal devices 02 (Figure 5 shows only one terminal device 02) connected to the network device 01. DL data and UL data can be transmitted between the network device 01 and the terminal device 02.

[0126] Network device 01 is a device capable of communicating with terminal device 02. In some embodiments, network device 01 may be an access network device, which may also be referred to as a radio access network (RAN) device, and is a device that provides wireless communication capabilities for terminal device 02. For example, the access network device may be a base station, which may be a next-generation nodeB (gNB) in 5G, an evolved nodeB (eNB or eNodeB) in LTE, a radio network controller (RNC), a nodeB (NB), a base station controller (BSC), a base station transceiver station (BTS), a home base station (such as a home nodeB or home evolved nodeB), a baseband unit (BBU), a transmitting and receiving point (TRP), a transmitting point (TP), a mobile switching center, and the like. The access network device can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario, or the network device can be a relay station, an access point, a vehicle-mounted device, a terminal device, a wearable device, and a device in a future mobile network.

[0127] Terminal device 02 is a device with wireless transceiver capabilities. Terminal device 02 can be a mobile terminal device or a non-mobile terminal device. For example, terminal device 02 can be a UE, a subscriber unit, a user station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a terminal, an access terminal, a user terminal, a wireless communication device, a user agent, or a user apparatus. The access terminal can be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a wireless local loop (WLL), a personal digital assistant (PAD), a handheld device with wireless communication capabilities, a computer device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a terminal device in a future-evolved public land mobile network (PLMN), etc., and the embodiments of the present application are not limited thereto.

[0128] Among them, data can be transmitted between the network device 01 and the terminal device 02 through air interface (radio) resources, and the air interface resources may include at least one of time domain resources, frequency domain resources and code domain resources. Specifically, when the network device 01 and the terminal device 02 perform data transmission, the network device 01 may send control information to the terminal device 02 through a control channel, such as a physical downlink control channel (PDCCH), thereby allocating a data channel to the terminal device 02, such as a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) resource. For example, the control information may indicate the symbol and / or resource block (RB) to which the data channel is mapped, and the network device 01 and the terminal device 02 perform data transmission through the data channel in the allocated time-frequency resources.

[0129] The network device 01 or terminal device 02 in Figure 5 of the embodiment of the present application can be implemented by a single device or a functional module within a single device, and the embodiment of the present application does not specifically limit this. It is understood that the above functions can be network elements in a hardware device, software functions running on dedicated hardware, virtualization functions instantiated on a platform, or chip systems. In the embodiment of the present application, the chip system can be composed of chips or can include chips and other discrete devices.

[0130] In a specific implementation, the network device 01 or terminal device 02 shown in Figure 5 may have the components shown in Figure 6. Figure 6 is a schematic diagram of the hardware structure of a communication device provided in an embodiment of the present application. As shown in Figure 6, the communication device 600 includes at least one processor 601, a communication line 602 and at least one communication interface 603. Furthermore, the communication device 600 may also include a memory 604. Among them, the processor 601, the memory 604 and the communication interface 603 can be connected through a communication line 602. In the embodiment of the present application, at least one can be one, two, three or more, and the embodiment of the present application is not limited.

[0131] The processor 601 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The processor may also be any other device having processing functionality, such as a circuit, a device, or a software module.

[0132] Communication line 602 may include a pathway for transmitting information between components included in communication device 600 .

[0133] The communication interface 603 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area network (WLAN), etc.) The communication interface 603 can be a module, circuit, transceiver or any device capable of achieving communication.

[0134] The memory 604 may be a read-only memory (ROM) or other type of static storage device that can store static information and / or instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and / or instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and can be accessed by a computer.

[0135] In one possible design, the memory 604 can exist independently of the processor 601, that is, the memory 604 can be a memory external to the processor 601. In this case, the memory 604 can be connected to the processor 601 via the communication line 602 to store instructions or program codes. When the processor 601 calls and executes the instructions or program codes stored in the memory 604, the preamble code repetition transmission method provided in the following embodiment of the present application can be implemented. In another possible design, the memory 604 can also be integrated with the processor 601, that is, the memory 604 can be an internal memory of the processor 601. For example, the memory 604 is a cache that can be used to temporarily store some data and / or instruction information.

[0136] As one implementation, processor 601 may include one or more CPUs, such as CPU0 and CPU1 in FIG6 . As another implementation, communication device 600 may include multiple processors, such as processor 601 and processor 607 in FIG6 . As yet another implementation, communication device 600 may further include an output device 605 and an input device 606. For example, input device 606 may be a device such as a keyboard, a mouse, a microphone, or a joystick, and output device 605 may be a device such as a display screen or a speaker.

[0137] It should be noted that the communication device 600 can be a general-purpose device or a dedicated device. For example, the communication device 600 can be a desktop computer, a portable computer, a network server, a mobile phone, a tablet computer, a wireless terminal, an embedded device, a chip system, or a device with a similar structure to that shown in FIG6 . The embodiments of the present application do not limit the type of the communication device 600 .

[0138] The following describes the method for repeatedly transmitting a preamble provided by an embodiment of the present application in conjunction with the communication system 00 shown in Figure 5. The various devices mentioned in the following method embodiments may have the components shown in Figure 6, which will not be described in detail.

[0139] FIG7 is a flow chart of a method for repeatedly transmitting a preamble provided in an embodiment of the present application. The method can be applied to a scenario in which a terminal device requests random access from a network device. As shown in FIG7 , the method can include the following steps S71 to S76.

[0140] S71. The network device sends configuration information. Correspondingly, the terminal device receives the configuration information from the network device. The configuration information may indicate PRACH resources for repeated transmission on the same beams or PRACH resources for repeated transmission on different beams.

[0141] In some embodiments, the configuration information may be included in broadcast signaling, or in control signaling or other signaling, and may be set according to actual usage requirements, and is not limited in the embodiments of the present application.

[0142] Exemplarily, the network device may use a semi-static configuration method to send RRC signaling to the terminal device, where the RRC signaling carries the above-mentioned configuration information. Of course, the network device may also use other methods to send configuration information to the terminal device, such as by sending a media access control (MAC) control element (CE) carrying configuration information, a system message, a physical layer signaling, downlink control information (DCI), or a paging message, which is not limited in the embodiments of the present application.

[0143] The above-mentioned PRACH resources may include code domain resources, time domain resources, and frequency domain resources. Among them, code domain resources refer to preambles repeatedly sent on the same beam, or preambles repeatedly sent on different beams. Time domain resources refer to the time used to repeatedly send preambles, such as frames, subframes, time slots, and symbols. Frequency domain resources refer to the frequency domain positions used to repeatedly send preambles. In the embodiment of the present application, the time domain resources and frequency domain resources used to repeatedly send preambles can be collectively referred to as RO, that is, RO can be understood as the timing of sending the preamble.

[0144] The following examples illustrate how to configure code domain resources, time domain resources, and frequency domain resources.

[0145] (1) Code domain resources

[0146] In the first implementation, the network device may configure a new preamble resource pool (referred to as a first resource pool), and the new preamble resource pool and the existing preamble resource pool (referred to as a second resource pool) may be generated using different configuration parameters.

[0147] The existing preamble resource pool / traditional preamble resource pool is a preamble resource pool configured according to the existing protocol / traditional protocol (such as R16). Any preamble in the existing preamble resource pool cannot be used for repeated transmission, that is, a preamble cannot be repeatedly transmitted on the same beam or on different beams. In combination with the description of the above embodiment, in accordance with the provisions of the existing protocol, the network device can configure the following three parameters: parameter msgA-TotalNumberofRA-Preambles-r16, used to configure the total number of existing preambles; parameter zeroCorrelationZoneConfig, used to configure the number of bits N of each shift of the root sequence of the existing preamble cs ; and, parameter msgA-PRACH-RootSequenceIndex-r16, used to configure the length L of the root sequence of the existing preamble RA After the terminal device obtains the above three parameters, it can generate an existing preamble resource pool, that is, a second resource pool, based on these three parameters by looking up a table.

[0148] The new preamble resource pool is the preamble resource pool configured in the embodiment of the present application. The new preamble resource pool is composed of one or more new preambles, and each new preamble in the new preamble resource pool can be used for repeated transmission, that is, a new preamble can be repeatedly transmitted on the same beam, and / or repeatedly transmitted on different beams. It should be emphasized that the present application can change the above three parameters specified in the existing protocol without changing the preamble generation method specified in the existing protocol (for example, without changing the above Table 1 and Table 2 specified in the existing protocol), and configure a set of new parameters different from the above three parameters, including: parameters msgA-TotalNumberofRA-Preambles-r CE , used to configure the total number of new preambles; parameter zeroCorrelationZoneConfig-rCE , used to configure the number of bits N of each shift of the root sequence of the new preamble cs ; and, parameter msgA-PRACH-RootSequenceIndex-r CE , used to configure the length L of the root sequence of the new preamble RA After the terminal device obtains the above three new parameters, it can generate a new resource pool different from the existing resource pool, that is, the first resource pool, based on the three new parameters by looking up the table.

[0149] The above parameters msgA-TotalNumberofRA-Preambles-r CE , parameter zeroCorrelationZoneConfig-r CE and parameter msgA-PRACH-RootSequenceIndex-r CE This is merely an example and does not limit the embodiments of the present application. In actual implementation, a set of other new parameters may be used to distinguish them from the three parameters specified in the existing protocol, such as: msgA-TotalNumberofRA-Preambles-r18, zeroCorrelationZoneConfig-r18, and msgA-PRACH-RootSequenceIndex-r18.

[0150] It should be noted that the embodiment of the present application does not limit the specific values ​​of the three parameters specified in the existing protocol and the three new parameters configured in the embodiment of the present application. The values ​​of the same type of parameters can be set to be the same or different according to actual needs. For example, the parameter msgA-TotalNumberofRA-Preambles-r16 and the parameter msgA-TotalNumberofRA-Preambles-r CE The value of both can be 64, that is, the total number of preambles configured by the two is the same. For example, if the parameter zeroCorrelationZoneConfig=6, the parameter zeroCorrelationZoneConfig-r CE =3, that is, the number of bits N of each shift of the root sequence configured by the two cs different.

[0151] For example, FIG8 shows a schematic diagram of an existing preamble resource pool and a new preamble resource pool. As shown in FIG8 , the existing preamble resource pool and the new preamble resource pool may include 64 preambles respectively. The indexes of the existing preambles in the existing preamble resource pool may be: preamble0, preamble1, ..., preamble63, and the indexes of the new preambles in the new preamble resource pool may be: preamble-r CE 0. preamble-r CE 1. ..., preamble-r CE 63.

[0152] In the second implementation, the network device may reuse an existing preamble resource pool (referred to as a second resource pool) and separately divide a sub-resource pool (referred to as a first resource pool) for repeatedly sending preambles from the existing preamble resource pool.

[0153] Network devices can configure the following parameters according to the existing protocol: parameter msgA-TotalNumberofRA-Preambles-r16, used to configure the total number of existing preambles; parameter zeroCorrelationZoneConfig, used to configure the number of bits N of each shift of the root sequence of the existing preamble cs ; and, parameter msgA-PRACH-RootSequenceIndex-r16, used to configure the length L of the root sequence of the existing preamble RA and root index. Furthermore, unlike existing protocols, network devices are specifically configured with the following new parameters: the index of the starting preamble in the sub-resource pool for repeated preamble transmission, and the number of preambles in the sub-resource pool for repeated preamble transmission. This allows the terminal device to generate an existing resource pool according to the parameters configured in the existing protocol, and then, according to the specially configured new parameters, to separately allocate a new resource pool from the existing resource pool specifically for repeated transmission, thereby enabling the new resource pool to reuse existing code resources.

[0154] For example, Figure 9 shows a schematic diagram of a multiplexing resource pool. Assuming that the indexes of the existing preambles in the existing preamble resource pool may be: preamble0, preamble1, ..., preamble63, and the index of the starting preamble in the sub-resource pool for repeatedly sending the preamble is 32, and the number of preambles in the sub-resource pool for repeatedly sending the preamble is 16, then as shown in Figure 9, the indexes of the preambles in the sub-resource pool for repeatedly sending the preamble may be: preamble32, preamble33, ..., preamble47. In addition, one or more other resource pools may be divided from the existing preamble resource pool, such as the other three sub-resource pools shown in Figure 9: a preamble sub-resource pool for contention based random access (CBRA), a preamble sub-resource pool for 2-step random access (2-step RACH procedure), and a preamble sub-resource pool for reduced capability UE.

[0155] (2) Time domain resources

[0156] The method for repeated transmission of the preamble provided in the embodiment of the present application can configure the time domain resources of the PRACH according to the existing protocol (such as R16). For example, when configuring the time domain RO of the PRACH, the network device can configure the parameter prach-ConfigurationIndex, and then the UE can determine the time domain transmission timing of the PRACH, that is, the time domain resources of the PRACH, by looking up the table according to the parameter prach-ConfigurationIndex. The specific description of the above embodiment can be referred to and will not be repeated here.

[0157] (3) Frequency domain resources

[0158] The method for repeated transmission of the preamble provided in the embodiment of the present application can configure the frequency domain resources of the PRACH according to the existing protocol (such as R16). For example, when configuring the frequency domain RO of the PRACH, the network device can configure the parameter msg-FrequencyStart and the parameter msg-FDM. Then, the UE can determine the starting position of the PRACH frequency domain resources according to the parameter msg-FrequencyStart, and determine the number of RBs occupied in the frequency domain according to the parameter msg-FDM. The specific description of the above embodiment can be referred to and will not be repeated here.

[0159] In addition, the network device also configures the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB, which indicates the mapping relationship between ROs and SSBs. Furthermore, when an SSB corresponds to multiple ROs, according to existing protocols, ROs within an SSB are selected in ascending order, first in the frequency domain and then in the time domain. Alternatively, the network device can be configured to select ROs within an SSB in ascending order, first in the time domain and then in the frequency domain.

[0160] In some embodiments, the configuration information not only configures code domain resources, time domain resources, and frequency domain resources, but also configures the number of times N that the preamble is repeatedly transmitted on the same beam, or the number of beams K used to repeatedly transmit the preamble. In this way, the terminal device can transmit PRACH multiple times on the same beam, or multiple times on different beams. The specific description of the following embodiments 1 and 2 can be referred to and will not be repeated here.

[0161] S72: The terminal device determines a preamble resource pool for repeated transmission based on the configuration information. The preamble resource pool includes one or more preambles, each of which is a length of L. RA ZC sequence.

[0162] Among them, L RA =839, or L RA =139, or L RA The lengths may be other than those in the embodiments of the present application.

[0163] In addition, any preamble in the preamble resource pool can be either a long preamble or a short preamble. Long preambles are classified into formats 0, 1, 2, and 3; short preambles are classified into nine types: A1, A2, A3, B1, B2, B3, B4, C0, and C2. In the time domain, a preamble consists of a cyclic prefix, a preamble sequence, and a spare guard period. This configuration is similar to the existing preamble configuration and is not detailed here.

[0164] If the configuration information of the network device contains: parameter msgA-TotalNumberofRA-Preambles-r CE , parameter zeroCorrelationZoneConfig-r CE and parameter msgA-PRACH-RootSequenceIndex-r CE, then the terminal device will generate a new preamble resource pool that is different from the existing preamble resource pool, namely the first resource pool.

[0165] If the configuration information of the network device includes: parameter msgA-TotalNumberofRA-Preambles-r16, parameter zeroCorrelationZoneConfig, parameter msgA-PRACH-RootSequenceIndex-r16, the index of the starting preamble in the sub-resource pool for repeatedly sending the preamble, and the number of preambles in the sub-resource pool for repeatedly sending the preamble, then the terminal device will separately divide a sub-resource pool for repeatedly sending the preamble from the existing preamble resource pool, that is, the first resource pool.

[0166] S73. The terminal device determines a beam from the multiple beams according to the measurement results of the multiple beams sent by the network device.

[0167] The signal strength of one beam determined from the multiple beams is greater than the signal strengths of the other beams in the multiple beams. That is, the first beam is the beam with the strongest signal strength among the multiple beams. For ease of description, the following embodiment refers to the one beam determined from the multiple beams as the strongest beam.

[0168] For example, the beams shown in Figure 4 are still used for illustration. As shown in Figure 4 (a), the base station can send four directional beams, namely SSB1, SSB2, SSB3, and SSB4, in different spatial directions in chronological order. After the UE measures the signal strength of these four SSBs, the measurement results are: SSB1 is -120dBm, SSB2 is -80dBm, SSB3 is -100dBm, and SSB4 is -100dBm. In this way, the UE can determine that SSB2 is the strongest beam.

[0169] S74. When the configuration information indicates PRACH resources for repeated transmission on the same beam, the terminal device repeatedly transmits the same preamble on multiple ROs of the strongest beam.

[0170] "Repeatedly sending the same preamble on multiple ROs in the strongest beam" means sending a preamble on each of the multiple ROs in the strongest beam, and the preambles sent on these ROs are the same. The preamble is any preamble randomly selected by the terminal device from the preamble resource pool for repeated transmission.

[0171] For example, assuming that the strongest beam is the SSB2 beam shown in Figure 4, combined with Figure 4, as shown in Figure 10, it is assumed that SSB2 includes 8 ROs: RO0, RO1, RO2, RO3, RO4, RO5, RO6 and RO7. The UE can arbitrarily select a group of ROs from these 8 ROs, such as RO1 and RO5, and randomly select a preamble from the preamble resource pool for repeated transmission, such as preamble32. Then, the UE can send preamble32 on RO0 and RO5 respectively. After receiving the two PRACH signals containing preamble32, the base station combines the two PRACH signals to generate gain, thereby achieving coverage enhancement. Then, based on the mapping relationship, the base station infers that SSB2 is the best downlink beam for the UE and sends DL data to the UE on SSB2.

[0172] S75. When the configuration information indicates PRACH resources for repeated transmission on different beams, the terminal device repeatedly transmits the same preamble on the same RO corresponding to K beams, where K is an integer greater than or equal to 2.

[0173] The K beams include the strongest beam and the (K-1) adjacent beams in the multiple beams. Accordingly, "repeatedly transmitting the same preamble on the same RO corresponding to the K beams" means transmitting a preamble on the RO with the same number in each of the K beams, and the preambles transmitted on these ROs are identical. The preamble is any preamble randomly selected by the terminal device from a preamble resource pool for repeated transmission.

[0174] For example, it is assumed that the strongest beam is the beam corresponding to SSB2 as shown in Figure 4, and the previous beam of SSB2 is SSB1, and the next beam of SSB2 is SSB3, that is, SSB1, SSB2 and SSB3 are three adjacent beams. Combined with Figure 4, as shown in Figure 11, SSB1, SSB2 and SSB3 each include four ROs: RO0, RO1, RO2 and RO3, that is, the ROs in SSB1, SSB2 and SSB3 are numbered the same. The UE can select RO2 from the four ROs and randomly select a preamble from the preamble resource pool for repeated transmission, such as preamble32. Then, the UE can send preamble32 on RO2 of SSB1, send preamble32 on RO2 of SSB2, and send preamble32 on RO2 of SSB3. After the base station receives the three PRACH signals containing preamble32, it combines these PRACH signals to generate gain, thereby achieving coverage enhancement. Then, based on the mapping relationship, the base station infers that SSB2 is the best downlink beam for the UE and sends DL data to the UE on SSB2.

[0175] S76. The network device sends DL data to the terminal device on the strongest beam.

[0176] In the method for repeated transmission of the preamble provided in an embodiment of the present application, since the network device configures PRACH resources for repeated transmission for the terminal device, such as code domain resources, time domain resources, and frequency domain resources, the terminal device can generate a preamble for repeated transmission according to the configuration parameters, and determine the RO for sending the preamble. Then, the terminal device repeatedly transmits the PRACH multiple times on the same beam, or repeatedly transmits the PRACH multiple times on different beams. Regardless of whether the PRACH is repeatedly transmitted on the same beam or repeatedly transmitted on different beams, each PRACH carries the same preamble, so that multiple PRACHs are combined to generate gain, thereby achieving PRACH coverage enhancement, thereby improving the reliability of the communication link and the success rate of random access.

[0177] The above embodiments mentioned repeated transmission of PRACH on the same beam and repeated transmission of PRACH on different beams. These two methods will be described in detail through the following embodiments 1 and 2 respectively.

[0178] Example 1

[0179] FIG12 is a flow chart of repeatedly transmitting PRACH on the same beam multiple times according to an embodiment of the present application. As shown in FIG12 , the method may include the following S21 to S27.

[0180] S21. The network device sends configuration information. Correspondingly, the terminal device receives the configuration information from the network device. The configuration information may indicate PRACH resources for repeated transmission on the same beam.

[0181] In combination with the description of the above embodiment, the network device can adopt the following two configuration methods:

[0182] In the first configuration mode, the configuration information can include the following parameters:

[0183] Parameter msgA-TotalNumberofRA-Preambles-r CE , used to configure the total number of new preambles;

[0184] Parameter zeroCorrelationZoneConfig-r CE , used to configure the number of bits N of each shift of the root sequence of the new preamble cs ;

[0185] Parameter msgA-PRACH-RootSequenceIndex-r CE , used to configure the length L of the root sequence of the new preamble RA and root index;

[0186] The parameter prach-ConfigurationIndex is used to configure the time domain resources of the preamble repeatedly transmitted by a single beam;

[0187] Parameters msg-FrequencyStart and msg-FDM, where the msg-FrequencyStart parameter is used to determine the starting position of the PRACH frequency domain resources and the msg-FDM parameter is used to determine the number of RBs occupied in the frequency domain; and

[0188] The parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is used to configure the mapping relationship between RO and SSB.

[0189] In the second configuration mode, the configuration information can include the following parameters:

[0190] The parameter msgA-TotalNumberofRA-Preambles-r16 is used to configure the total number of existing preambles;

[0191] The parameter zeroCorrelationZoneConfig is used to configure the number of bits N of each shift of the root sequence of the existing preamblecs ;

[0192] The parameter msgA-PRACH-RootSequenceIndex-r16 is used to configure the length L of the root sequence of the existing preamble RA and root index;

[0193] The index of the starting preamble in the sub-resource pool of the preamble used for repeated transmission of a single beam, where the sub-resource pool is part of the existing preamble resource pool, that is, the sub-resource pool is included in the existing preamble resource pool;

[0194] The number of preambles in the sub-resource pool of preambles used for repeated transmission of a single beam, where the sub-resource pool is part of the existing preamble resource pool, that is, the sub-resource pool is included in the existing preamble resource pool;

[0195] The parameter prach-ConfigurationIndex is used to configure the time domain resources of the preamble repeatedly transmitted by a single beam;

[0196] Parameters msg-FrequencyStart and msg-FDM, where the parameter msg-FrequencyStart is used to determine the starting position of the PRACH frequency domain resources, and the parameter msg-FDM is used to determine the number of RBs occupied in the frequency domain;

[0197] And, the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is used to configure the mapping relationship between RO and SSB.

[0198] Regardless of whether the first or second configuration is used, the terminal device cannot determine which ROs of the strongest beam should be used to repeatedly transmit the same preamble. As a first possible implementation, the terminal device can randomly select multiple ROs for repeated preamble transmission. As a second possible implementation, the network device can configure multiple ROs for repeated preamble transmission for the terminal device.

[0199] For example, with respect to the second possible implementation manner, in order to determine the RO used for repeatedly sending the same preamble, the configuration information may further include the following parameters ① and ②.

[0200] ① The parameter msg1-repetition-number (also called the first parameter) is used to configure the number of times N that the preamble is repeated on the same beam. That is, the number of ROs included in a group of ROs used to repeatedly transmit the same preamble on a beam. N is an integer greater than or equal to 2.

[0201] Assuming that the number of ROs included in an SSB is M, then N=2,...,M.

[0202] As an optional implementation, N and M may also satisfy the following conditions:

[0203] in, is the floor symbol, j represents the number of packets contained in the same beam, and j is a positive integer.

[0204] As a special case, when j=1, N=M, that is, all ROs included in the same beam belong to the same group, and these ROs are used to repeatedly send the same preamble.

[0205] In some embodiments, any RO of an SSB belongs to a certain group, that is, any RO of an SSB can be used as an RO for repeatedly sending a preamble.

[0206] For example, assuming that SSB1 includes 8 ROs, the network device can configure N to be 2, 4, or 8. When N=2, SSB1 includes 4 packets, each packet includes 2 ROs for repeatedly sending the same preamble; when N=4, SSB1 includes 2 packets, each packet includes 4 ROs for repeatedly sending the same preamble; when N=8, SSB1 includes 1 packet, each packet includes 8 ROs for repeatedly sending the same preamble.

[0207] For another example, assuming that SSB1 includes 30 ROs, the network device can configure N to be 2, 3, 5, 6, 10, 15 or 30. When N=2, SSB1 includes 15 packets, each packet includes 2 ROs for repeatedly sending the same preamble; when N=3, SSB1 includes 10 packets, each packet includes 3 ROs for repeatedly sending the same preamble; when N=5, SSB1 includes 6 packets, each packet includes 5 ROs for repeatedly sending the same preamble; when N=6, SSB1 includes 5 packets, each packet includes 6 ROs for repeatedly sending the same preamble; when N=10, SSB1 includes 3 packets, each packet includes 10 ROs for repeatedly sending the same preamble; when N=15, SSB1 includes 2 packets, each packet includes 15 ROs for repeatedly sending the same preamble; when N=30, SSB1 includes 1 packet, each packet includes 30 ROs for repeatedly sending the same preamble.

[0208] In other embodiments, one or more ROs of an SSB do not belong to any group, that is, a part of the ROs of an SSB may be used as ROs for repeatedly sending preambles, while another part of the ROs may not be used as ROs for repeatedly sending preambles.

[0209] For example, assuming that SSB1 includes 9 ROs, the network device can configure N to 2 or 4. When N=2, SSB1 includes 4 packets, each packet includes 2 ROs for repeatedly sending the same preamble, and 1 RO remains; when N=4, SSB1 includes 2 packets, each packet includes 4 ROs for repeatedly sending the same preamble, and 1 RO remains.

[0210] It should be understood that the larger the value of the number of times N of repeated transmission on the same beam is, the more ROs each group includes, the greater the gain generated by combining, and the better the coverage enhancement effect.

[0211] The second parameter, ro-repetition-interval, indicates the interval between repeated ROs (ROs) on the same beam, which can be denoted as k. This is the interval between any two adjacent ROs in any group of ROs that repeatedly transmit the same preamble on a beam. k = 1, ..., M, where M is the number of ROs in an SSB.

[0212] For example, assuming that SSB1 includes six ROs: RO0, RO1, RO2, RO3, RO4, and RO5, and N = 3, then k = 1 or 2. When k = 1, RO0, RO1, and RO2 form one group, and RO3, RO4, and RO5 form another group; when k = 2, RO0, RO2, and RO4 form one group, and RO1, RO3, and RO5 form another group.

[0213] In addition to the above parameters ① and ②, the configuration information sent by the network device may also include the following parameter ③.

[0214] ③ The parameter msg1-repetion-enable (also called the third parameter) is used to indicate whether to enable repeated transmission of the same preamble on the same beam.

[0215] As an optional implementation method, the parameter msg1-repetion-enable can be an enumeration type.

[0216] For example, if the parameter msg1-repetion-enable is in the following format:

[0217] msg1-repetion-enable ENUMERATED{enabled},

[0218] This parameter is used to enable the repeated transmission of the same preamble in the same beam.

[0219] For example, if the parameter msg1-repetion-enable is in the following format:

[0220] msg1-repetion-enable ENUMERATED{disenabled},

[0221] This parameter is used to indicate that the repeated transmission of the same preamble in the same beam is disabled.

[0222] For another example, the network device may not be configured with the parameter msg1-repetion-enable, that is, the parameter msg1-repetion-enable is not carried in the configuration information. In this case, the default is to disable repeated sending of the same preamble in the same beam.

[0223] As an optional implementation, the parameter msg1-repetion-enable can be a numeric value.

[0224] For example, when msg1-repetion-enable=0, it indicates that the same preamble can be repeatedly sent in the same beam. When msg1-repetion-enable=1, it indicates that the same preamble cannot be repeatedly sent in the same beam.

[0225] For another example, when msg1-repetion-enable=1, it indicates that the same preamble can be repeatedly sent in the same beam, and when msg1-repetion-enable=0, it indicates that the same preamble can not be repeatedly sent in the same beam.

[0226] It should be understood that the parameter msg1-repetion-enable is equivalent to an enable switch. By setting this parameter, the terminal device can be triggered to execute the single-beam repeated transmission process.

[0227] S22. If the configuration information of the network device includes: parameter msgA-TotalNumberofRA-Preambles-r CE , parameter zeroCorrelationZoneConfig-r CE and parameter msgA-PRACH-RootSequenceIndex-r CE , then the terminal device generates a new preamble resource pool that is different from the existing preamble resource pool.

[0228] Alternatively, if the configuration information of the network device includes: parameter msgA-TotalNumberofRA-Preambles-r16, parameter zeroCorrelationZoneConfig, parameter msgA-PRACH-RootSequenceIndex-r16, index of the starting preamble for single-beam repeated transmission, and the number of preambles in the sub-resource pool for preamble repeated transmission of single beam, then the terminal device separately divides a sub-resource pool for repeated transmission of preamble from the existing preamble resource pool.

[0229] For the specific implementation of S22, please refer to the description of S71 and S72 above, which will not be repeated here.

[0230] S23. The terminal device calculates the total number of ROs included in the same SSB within the preset time based on the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB, the parameter msg-FDM, and the parameter prach-ConfigurationIndex, following the rule of frequency domain first and time domain second (specified in the existing protocol) or the rule of time domain first and frequency domain second (configured by the network device). The total number of ROs included in the same SSB within the preset time can be recorded as M.

[0231] Since the parameters msg-FDM and prach-ConfigurationIndex are used to configure the time-frequency domain of RO, and the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is used to configure the mapping relationship between RO and SSB, the terminal device can calculate the number of ROs included in the same SSB based on these parameters.

[0232] The above-mentioned "preset time" may also be referred to as a preset period, preset duration, or preset time period, which is a period of time specified by the protocol or a period of time configured for the network device. In some embodiments, the above-mentioned "preset time" may be an association period. Within a mapping period, all SSBs are mapped to ROs. In other embodiments, the above-mentioned "preset time" may be an association pattern period. Within a mapping pattern period, all SSBs are mapped to ROs. For example, a mapping pattern period may be 160ms.

[0233] It should be understood that the above-mentioned mapping period and mapping pattern period are exemplary descriptions. In actual implementation, other times can also be defined or configured as "preset time", and the duration of the "preset time" can be set according to actual usage requirements, which is not limited in the embodiments of this application.

[0234] S24. The terminal device starts from the initial RO (which can be recorded as s) of the same SSB, calculates the various packets used for repeated transmission of the preamble in a single beam, and the number of ROs contained in each packet (which can be recorded as N), that is, calculates the number of times the preamble is repeatedly transmitted in each packet of the single beam as N.

[0235] ROs within the same SSB are mapped in ascending order, either frequency domain first, time domain second, or time domain first, frequency domain second. The frequency domain first, time domain second, rule is protocol-defined, while the time domain first, frequency domain second is configured by the network device. The initial RO is the first RO mapped within the same SSB. Typically, the initial RO is indexed or numbered RO0 or RO1. If the initial RO is RO0, s = 0; otherwise, if the initial RO is RO1, s = 1.

[0236] Typically, the protocol specifies that ROs within the same beam within a preset time period are sorted by frequency domain first, then time domain, and network devices do not need to specifically configure this sorting rule. If you need to set the time domain first, then frequency domain, sorting rule for ROs within the same beam within a preset time period, the network device can set this sorting rule in the configuration information.

[0237] Specifically, when the configuration information also includes preset rules, the ROs included in the same beam within the preset time are sorted according to the rule of time domain first and frequency domain later; or, when the configuration information does not include preset rules, the ROs included in the same beam within the preset time are sorted according to the rule of frequency domain first and time domain later.

[0238] In some embodiments, the RO of a group can be expressed as: {(s+nk)modM}. Here, s represents the first RO mapped in a group, n = (0, 1, ..., N-1), N represents the number of times the preamble is repeated on the same beam (i.e., the number of ROs contained in a group), k represents the RO interval between repeated preamble transmissions on the same beam, mod is a mathematical operator - the modulo operator, and M represents the total number of ROs contained in the same SSB. After grouping the i-th group using the above formula, grouping is continued using formula s++ to group the i+1th group, and so on, until s>M and grouping is stopped.

[0239] Example 1: Assuming s = 0, M = 8, k = 4, and N = 2, substituting these values ​​into the above formula yields:

[0240] Group 1: {(s+nk)modM}={(0+(0,1)×4)mod8}={0,4};

[0241] Group 2 {(s+nk)modM}={(1+(0,1)×4)mod8}={1,5};

[0242] Group 3 {(s+nk)modM}={(2+(0,1)×4)mod8}={2,6};

[0243] Group 4 {(s+nk)modM}={(3+(0,1)×4)mod8}={3,7}.

[0244] For example, the ordering of ROs within the same SSB, first in the frequency domain and then in the time domain, is used. As shown in Figure 13, within a preset timeframe, there are three SSBs: SSB1, SSB2, and SSB3. The ROs within these three SSBs are numbered RO0 through RO7. For any SSB within the preset timeframe, RO0 and RO4 are filled with pattern 1, indicating that they belong to group 1; RO1 and RO5 are filled with pattern 2, indicating that they belong to group 2; RO2 and RO6 are filled with pattern 3, indicating that they belong to group 3; and RO3 and RO7 are filled with pattern 4, indicating that they belong to group 4.

[0245] Let's take the example of ROs within the same SSB being sorted in the time domain first and then the frequency domain. As shown in Figure 14, within a preset timeframe, there are three SSBs: SSB1, SSB2, and SSB3. The ROs within these three SSBs are numbered RO0 through RO7. For any SSB within the preset timeframe, RO0 and RO4 are filled with pattern 1, indicating that they belong to group 1; RO1 and RO5 are filled with pattern 3, indicating that they belong to group 2; RO2 and RO6 are filled with pattern 2, indicating that they belong to group 3; and RO3 and RO7 are filled with pattern 4, indicating that they belong to group 4.

[0246] Example 2: Assuming s = 0, M = 8, k = 1, and N = 2, substituting these values ​​into the above formula yields:

[0247] Group 1: {(s+nk)modM}={(0+(0,1)×1)mod8}={0,1};

[0248] Group 2 {(s+nk)modM}={(2+(0,1)×1)mod8}={2,3};

[0249] Group 3 {(s+nk)modM}={(4+(0,1)×1)mod8}={4,5};

[0250] Group 4 {(s+nk)modM}={(6+(0,1)×1)mod8}={6,7}.

[0251] It should be noted that, since any two groups cannot contain the same RO, in the above calculation process, the values ​​s=0, s=2, s=4 and s=6 are taken respectively, while s=1, s=3 and s=5 are discarded.

[0252] For example, the ordering of ROs within the same SSB, first in the frequency domain and then in the time domain, is used. As shown in Figure 15, a preset time period includes three SSBs: SSB1, SSB2, and SSB3. The ROs within these three SSBs are numbered RO0 to RO7. For any SSB within the preset time period, RO0 and RO1 are filled with pattern 1, indicating that they belong to group 1; RO2 and RO3 are filled with pattern 2, indicating that they belong to group 2; RO4 and RO5 are filled with pattern 3, indicating that they belong to group 3; and RO6 and RO7 are filled with pattern 4, indicating that they belong to group 4.

[0253] Let's take the example of sorting ROs within the same SSB in the time domain first and then the frequency domain as an example. As shown in Figure 16, within a preset time period, there are three SSBs: SSB1, SSB2, and SSB3. The ROs within these three SSBs are numbered RO0 to RO7. For any SSB within the preset time period: RO0 and RO1 are filled with pattern 1, indicating that RO0 and RO1 belong to group 1; RO2 and RO3 are filled with pattern 2, indicating that RO2 and RO3 belong to group 2; RO4 and RO5 are filled with pattern 3, indicating that RO4 and RO5 belong to group 3; RO6 and RO7 are filled with pattern 4, indicating that RO6 and RO7 belong to group 4.

[0254] With reference to the description of FIG. 13 to FIG. 16 in the above embodiment, the following conclusions can be drawn:

[0255] 1. ROs within the same SSB can be sorted by frequency domain first and time domain second (as shown in Figure 13 or Figure 15), or by time domain first and frequency domain second (as shown in Figure 14 or Figure 16). The frequency domain first and time domain second rule is specified by the protocol (i.e., the default), while the time domain first and frequency domain second rule is configured by the network device.

[0256] 2. The time domain resources of each RO in the same group are the same, that is, PRACH can be repeatedly sent on different frequency domain resources at the same time; or, the frequency domain resources of each RO in the same group are the same, that is, PRACH can be repeatedly sent on the same frequency domain at different times.

[0257] Regarding the case where the time domain resources of each RO in the same group are the same but the frequency domain resources are different: as shown in Figure 14, if the terminal device selects group 1 of SSB1, RO0 and RO4 occupy different frequency domain resources at the same time, and the terminal device can send the same preamble on RO0 and RO4 of SSB1 at the same time. As shown in Figure 15, if the terminal device selects group 1 of SSB1, RO0 and RO1 occupy different frequency domain resources at the same time, and the terminal device can send the same preamble on RO0 and RO1 of SSB1.

[0258] Regarding the case where the frequency domain resources of each RO in the same group are the same but the time domain resources are different: as shown in Figure 13, if the terminal device selects group 1 of SSB1, RO0 and RO4 occupy the same frequency domain resources at different times, and the terminal device can send the same preamble on RO0 and RO4 of SSB1 in a time-sharing manner. As shown in Figure 16, if the terminal device selects group 1 of SSB1, RO0 and RO1 occupy the same frequency domain resources at different times, and the terminal device can send the same preamble on RO0 and RO1 of SSB1 in a time-sharing manner.

[0259] The above embodiment provides two scenarios: one scenario is that the time domain resources of the ROs in the same group are the same, but the frequency domain resources are different; the other scenario is that the frequency domain resources of the ROs in the same group are the same, but the time domain resources are different. The embodiment of the present application also provides another scenario: there are ROs in the same group with different time domain resources and different frequency domain resources.

[0260] For example, as shown in Figure 17, the base station broadcasts SSB1, SSB2, and SSB3 to the UE in sequence. The UE determines that SSB3 is the strongest beam and selects to repeatedly transmit the same preamble on RO0, RO4, RO8, and RO12 of SSB3. Among these ROs, those with the same time domain resources but different frequency domain resources are: RO0 and RO4, RO8 and RO12; those with different time domain resources but the same frequency domain resources are: RO0 and RO8, RO4 and RO12; and those with different time domain resources and different frequency domain resources are: RO0 and RO12, RO4 and RO8.

[0261] S25. The terminal device determines the strongest beam from the multiple beams based on the measurement results of the multiple beams sent by the network device.

[0262] S26. The terminal device repeatedly transmits the same preamble on each RO included in any group of the strongest beam. The arbitrary group is a group randomly selected by the terminal device from multiple groups. The preamble is a preamble randomly selected by the terminal device from a preamble resource pool for repeated transmission.

[0263] S27. The network device sends DL data to the terminal device on the strongest beam.

[0264] For the implementation of S25 to S27, please refer to the description of S73, S74 and S76 above, which will not be repeated here.

[0265] In the resource configuration method for single beam repeated transmission provided in the embodiment of the present application, two configuration methods for the preamble resource pool for repeated transmission are provided: one is to use the parameter msgA-TotalNumberofRA-Preambles-r CE , parameter zeroCorrelationZoneConfig-r CE and parameter msgA-PRACH-RootSequenceIndex-r CE , generate a new preamble resource pool; the other is to use the index of the starting preamble in the sub-resource pool of the preamble for repeated transmission, and the number of preambles in the sub-resource pool of the preamble for repeated transmission, to separately divide a sub-resource pool from the existing preamble resource pool. In addition, the embodiment of the present application newly adds the parameter msg1-repetion-enable, the number of repeated transmissions N on the same beam, and the interval ro-repetition-interval of repeated transmissions on the same beam, so as to configure the code domain resources, time domain resources and frequency domain resources for repeated transmission for the terminal device. In this way, the terminal device can generate a preamble for repeated transmission according to the configuration parameters, and determine the RO for sending the preamble. Then, the terminal device repeatedly transmits PRACH multiple times on the same beam, and each PRACH carries the same preamble, so that multiple PRACHs are combined to generate gain, thereby achieving coverage enhancement of PRACH, thereby improving the success rate of random access.

[0266] Example 2

[0267] The above embodiment 1 is illustrated by taking the example of the terminal device selecting the strongest beam to send PRACH. In the NR system, the number of beams transmitted by the network device is large, sometimes as many as 64, and because the beam has directional directivity, each beam may be very thin. In this way, when the terminal device moves quickly, the following problems may exist: As shown in Figure 18, at time t1, the terminal device detects that SSB2 broadcast by the network device is the strongest beam among all beams. In the short period of time from time t1 to time t2, the position of the terminal device has changed. Because the beam has directional directivity, after the position of the terminal device has changed, SSB2 may no longer be the strongest beam for this terminal device. If the terminal device still sends PRACH on SSB2, random access may fail due to weak signal. In order to solve similar problems, the embodiment of the present application also provides a method for repeatedly transmitting PRACH on different beams.

[0268] Figure 19 is a schematic diagram of a process for repeatedly transmitting PRACH on different beams according to an embodiment of the present application. As shown in Figure 19, the method may include the following S91 to S96.

[0269] S91. The network device sends configuration information. Correspondingly, the terminal device receives the configuration information from the network device. The configuration information may indicate PRACH resources for repeated transmission on different beams.

[0270] In combination with the description of the above embodiment, the network device can adopt the following two configuration methods:

[0271] In the first configuration mode, the configuration information can include the following parameters:

[0272] Parameter msgA-TotalNumberofRA-Preambles-r CE , used to configure the total number of new preambles;

[0273] Parameter zeroCorrelationZoneConfig-r CE , used to configure the number of bits N of each shift of the root sequence of the new preamble cs ;

[0274] Parameter msgA-PRACH-RootSequenceIndex-r CE , used to configure the length L of the root sequence of the new preamble RA and root index;

[0275] The parameter prach-ConfigurationIndex is used to configure the time domain resources of the preamble sent repeatedly by multiple beams;

[0276] Parameters msg-FrequencyStart and msg-FDM, where the parameter msg-FrequencyStart is used to determine the starting position of the PRACH frequency domain resources, and the parameter msg-FDM is used to determine the number of RBs occupied in the frequency domain;

[0277] And, the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is used to configure the mapping relationship between RO and SSB.

[0278] In the second configuration mode, the configuration information can include the following parameters:

[0279] The parameter msgA-TotalNumberofRA-Preambles-r16 is used to configure the total number of existing preambles;

[0280] The parameter zeroCorrelationZoneConfig is used to configure the number of bits N of each shift of the root sequence of the existing preamble cs ;

[0281] The parameter msgA-PRACH-RootSequenceIndex-r16 is used to configure the length L of the root sequence of the existing preamble RA and root index;

[0282] The index of the starting preamble in the sub-resource pool of the preamble used for multi-beam repeated transmission, where the sub-resource pool belongs to a part of the existing preamble resource pool, that is, the sub-resource pool is included in the existing preamble resource pool;

[0283] The parameter numberOfRA-PremblesRepetion-MultiBeam specifies the number of preambles in the sub-resource pool used for multi-beam repetitive transmission of preambles. This sub-resource pool is part of the existing preamble resource pool, that is, the sub-resource pool is included in the existing preamble resource pool.

[0284] The parameter prach-ConfigurationIndex is used to configure the time domain resources of the preamble sent repeatedly by multiple beams;

[0285] Parameters msg-FrequencyStart and msg-FDM, where the parameter msg-FrequencyStart is used to determine the starting position of the PRACH frequency domain resources, and the parameter msg-FDM is used to determine the number of RBs occupied in the frequency domain;

[0286] And, the parameter ssb-perRACH-OccasionAndCB-PreamblesPerSSB is used to configure the mapping relationship between RO and SSB.

[0287] It should be noted that the parameter msgA-TotalNumberofRA-Preambles-r in the above configuration method 1 CE , as well as the parameter numberOfRA-PremblesRepetion-MultiBeam in the second configuration method, can be used to configure the number of preambles used for multi-beam repeated transmission.

[0288] Regardless of whether the first or second configuration is used, the terminal device cannot determine which ROs of the beams to repeatedly transmit the same preamble. As a first possible implementation, the terminal device can randomly select ROs of several beams for repeated preamble transmission. However, the signal strength of the randomly selected beams may be weak, resulting in poor coverage enhancement. As a second possible implementation, the network device can configure K beams for the terminal device to repeatedly transmit the preamble.

[0289] Exemplarily, for the above-mentioned second possible implementation method, in order to determine K beams used for repeatedly sending the same preamble, the above-mentioned configuration information may also include the following parameter ①.

[0290] The parameter msg1-repetition-multibeam-number (also called the fourth parameter) is used to configure the number of beams, K, on ​​which the preamble is repeated. This means that the same preamble is repeated on K beams. K is an integer greater than or equal to 2.

[0291] It should be understood that the larger the value of K, the number of beams used to repeatedly send the preamble, the more beams used for merging, the greater the gain generated by merging the PRACHs transmitted on multiple beams, and the better the coverage enhancement effect.

[0292] In addition to the above parameters ①, the configuration information sent by the network device may also include the following parameters ②.

[0293] ② The parameter msg1-repetion-multibeam-enable (also known as the fifth parameter) is used to indicate whether to enable repeated transmission of the same preamble on different beams.

[0294] As an optional implementation, the parameter msg1-repetion-multibeam-enable can be an enumeration type.

[0295] For example, if the parameter msg1-repetion-multibeam-enable is of the following form:

[0296] msg1-repetion-multibeam-enable ENUMERATED{enabled},

[0297] This parameter is used to indicate whether to enable repeated transmission of the same preamble on different beams.

[0298] For example, if the parameter msg1-repetion-multibeam-enable is in the following format:

[0299] msg1-repetion-multibeam-enable ENUMERATED{disenabled},

[0300] This parameter is used to indicate that the repeated transmission of the same preamble on different beams is disabled.

[0301] For another example, the network device may not be configured with the parameter msg1-repetion-multibeam-enable, that is, the parameter msg1-repetion-multibeam-enable is not carried in the configuration information. In this case, the default is to disable repeated sending of the same preamble on different beams.

[0302] As an optional implementation, the parameter msg1-repetion-multibeam-enable can be a numeric value.

[0303] For example, when msg1-repetion-multibeam-enable=0, it indicates that the same preamble can be repeatedly sent on different beams. When msg1-repetion-multibeam-enable=1, it indicates that the same preamble can not be repeatedly sent on different beams.

[0304] For another example, when msg1-repetion-multibeam-enable=1, it indicates that the same preamble can be repeatedly sent on different beams. When msg1-repetion-multibeam-enable=0, it indicates that the same preamble can not be repeatedly sent on different beams.

[0305] It should be understood that the parameter msg1-repetion-multibeam-enable is equivalent to an enable switch. By setting this parameter, the terminal device can be triggered to execute the multi-beam repetition transmission process.

[0306] S92. If the configuration information of the network device includes the parameter msgA-TotalNumberofRA-Preambles-r CE , parameter zeroCorrelationZoneConfig-r CE and parameter msgA-PRACH-RootSequenceIndex-rCE , then the terminal device generates a new preamble resource pool that is different from the existing preamble resource pool, that is, the first resource pool.

[0307] Alternatively, if the configuration information of the network device includes: parameter msgA-TotalNumberofRA-Preambles-r16, parameter zeroCorrelationZoneConfig, parameter msgA-PRACH-RootSequenceIndex-r16, index of the starting preamble for multi-beam repeated transmission, and parameter numberOfRA-PremblesRepetion-MultiBeam, then the terminal device separately allocates a sub-resource pool of preambles for multi-beam repeated transmission from the existing preamble resource pool.

[0308] For the specific implementation of S92, please refer to the description of S71 and S72 above, which will not be repeated here.

[0309] S93, the terminal device according to the parameter msgA-TotalNumberofRA-Preambles-r CE , the number K of beams used to repeatedly send the preamble and the first resource pool, or calculate the preamble corresponding to each beam according to the parameter numberOfRA-PremblesRepetion-MultiBeam, the number K of beams used to repeatedly send the preamble and the first resource pool.

[0310] If the configuration information includes the parameter msgA-TotalNumberofRA-Preambles-r CE and parameter K, then the terminal device can use the formula msgA-TotalNumberofRA-Preambles-r CE / K, calculate the number of preambles corresponding to each beam. Alternatively, if the configuration information includes the parameter numberOfRA-PremblesRepetion-MultiBeam and the parameter K, the terminal device can use the formula numberOfRA-PremblesRepetion-MultiBeam / K to calculate the number of preambles corresponding to each beam.

[0311] As an optional implementation, the parameter K can not only represent the number of beams used to repeatedly send the preamble, but also be used to indicate that the same preamble is multiplexed every K beams.

[0312] For example, assuming numberOfRA-PremblesRepetion-MultiBeam = 36, the index of the starting preamble is 28, and K = 3, the number of preambles that can be used for each SSB is 12. As shown in Figure 20, the preamble resource pool for multi-beam repeated transmission includes: preambles 28 to 63. When performing multi-beam repeated transmission, the preambles that can be used for each beam are: SSB1: 28 to 39; SSB2: 40 to 51; SSB3: 52 to 63; SSB4: 28 to 39; SSB5: 40 to 51; SSB6: 52 to 63; SSB7: 28 to 39; SSB8: 40 to 51; SSB9: 52 to 63... and so on. Every 3 beam preambles will be reused.

[0313] S94. The terminal device determines the strongest beam from the multiple beams based on the measurement results of the multiple beams sent by the network device.

[0314] After the terminal device determines the strongest beam from the beams, the terminal device can determine K beams for repeatedly sending the preamble based on the strongest beam. In combination with the description of S93 above, the terminal device can allocate an available preamble to each of the K beams based on the configuration information.

[0315] As a possible implementation, the terminal device can randomly select a preamble from the preamble codes in the K beams selected for repeated transmission, and transmit the preamble on the same RO corresponding to each of the K beams. However, this approach has a problem: the network device cannot determine which of the K beams is the strongest beam. It simply randomly selects a beam from the K beams as the strongest beam, which may cause a non-strongest beam to be mistakenly identified as the strongest beam. To address this issue, an embodiment of the present application provides another possible implementation: a preamble is randomly selected from the preamble corresponding to the strongest beam, and the preamble is then repeatedly transmitted on the same RO corresponding to each of the K beams.

[0316] S95. The terminal device repeatedly sends the same preamble on the same RO corresponding to K beams including the strongest beam.

[0317] The received signal strength of K beams is greater than that of the other beams, indicating that these K beams have the best downlink signal quality. "Repeatedly transmitting the same preamble on the same ROs corresponding to the K beams" means transmitting a preamble on the RO with the same number in each of the K beams, and the preambles transmitted on these ROs are identical. This preamble is randomly selected by the terminal device from the preambles corresponding to the strongest beam.

[0318] It should be noted that the above K beams are K spatially adjacent beams continuously sent by the network device, that is, during the broadcasting of the K beams, the network device does not broadcast other beams.

[0319] The following is an example of how to select K beams.

[0320] As the first implementation method, the K beams include: the strongest beam, the beam broadcast before the strongest beam, and the beam broadcast before and after the strongest beam. For example, as shown in (a) in Figure 21, the network device broadcasts SSB1, SSB2, SSB3, SSB4, SSB5, SSB6, and SSB7 in sequence. After UE1 measures these beams, it determines that SSB3 is the strongest beam. If K = 3, then UE1 can repeatedly send the same preamble on the same RO corresponding to SSB2, SSB3, and SSB4. The preamble is a preamble randomly selected by UE1 from the preamble corresponding to SSB3.

[0321] As a second implementation method, the terminal device determines K beams according to the moving direction, including: the strongest beam, the beam broadcast after the strongest beam, and the beam direction of the beam broadcast after the strongest beam is consistent with the moving direction of the terminal device. For example, as shown in (b) in Figure 21, the network device broadcasts SSB1, SSB2, SSB3, SSB4, SSB5, SSB6 and SSB7 in sequence. After UE1 measures these beams, it determines that SSB3 is the strongest beam. If K=3, and the moving direction of the terminal device is close to the beam direction of SSB4, then UE1 can repeatedly send the same preamble on the same RO corresponding to SSB3, SSB4 and SSB5. The preamble is a preamble randomly selected by UE1 from the preamble corresponding to SSB3.

[0322] As a third implementation method, the terminal device determines K beams according to the moving direction, including: the strongest beam, the beam broadcast before the strongest beam, and the beam direction of the beam broadcast before the strongest beam is consistent with the moving direction of the terminal device. For example, as shown in (c) in Figure 21, the network device broadcasts SSB1, SSB2, SSB3, SSB4, SSB5, SSB6 and SSB7 in sequence. After UE1 measures these beams, it determines that SSB3 is the strongest beam. If K=3, and the moving direction of the terminal device is close to the beam direction of SSB2, then UE1 can repeatedly send the same preamble on the same RO corresponding to SSB1, SSB2 and SSB3. The preamble is a preamble randomly selected by UE1 from the preamble corresponding to SSB3.

[0323] As the fourth implementation method, the above embodiment is described using K as an odd number. In actual implementation, K may also be an even number. In this case, the terminal device can determine the (K-1) beams adjacent to the strongest beam and with the strongest signal strength based on the signal strength of each beam. As shown in (d) of Figure 21, the network device broadcasts SSB1, SSB2, SSB3, SSB4, SSB5, SSB6, and SSB7 in sequence. After UE1 measures these beams, the measurement results are SSB1 is -105dBm, SSB2 is -100dBm, SSB3 is -80dBm, SSB4 is -90dBm, SSB5 is -110dBm, SSB6 is -115dBm, and SSB7 is -120dBm. Because the received signal strengths of SSB1, SSB2, SSB3, and SSB4 are greater than those of other SSBs, and SSB3 is the strongest beam, UE1 can repeatedly send the same preamble on the same RO corresponding to SSB1, SSB2, SSB3, and SSB4. This preamble is randomly selected by the terminal device from the preamble corresponding to SSB3.

[0324] S96. The network device sends DL data to the terminal device on the strongest beam.

[0325] After receiving the repeatedly transmitted PRACH on K beams, the network device can determine that the SSB corresponding to the preamble is the strongest beam based on the mapping relationship between the preamble and the SSB carried by the PRACH. In other words, the terminal device uses an implicit notification method to inform the network device of the beam information of the terminal device, so that the network device can send DL data to the terminal device on the strongest beam.

[0326] When each terminal device is located at a different location in the cell, the strongest beam determined by each terminal device is also different. When performing multiple PRACH repetition transmissions using different beams, the multiple beams used by each terminal device may be beam-reused.

[0327] For example, as shown in (a) of Figure 22, the network device broadcasts SSB1, SSB2, SSB3, SSB4, SSB5 and SSB6 in sequence. After measuring these beams, UE1 determines that SSB2 is the strongest beam. After measuring these beams, UE2 determines that SSB4 is the strongest beam. As shown in (b) of Figure 22, UE1 can repeatedly send preamble x on RO2 of SSB1, SSB2 and SSB3. Preamble x is a preamble randomly selected by the terminal device from the preamble corresponding to SSB2. As shown in (c) of Figure 22, UE2 can repeatedly send preamble y on RO0 of SSB3, SSB4 and SSB5. Preamble y is a preamble randomly selected by the terminal device from the preamble corresponding to SSB4. After receiving the PRACH from UE1, the network device determines that SSB2 is the strongest beam of UE1 based on preamble x. After receiving the PRACH from UE2, the network device determines that SSB4 is the strongest beam of UE2 based on preamble y.

[0328] In addition, the above-mentioned embodiment 2 is illustrated by taking the example of a terminal device repeatedly transmitting the same preamble on K ROs of K beams, which does not limit the embodiment of the present application. As shown in Figure 23, when UE1 selects SSB1, SSB2 and SSB3 as beams for repeatedly transmitting PRACH, RO0, RO4, RO8 and RO12 of SSB1, RO0, RO4, RO8 and RO12 of SSB2, and RO0, RO4, RO8 and RO12 of SSB3 can all be used to send the same preamble. In other words, the embodiment of the present application can also realize multiple PRACH repeated transmissions of the same beam, and multiple PRACH repeated transmissions of different beams.

[0329] In the resource configuration method for multi-beam repeated transmission provided in an embodiment of the present application, two configuration methods for the preamble resource pool for repeated transmission are provided: one is to use the parameter msgA-TotalNumberofRA-Preambles-rCE, the parameter zeroCorrelationZoneConfig-rCE and the parameter msgA-PRACH-RootSequenceIndex-rCE to generate a new preamble resource pool for multi-beam repeated transmission; the other is to use the index of the starting preamble in the sub-resource pool of the preamble for repeated transmission and the number of preambles in the sub-resource pool of the preamble for repeated transmission to separately divide a sub-resource pool for multi-beam repeated transmission from the existing preamble resource pool. In addition, the embodiment of the present application newly adds the parameter msg1-repetion-multibeam-enable, which is used to set the number K of beams for repeated transmission of the preamble, thereby configuring the code domain resources, time domain resources and frequency domain resources for multi-beam repeated transmission for the terminal device. In this way, the terminal device can generate a preamble for repeated transmission based on the configuration parameters and determine the RO used to send the preamble. It can then repeatedly transmit the PRACH on multiple beams, thereby combining multiple PRACHs to generate gain, achieving PRACH coverage enhancement and thus improving the success rate of random access. In addition, by configuring an available preamble for each of the K beams and using the preamble of the strongest beam for multi-beam repetition, the network device can determine the strongest beam from the K beams and send DL data to the terminal device on the strongest beam.

[0330] It should be noted that, in order to more clearly illustrate the configuration method of the RO of each SSB, the embodiment of the present application is described by taking the same RO numbering for different SSBs as an example. As shown in Figures 3 to 16, the ROs in SSB1, SSB2, and SSB3 are all numbered RO0 to RO7, which does not limit the embodiment of the present application. In actual implementation, the network device may also follow the following principle: first arrange the SSBs in ascending order of frequency domain first and then time domain, and then arrange the ROs of all SSBs within a preset time (mapping period or mapping pattern period) in ascending order.

[0331] For example, as shown in FIG24 , a preset time includes three SSBs: SSB1, SSB2, and SSB3. The ROs in SSB1 are numbered RO0 to RO3, the ROs in SSB2 are numbered RO4 to RO7, and the ROs in SSB3 are numbered RO8 to RO11. The corresponding identical ROs of these three SSBs may be RO0, RO4, and RO8 filled with pattern 1, or RO1, RO5, and RO9 filled with pattern 2, or RO2, RO6, and RO10 filled with pattern 3, or RO3, RO7, and RO11 filled with pattern 4. Among them, RO0, RO4, and RO8 have the same frequency domain position but different time domain positions; RO1, RO5, and RO9 have the same frequency domain position but different time domain positions; RO2, RO6, and RO10 have the same frequency domain position but different time domain positions; RO3, RO7, and RO11 have the same frequency domain position but different time domain positions.

[0332] Figure 25 shows a structural diagram of a communication device provided in an embodiment of the present application. The communication device 250 can be a terminal device, a chip in the terminal device, a system on a chip, or other device capable of implementing the functions of the terminal device in the above method. The communication device 250 can be used to perform the functions of the terminal device involved in the above method embodiment. As shown in Figure 25, the communication device 250 includes: a transmission module 251 and a processing module 252.

[0333] Transmission module 251 may be configured to receive configuration information from a network device. This configuration information may indicate PRACH resources for repeated transmission on the same beam or different beams. The PRACH resources include: a preamble for repeated transmission and an RO for repeated transmission of the preamble. Processing module 252 may be configured to determine, based on the configuration information, multiple ROs in a single beam or ROs in multiple beams for repeated transmission of the preamble. Transmission module 251 may also be configured to repeatedly transmit the same preamble on multiple ROs in a beam or on the same corresponding ROs in multiple beams.

[0334] In some embodiments, the configuration information may include preamble configuration parameters. The processing module 252 may also be configured to generate a first resource pool according to the preamble configuration parameters. The first resource pool includes one or more preambles for repeated transmission.

[0335] In some embodiments, the preamble configuration parameters may include: the number of preambles for repeated transmission, the number of bits of each shift of the root sequence of the repeatedly transmitted preamble, and the root index of the repeatedly transmitted preamble. The processing module 252 may be specifically configured to generate a first resource pool based on the number of preambles for repeated transmission, the number of bits of each shift of the root sequence of the repeatedly transmitted preamble, and the root index of the repeatedly transmitted preamble.

[0336] In some embodiments, the preamble configuration parameters may include: a starting index of a preamble for repeated transmission and the number of preambles for repeated transmission. The processing module 252 may be specifically configured to: divide the first resource pool from the second resource pool based on the starting index of the preamble for repeated transmission and the number of preambles for repeated transmission. The second resource pool may be generated based on the following parameters: the number of preambles for non-repeated transmission, the number of bits of each shift of the root sequence of the preamble for non-repeated transmission, and the root index of the preamble for non-repeated transmission.

[0337] In some embodiments, the configuration information may further include a first parameter and a second parameter, where the first parameter indicates the number of times N the preamble is repeatedly transmitted on the same beam, and the second parameter indicates the RO interval for repeatedly transmitting the preamble on the same beam, where N is an integer greater than or equal to 2. The processing module 252 may be specifically configured to determine N ROs in a beam based on the first parameter and the second parameter, and repeatedly transmit the same preamble on the N ROs.

[0338] In some embodiments, the configuration information may further include: a third parameter, where the third parameter is used to indicate whether to enable repeated transmission of the same preamble on the same beam.

[0339] In some embodiments, the configuration information may further include: a fourth parameter, which is used to indicate the number K of beams in which the multi-beam preamble is repeatedly transmitted. The processing module 252 may be specifically configured to: determine the preamble corresponding to each of the K beams based on the fourth parameter, the first resource pool, and the number of preambles to be repeatedly transmitted; and repeatedly transmit the same preamble on the same RO corresponding to the K beams. The K beams include the strongest beam, which is the beam with the strongest signal strength received by the terminal device among all beams transmitted by the network device, and the same preamble is a preamble randomly selected by the terminal device from the preamble corresponding to the strongest beam.

[0340] In some embodiments, the fourth parameter may also be used to indicate that the same preamble is reused every K beams. It is understood that the preamble used for repeated transmission may be reused every K beams.

[0341] In some embodiments, the configuration information may further include a fifth parameter, which is used to indicate whether to enable repeated transmission of the same preamble on different beams. It is understood that the fifth parameter is equivalent to an enable switch, and by setting this parameter, the terminal device can be triggered to perform multiple PRACH retransmissions on different beams.

[0342] In some embodiments, the corresponding identical ROs of the K beams are: identically numbered ROs in each beam of the plurality of beams.

[0343] Figure 26 shows a structural diagram of another communication device provided in an embodiment of the present application. The communication device 260 can be a network device, a chip in a network device, a system-on-chip, or other device capable of implementing the functions of the network device in the above method. The communication device 260 can be used to perform the functions of the network device involved in the above method embodiment. As shown in Figure 26, the communication device 260 includes: a transmission module 261 and a configuration module 262.

[0344] Transmission module 261 can be used to send configuration information configured by configuration module 262 to a terminal device. The configuration information can indicate PRACH resources for repeated transmission on the same beam or different beams. The PRACH resources include: a preamble for repeated transmission and an RO for repeated transmission of the preamble. Transmission module 261 can also be used to receive multiple PRACHs from multiple ROs in a beam, or multiple PRACHs from ROs in multiple beams, from a terminal device, where each of the multiple PRACHs carries the same preamble.

[0345] In some embodiments, the configuration information may include preamble configuration parameters, and the preamble configuration parameters are used to generate a preamble resource pool for repeated transmission, that is, a first resource pool. The first resource pool includes one or more preambles for repeated transmission.

[0346] In some embodiments, the preamble configuration parameters may include: the number of preambles for repeated transmission, the number of bits of the root sequence of the preamble for repeated transmission each time, and the root index of the preamble for repeated transmission.

[0347] In some embodiments, the preamble configuration parameters may include: a starting index of a preamble for repeated transmission, and the number of preambles for repeated transmission.

[0348] In some embodiments, the configuration information may include: a first parameter and a second parameter, the first parameter is used to indicate the number of times N that the preamble is repeatedly sent on the same beam, and the second parameter is used to indicate the RO interval for repeatedly sending the preamble on the same beam.

[0349] In some embodiments, the configuration information may further include: a third parameter, where the third parameter is used to indicate whether to enable repeated transmission of the same preamble on the same beam.

[0350] In some embodiments, the configuration information may further include: a fourth parameter, where the fourth parameter is used to indicate the number K of beams for multi-beam repeated transmission of preamble.

[0351] In some embodiments, the fourth parameter may also be used to indicate that the same preamble is multiplexed every K beams.

[0352] In some embodiments, the configuration information may further include: a fifth parameter, where the fifth parameter is used to indicate whether to enable repeated transmission of the same preamble on different beams.

[0353] The embodiment of the present application also provides a computer-readable storage medium having a computer program stored therein; when the computer-readable storage medium is run on a terminal device or a network device, the terminal device or the network device executes the method shown above. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that includes one or more media that can be integrated. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, or a tape), an optical medium, or a semiconductor medium (for example, a solid state disk (SSD)), etc.

[0354] An embodiment of the present application further provides a computer program product, which includes computer program code. When the computer program code runs on a computer, the computer executes the methods in the above embodiments.

[0355] The present application also provides a chip that is coupled to a memory and is used to read and execute computer programs or instructions stored in the memory to perform the methods in the above embodiments. The chip can be a general-purpose processor or a dedicated processor. It should be noted that the chip can be implemented using the following circuits or devices: one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing the various functions described throughout this application.

[0356] It should be noted that the terms "first" and "second" in the specification, claims, and drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0357] It should be understood that in the present application, "at least one" means one or more, "more than one" means two or more, "at least two" means two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0358] It should be understood that in the embodiments of the present application, "B corresponding to A" means that B is associated with A. For example, B can be determined based on A. It should also be understood that determining B based on A does not mean determining B based solely on A; B can also be determined based on A and / or other information. In addition, the "connection" in the embodiments of the present application refers to various connection methods, such as direct connection and indirect connection, to achieve communication between devices, and the embodiments of the present application do not impose any limitations on this.

[0359] Unless otherwise specified, the "transmission" (transmit / transmission) appearing in the embodiments of the present application refers to bidirectional transmission, including the actions of sending and / or receiving. Specifically, the "transmission" in the embodiments of the present application includes the sending of data, the receiving of data, or the sending of data and the receiving of data. In other words, the data transmission here includes uplink and / or downlink data transmission. Data may include channels and / or signals, uplink data transmission refers to uplink channel and / or uplink signal transmission, and downlink data transmission refers to downlink channel and / or downlink signal transmission.

[0360] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0361] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0362] Units described as separate components may or may not be physically separate, and components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0363] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0364] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a device, such as a single-chip microcomputer, chip, etc., or a processor to execute all or part of the steps of the method provided in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks or optical disks.

[0365] The above content is only a specific embodiment of this application, but the scope of protection of this application is not limited to this. Any changes or replacements within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for repeatedly sending a preamble, characterized in that: The method comprises: The terminal device receives configuration information from the network device, where the configuration information indicates a physical random access channel (PRACH) resource for repeated transmission on the same beam or different beams, where the PRACH resource includes: a preamble for repeated transmission and a random access signal opportunity (RO) for repeated transmission of the preamble; The terminal device repeatedly sends the same preamble code on multiple ROs of one beam or on the corresponding same ROs of multiple beams according to the configuration information.

2. The method according to claim 1, characterized in that The configuration information includes preamble configuration parameters; The method further comprises: The terminal device generates a first resource pool according to the preamble configuration parameters, where the first resource pool includes one or more preambles for repeated transmission, and the same preamble is a preamble randomly selected by the terminal device from the first resource pool.

3. The method according to claim 2, characterized in that The preamble configuration parameters include: the number of preambles for repeated transmission, the number of bits of the root sequence of the preamble for repeated transmission each time, and the root index of the preamble for repeated transmission.

4. The method according to claim 2, characterized in that The preamble configuration parameters include: a starting index of the preamble for repeated transmission, and the number of preambles for repeated transmission; The terminal device generates a first resource pool according to the preamble configuration parameter, including: The terminal device divides the first resource pool from the second resource pool according to the starting index of the preamble code for repeated transmission and the number of the preamble codes for repeated transmission; The second resource pool is generated according to the following parameters: the number of preambles for non-repeated transmission, the number of bits of each shift of the root sequence of the preamble for non-repeated transmission, and the root index of the preamble for non-repeated transmission.

5. The method according to any one of claims 1 to 4, characterized in that The configuration information includes: a first parameter and a second parameter, the first parameter is used to indicate the number of times N that the preamble code is repeatedly sent on the same beam, and the second parameter is used to indicate the RO interval for repeatedly sending the preamble code on the same beam, where N is an integer greater than or equal to 2; The terminal device repeatedly sends the same preamble code on multiple ROs of a beam according to the configuration information, including: The terminal device determines N ROs in the one beam according to the first parameter and the second parameter, and repeatedly sends the same preamble code on the N ROs.

6. The method according to claim 5, characterized in that The N ROs belong to the same group, where the same group is a group randomly selected by the terminal device from the groups included in the one beam; Before determining N ROs in the one beam, the method further includes: The terminal device determines a total number M of ROs included in the same beam within a preset time; The terminal device uses the following formula to determine each group used for repeatedly transmitting the preamble code in the same beam: {(s+nk)mod M}; Wherein, s represents the first RO mapped in each group of the same beam, n = (0, 1, ..., N-1), k represents the RO interval for repeatedly sending the preamble code on the same beam, mod is the modulo operator, s ≤ M.

7. The method according to claim 6, characterized in that The preset time is a mapping period or a mapping pattern period.

8. The method according to claim 6, characterized in that When the configuration information also includes a preset rule, the ROs included in the same beam within the preset time are sorted according to the rule of time domain first and frequency domain second; or, when the configuration information does not include the preset rule, the ROs included in the same beam within the preset time are sorted according to the rule of frequency domain first and time domain second.

9. The method according to claim 6, characterized in that The time domain resources of the ROs in the group are the same, but the frequency domain resources are different; or, The ROs in the group have different time domain resources but the same frequency domain resources; or The one group contains ROs having different time domain resources and different frequency domain resources.

10. The method according to any one of claims 5 to 9, characterized in that The one beam is the strongest beam, and the strongest beam is the beam with the strongest signal strength received by the terminal device among all beams sent by the network device.

11. The method according to any one of claims 5 to 10, characterized in that The configuration information also includes: a third parameter, and the third parameter is used to indicate whether to enable repeated transmission of the same preamble code on the same beam.

12. The method according to any one of claims 2 to 4, characterized in that The configuration information includes: a fourth parameter, the fourth parameter is used to indicate the number K of beams for multi-beam repeated transmission of preamble codes, K is an integer greater than or equal to 2; the preamble code configuration parameter includes: the number of preamble codes for repeated transmission; The terminal device repeatedly sends the same preamble code on the same RO corresponding to the multiple beams according to the configuration information, including: The terminal device determines, based on the fourth parameter, the first resource pool, and the number of preambles for repeated transmission, a preamble corresponding to each of the K beams; The terminal device repeatedly sends the same preamble code on the corresponding same RO of the K beams, and the K beams include the strongest beam, which is the beam with the strongest signal strength received by the terminal device among all beams sent by the network device, and the same preamble code is a preamble code randomly selected by the terminal device from the preamble codes corresponding to the strongest beam.

13. The method according to claim 12, characterized in that The number of preamble codes corresponding to each of the K beams is equal to: the number of preamble codes for repeated transmission divided by the number K.

14. The method according to claim 12, characterized in that The fourth parameter is also used to indicate that the same preamble code is multiplexed every K beams.

15. The method according to claim 12, characterized in that The signal strengths of the K beams are greater than the signal strengths of other beams sent by the network device.

16. The method according to claim 12, characterized in that The K beams include: the strongest beam, beams broadcast before the strongest beam, and beams broadcast before and after the strongest beam; or, The K beams include: the strongest beam, and the beams broadcast before the strongest beam; or, The K beams include: the strongest beam, and the beams broadcast after the strongest beam.

17. The method according to any one of claims 12 to 15, characterized in that The configuration information also includes: a fifth parameter, and the fifth parameter is used to indicate whether to enable repeated transmission of the same preamble code on different beams.

18. The method according to any one of claims 12 to 17, characterized in that The same ROs corresponding to the K beams are: ROs with the same number in each of the K beams.

19. A method for repeatedly sending a preamble, characterized in that: The method comprises: The network device sends configuration information to the terminal device, where the configuration information indicates PRACH resources for repeated transmission on the same beam or different beams, where the PRACH resources include: a preamble for repeated transmission and an RO for repeated transmission of the preamble; The network device receives multiple PRACHs on multiple ROs from one beam, or multiple PRACHs on ROs from multiple beams from the terminal device; wherein each of the multiple PRACHs carries the same preamble code.

20. The method according to claim 19, characterized in that The configuration information includes preamble configuration parameters, and the preamble configuration parameters are used to generate a preamble resource pool for repeated transmission.

21. The method according to claim 20, characterized in that The preamble configuration parameters include: the number of preambles for repeated transmission, the number of bits of each shift of the root sequence of the preamble for repeated transmission, and the root index of the preamble for repeated transmission; Alternatively, the preamble configuration parameters include: a starting index of a preamble for repeated transmission, and the number of preambles for repeated transmission.

22. The method according to any one of claims 19 to 21, characterized in that The configuration information includes: a first parameter and a second parameter, the first parameter is used to indicate the number of times N that the preamble code is repeatedly sent on the same beam, and the second parameter is used to indicate the RO interval for repeatedly sending the preamble code on the same beam.

23. The method according to claim 22, characterized in that The configuration information further includes a preset rule, where the preset rule is that the ROs included in the same beam within a preset time are sorted according to a rule of firstly in the time domain and then in the frequency domain.

24. The method according to claim 23, wherein The preset time is a mapping period or a mapping pattern period.

25. The method according to any one of claims 22 to 24, characterized in that The configuration information also includes: a third parameter, and the third parameter is used to indicate whether to enable repeated transmission of the same preamble code on the same beam.

26. The method according to any one of claims 19 to 21, characterized in that The configuration information includes: a fourth parameter, where the fourth parameter is used to indicate the number K of beams for multi-beam repeated transmission of preamble codes.

27. The method according to claim 26, characterized in that The fourth parameter is also used to indicate that the same preamble code is multiplexed every K beams.

28. The method according to claim 26 or 27, characterized in that The configuration information also includes: a fifth parameter, and the fifth parameter is used to indicate whether to enable repeated transmission of the same preamble code on different beams.

29. The method according to any one of claims 19 to 28, characterized in that The one beam is the strongest beam, or the multiple beams include the strongest beam; wherein the strongest beam is the beam with the strongest signal strength received by the terminal device among all beams sent by the network device; The method further comprises: The network device sends downlink data to the terminal device on the strongest beam.

30. A communication device, characterized in that: The communication device includes a processor, a communication interface, and a memory coupled to the processor and the communication interface; The memory stores instructions, and when the processor executes the instructions, the communication device executes the preamble code repetition transmission method according to any one of claims 1 to 18, or the communication device executes the preamble code repetition transmission method according to any one of claims 19 to 29.

31. A communication system, characterized in that: The communication system includes terminal equipment and network equipment; The terminal device is used to execute the preamble code repetition sending method according to any one of claims 1 to 18, and the network device is used to execute the preamble code repetition sending method according to any one of claims 19 to 29.

32. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program; Wherein, when the computer program is run on a terminal device, the terminal device executes the preamble code repetition sending method as described in any one of claims 1 to 18; or, when the computer program is run on a network device, the network device executes the preamble code repetition sending method as described in any one of claims 19 to 29.

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