CN117336739A

CN117336739A - Physical random access channel repeated transmission method, device, terminal and storage medium

Info

Publication number: CN117336739A
Application number: CN202210716833.2A
Authority: CN
Inventors: 李南希; 朱剑驰; 尹航; 佘小明; 陈鹏
Original assignee: China Telecom Corp Ltd
Current assignee: China Telecom Corp Ltd
Priority date: 2022-06-23
Filing date: 2022-06-23
Publication date: 2024-01-02

Abstract

The disclosure provides a physical random access channel repeated transmission method, a device, a terminal and a storage medium, and relates to the technical field of mobile communication. The PRACH repeated transmission method comprises the following steps: detecting a synchronous signal block broadcasted by a network side; determining a beam strategy of PRACH repeated transmission; and performing PRACH repeated transmission at PRACH transmission occasions according to the beam strategy. By the method, the PRACH transmission strategy of the terminal is adapted to the network and environment states at the transmission time, and the coverage performance and the transmission success rate of the PRACH are improved.

Description

Physical random access channel repeated transmission method, device, terminal and storage medium

Technical Field

The present disclosure relates to the field of mobile communications technologies, and in particular, to a method, an apparatus, a terminal, and a storage medium for PRACH (Physical Random Access Channel ) retransmission.

Background

In the related art, a UE (User Equipment) transmits a Preamble on a PRACH (Physical Random Access Channel ) transmission occasion indicated by a base station. According to the time-frequency position of the PRACH transmission time, the UE can calculate and obtain a corresponding RA-RNTI (RA Radio Network Temporary Identity, random access radio network temporary identifier) value; then, the UE monitors PDCCH in a RAR (Random Access Response ) time window, descrambles and detects downlink control information DCI 1_0, and further identifies the RAPID (Random Access Preamble Identifier, random preamble identifier) number in RAR information scheduled by the DCI (Downlink Control Information ), and the PRACH transmission is successful; otherwise the UE needs to retransmit a new PRACH, which would introduce additional delay. PRACH is a potentially coverage limited channel, especially for the high frequency band.

The current 3GPP NR real-17 protocol does not yet support repeated transmission of PRACH.

Disclosure of Invention

It is an object of the present disclosure to improve the coverage performance of PRACH.

According to an aspect of some embodiments of the present disclosure, a PRACH retransmission method is provided, including: detecting SSBs (Synchronization Signal block, synchronization signal blocks) broadcast by the network side; determining a beam strategy of PRACH repeated transmission; and performing PRACH repeated transmission at PRACH transmission occasions according to the beam strategy.

In some embodiments, the method further comprises: monitoring PDCCH in an RAR time window, and detecting DCI; determining corresponding PRACH transmission time according to RA-RNTI used by DCI of successful descrambling scheduling random access response RAR; message transmission is performed using the same transmit beam as the corresponding PRACH transmission occasion.

In some embodiments, the beam strategy comprises: the same transmit beam is employed at multiple PRACH transmission occasions or different transmit beams are employed at multiple PRACH transmission occasions.

In some embodiments, determining the beam strategy for PRACH retransmission comprises: and determining a beam strategy according to the system working frequency point, the Radio Resource Control (RRC) indication information or the signal receiving condition of the SSB.

In some embodiments, determining the beam strategy for PRACH retransmission comprises: determining a system working frequency point; under the condition that a system working frequency point belongs to a first frequency band, the same transmitting wave beam is adopted at a plurality of PRACH transmission occasions; and under the condition that the system working frequency point belongs to the second frequency band, different transmitting beams are adopted at a plurality of PRACH transmission occasions.

In some embodiments, the first frequency band is the FR1 frequency band for 5G communications and the second frequency band is the FR2 frequency band for 5G communications.

In some embodiments, determining the beam strategy for PRACH retransmission comprises: acquiring RRC indication information, wherein the RRC indication information carries a beam strategy; the beam strategy in the RRC indication information is determined.

In some embodiments, determining the beam strategy for PRACH retransmission comprises: the beam strategy is determined according to the reference signal received power RSRP of the received SSB.

In some embodiments, determining the beam strategy from the RSRP of the receiving SSB comprises: adopting the same transmitting wave beam at a plurality of PRACH transmission occasions under the condition that RSRP is larger than a preset first threshold and the difference value between the RSRP and the preset first threshold is larger than a preset first difference value; and under the condition that the RSRP is smaller than or equal to a preset first threshold or the difference value between the RSRP and the preset first threshold is smaller than or equal to a preset first value, different transmitting beams are adopted in a plurality of PRACH transmission occasions.

In some embodiments, determining the beam strategy from the reference signal received power RSRP for receiving SSBs comprises: under the condition that RSRP of a plurality of SSBs received in the first time length is larger than a preset second threshold, adopting the same transmitting beam at a plurality of PRACH transmission occasions; and under the condition that the minimum value in RSRP of the SSBs received in the first time length is smaller than or equal to a preset second threshold, adopting different transmitting beams at a plurality of PRACH transmission occasions.

In some embodiments, the first time length is a transmission period of the SSB.

In some embodiments, determining the beam strategy from the reference signal received power RSRP (Reference Signal Receiving Power, reference signal received power) that receives the SSB comprises: when the RSRP of the SSBs received in the second time period is greater than a third threshold value and the difference between the maximum value and the next-largest value in the RSRP values is greater than a predetermined second value, different transmission beams are adopted at a plurality of PRACH transmission occasions; and when the minimum value of the RSRP of the SSBs received in the second time length is smaller than or equal to a preset third threshold or the difference value between the maximum value and the next largest value in the RSRP values is smaller than or equal to a preset second value, adopting the same transmitting wave beam in a plurality of PRACH transmission occasions.

In some embodiments, the second time length is a transmission period of the SSB.

In some embodiments, the method further comprises: selecting an antenna panel with the maximum RSRP as a target antenna panel according to the RSRP of the received SSB; performing PRACH repeat transmission includes: and carrying out PRACH repeated transmission through the target antenna panel.

In some embodiments, performing PRACH repeat transmission at a PRACH transmission occasion according to a beam strategy comprises: according to PRACH resources configured by a network side, determining PRACH transmission time associated with the selected SSB; PRACH repeat transmissions are made on the associated PRACH transmission occasion.

In some embodiments, where the determined beam strategy is to employ different transmit beams for a plurality of PRACH transmission occasions, the transmit beams for the PRACH transmission occasions for the same time domain symbol position are the same; the transmit beams of PRACH transmission occasions for different time domain symbol positions are different.

In some embodiments, detecting DCI includes: descrambling and detecting DCI according to the RA-RNTI corresponding to the RAR time window, wherein when the network side equipment detects the same Preamble from the same terminal on PRACH transmission occasions of different time domain symbol positions, the network side equipment determines the RA-RNTI according to the time-frequency position of the PRACH transmission occasion corresponding to the Preamble with the largest receiving power, scrambles the DCI for scheduling the RAR by using the determined RA-RNTI, and carries the corresponding RAID through RAR information.

In some embodiments, performing message transmission using the same transmit beam as the corresponding PRACH transmission occasion comprises: transmission of Msg3 (Message 3 of the random access procedure) is performed using the same transmission beam as the corresponding PRACH transmission occasion.

According to an aspect of some embodiments of the present disclosure, there is provided a PRACH retransmission apparatus, including: an SSB detection unit configured to detect a network-side broadcast SSB; a beam strategy determination unit configured to determine a beam strategy of PRACH repeated transmission; and a transmission unit configured to perform PRACH retransmission at a PRACH transmission occasion according to the beam strategy.

In some embodiments, the apparatus further comprises: a DCI detection unit configured to monitor PDCCH in an RAR time window and detect DCI; a transmit beam determining unit configured to determine a transmit beam used for a corresponding PRACH transmission occasion according to an RA-RNTI used by DCI for successfully descrambling and scheduling a random access response RAR; and a message transmitting unit configured to perform message transmission using the same transmission beam as the corresponding PRACH transmission occasion.

In some embodiments, the apparatus further comprises: a target antenna determination unit configured to select an antenna panel having the largest RSRP as a target antenna panel according to the RSRP of the reception SSB; the transmission unit is configured to perform PRACH repeat transmission through the target antenna panel.

According to an aspect of some embodiments of the present disclosure, there is provided a PRACH retransmission apparatus, including: a memory; and a processor coupled to the memory, the processor configured to perform any of the PRACH retransmission methods above based on instructions stored in the memory.

According to an aspect of some embodiments of the present disclosure, a computer-readable storage medium is presented, on which is stored computer program instructions, which when executed by a processor, implement the steps of any of the PRACH repeat transmission methods mentioned above.

According to an aspect of some embodiments of the present disclosure, a terminal is provided, including any one of the PRACH retransmission apparatuses above.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate and explain the present disclosure, and together with the description serve to explain the present disclosure. In the drawings:

fig. 1 is a flow chart of some embodiments of a PRACH retransmission method of the present disclosure.

Fig. 2A is a schematic diagram of some embodiments of a PRACH retransmission method of the present disclosure.

Fig. 2B is a schematic diagram of further embodiments of the PRACH retransmission method of the present disclosure.

Fig. 3 is a flow chart of further embodiments of the PRACH retransmission method of the present disclosure.

Fig. 4 is a schematic diagram of some embodiments of a PRACH retransmission apparatus of the present disclosure.

Fig. 5 is a schematic diagram of other embodiments of a PRACH retransmission apparatus of the present disclosure.

Fig. 6 is a schematic diagram of further embodiments of PRACH retransmission apparatuses of the present disclosure.

Fig. 7 is a schematic diagram of some embodiments of a terminal of the present disclosure.

Detailed Description

The technical scheme of the present disclosure is described in further detail below through the accompanying drawings and examples.

A flow chart of some embodiments of the PRACH retransmission method of the present disclosure is shown in fig. 1.

In step 120, SSBs broadcast on the network side are detected. In some embodiments, the terminal performs a cell search in an attempt to detect SSBs broadcast on the network side.

In step 140, the terminal determines a beam strategy for PRACH repeated transmission according to a preset rule. The beam strategy refers to a strategy for selecting a transmitting beam in PRACH repeated transmission, and the beam strategy is as follows: and the terminal adopts the same or different transmitting beams to carry out PRACH repeated transmission at a plurality of PRACH transmission occasions. In some embodiments, the different beams may be differently shaped beams, such as by adjusting parameters of the base elements of the phased array such that signals at certain angles obtain constructive interference and signals at other angles obtain destructive interference. In some embodiments, the transmit beams may be made different by using parameters of the base units of different phased arrays. In some embodiments, different transmit beam types may be preset, and a corresponding number of transmit beams may be selected among the preset transmit beam types after determining the beam strategy.

In some embodiments, the terminal may use either the same transmit beam or a different transmit beam according to a predetermined rule. In some embodiments, employing the same transmit beam at multiple PRACH transmission occasions refers to employing the same transmit beam at different PRACH transmission occasions. In some embodiments, employing different transmit beams at multiple PRACH transmission occasions means that the transmit beams employed at different PRACH transmission occasions are not exactly the same, i.e., there are at least two transmit beams. In some embodiments, employing different transmit beams at multiple PRACH transmission occasions may be: the transmission beams of the PRACH transmission occasions with the same time domain symbol positions are the same, and the transmission beams of the PRACH transmission occasions with different time domain symbol positions are different, so that the realization difficulty is reduced, and the popularization and the application are facilitated.

In some embodiments, the preset rule may be to determine the beam strategy according to any one of a system operating frequency point, RRC indication information, or a signal reception condition of the SSB.

In some embodiments, under the condition that the preset rule is to determine the beam strategy of the PRACH repeated transmission according to the system working frequency point, the terminal may determine the system working frequency point first, and further determine the frequency band to which the system working frequency band belongs. In some embodiments, under the condition that the system operating frequency point belongs to a preset first frequency band, the same transmitting beam is adopted at a plurality of PRACH transmission occasions; under the condition that the system working frequency point belongs to a preset second frequency band, different transmitting beams are adopted at a plurality of PRACH transmission occasions. In some embodiments, the first frequency band is the FR1 frequency band for 5G communications and the second frequency band is the FR2 frequency band for 5G communications.

By the method, different transmitting beams can be adopted in the FR2 frequency band with a relatively higher working frequency band, so that the coverage performance of the PRACH is improved, and the probability of successful PRACH transmission is improved.

In some embodiments, the network side device may determine a beam policy to be adopted by the terminal, and carry the beam policy through RRC indication information. Under the condition that the preset rule is that the beam strategy of PRACH repeated transmission is determined according to the RRC indication information, the terminal can acquire the RRC indication information, and then the beam strategy is determined to be the beam strategy carried in the RRC indication information. In some embodiments, the network side device, such as a base station, may determine a beam policy according to factors such as current wireless transmission quality, transmission success rate or network busyness, and send the beam policy to the terminal through RRC indication information. In some embodiments, the beam strategy carried in the RRC indication information may be a beam strategy type identifier, and the terminal determines the beam strategy to be used according to the corresponding relationship between the recorded beam strategy type identifier and the beam strategy. By the method, the control capability of the network side to the terminal can be improved by controlling the beam strategy adopted by the terminal by the network side.

In some embodiments, in the case that the preset rule is to determine the beam strategy of PRACH retransmission according to the signal reception condition of the SSB, the terminal may determine the beam strategy according to the reference signal received power RSRP of the received SSB.

In some embodiments, the terminal may determine the beam strategy based on the RSRP (Reference Signal Receiving Power, reference signal received power) of the SSB received at a single time. In some embodiments, the terminal compares the RSRP of the SSB with a predetermined first threshold, and determines the beam strategy to employ the same transmit beam at a plurality of PRACH transmission occasions if the RSRP is greater than the predetermined first threshold and the difference from the predetermined first threshold is greater than the predetermined first difference; and determining a beam strategy to adopt different transmitting beams at a plurality of PRACH transmission occasions under the condition that the RSRP is smaller than or equal to a preset first threshold or the difference value between the RSRP and the preset first threshold is smaller than or equal to a preset first value. By the method, the beam strategy can be determined according to the RSRP which can reflect the wireless signal strength, under the condition of good RSRP signals, the same transmitting beam is adopted at a plurality of PRACH transmission occasions, and under the condition of bad RSRP signals, different transmitting beams are adopted at a plurality of PRACH transmission occasions, so that the probability of transmission failure under the condition of bad wireless signal strength is reduced, the coverage performance of PRACH is improved, and the probability of successful PRACH transmission is improved.

In some embodiments, the terminal may also determine the beam strategy based on the RSRP of the SSB received multiple times.

In some embodiments, if RSRP of the SSBs received by the terminal in the first time period are all greater than a predetermined second threshold, determining that the selected beam strategy is to employ the same transmit beam at a plurality of PRACH transmission occasions; and if the minimum value of RSRP of the SSBs received by the terminal in the first time length is smaller than or equal to a preset second threshold, determining the selected beam strategy to adopt different transmitting beams at a plurality of PRACH transmission occasions. In some embodiments, the number of the plurality of SSBs is not less than 2. In some embodiments, the first time length is a transmission period of the SSB. In some embodiments, the transmission period of the SSB defaults to a length of 2 system frames (20 ms). By the method, the selected beam strategy can be determined according to the wireless signal intensity in a period of time, and the same transmitting beam is adopted in a plurality of PRACH only when the wireless signal intensity in a period of time can meet the requirement, so that the probability of transmission failure under the conditions of poor wireless signal intensity and sudden change is further reduced, the coverage performance of the PRACH is improved, and the probability of successful PRACH transmission is improved.

In some embodiments, if RSRP of the SSBs received by the terminal in the second time period is greater than the third threshold and a difference between a maximum value and a next-largest value of the RSRP values is greater than a predetermined second value, determining the selected beam strategy to employ different transmission beams at the PRACH transmission occasions; and if the minimum value of the RSRP of the SSBs received in the second time length is smaller than or equal to a preset third threshold or the difference value between the maximum value and the next largest value in the RSRP values is smaller than or equal to a preset second value, adopting the same transmitting wave beam in a plurality of PRACH transmission occasions. In some embodiments, the number of the plurality of SSBs is not less than 2. In some embodiments, the second time length is a transmission period of the SSB. In some embodiments, the transmission period of the SSB defaults to a length of 2 system frames (20 ms). By the method, the wave beam strategy can be selected by utilizing the fluctuation condition of the RSRP, and under the condition of larger fluctuation, different transmitting wave beams are adopted for a plurality of PRACH, so that the probability of transmission failure caused by signal strength fluctuation is reduced, the coverage performance of the PRACH is further improved, and the probability of successful PRACH transmission is improved.

In some embodiments, the first time length and the second time length may be set or adjusted as required, and may be the same or different. In some embodiments, the predetermined first, second, and third thresholds may be set or adjusted as desired, and any two thresholds may be the same or different. By such a method, the controllability can be improved.

In step 160, PRACH retransmission is performed at a PRACH transmission occasion according to a beam strategy. In some embodiments, the terminal may determine, according to PRACH resources configured by the network side, a PRACH transmission occasion associated with the selected SSB, and further perform PRACH retransmission on the associated PRACH transmission occasion.

In some embodiments, as shown in fig. 2A, the terminal selects ssb#1 in the cell search phase, and PRACH transmission occasions associated with ssb#1 are PRACH transmission occasions #0, #2, #4, and #6. If the beam strategy is selected to use the same transmit beam at multiple PRACH transmission occasions, the same PRACH transmission beam is used at transmission occasions #0, #2, #4, #6.

In some embodiments, as shown in fig. 2B, the terminal selects ssb#1 in the cell search phase, and PRACH transmission occasions associated with ssb#1 are PRACH transmission occasions #0, #2, #4, and #6. If the beam strategy selected by the terminal is that different transmission beams are adopted at a plurality of PRACH transmission occasions, the terminal adopts the same transmission beam (beam # 1) at the two transmission occasions because the time domain symbol positions of the PRACH transmission occasions #0 and #2 are the same; the same terminal uses the same transmission beam (beam # 2) at PRACH transmission occasions #4 and #6.

Based on the mode in the above embodiment, different beam strategies for PRACH transmission are set, and a proper beam strategy is selected according to the received SSB and a preset rule, so that the PRACH transmission strategy can adapt to the network and environmental conditions at the transmission time, and the coverage performance and the transmission success rate of the PRACH are improved.

In some embodiments, in the PRACH transmission method disclosed in the present disclosure, for a case where a terminal has a plurality of antenna panels (panels), each antenna Panel is configured to receive a radio signal within a certain range (for example, the terminal is configured with two antenna panels, a first Panel is configured to receive a radio signal within a first spatial direction range, and a second Panel is configured to receive a radio signal within a second spatial direction range), an antenna Panel with the largest RSRP may be selected as a target antenna Panel according to the RSRP of the receiving SSB, and further PRACH retransmission is performed through the target antenna Panel when PRACH retransmission is performed, so as to further improve the coverage performance and the transmission success rate of the PRACH.

In some embodiments, as shown in fig. 1, the PRACH retransmission method of the present disclosure may further comprise steps 170-180.

In step 170, the terminal monitors PDCCH in the RAR time window, detects DCI, and further determines a corresponding PRACH transmission opportunity according to RA-RNTI used by DCI for successfully descrambling and scheduling RAR. In some embodiments, the manner of detecting DCI and scheduling RAR may be any one of the related art.

In some embodiments, when the network side device detects the same Preamble from the same terminal on PRACH transmission occasions of different time domain symbol positions, the network side device determines RA-RNTI according to the time-frequency position of the PRACH transmission occasion corresponding to the Preamble with the largest received power, scrambles DCI for scheduling RAR by using the determined RA-RNTI, carries the corresponding RAPID identifier through RAR information, and sends the same through PDCCH. After finishing one PRACH transmission, the terminal side monitors PDCCH in a corresponding RAR time window, descrambles and detects DCI according to RA-RNTI corresponding to the RAR time window.

In some embodiments, the terminal may monitor the PDCCH within a corresponding RAR time window after completing one PRACH transmission. When the terminal determines that RAR can be successfully scheduled, the PRACH transmission is successful, the terminal can determine DCI triggering the successful scheduling of the RAR, further determine RA-RNTI used for descrambling the DCI, then determine corresponding PRACH transmission opportunity according to the association relation between the RA-RNTI and the PRACH transmission opportunity, and further determine a transmitting beam used under the corresponding PRACH transmission opportunity. In some embodiments, when determining that the PRACH transmission is successful, the terminal may directly determine that the corresponding PRACH transmission opportunity may be determined according to the association relationship between the DCI and the PRACH transmission time.

In step 180, the terminal performs message transmission using the same transmission beam as the corresponding PRACH transmission occasion. In some embodiments, the terminal performs transmission of Msg3 using the same transmit beam as the corresponding PRACH transmission occasion.

In some embodiments, if the beam strategy employed in the preamble step 140 is to employ the same transmit beam at multiple PRACH transmission occasions, then in step 180, the transmission of Msg3 is performed using the same transmit beam as any PRACH transmission occasion. If the beam strategy employed in the preamble step 140 is to employ different transmit beams at multiple PRACH transmission occasions, then in step 180, the transmission of Msg3 is performed using the same transmit beam as the PRACH transmission occasion determined in step 170.

In some embodiments, as shown in fig. 2B, the network side detects the same preambles at PRACH transmission occasions #0, #2, #4, and #6, and determines that these preambles are multiple PRACH transmissions sent by the same user. In addition, assuming that the network detects that the Preamble received power detected at the PRACH transmission opportunity #6 is strongest, the network side calculates and obtains an RA-RNTI according to the time-frequency position of the PRACH transmission opportunity #6, and uses the RA-RNTI to scramble DCI 1_0 of the scheduled RAR, and simultaneously places the corresponding RAPID number into the RAR information. The UE uses RA-RNTI corresponding to PRACH transmission time #6 to descramble DCI 1_0 successfully, and can identify the RAID number in RAR information scheduled by the DCI, so that the UE successfully transmits the PRACH. At this time, the UE transmits Msg3 using PRACH transmit beam at PRACH transmission timing #6, i.e., beam # 2.

By the method, the success rate of PRACH transmission can be improved, the burden of repeated transmission is reduced, and the quality and success rate of Msg3 transmission can be improved.

A flowchart of further embodiments of the PRACH retransmission method of the present disclosure is shown in fig. 3.

In step 320, the terminal performs cell search in an attempt to detect SSB broadcasted on the network side

In step 340, a beam strategy for PRACH retransmission is determined.

In step 350, the terminal selects an antenna panel with the largest RSRP as a target antenna panel according to the RSRP of the received SSB.

In some embodiments, there is no order requirement between the steps 340, 350, and in some embodiments, the steps 340, 350 may be performed in parallel.

In step 360, the terminal performs PRACH repeat transmission through the target antenna panel at the PRACH transmission opportunity according to the selected beam strategy. In some implementations, after determining the beam strategy, the terminal may select a specific transmit beam according to a preset.

In step 370, after performing PRACH transmission, the terminal descrambles and detects DCI according to the RA-RNTI corresponding to the RAR time window.

In step 380, the terminal performs transmission of Msg3 using the same transmit beam as the corresponding PRACH transmission occasion.

By means of the method in the embodiment, the terminal with the plurality of antenna panels can select the panel with higher RSRP to execute PRACH transmission, so that PRACH coverage performance is improved in the aspects of the type of the transmitting beam and the selected antenna panel, and the success rate of PRACH transmission is further improved.

A schematic diagram of some embodiments of PRACH retransmission apparatus 41 of the present disclosure is shown in fig. 4.

The SSB detection unit 411 can detect SSBs broadcast on the network side. In some embodiments, SSB detection unit 411 performs cell search in an attempt to detect SSBs broadcast on the network side.

The beam policy determining unit 412 may determine a beam policy of PRACH repeated transmission according to a preset rule. The beam strategy refers to a strategy for selecting a transmission beam in PRACH retransmission, and includes using the same or different transmission beams to perform PRACH retransmission at a plurality of PRACH transmission occasions. In some embodiments, employing the same transmit beam at multiple PRACH transmission occasions refers to employing the same transmit beam at different PRACH transmission occasions. In some embodiments, employing different transmit beams at multiple PRACH transmission occasions means that the transmit beams employed at different PRACH transmission occasions are not exactly the same, i.e., there are at least two transmit beams. In some embodiments, employing different transmit beams at multiple PRACH transmission occasions may be: the transmission beams of the PRACH transmission occasions of the same time domain symbol positions are the same, and the transmission beams of the PRACH transmission occasions of different time domain symbol positions are different.

The transmission unit 413 can perform PRACH retransmission at a PRACH transmission occasion according to a beam strategy. In some embodiments, the transmission unit 413 may determine, according to PRACH resources configured by the network side, a PRACH transmission occasion associated with the selected SSB, and further perform PRACH retransmission on the associated PRACH transmission occasion.

The device can enable the PRACH transmission strategy to be suitable for the network and environment states at the transmission moment, and improve the coverage performance and the transmission success rate of the PRACH.

In some embodiments, the beam strategy determination unit 412 can determine the beam strategy from the system operating frequency points. In some embodiments, under the condition that the system operating frequency point belongs to a preset first frequency band, the same transmitting beam is adopted at a plurality of PRACH transmission occasions; under the condition that the system working frequency point belongs to a preset second frequency band, different transmitting beams are adopted at a plurality of PRACH transmission occasions. In some embodiments, the first frequency band is the FR1 frequency band for 5G communications and the second frequency band is the FR2 frequency band for 5G communications.

The device can adopt different transmitting beams in the FR2 frequency band with a relatively higher frequency band, so that the coverage performance of the PRACH is improved, and the probability of successful PRACH transmission is improved.

In some embodiments, the beam policy determining unit 412 may determine a beam policy according to an RRC indication message, where the network side device may determine the beam policy that needs to be adopted by the terminal, and carry the beam policy through the RRC indication message. The device can control the beam strategy adopted by the terminal through the network side, and improve the control capability of the network side to the terminal.

In some embodiments, the beam policy determining unit 412 is capable of determining the beam policy according to the signal reception situation of the SSB, such as determining the beam policy according to the reference signal received power RSRP of the received SSB. Specifically, the terminal may determine the beam policy according to RSRP of the SSB received once, or may determine the beam policy according to RSRP of the SSB received multiple times. The device can reduce the probability of transmission failure under the condition of poor wireless signal strength, improve the coverage performance of PRACH and improve the probability of successful PRACH transmission.

In some embodiments, as shown in fig. 4, the PRACH retransmission apparatus 41 may further include a DCI detection unit 414 and a transmit beam determination unit 415.

DCI detection section 414 can monitor the PDCCH in the RAR time window and detect DCI.

The transmit beam determining unit 415 can determine the transmit beam used for the corresponding PRACH transmission occasion according to the RA-RNTI used by the DCI for successfully descrambling and scheduling the RAR.

The message transmission unit 416 can perform message transmission using the same transmission beam as the corresponding PRACH transmission occasion. In some embodiments, the message sending unit 416 performs transmission of Msg3 using the same transmit beam as the corresponding PRACH transmission occasion.

The device can not only improve the success rate of PRACH transmission and reduce the burden of repeated transmission, but also improve the quality of Msg3 transmission.

In some embodiments, as shown in fig. 4, the PRACH retransmission apparatus 41 may further include a target antenna determining unit 417, where the target antenna determining unit 417 may be capable of selecting, when the terminal is provided with a plurality of antenna panels, an antenna panel with the largest RSRP as the target antenna panel according to the RSRP of the SSB received by the SSB detecting unit 411. The transmission unit 413 can perform PRACH retransmission through the target antenna panel. The device can enable the terminal with a plurality of antenna panels to select the panel with higher RSRP to execute PRACH transmission, thereby improving PRACH coverage performance in the aspects of the type of transmitting wave beam and the selected antenna panel and further improving the success rate of PRACH transmission.

A schematic structural diagram of an embodiment of the PRACH retransmission apparatus of the present disclosure is shown in fig. 5. The PRACH retransmission apparatus comprises a memory 501 and a processor 502. Wherein: memory 501 may be a magnetic disk, flash memory, or any other non-volatile storage medium. The memory is used to store instructions in the corresponding embodiment of the PRACH retransmission method above. Processor 502 is coupled to memory 501 and may be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. The processor 502 is configured to execute instructions stored in the memory, so as to improve coverage performance of the PRACH and improve probability of success of PRACH transmission.

In one embodiment, as also shown in fig. 6, the PRACH retransmission apparatus 600 includes a memory 601 and a processor 602. The processor 602 is coupled to the memory 601 through a BUS 603. The PRACH retransmission apparatus 600 may also be connected to an external storage 605 via a storage interface 604 for invoking external data, and may also be connected to a network or another computer system (not shown) via a network interface 606. And will not be described in detail herein.

In this embodiment, the data instruction is stored in the memory, and then the processor processes the instruction, so that the coverage performance of the PRACH can be improved, and the probability of successful PRACH transmission can be improved.

In another embodiment, a computer readable storage medium has stored thereon computer program instructions which, when executed by a processor, implement the steps of the method in the corresponding embodiments of the PRACH repeat transmission method. It will be apparent to those skilled in the art that embodiments of the present disclosure may be provided as a method, apparatus, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

A schematic diagram of some embodiments of a terminal 70 of the present disclosure is shown in fig. 7.

The PRACH retransmission apparatus 71 may be any of those mentioned above.

In some embodiments, the terminal 70 is provided with an antenna panel, and the terminal 70 performs PRACH transmission by selecting a beam type according to the beam strategy determined by the PRACH retransmission apparatus 71 through the antenna panel.

In some embodiments, the terminal 70 is provided with a plurality of antenna panels, and the terminal 70 can select an antenna panel with the highest RSRP of the SSB, and select a beam type to perform PRACH transmission according to the beam strategy determined by the PRACH retransmission apparatus 71.

The PRACH transmission strategy of the terminal can be adapted to the network and environment states at the transmission time, and the coverage performance and the transmission success rate of the PRACH are improved.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Thus far, the present disclosure has been described in detail. In order to avoid obscuring the concepts of the present disclosure, some details known in the art are not described. How to implement the solutions disclosed herein will be fully apparent to those skilled in the art from the above description.

The methods and apparatus of the present disclosure may be implemented in a number of ways. For example, the methods and apparatus of the present disclosure may be implemented by software, hardware, firmware, or any combination of software, hardware, firmware. The above-described sequence of steps for the method is for illustration only, and the steps of the method of the present disclosure are not limited to the sequence specifically described above unless specifically stated otherwise. Furthermore, in some embodiments, the present disclosure may also be implemented as programs recorded in a recording medium, the programs including machine-readable instructions for implementing the methods according to the present disclosure. Thus, the present disclosure also covers a recording medium storing a program for executing the method according to the present disclosure.

Finally, it should be noted that: the above embodiments are merely for illustrating the technical solution of the present disclosure and are not limiting thereof; although the present disclosure has been described in detail with reference to preferred embodiments, those of ordinary skill in the art will appreciate that: modifications may be made to the specific embodiments of the disclosure or equivalents may be substituted for part of the technical features; without departing from the spirit of the technical solutions of the present disclosure, it should be covered in the scope of the technical solutions claimed in the present disclosure.

Claims

1. A physical random access channel repeated transmission method comprises the following steps:

detecting a synchronous signal block SSB broadcasted by a network side;

determining a beam strategy of PRACH repeated transmission;

and executing PRACH repeated transmission at PRACH transmission time according to the beam strategy.

2. The method of claim 1, further comprising:

monitoring PDCCH in a random access response RAR time window, and detecting downlink control information DCI;

determining corresponding PRACH transmission time according to a random access radio network temporary identifier RA-RNTI used by DCI of a successful descrambling scheduling random access response RAR;

and performing message transmission by adopting a transmitting beam which is the same as the corresponding PRACH transmission occasion.

3. The method of claim 1, wherein the beam strategy comprises: the same transmit beam is employed at multiple PRACH transmission occasions or different transmit beams are employed at multiple PRACH transmission occasions.

4. The method of claim 1, wherein the determining a beam strategy for PRACH retransmission comprises: and determining the beam strategy according to the system working frequency point, the Radio Resource Control (RRC) indication information or the signal receiving condition of the SSB.

5. The method of claim 1, wherein the determining a beam strategy for PRACH retransmission comprises:

determining a system working frequency point;

under the condition that the system working frequency point belongs to a first frequency band, adopting the same transmitting wave beam at a plurality of PRACH transmission occasions;

and under the condition that the system working frequency point belongs to the second frequency band, different transmitting beams are adopted at a plurality of PRACH transmission occasions.

6. The method of claim 5, wherein the first frequency band is an FR1 frequency band for 5G communications and the second frequency band is an FR2 frequency band for 5G communications.

7. The method of claim 1, the determining a beam strategy for PRACH retransmission comprising:

acquiring RRC indication information, wherein the RRC indication information carries the beam strategy;

and determining a beam strategy in the RRC indication information.

8. The method of claim 1, wherein the determining a beam strategy for PRACH retransmission comprises: and determining the beam strategy according to the Reference Signal Received Power (RSRP) of the SSB.

9. The method of claim 8, wherein the determining the beam policy from the RSRP receiving the SSB comprises:

adopting the same transmitting wave beam at a plurality of PRACH transmission occasions under the condition that the RSRP is larger than a preset first threshold and the difference value between the RSRP and the preset first threshold is larger than a preset first difference value;

and under the condition that the RSRP is smaller than or equal to a preset first threshold or the difference value between the RSRP and the preset first threshold is smaller than or equal to a preset first value, different transmitting beams are adopted in a plurality of PRACH transmission occasions.

10. The method of claim 8, wherein the determining the beam strategy from a reference signal received power, RSRP, at which the SSB is received comprises:

under the condition that RSRP of a plurality of SSBs received in the first time length is larger than a preset second threshold, adopting the same transmitting beam at a plurality of PRACH transmission occasions;

and under the condition that the minimum value in RSRP of the SSBs received in the first time length is smaller than or equal to a preset second threshold, adopting different transmitting beams at a plurality of PRACH transmission occasions.

11. The method of claim 10, wherein the first time length is a transmission period of SSB.

12. The method of claim 8, wherein the determining the beam strategy from a reference signal received power, RSRP, at which the SSB is received comprises:

when the RSRP of the SSBs received in the second time period is greater than a third threshold value and the difference between the maximum value and the next-largest value in the RSRP values is greater than a predetermined second value, different transmission beams are adopted at a plurality of PRACH transmission occasions;

and under the condition that the minimum value of RSRP of the SSB received in the second time length is smaller than or equal to a preset third threshold or the difference value between the maximum value and the next-largest value in the RSRP values is smaller than or equal to a preset second value, adopting the same transmitting wave beam in a plurality of PRACH transmission occasions.

13. The method of claim 12, wherein the second length of time is a transmission period of the SSB.

14. The method of claim 1, further comprising: selecting an antenna panel with the maximum RSRP as a target antenna panel according to the RSRP of the received SSB;

the performing PRACH repeated transmissions includes: and carrying out PRACH repeated transmission through the target antenna panel.

15. The method of any of claims 1-14, wherein the performing PRACH repeat transmission at a PRACH transmission occasion according to the beam policy comprises:

according to PRACH resources configured by a network side, determining PRACH transmission time associated with the selected SSB;

and carrying out PRACH repeated transmission on the associated PRACH transmission occasion.

16. The method of any of claims 1-14, wherein, in the case where the determined beam strategy is that different transmit beams are employed for a plurality of PRACH transmission occasions, the transmit beams of PRACH transmission occasions for the same time domain symbol location are the same; the transmit beams of PRACH transmission occasions for different time domain symbol positions are different.

17. The method of claim 2, wherein the detecting DCI comprises: descrambling and detecting DCI according to the RA-RNTI corresponding to the RAR time window,

when the network side equipment detects the same Preamble from the same terminal on PRACH transmission occasions of different time domain symbol positions, the network side equipment determines RA-RNTI according to the time-frequency position of the PRACH transmission occasion corresponding to the Preamble with the largest receiving power, scrambles DCI for scheduling RAR by using the determined RA-RNTI, and carries corresponding RAPID through RAR information.

18. The method of claim 2, wherein the performing message transmission with the same transmit beam as the corresponding PRACH transmission occasion comprises:

and transmitting the message 3Msg3 of the random access procedure by adopting a transmitting beam which is the same as the corresponding PRACH transmission occasion.

19. A physical random access channel retransmission apparatus, comprising:

a synchronization signal block SSB detection unit configured to detect a network side broadcast SSB;

a beam strategy determination unit configured to determine a beam strategy of PRACH repeated transmission;

and a transmission unit configured to perform PRACH repeat transmission at a PRACH transmission occasion according to the beam strategy.

20. The apparatus of claim 19, further comprising:

a Downlink Control Information (DCI) detection unit configured to monitor a PDCCH in a RAR time window and detect DCI;

a transmit beam determining unit configured to determine a transmit beam used for a corresponding PRACH transmission occasion according to an RA-RNTI used by DCI for successfully descrambling and scheduling a random access response RAR;

and a message transmitting unit configured to perform message transmission using the same transmission beam as the corresponding PRACH transmission occasion.

21. The apparatus of claim 20, further comprising: a target antenna determination unit configured to select an antenna panel having the largest RSRP as a target antenna panel according to the RSRP of the reception SSB;

the transmission unit is configured to perform PRACH repeat transmission through the target antenna panel.

22. A physical random access channel retransmission apparatus, comprising:

a memory; and

a processor coupled to the memory, the processor configured to perform the method of any of claims 1-18 based on instructions stored in the memory.

23. A computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the method of any of claims 1 to 18.

24. A terminal comprising the physical random access channel PRACH retransmission apparatus of any one of claims 19 to 22.