WO2024174553A1

WO2024174553A1 - Prach repetition with different beams

Info

Publication number: WO2024174553A1
Application number: PCT/CN2023/125796
Authority: WO
Inventors: Ruixiang MA; Yuantao Zhang; Hongmei Liu; Zhi YAN
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2023-10-20
Filing date: 2023-10-20
Publication date: 2024-08-29
Anticipated expiration: 2026-04-20

Abstract

Various aspects of the present disclosure relate to PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams. In an aspect, a user equipment transmits, to a base station, physical random access channel (PRACH) transmission repetitions using a plurality of beams. Then, in response to the PRACH transmission repetitions, the UE receives, from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access -radio network temporary identifier (RA-RNTI) during at least one monitoring window. Further, the UE transmits, to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI. In this way, communication performance can be improved.

Description

PRACH REPETITION WITH DIFFERENT BEAMS

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to a user equipment (UE) , a base station, processors for wireless communication, methods, and non-transitory computer readable media for physical random access channel (PRACH) repetitions with different beams.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may be otherwise known as an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. Each network communication devices, such as a base station may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

PRACH might be the bottleneck channel if short PRACH format (e.g., PRACH format B4 as defined in 38.211) is used. Therefore, a solution has been proposed for transmitting PRACH repetitions using same beams. In this case, the RAR PDCCH monitoring window is based on the RO of the last PRACH repetition. Meanwhile, evaluations showed that if using different finer beams in the PRACH repetitions, there will be noticeable performance gain on detecting PRACH over PRACH repetition using a single wider beam. Therefore, it needs to be further studied regarding multiple PRACH transmissions or PRACH repetitions.

SUMMARY

The present disclosure relates to a UE, a base station, processors for wireless communication, methods, and non-transitory computer readable media for PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams. Embodiments of the disclosure can improve communication efficiency and quality.

In a first aspect of the solution, a user equipment (UE) is provided. The UE comprises a processor and a transceiver coupled to the processor, wherein the processor is configured to: transmit, via the transceiver and to a base station, physical random access channel (PRACH) transmission repetitions using a plurality of beams; in response to the PRACH transmission repetitions, receive, via the transceiver and from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access -radio network temporary identifier (RA-RNTI) during at least one monitoring window; and transmit, via the transceiver and to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

In some implementations of the UE, the PUSCH transmission is transmitted using a first beam among the plurality of beams, wherein the first beam is indicated by the DCI.

In some implementations of the UE, the number of PRACH transmission repetitions is N, the N PRACH transmission repetitions comprise M PRACH groups, and wherein one of the M PRACH groups comprises PRACH transmission repetitions associated with one of: a same beam, a same synchronization signal and physical broadcast channel (PBCH) block (SSB) , a same channel state information reference signal (CSI-RS) , or a same spatial filter, or one of the M PRACH groups comprises one PRACH transmission.

In some implementations of the UE, wherein the processor is configured to perform one of the following: indicating, via the transceiver and to the base station, a value of M, receiving, via the transceiver and from the base station, the value of M, or determining, as the value of M, the number of used SSBs for the N PRACH transmission repetitions.

In some implementations of the UE, wherein receiving the value of M comprises receiving the value of M via a system information block (SIB) .

In some implementations of the UE, wherein the system information block (SIB) comprises a system information block 1 (SIB1) .

In some implementations of the UE, wherein the indicating a value of M is by a PRACH resource for the PRACH transmission repetitions, and the PRACH resource comprises a preamble and a random access channel (RACH) occasion.

In some implementations of the UE, wherein different PRACH resources are used to indicate different value of M.

In some implementations of the UE, every N/M continuous PRACH repetitions among the PRACH transmission repetitions belong to one group among the M PRACH groups, or each M continuous PRACH repetitions among the N PRACH transmission repetitions belong to the M PRACH groups.

In some implementations of the UE, wherein in the case that the value of M is larger than N, the processor is further configured to set M as N.

In some implementations of the UE, wherein the at least one monitoring window comprises one monitoring window determined based on one of the following: one PRACH repetition among the N PRACH transmission repetitions, or one PRACH group among the M PRACH groups.

In some implementations of the UE, wherein the one monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups.

In some implementations of the UE, wherein the at least one monitoring window comprises M monitoring windows, and the processor is further configured to: determine M monitoring windows based on the M PRACH groups, wherein each monitoring window among the M monitoring windows is corresponding to each PRACH group among the M PRACH groups.

In some implementations of the UE, wherein the processor is further configured to: determine a second monitoring window with a configured length based on one PRACH repetition among the PRACH transmission repetitions or one PRACH group among the M PRACH groups; and divide the second monitoring window into the M monitoring windows, and each monitoring window among the M monitoring windows is corresponding to one of the M PRACH groups.

In some implementations of the UE, wherein the second monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups.

In some implementations of the UE, wherein the processor is further configured to: determine each monitoring window among the M monitoring window based on each group among the M PRACH groups, wherein one monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition of the each corresponding PRACH group among the M PRACH groups.

In some implementations of the UE, wherein a first monitoring window among the plurality of monitoring windows starts from the one PRACH repetition in the first PRACH group among the M PRACH groups, and the other monitoring windows among the M monitoring window are continuous in time domain following the first monitoring window, wherein the length of each of the M monitoring windows is the same.

In some implementations of the UE, wherein the processor is further configured to determine a RA-RNTI based on one of the following: a first PRACH repetition among the N PRACH transmission repetitions, a last PRACH repetition among the N PRACH transmission repetitions, a first PRACH repetition of the first or last PRACH group among the M PRACH groups, a last PRACH repetition of the first or last PRACH group among the M PRACH groups, a beam index of the first or last PRACH group among the M PRACH groups, or a group index of the first or last PRACH group among the M PRACH groups.

In some implementations of the UE, wherein the processor is configured to transmit the PUSCH transmission by: in response to receiving the DCI in a monitoring window, transmitting the PUSCH transmission using same beam as the PRACH group corresponding to the monitoring window.

In some implementations of the UE, wherein the processor is configured to receive the DCI by: receiving the DCI with CRC scrambled by M RA-RNTIs corresponding to the M PRACH groups during at least one monitoring window, wherein for one PRACH group of the M PRACH groups, the processor is configured to determine a RA-RNTI corresponding to the one PRACH group based on one of the following: the RO of the last or first PRACH repetition in the one RRACH group, a beam index indicating a beam among the plurality of beams, the beam being associated with the one PRACH group, or a group index of the one PRACH group.

In some implementations of the UE, wherein the processor is configured to determine the first beam by: in response to receiving the DCI with CRC scrambled by a RA-RNTI in a monitoring window, determining the first beam is same as a beam among the plurality of beams associated the one PRACH groups corresponding to the RA-RNTI.

In some implementations of the UE, wherein the processor is configured to determine the first beam by: obtaining a beam indicator in the RAR UL grant, wherein the beam indicator indicates the first beam for the PUSCH transmission.

In some implementations of the UE, wherein the beam indicator comprises a plurality of bits, the number of the plurality of bits is based on the value of M, and the plurality of bits are in at least one field of the following: a time domain resource assignment (TDRA) information field, a modulation and coding (MCS) information field, a transmit power control (TPC) information field, a channel state information (CSI) request information field, or a frequency domain resource assignment (FDRA) information field.

In some implementations of the UE, the processor is further configured to: transmit, via the transceiver and to the base station, second PRACH transmission repetitions associated with a second plurality of beams; receive a second DCI with CRC scrambled with temporary cell -radio network temporary identifier (TC-RNTI) scheduling second PUSCH transmission; and obtain a second beam indicator in the second DCI, wherein the second beam indicator indicates a second beam for the second PUSCH transmission, wherein the second beam indicator comprises a plurality of bits in the second DCI, the number of the plurality of bits is based on the value of M, and the plurality of bits is in a hybrid automatic repeat request (HARQ) process number (HPN) field.

In some implementations of the UE, the processor is further configured to: transmit, via the transceiver and to the base station, second PRACH transmission repetitions associated with a second plurality of beams; receive a second DCI with CRC scrambled with temporary cell -radio network temporary identifier (TC-RNTI) scheduling second PUSCH transmission; and transmitting the second PUSCH transmission using the first beam.

In some implementations of the UE, the processor is further configured to: receive a third DCI with CRC scrambled with cell -radio network temporary identifier (C-RNTI) scheduling a third PUSCH transmission; and determine a resource for the third PUSCH transmission based on a search space set where the third DCI is received.

In some implementations of the UE, wherein in the case that the third DCI is received in UE specific search space, the processor is further configured to: determine repetitions for the third PUSCH transmission based on a repetition number configured by the base station via a radio resource control (RRC) signaling, or in the case that the third DCI is received in a common search space, the processor is further configured to: determine repetitions for the third PUSCH transmission based on a repetition number configured by a system information block 1 (SIB1) .

In some implementations of the UE, wherein the third PUSCH transmission is transmitted in K continuous available slots, and in the case that the third DCI is received in a common search space, a slot is an available slot if the indicated resource by the third DCI in the slot is overlapped with a flexible symbol, in the case that the third DCI is received in UE specific search space, a slot is not an available slot if the indicated resource by the third DCI in the slot is overlapped with a flexible symbol.

In some implementations of the UE, wherein the third PUSCH transmission is transmitted in K continuous slots, and the processor is further configured to: in the case that the third DCI is received in a common search space, determining whether the PUSCH repetitions in the K continuous slots are to be used for joint channel estimation or not based on SIB1or determining the PUSCH repetition in the K continuous slots are not to be used for joint channel estimation, in the case that the third DCI is received in UE specific search space, determining whether the PUSCH repetitions in the K continuous slots are to be used for joint channel estimation or not based on RRC signaling.

In a second aspect of the solution, a processor for wireless communication is provided. The processor comprises at least one memory and a controller coupled with the at least one memory and configured to cause the controller to: transmit, to a base station, physical random access channel (PRACH) transmission repetitions associated using a plurality of beams; in response to the PRACH transmission repetitions, receive, from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and transmit, to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

In a third aspect of the solution, a method performed by a user equipment (UE) is provided. The method comprises: transmitting, to a base station, physical random access channel (PRACH) transmission repetitions associated using a plurality of beams; in response to the PRACH transmission repetitions, receiving, from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and transmitting, to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

In a fourth aspect of the solution, a base station (BS) is provided. The base station comprises a processor and a transceiver coupled to the processor, wherein the processor is configured to: receive, via the transceiver and from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams; in response to the PRACH transmission repetitions, transmit, via the transceiver and to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and receive, via the transceiver and from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

In some implementations of the base station, wherein the DCI indicates a first beam among the plurality of beams, and the PUSCH transmission is transmitted by the UE using the first beam.

In some implementations of the base station, wherein the number of PRACH transmission repetitions is N, the N PRACH transmission repetitions comprise M PRACH groups, and wherein one of the M PRACH groups comprise PRACH transmission repetitions associated with one of: a same beam, a same synchronization signal and physical broadcast channel (PBCH) block (SSB) , a same channel state information reference signal (CSI-RS) , or a same spatial filter, or one of the M PRACH groups comprise one PRACH transmission.

In some implementations of the base station, wherein the processor is configured to perform one of the following: receiving, via the transceiver and from the UE, a value of M, or indicating, via the transceiver and to the UE, the value of M.

In some implementations of the base station, wherein indicating the value of M comprises indicating the value of M via a system information block (SIB) .

In some implementations of the base station, wherein the system information block (SIB) comprises a system information block 1 (SIB1) .

In some implementations of the base station, wherein a PRACH resource for the PRACH transmission repetitions comprise a preamble and a random access channel (RACH) occasion.

In some implementations of the base station, wherein different PRACH resources are used to indicate different value of M.

In some implementations of the base station, wherein: every N/M continuous PRACH repetitions among the PRACH transmission repetitions belong to one group among the M PRACH groups, or each M continuous PRACH repetitions among the N PRACH transmission repetitions belong to the M PRACH groups.

In some implementations of the base station, wherein the at least one monitoring window comprise one monitoring window determined based on one of the following: a PRACH repetition among the N PRACH transmission repetitions, or a PRACH group among the M PRACH groups.

In some implementations of the base station, wherein the one monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups, wherein each monitoring window is corresponding to each PRACH group.

In some implementations of the base station, wherein the at least one monitoring window comprises M monitoring windows, and the M monitoring windows is determined by the UE based on the M PRACH groups, wherein each monitoring window among the M monitoring windows is corresponding to each PRACH group among the M PRACH groups.

In some implementations of the base station, wherein a monitoring window among the at least one of monitoring window is determined by the UE based on an associated group among the M PRACH groups, wherein the monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups.

In some implementations of the base station, wherein a first monitoring window among the plurality of monitoring windows starts from one PRACH repetition in the first PRACH group among the M PRACH groups, and the other monitoring windows among the M monitoring window are continuous in time domain following the first monitoring window, wherein the length of each of the M monitoring windows is the same.

In some implementations of the base station, wherein the processor is configured to determine the first beam by one of the following: determining a PRACH group among the M PRACH groups, wherein the PRACH group is associated with the RA-RNTI, or determining a beam indicator to be comprised in the DCI, wherein the beam indicator indicates the first beam for the PUSCH transmission.

In some implementations of the base station, wherein the beam indicator comprises a plurality of bits in the DCI, the number of the plurality of bits is based on the value of M, and the plurality of bits is in at least one field of the following: a time domain resource assignment (TDRA) information field, a modulation and coding (MCS) information field, a transmit power control (TPC) information field, a channel state information (CSI) request information field, or a frequency domain resource assignment (FDRA) information field.

In some implementations of the base station, wherein the processor is further configured to: receive, via the transceiver and from the UE, second PRACH transmission repetitions associated with a second plurality of beams; determining a second beam indicator to be comprised in the second DCI, wherein the second beam indicator indicates a second beam for the second PUSCH transmission; and transmit, via the transceiver and to the UE, a second DCI with CRC scrambled with temporary cell -radio network temporary identifier (TC-RNTI) scheduling a second PUSCH transmission, wherein the second beam indicator comprises a plurality of bits in the second DCI, and the plurality of bits is in a hybrid automatic repeat request (HARQ) process number (HPN) field.

In some implementations of the base station, wherein the processor is further configured to: receive, via the transceiver and from the UE, second PRACH transmission repetitions associated with a second plurality of beams; transmit, via the transceiver and to the UE, a second DCI with CRC scrambled with temporary cell -radio network temporary identifier (TC-RNTI) scheduling a second PUSCH transmission; and determining the second PUSCH transmission to be transmitted by the UE using the first beam.

In some implementations of the base station, wherein the RA-RNTI is determined by the UE based on one of the following: a first PRACH repetition among the N PRACH transmission repetitions, a last PRACH repetition among the N PRACH transmission repetitions, a first PRACH repetition of the first or last PRACH group among the M PRACH groups, a last PRACH repetition of the first or last PRACH group among the M PRACH groups, a beam index of the first or last PRACH group among the M PRACH groups, or a group index of the first or last PRACH group among the M PRACH groups.

In some implementations of the base station, wherein the processor is configured to transmit the DCI by: transmitting the DCI with CRC scrambled by M RA-RNTIs corresponding to the M PRACH groups during at least one monitoring window, wherein for one PRACH group of the M PRACH groups, a RA-RNTI is determined by the UE based on one of the following: the RO of the last or first PRACH repetition in the one RRACH group, a beam index indicating a beam among the plurality of beams, the beam being associated with the one PRACH group, or a group index of the one PRACH group.

In some implementations of the base station, wherein the processor is further configured to: determine a resource for third PUSCH transmission based on a search space set where the third DCI is to be transmitted, wherein the third DCI comprises a CRC scrambled with cell –radio network temporary identifier (C-RNTI) and schedules the third PUSCH transmission; and transmit, via the transceiver and to the UE, the third DCI.

In some implementations of the base station, wherein in the case that the resource is in UE specific search space, the processor is further configured to: determine a repetition number for the third PUSCH transmission to be repeated; and transmit, via the transceiver and to the UE, the repetition number via a radio resource control (RRC) signaling, wherein the RRC signaling is comprised in the third DCI.

In some implementations of the base station, wherein the processor is configured to receive the repetitions for a third PUSCH transmission based on the repetition number.

In some implementations of the base station, wherein in the case that the resource is in a common search space, the processor is further configured to: determine a repetition number for the third PUSCH transmission to be repeated; and transmit, via the transceiver and to the UE, a system information block 1 (SIB1) comprising the repetition number, wherein the SIB1 is comprised in the third DCI.

In a fifth aspect of the solution, a processor for wireless communication is provided. The processor comprises at least one memory and a controller coupled with the at least one memory and configured to cause the controller to: receive, from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams; in response to the PRACH transmission repetitions, transmit, to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and receive, from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

In a sixth aspect of the solution, a method performed by a base station (BS) is provided. The method comprises: receiving, from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams; in response to the PRACH transmission repetitions, transmitting, to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and receiving, from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an example of a wireless communications system that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure.

FIG. 1B illustrates a schematic diagram of a NR 4-step RACH procedure associated with aspects of the present disclosure.

FIG. 1C illustrates a schematic diagram of a 1-to-1 association between RACH occasions and SSBs associated with aspects of the present disclosure.

FIG. 1D illustrates a schematic diagram of a N-to-1 association between RACH occasions and SSBs associated with aspects of the present disclosure.

FIG. 1E illustrates a schematic diagram of a 1-to-N association between RACH occasions and SSBs associated with aspects of the present disclosure.

FIG. 1F illustrates a schematic diagram of multiple PRACH transmissions with same beams associated with aspects of the present disclosure.

FIG. 2 illustrates a signaling chart illustrating an example communication process in accordance with aspects of the present disclosure.

FIG. 3A illustrates a schematic diagram of an example PRACH transmission repetitions in accordance with aspects of the present disclosure.

FIG. 3B illustrates a schematic diagram of another example PRACH transmission repetition in accordance with aspects of the present disclosure.

FIG. 3C illustrates a schematic diagram of further another example PRACH transmission repetition in accordance with aspects of the present disclosure.

FIG. 4A illustrates a schematic diagram of an example monitoring window corresponding to multiple PRACH groups in accordance with aspects of the present disclosure.

FIG. 4B illustrates a schematic diagram of multiple monitoring windows corresponding to multiple PRACH groups in accordance with aspects of the present disclosure.

FIGS. 4C and 4D illustrate schematic diagrams of examples of multiple monitoring windows corresponding to multiple PRACH groups in accordance with aspects of the present disclosure.

FIG. 4E illustrates a schematic diagram of an example of multiple monitoring windows corresponding to one PRACH group in accordance with aspects of the present disclosure.

FIGS. 4F and 4G illustrate schematic diagrams of examples of multiple monitoring windows corresponding to multiple PRACH groups in accordance with aspects of the present disclosure.

FIGS. 5 and 6 illustrate examples of processors that support PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure.

FIGS. 7 and 8 illustrate flowcharts of methods that support PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure.

FIGS. 9 and 10 illustrate flowcharts of methods that support PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

DETAILED DESCRIPTION

Principles of the present disclosure will now be described with reference to some embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below. In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an example embodiment, ” “an embodiment, ” “some embodiments, ” and the like indicate that the embodiment (s) described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment (s) . Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” or the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element could also be termed as a second element, and similarly, a second element could also be termed as a first element, without departing from the scope of embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms. In some examples, values, procedures, or apparatuses are referred to as “best, ” “lowest, ” “highest, ” “minimum, ” “maximum, ” or the like. It will be appreciated that such descriptions are intended to indicate that a selection among many used functional alternatives can be made, and such selections need not be better, smaller, higher, or otherwise preferable to other selections.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments. As used herein, the singular forms “a, ” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises, ” “comprising, ” “has, ” “having, ” “includes” and/or “including, ” when used herein, specify the presence of stated features, elements, components and/or the like, but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof. For example, the term “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ” The term “based on” is to be read as “based at least in part on. ” The term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ” The term “another embodiment” is to be read as “at least one other embodiment. ” The use of an expression such as “A and/or B” can mean either “only A” or “only B” or “both A and B. ” Other definitions, explicit and implicit, may be included below.

In 5G NR system, the random-access procedure is utilized for various purposes. It is utilized by a UE in initial access to find a cell to camp on; or utilized by a RRC IDLE/INACTIVE UE to switch to RRC CONNECTED to start data transmission/reception; or utilized by a RRC connected UE to re-establish the lost UL synchronization, etc. The random-access procedure will be described in more detail later with reference to FIG. 1B.

In legacy PRACH transmission, NR supports preamble transmission without repetition. However, as mentioned above, PRACH might be the bottleneck channel if short PRACH format (e.g., PRACH format B4 as defined in 38.211) is used. Therefore, a solution has been proposed for transmitting PRACH repetitions using same beams. In this case, as will be described in more detail with reference to FIG. 1F, the RAR PDCCH monitoring window is based on the RO of the last PRACH repetition, which means UE attempts to detect a DCI format 0_0 with CRC scrambled by a corresponding RA-RNTI during a window controlled by higher layers. The window starts at the first symbol of the earliest CORESET the UE is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last PRACH repetition. The DCI is identified by a RA-RNTI, which is determined by the time/frequency position of the RO in which the last PRACH repetition is transmitted.

Meanwhile, evaluations showed that if different finer beams are used in the PRACH repetitions, there will be noticeable performance gain on detecting PRACH over PRACH repetition using a single wider beam. Therefore, multiple PRACH transmission using different finer beams needs to be further studied.

On the other hand, PUSCH repetition would increase the coverage performance, so it may also be considered. However, PUSCH scheduled by DCI format 0_0 with CRC scrambled by C-RNTI does not support repetitions considering this DCI would be used for scheduling the UE when the RRC parameter has not been received or RRC is reconstructed, while the PUSCH repetition type and PUSCH repetition number should be configured by RRC signalling. However, considering the DCI format 0_0 with CRC scrambled by C-RNTI could also be received in UE specific search space, the PUSCH scheduled by the DCI can support PUSCH repetition in this case.

In view of the above, embodiments of the present disclosure provide a solution for PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams. In an aspect of the solution, a UE transmits, to a base station, PRACH transmission repetitions using a plurality of beams. The base station, on the other end of communication, receives, from a user equipment (UE) , the PRACH transmission repetitions, and, in response to the PRACH transmission repetitions, transmits, to the UE, DCI with cyclic redundancy check (CRC) scrambled by at least one RA-RNTI during at least one monitoring window. Then, at the UE, the UE receives, from the base station, the DCI with cyclic redundancy check (CRC) scrambled by at least one RA-RNTI during the at least one monitoring window. Then, the UE transmits, to the base station, a PUSCH transmission based on a RAR uplink (UL) grant scheduled by the DCI. On the other side of communication, the base station receives, from the UE, the PUSCH transmission based on the RAR UL grant. Furthermore, the PUSCH transmission may be repeated based on configuration via RRC signaling or SIB1. In this way, communication performance can be improved. For example, UE can monitor a DCI at an earlier stage than the legacy schemes, which means that the processing time, for example, during a random access procedure, can be reduced. Further, UE can transmit the PUSCH transmission using a best beam among the multiple different Tx beams used for the PRACH transmission repetitions, which means the possibilities that the gNB can receive the PUSCH transmission successfully can be increased. At the meantime, the coverage performance can also be enhanced.

FIG. 1A illustrates an example of a wireless communications system 100 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 102 (also referred to as network equipment (NE) or network device) , one or more UEs 104, a core network 106, and a packet data network 108. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a 5G network, such as an NR network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more network entities 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the network entities 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a radio access network (RAN) , a base transceiver station, an access point, a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. A network entity 102 and a UE 104 may communicate via a communication link 110, which may be a wireless or wired connection. For example, a network entity 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

A network entity 102 may provide a geographic coverage area 112 for which the network entity 102 may support services (e.g., voice, video, packet data, messaging, broadcast, etc. ) for one or more UEs 104 within the geographic coverage area 112. For example, a network entity 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, a network entity 102 may be moveable, for example, a satellite associated with a non- terrestrial network. In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas 112 may be associated with different network entities 102. Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a mobile device, a wireless device, a remote device, a remote unit, a handheld device, or a subscriber device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples. In some implementations, a UE 104 may be stationary in the wireless communications system 100. In some other implementations, a UE 104 may be mobile in the wireless communications system 100.

The one or more UEs 104 may be devices in different forms or having different capabilities. Some examples of UEs 104 are illustrated in FIG. 1A. A UE 104 may be capable of communicating with various types of devices, such as the network entities 102, other UEs 104, or network equipment (e.g., the core network 106, the packet data network 108, a relay device, an integrated access and backhaul (IAB) node, or another network equipment) , as shown in FIG. 1A. Additionally, or alternatively, a UE 104 may support communication with other network entities 102 or UEs 104, which may act as relays in the wireless communications system 100.

A UE 104 may also be able to support wireless communication directly with other UEs 104 over a communication link 114. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

A network entity 102 may support communications with the core network 106, or with another network entity 102, or both. For example, a network entity 102 may interface with the core network 106 through one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The network entities 102 may communicate with each other over the backhaul links 116 (e.g., via an X2, Xn, or another network interface) . In some implementations, the network entities 102 may communicate with each other directly (e.g., between the network entities 102) . In some other implementations, the network entities 102 may communicate with each other or indirectly (e.g., via the core network 106) . In some implementations, one or more network entities 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

In some implementations, a network entity 102 may be configured in a disaggregated architecture, which may be configured to utilize a protocol stack physically or logically distributed among two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 102 may include one or more of a central unit (CU) , a distributed unit (DU) , a radio unit (RU) , a RAN Intelligent Controller (RIC) (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) system, or any combination thereof.

An RU may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 102 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 102 may be located in distributed locations (e.g., separate physical locations) . In some implementations, one or more network entities 102 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

Split of functionality between a CU, a DU, and an RU may be flexible and may support different functionalities depending upon which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combinations thereof) are performed at a CU, a DU, or an RU. For example, a functional split of a protocol stack may be employed between a CU and a DU such that the CU may support one or more layers of the protocol stack and the DU may support one or more different layers of the protocol stack. In some implementations, the CU may host upper protocol layer (e.g., a layer 3 (L3) , a layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU may be connected to one or more DUs or RUs, and the one or more DUs or RUs may host lower protocol layers, such as a layer 1 (L1) (e.g., physical (PHY) layer) or an L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160.

Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU and an RU such that the DU may support one or more layers of the protocol stack and the RU may support one or more different layers of the protocol stack. The DU may support one or multiple different cells (e.g., via one or more RUs) . In some implementations, a functional split between a CU and a DU, or between a DU and an RU may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU, a DU, or an RU, while other functions of the protocol layer are performed by a different one of the CU, the DU, or the RU) .

A CU may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU may be connected to one or more DUs via a midhaul communication link (e.g., F1, F1-c, F1-u) , and a DU may be connected to one or more RUs via a fronthaul communication link (e.g., open fronthaul (FH) interface) . In some implementations, a midhaul communication link or a fronthaul communication link may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 102 that are in communication via such communication links.

The core network 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The core network 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more network entities 102 associated with the core network 106.

The core network 106 may communicate with the packet data network 108 over one or more backhaul links 116 (e.g., via an S1, N2, N2, or another network interface) . The packet data network 108 may include an application third 118. In some implementations, one or more UEs 104 may communicate with the application third 118. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the core network 106 via a network entity 102. The core network 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application third 118 using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the core network 106 (e.g., one or more network functions of the core network 106) .

In the wireless communications system 100, the network entities 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communications) . In some implementations, the network entities 102 and the UEs 104 may support different resource structures. For example, the network entities 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the network entities 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the network entities 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The network entities 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., OFDM symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the network entities 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the network entities 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g., control information, data) . In some implementations, FR2 may be used by the network entities 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

FIG. 1B illustrates a schematic diagram of a NR 4-step RACH procedure 100B associated with aspects of the present disclosure. As shown in FIG. 1B, the RACH procedure 100B starts at UE (for example, UE 104 as illustrated in FIG. 1A) transmitting a Msg1 preamble to the gNB (for example, network entity 102 as illustrated in FIG. 1A) in a valid RACH occasion (RO) . Then, in response to the Msg1, the gNB transmits a random access response (RAR) in Msg2 to the UE; in the other direction, the UE receives the RAR in Msg2. Msg2 from the gNB indicates that the gNB receives the preamble in Msg1 from the UE and provides, to the UE, necessary information for transmission of Msg3 and Msg4. The RAR is received in a RA response window (which is also referred to as “monitoring window” hereafter) , which starts after a time gap after the UE transmits Msg1. The Msg3 and Msg4 are used to solve potential collisions due to simultaneous transmissions of the same preamble from different UEs.

Preamble transmission takes place in a configurable subset of slots that is configured in a PRACH configuration period. Furthermore, within these slots, there may be one or multiple frequency domain RACH occasions (ROs) covering multiple consecutive resource blocks. A RO may refer to a time-frequency resource in a PDSCH region of a time-frequency subchannel. For example, the time-frequency resource may have a width of one symbol in the time domain, and have a width of 5 RBs in the frequency domain.

The ROs are associated with SSBs that may be transmitted with different beams. The SSBs consists of PSS/SSS and PBCH for the UE to synchronize to the DL, obtain the cell ID, and acquire the system information. The UE will measure the channel status of each SSB, select the one with good channel quality, and transmit a preamble in a RO that is associated with the SSB. The indexes of available SSBs can be obtained in the system information.

The association of SSBs (beams) and ROs could be 1-to-1, 1-to-N, or N-to-1 depending on network configuration, which will be explained in more detail with reference to FIGS. 1C, 1D and 1E.

FIG. 1C illustrates a schematic diagram of example SSBs 100C having a 1-to-1 association with RACH occasions associated with aspects of the present disclosure. In FIG. 1C, 8 SSBs with indexes from 0 to 7 (SSB#0 –SSB#7) are assumed, and there is one RO in frequency domain for each of the 8 SSBs. In other words, RO#0 (i.e, a RO with an index of 0) is associated with SSB#0 (i.e, the SSB with an index of 0) , RO#1 is associated with SSB#1, …, and RO#7 is associated with SSB#7. In this case, one RO is used to transmit a preamble associated with one SSB which is associated with the one RO. More specifically, RO#0 is used to transmit a preamble associated with SSB#0, RO#1 is used to transmit a preamble associated with SSB#1, …, and RO#7 is used to transmit a preamble associated with SSB#7.

FIG. 1D illustrates a schematic diagram of other example SSBs 100D having a N-to-1 association with RACH occasions associated with aspects of the present disclosure. In FIG. 1D, 8 SSBs (SSB#0 –SSB#7) are assumed, and there is one RO in frequency domain associated with two of the 8 SSBs. In other words, as illustrated in FIG. 1D, RO#0 is associated with SSB#0 and SSB#1, RO#1 is associated with SSB#2 and SSB#3, …, and RO#7 is associated with SSB#6 and SSB#7. In this case, one RO is used to transmit a preamble associated with two SSBs which are associated with the one RO. More specifically, RO#0 is used to transmit preamble (s) associated with SSB#0 and SSB#1, RO#1 is used to transmit preamble (s) associated with SSB#1 and SSB#2, …, and RO#7 is used to transmit preamble (s) associated with SSB#6 and SSB#7. It is to be noted though here is described like “RO#0 is used to transmit preamble (s) associated with SSB#0 and SSB#1” , in a time period defined by RO#0, a preamble associated with SSB#0 is transmitted, or a preamble associated with SSB#1 is transmitted; but the preamble associated with SSB#0 and the preamble associated with SSB#1 will not be transmitted at the same time.

FIG. 1E illustrates a schematic diagram of other example SSBs 100E having a 1-to-N association with RACH occasions associated with aspects of the present disclosure. In FIG. 1C, 8 SSBs (SSB#0 –SSB#7) are assumed, and there is two ROs in frequency domain for each of the 8 SSBs. In other words, as illustrated in FIG. 1E, RO#0 and RO#1 are associated with SSB#0, RO#2 and RO#3 are associated with SSB#1, …, and RO#14 and RO#15 are associated with SSB#7. In this case, two ROs are used to transmit a preamble associated with one SSB which is associated with the two ROs. More specifically, RO#0 and RO#1 are used to transmit a preamble associated with SSB#0, RO#2 and RO#3 are used to transmit a preamble associated with SSB#1, …, and RO#14 and RO#15 are used to transmit a preamble associated with SSB#7.

The association between ROs and SSBs is performed periodically in each SSB to RO association period. The association period is X (X is an integer) times of the PRACH configuration period, and contains one or multiple SSB-to-RO mapping cycles. The duration of the association period is the minimum period such that within the association period, each SSB is associated with at least one RO. The association period may be of any suitable granularity and may have any suitable length in time domain. For example, the association period may be P slot (s) or subframe (s) , here P may be 1, 2, 3, …, etc.

In response to a PRACH transmission, a UE attempts to detect a DCI format 0_0 with CRC scrambled by a corresponding RA-RNTI during a window controlled by higher layers. The window starts at the first symbol of the earliest CORESET the UE is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the PRACH occasion corresponding to the PRACH transmission, where the symbol duration corresponds to the SCS for Type1-PDCCH CSS set. The DCI is identified by a RA-RNTI, which is determined by the time/frequency position of the RO that a preamble is transmitted in. That is, for different RO, the corresponding RA-RNTI is different.

The RAR contains a RAR UL grant which schedules a PUSCH transmission (Msg3) from the UE. Typically, the Msg3 and the SS/PBCH block (SSB block) the UE used for PRACH association have same DM-RS antenna port quasi co-location properties. In other words, the msg3 is transmitted using the same beam as msg1.

The contents of the RAR UL grant, starting with the MSB and ending with the LSB, are given in the following Table 1.

Table 1: Random Access Response Grant Content field size

If the value of the frequency hopping flag is 0, the UE transmits the PUSCH without frequency hopping; otherwise, the UE transmits the PUSCH with frequency hopping.

The UE determines the MCS of the PUSCH transmission from the first sixteen indexes of the applicable MCS index table for PUSCH] .

The TPC command value δ_ (msg2, b, f, c) is used for setting the power of the PUSCH transmission, which is interpreted according to Table 2.

The CSI request field is reserved.

The ChannelAccess-CPext field indicates a channel access type and CP extension for operation with shared spectrum channel access if channelAccessMode ="semiStatic" is provided.

Table 2: TPC Command δ_{msg2, b, f, c} for PUSCH

FIG. 1F illustrates a schematic diagram of multiple PRACH transmissions 100F with same beams associated with aspects of the present disclosure.

For PRACH, NR supports preamble transmission without repetition. However, it has been identified in 3GPP Rel. 17 that PRACH might be the bottleneck channel if short PRACH format (e.g., PRACH format B4 as defined in 38.211) is used. Therefore, in Rel-18, following objective has been agreed to specify PRACH coverage enhancements, and the detailed objectives in the WID are listed below.:

More specifically, multiple PRACH transmissions (for example, those PRACH transmissions 100F shown in FIG. 1F) with same beams has been specified. In the example illustrated in FIG. 1F, 4 PRACH transmissions 100F are transmitted using same beams. The RAR PDCCH monitoring window is based on the RO of the last PRACH repetition (here, the 4th repetition among the 4 PRACH transmissions 100F) . In other words, UE attempts to detect a DCI format 0_0 with CRC scrambled by a corresponding RA-RNTI during a window controlled by higher layers. The window starts at the first symbol of the earliest CORESET the UE is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last PRACH repetition (here, the 4th repetition as illustrated in FIG. 1F) . The DCI is identified by a RA-RNTI, which is determined by the time/frequency position of the RO in which the last PRACH repetition is transmitted.

Meanwhile, evaluations showed that if different finer beams are used in the PRACH repetitions (herein also referred to as “PRACH transmission repetitions” ) , there will be noticeable performance gain on detecting PRACH over PRACH repetition using a single wider beam. Therefore, multiple PRACH transmission using different finer beams needs to be further studied. From UE point of view, the finer beams that are used for PRACH repetitions might be based on implementation. While in gNB side, it might be beneficial to know whether the UEs are using same or different Tx beams to transmit the PRACH repetitions. Based on this, the gNB might indicate the best Tx beam to the UE for Msg3 transmission. This helps to improve the Msg3 detection performance, which would be discussed in Release 19 (Rel-19) of the 3GPP specifications. However, how the gNB indicates the best beam for Msg3 transmission should be discussed in more detail. Such issues are discussed in the following with references to FIGS. 2 –8.

FIG. 2 illustrates a signaling chart illustrating an example communication process 200 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the communication process 200 will be described with reference to FIG. 1A. The communication process 200 may involve a user equipment (UE) 210 and a base station (BS) 220. UE 210 may be an example of the UE 104 as illustrated in FIG. 1A, and BS 220 may be an example of the network entity 102 as illustrated in FIG. 1A.

As illustrated in FIG. 2, the UE 210 transmits (230) , to the base station 220, PRACH transmission repetitions 201 using a plurality of beams, which will be described in details with reference to FIGS. 3A –3C later. On the other side of communication, the base station 220 receives (232) the PRACH transmission repetitions 201 from the UE 210. In response to the received PRACH transmission repetitions 201, the base station 220 transmits (240) , to the UE 210, DCI 202 with CRC scrambled by at least one RA-RNTI. At the UE 210, it receives (242) , from the base station 220, the DCI 202 with CRC scrambled by the at least one RA-RNTI during at least one monitoring window. This will be described in more detail with reference to FIGS. 4A –4G. Then, UE 210 transmits (250) , to the base station 220, a PUSCH transmission 203 based on a RAR uplink (UL) grant scheduled by the DCI 202. On the other side of communication, the base station 220 receives (252) , from the UE 210, the PUSCH transmission 203. Details about PUSCH transmission 203, for example, whether it should be repeated or not as well as how to configure repetitions of the PUSCH transmission 203, will be described in more detail later.

Specifically, the DCI 202 from the base station 220 may indicate a first beam among the plurality of beams, for example, for transmission of the PUSCH transmission 203, such that UE 210 may transmit (250) the PUSCH transmission 203 using the first beam. For example, the first beam may be a beam among the plurality of beams through which the base station 220 detects (or receives) , for the first time, one PRACH repetition among the PRACH transmission repetitions 201. Alternatively, the first beam may be a beam among the plurality of beams through which the base station 220 detects (or receives) one PRACH repetition among the PRACH transmission repetitions 201 with a performance metric no less than a predetermined or predefined threshold. The performance metric may be one of received signal strength indicator (RSSI) , received power, or signal-to-noise ratio (SNR) , etc.. Alternatively, the first beam may be a beam among the plurality of beams through which the base station 220 detects (or receives) one PRACH repetition among the PRACH transmission repetitions 201 with a performance metric smaller than other beams among the PRACH transmission repetitions 201.

In some example embodiments, the number of PRACH transmission repetitions 201 is N, the N PRACH transmission repetitions 201 comprise M PRACH groups. One of the M PRACH groups may comprise PRACH transmission repetitions associated with one of: a same beam, a same SSB, a same CSI-RS, or a same spatial filter. Alternatively, one of the M PRACH groups may comprise one PRACH transmission.

As to the value of M, the UE 210 may indicate the value of M to the base station 220. On the other side of communication, the base station 220 may receive the value of M from UE 210. For example, the UE 210 may indicate the value of M by a PRACH resource for the PRACH transmission repetitions 201. Here, the PRACH resource may comprise a preamble and a random access channel (RACH) occasion (“RACH occasion” herein is also referred to as “RO” for short) . In this case, different PRACH resources may be used to indicate different value of M.

Alternatively, the base station 220 may indicate the value of M to the UE 210. In other words, the UE 210 may receive the value of M from the base station 220. For example, the UE 210 may receive the value of M via a system information block (SIB) . Specifically, the SIB may comprise a SIB1. If the value of M received from the base station 220 is larger than N, UE 210 may set M as N. Alternatively, the UE 210 may determine, as the value of M, the number of used SSBs for the N PRACH transmission repetitions 201.

In some circumstances, every N/M continuous PRACH repetitions among the PRACH transmission repetitions may belong to one group among the M PRACH groups. In some other circumstances, each M continuous PRACH repetitions among the N PRACH transmission repetitions may belong to the M PRACH groups.

In some example embodiments, the at least one monitoring window may comprise one monitoring window, and the one monitoring window may be determined based on one PRACH repetition among the N PRACH transmission repetitions 201. Alternatively, the one monitoring window may be determined based on one PRACH group among the M PRACH groups. For example, the one monitoring window may start at the first symbol of the earliest control resource set (CORESET) the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions 201 or the last or first PRACH group among the M PRACH groups.

The at least one monitoring window may comprise M monitoring windows. The UE 210 may determine M monitoring windows based on the M PRACH groups. Each monitoring window among the M monitoring windows may correspond to each PRACH group among the M PRACH groups. In this case, UE 210 may further determine a second monitoring window with a configured length based on one PRACH repetition among the PRACH transmission repetitions 201 or one PRACH group among the M PRACH groups, and then divide the second monitoring window into the M monitoring windows. Here, each monitoring window among the M monitoring windows may correspond to one of the M PRACH groups. The second monitoring window may start at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups.

Alternatively, UE 210 may determine each monitoring window among the M monitoring window based on each group among the M PRACH groups. Here, one monitoring window may start at the first symbol of the earliest CORESET the UE is configured to receive PDCCH for Type1-PDCCH CSS set that is at least one symbol, after the last symbol of the last or first PRACH repetition of each corresponding PRACH group among the M PRACH groups.

Alternatively, a first monitoring window among the plurality of monitoring windows may start from one PRACH repetition in the first PRACH group among the M PRACH groups, and the other monitoring windows among the M monitoring window may be continuous in time domain following the first monitoring window. Here, the length of each of the M monitoring windows may be the same.

UE 210 may determine a RA-RNTI based on the first or last PRACH repetition among the N PRACH transmission repetitions 201. Alternatively, UE 210 may determine a RA-RNTI based on the first or last PRACH repetition of the first or last PRACH group among the M PRACH groups. Alternatively, UE 210 may determine a RA-RNTI based on a beam index of the first or last PRACH group among the M PRACH groups, or a group index of the first or last PRACH group among the M PRACH groups.

In order to receive (242) the DCI 202, UE 210 may receive (242) the DCI 202 with CRC scrambled by M RA-RNTIs corresponding to the M PRACH groups during at least one monitoring window. Here, for one PRACH group of the M PRACH groups, UE 210 may determine a RA-RNTI corresponding to the one PRACH group based on one of the RO of the last or first PRACH repetition in the one RRACH group, a beam index indicating a beam among the plurality of beams (the beam is associated with the one PRACH group) , or a group index of the one PRACH group. In this case, UE 210 may, in response to receiving (242) the DCI 202 with CRC scrambled by a RA-RNTI in a monitoring window, determine that the first beam is same as a beam among the plurality of beams associated the one PRACH groups corresponding to the RA-RNTI.

On the other hand, the base station 220 may determine a PRACH group among the M PRACH groups, where the PRACH group is associated with a first beam through which the base station 220 receives the PRACH transmission repetitions 201. In this case, the base station may convey information about the first beam via the RA-RNTI comprised in the DCI 202, because the RA-RNTI is associated with the PRACH group which is associated with the first beam. Alternatively, the base station 220 may determine a beam indicator to be comprised in the DCI 202. The beam indicator may indicate the first beam for the PUSCH transmission. In this case, information about the first beam can be indicated by the RA-RNTI comprised in the DCI 202. In addition or as an alternative, the information about the first beam can also be indicated by the beam indicator comprised in the DCI 202. At UE 210, in order to determine the first beam, UE 210 may obtain a beam indicator in the RAR UL grant. Here, the beam indicator may indicate the first beam for the PUSCH transmission 203. In this case, the beam indicator may comprise a plurality of bits; the number of the plurality of bits may be based on the value of M. The plurality of bits may be in at least one field of: a time domain resource assignment (TDRA) information field, a modulation and coding (MCS) information field, a transmit power control (TPC) information field, a channel state information (CSI) request information field, or a frequency domain resource assignment (FDRA) information field.

In addition, UE 210 may further transmit, to the base station 220, second PRACH transmission repetitions associated with a second plurality of beams. The base station 220 may receive, from UE 210, the second PRACH transmission repetition. Then, the base station may determine a second beam indicator to be comprised in the second DCI. Here, the second beam indicator may indicate a second beam for the UE 210 to transmit the second PUSCH transmission. Then, the base station 220 may transmit, to UE 210, a second DCI comprising the second beam indicator with CRC scrambled with TC-RNTI scheduling the second PUSCH transmission of UE 210. On UE side, UE 210 may receive the second DCI, and obtain a second beam indicator in the second DCI. Here, the second beam indicator may comprise a plurality of bits in the second DCI, the number of the plurality of bits may be based on the value of M (i.e., the number of PRACH groups) , and the plurality of bits may be in a hybrid automatic repeat request (HARQ) process number (HPN) field. Alternatively, the base station 220 may determine that the second PUSCH transmission is to be transmitted by the UE 210 using the first beam and indicate such information to UE 210, for example, via the second DCI, such that UE 210 may transmit the second PUSCH transmission using the first beam.

Additionally, the base station 220 may further determine a resource for third PUSCH transmission based on a search space set where the third DCI is to be transmitted; and transmit the third DCI to the UE 210. Here, the third DCI comprises a CRC scrambled with C-RNTI and schedules the third PUSCH transmission. More specifically, the resource is in UE specific search space, the base station 220 may determine a repetition number for the third PUSCH transmission to be repeated; and transmit, to the UE 210, the repetition number via a RRC signaling, which is comprised in the third DCI. This means that, the base station 220 may anticipate to receive the repetitions for the third PUSCH transmission based on the repetition number. Alternatively, if the resource is in a common search space, the base station 220 may determine a repetition number for the third PUSCH transmission to be repeated; and transmit, via the transceiver and to the UE, a system information block 1 (SIB1) comprising the repetition number, wherein the SIB1 is comprised in the third DCI.

Accordingly, on the other side of communication, UE 210 may further receive a third DCI with CRC scrambled with cell -radio network temporary identifier (C-RNTI) scheduling a third PUSCH transmission, and determine a resource for the third PUSCH transmission based on a search space set where the third DCI is received. More specifically, when the third DCI is received in UE specific search space of UE 210, UE 210 may further determine repetitions for the third PUSCH transmission based on a repetition number configured by the base station 220 via a RRC signaling. Alternatively, when the third DCI is received in a common search space, UE 210 may determine repetitions for the third PUSCH transmission based on a repetition number configured by a SIB1. In some example embodiments, UE 210 may transmit the third PUSCH transmission in K continuous available slots. Here, when the third DCI is received in a common search space for UE 210 together with other UEs, a slot is an available slot if the indicated resource by the third DCI in the slot is overlapped with a flexible symbol. Alternatively, when the third DCI is received in UE specific search space for UE 210 only, a slot is not an available slot if the indicated resource by the third DCI in the slot is overlapped with a flexible symbol. Alternatively, when UE 210 transmits the third PUSCH transmission in K continuous slots, if the third DCI is received in a common search space, UE 210 may determine whether the PUSCH repetitions in the K continuous slots are to be used for joint channel estimation or not based on SIB1, or UE 210 may determine the PUSCH repetitions in the K continuous slots are not to be used for joint channel estimation. Alternatively, when the third DCI is received in UE specific search space, UE 210 may determine whether the PUSCH repetitions in the K continuous slots are to be used for joint channel estimation or not based on RRC signaling.

In this way, the base station 220 can indicate, to the UE 210 via the DCI 202, the best beam for PUSCH transmission 203, therefore, communication performance between UE 210 and the base station 220 can be improved. For example, UE 210 can monitor a DCI (for example, the DCI 202 as illustrated in FIG. 2) at an earlier stage than the legacy schemes, which means that the processing time, for example, during a random access procedure, can be reduced. Further, UE 210 can transmit the PUSCH transmission 203 using a best beam among the multiple different Tx beams used for the PRACH transmission repetitions 201, which means the possibilities that the base station 220 can receive the PUSCH transmission 203 successfully can be increased. At the meantime, the coverage performance of the base station 220 can also be enhanced.

As mentioned above with reference to FIG. 2, according to the present disclosure, UE 210 transmits PRACH transmission repetitions 201 using a plurality of beams to the base station 220. This will be described in more detail with reference to FIGS. 3A –3C. In the following description, it is assumed that the number of PRACH transmission repetitions 201 is N, and the N PRACH transmission repetitions 201 includes M PRACH groups. Here, “M” refers to the number of PRACH groups the N PRACH transmission repetitions 201 is divided into. Each group among the M PRACH groups include the PRACH repetition (s) with same beams among the N PRACH transmission repetitions 201. In other words, each group includes the PRACH repetition (s) which is transmitted from UE 210 to the base station 220 using a same beam. Alternatively, each group may include PRACH repetition corresponding to same SSB/CSI-RS. Alternatively, each group may include one repetition. In this case, each PRACH repetition among the N PRACH transmission repetitions 201 may be included in a unique group, and PRACH repetition (s) in a PRACH group may be transmitted from UE 210 to the base station 220 using a same beam.

As to the determination of the value of M, as mentioned above, the UE 210 may indicate the value of M to the base station 220. Alternatively, the base station 220 may indicate the value of M to the UE 210. More specifically, UE 210 may indicate, to the base station 220 and as the value of M, the number of beams to be used for transmitting the PRACH transmission repetitions 201, for example, through the PRACH resource used for the PRACH transmission repetitions 201. In other words, M is number of beams used for PRACH transmission repetitions 201. Here, a RRACH resource may include a preamble and a RO. For different number of beams (i.e., for different value of M) , separate RO and/or separate preamble may be configured. In one example, if UE 210 uses a first preamble to transmit the PRACH transmission repetitions 201, then it means the number of beams is a (i.e., the value of M is a) , and if UE 210 uses a second preamble to transmit the PRACH transmission repetitions 201, then it means the number of beams is b (i.e., the value of M is b) . In another example, if UE 210 uses RO#2 as illustrated in FIG. 1C to transmit the PRACH transmission repetitions 201, then it means the number of beam is p (i.e., the value of M is p) , and if UE 210 uses RO#5 as illustrated in FIG. 1C to transmit the PRACH transmission repetitions 201, then it means the number of beam is q (i.e., the value of M is q) .

For example, in the examples as illustrated in FIGS. 3A –3C, different patterns represent different beams (i.e. different patterns represent different PRACH groups) . FIG. 3A illustrates a schematic diagram of example PRACH groups 300A in accordance with aspects of the present disclosure. As illustrated in FIG. 3A, there are a PRACH repetitions in each of the 4 PRACH groups 300A, i.e., N = 4. At the same time, there are 4 patterns, i.e., M = 4, in other words, there are 4 PRACH groups.

FIG. 3B illustrates a schematic diagram of another example PRACH groups 300B in accordance with aspects of the present disclosure. As illustrated in FIG. 3B, there are also 4 patterns, i.e., M = 4, there are 4 PRACH groups. However, FIG. 3B differs from FIG. 3A in that there are two PRACH repetitions in each of the 4 PRACH groups 300A, i.e., N = 8 (= 4 *2 ) .

FIG. 3C illustrates a schematic diagram of further another example PRACH groups 300C in accordance with aspects of the present disclosure. As illustrated in FIG. 3C, there are also 4 patterns, i.e., M = 4, there are 4 PRACH groups. However, FIG. 3C differs from FIG. 3A in that there are two PRACH repetitions in each of the 4 PRACH groups 300A, i.e., N = 8 (= 4 *2 ) . FIG. 3C differs from FIG. 3B in that, in FIG. 3B, PRACH repetitions in a same group among the 4 PRACH groups appears continuously, while in FIG. 3C, PRACH repetitions in a same group among the 4 PRACH groups appears discontinuously.

Alternatively, the base station 220 may indicate the number of beams (i.e., the value of M) which may be used for the UE 210 to transmit (230) the PRACH transmission repetitions 201. For example, the base station 220 may indicate the number of beams in a system information block (SIB) .

Alternatively, the value of M may be determined by the used number of SSBs for the N PRACH transmission repetitions 201. As mentioned above, the PRACH are transmitted in valid PRACH occasions, and all respective valid PRACH occasions are consecutive in time domain and use same frequency resources and are associated with one SS/PBCH index in the configured SSB pattern. For example, assuming N = 8, and the used SSB is 00011122 (here, each bit may be interpreted as the SSB index shown in FIGS. 1C –1E, for example, in FIG. 1C, “SSB#2” means a SSB with an index of “2” ) , then UE 210 can determine M = 3, since there are three SSBs (i.e., SSB#0, SSB#1 and SSB#2) used by the UE 210 to transmit 8 PRACH transmission repetitions 201.

Alternatively, the base station 220 may indicate the number of M (i.e., the value of M) by SIB1. Then N PRACH transmission repetitions 201 may be divided into M PRACH groups. For example, every N/M continuous PRACH repetitions may belong to one group among the M PRACH groups, as illustrated in FIGS. 3B and 3C. Alternatively, every M continuous PRACH repetition may belong to M different PRACH groups, as illustrated in FIG. 3A. For the last group, the number of PRACH repetitions may be less than M.

For example, in FIGS. 3A –3C, if the value of M is not determined by the UE 210 but indicated from the base station 220, and the base station 220 indicates M = 4. In this case, when N = 4 (which is the case of FIG. 3A) , each PRACH repetition among the 4 PRACH transmission repetitions 201 belongs to one PRACH group among the 4 PRACH groups. If N = 8 (which is the case for FIGS. 3B and 3C) , each 2 PRACH repetitions with same pattern belongs to a same PRACH group. If the bases station 220 indicates a number of M and the indicated number is larger than N, then the UE 210, in response to reception of the indication, may determine to set M as N. For example, when N = 4 (which is the case of FIG. 3A) , and the base station 220 indicates “6” as the value of M, then the UE 210, in response to reception of the indication of the value of M as “6” , may determine the value of M as 4 (the value of N) , after determining that the indicated value of M (in this case, “6” ) is larger than N.

As mentioned above with reference to FIG. 2, according to the present disclosure, in response to the PRACH transmission repetitions 201, UE 210 attempts to detect and receives, from the base station 220, DCI 202 with CRC scrambled by at least one RA-RNTI during at least one monitoring window. This will be described in more detail with reference to FIGS. 4A –4G.

The at least one window may include one window, and the window may be determined according to the last or first PRACH repetition or PRACH group, as shown in FIG. 4A. FIG. 4A illustrates a schematic diagram of an example monitoring window 400A corresponding to multiple PRACH groups in accordance with aspects of the present disclosure. In the example shown in FIG. 4A, the window is determined according to the last PRACH repetition, i.e., the last PRACH repetition of the last PRACH group.

For example, in the example illustrated in FIG. 4A, the window may start at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last PRACH repetition. RNTI1, RNTI2, RNTI3 and RNTI4 may correspond to the 4 PRACH groups, respectively, and are all detected in the same window.

FIG. 4B illustrates a schematic diagram of multiple monitoring windows 400B corresponding to multiple PRACH groups in accordance with aspects of the present disclosure. In the example shown in FIG. 4B, the at least one window includes M windows, and each window is determined based on the M PRACH groups. In this case, an initial monitoring window may be determined according to the first or last PRACH repetition or PRACH group with a pre-configured or pre-determined length, then the initial monitoring window may be divided into M monitoring windows with same length, as shown in FIG. 4B. The initial window may start at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last or first PRACH repetition or last or first PRACH group. As a specific example, the initial monitoring window may be determined as the window shown in FIG. 4A, i.e., the initial window may start at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last PRACH repetition among the PRACH transmission repetitions 201.

In the example shown in FIG. 4B, if a PDCCH monitoring occasion is cross two sub windows, then the occasion belongs to the last window. For example, if each of the sub window has a length of 2.5 ms, and the PDCCH monitoring occasion is at3 ms, or in other words thus is cross two sub windows (for example, here, assuming sub window 2 and sub window 3) , then the PDCCH monitoring occasion belongs to the last window (here, sub window 3) .

FIGS. 4C and 4D illustrate schematic diagrams of examples of multiple monitoring windows corresponding to multiple PRACH groups in accordance with aspects of the present disclosure. In the example shown in FIG. 4C, each monitoring window among the multiple monitoring windows 400C is determined according to each PRACH transmission group. Since there are M PRACH groups, the number of monitoring windows is also M. Here, M = 4. Each of the M monitoring windows starts at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last or first PRACH repetition in each PRACH group. For example, window 1 starts at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last (or first) PRACH repetition in the first PRACH group, window 2 starts at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last (or first) PRACH repetition in the second PRACH group, window 3 starts at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last (or first) PRACH repetition in the third PRACH group, and window 4 starts at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last (or first) PRACH repetition in the fourth PRACH group. In this case, UE 210 may detects RNTI1 corresponding to the first PRACH group in window 1, detects RNTI2 corresponding to the second PRACH group in window 2, detects RNTI3 corresponding to the third PRACH group in window 3, and detects RNTI4 corresponding to the fourth PRACH group in window 4.

FIG. 4D differs from FIG. 4C in that, among the multiple monitoring windows 400D, the starting point of window 2, window 3 and window 4 is not based on the respective corresponding PRACH groups, but the next window stars at the ending point of the current window in the time domain. For example, window 2 starts at the ending point of window 1, window 3 starts at the ending point of window 2, and window 4 starts at the ending point of window 3. Put it another way, in the example shown in FIG. 4D, the first monitoring window (i.e., window 1 shown in FIG. 4D) starts from the first or last PRACH repetition in the first PRACH group. More specifically, the first monitoring window (here, window 1) may start at the first symbol of the earliest CORESET the UE 210 is configured to receive PDCCH for Type1-PDCCH CSS set, that is at least one symbol, after the last symbol of the last (or first) PRACH repetition of the first PRACH group. The other monitoring windows (here, window 2, window 3 and window 4) follows the previous monitoring window in time domain, and all the monitoring windows may have a same length configured by the base station 220. In this case, similar as the example shown in FIG. 4B, if a PDCCH monitoring occasion is cross two sub windows, then if there is PDCCH received in the subwindow, we assume the PDCCH is received in the PDCCH monitoring occasion belongs to the last window.

FIG. 4E illustrates a schematic diagram of an example of multiple RNTIs 400E corresponding to one PRACH group in accordance with aspects of the present disclosure. In this case, UE 210 attempts to detect a DCI format 0_0 with CRC scrambled by single RA-RNTI during the M monitoring windows. The RA-RNTI is determined based on the RO wherein the last or first RRACH repetition transmitted or based on the RO of the first or last PRACH repetition of the first or last PRACH group. In the specific example shown in FIG. 4E, RNTI1, which is a RA-RNTI, may be determined based on the RO in which the last or first RRACH repetition is transmitted or based on the RO of the first or last PRACH repetition of the first PRACH group. The RNTI1 may be detected during the 4 monitoring windows, i.e., window 1, window 2, window 3 and window 4, for example, as shown in FIG. 4D. Here, each monitoring window among the 4 monitoring windows corresponds to a PRACH group as illustrated in FIG. 4E. If the RNTI1 is detected in a monitoring window, for example, window 3, then the base station 220 may determine that the beam for transmitting the third PRACH group which is corresponding to (or, associated with) window 3 is the best beam for the UE 210 to transmit the PUSCH transmission 203.

FIGS. 4F and 4G illustrate schematic diagrams of examples of multiple RNTIs corresponding to multiple PRACH groups in accordance with aspects of the present disclosure. In the examples illustrated in FIGS. 4F and 4G, UE 210 attempts to detect a DCI format 0_0 with CRC scrambled by M RA-RNTI during the M monitoring windows. For each monitoring window, the RA-RNTI may be determined by the RO of the last (or first) PRACH repetition in the RO group corresponding to the monitoring window. Alternatively, for each window, the RA-RNTI may be determined by a new parameter which represents the beam index or group index corresponding to the monitoring window.

For example, in FIG. 4F, the 4 monitoring windows (for example, window 1, window 2, window 3 and window 4 as illustrated in FIG. 4D) may be determined as in FIG. 4D. In each monitoring window, a RNTI (for example, RA-RNTI) among the multiple RNTIs 400F corresponding to the monitoring window is detected. More specifically, window 1, window 2, window 3 and window 4 correspond to the 4 PRACH groups as illustrated in FIGS. 4F and 4D, RNTI1, RNTI2, RNTI3 and RNTI4 also correspond to the 4 PRACH groups, and are detected in their corresponding monitoring windows, respectively. For example, RNTI1 as shown in FIG. 4F is to be detected in window 1 as shown in FIG. 4D, RNTI2 as shown in FIG. 4F is to be detected in window 2 as shown in FIG. 4D, RNTI3 as shown in FIG. 4F is to be detected in window 3 as shown in FIG. 4D, and RNTI4 as shown in FIG. 4F is to be detected in window 4 as shown in FIG. 4D.

As mentioned above, each PRACH group may include PRACH repetition (s) which is transmitted by UE 210 using a same beam. Therefore, for the example shown in FIG. 4F, it can also be referred to as that, RA-RNTI may be determined by a new parameter which represents the beam index, instead of the group index. Alternatively, the RO (s) in which a repetition in a PRACH group is transmitted by the UE 210 may form a RO group, which corresponds to the PRACH group. In this sense, for the example shown in FIG. 4F, it can also be referred to as that, RA-RNTI may be determined by the RO(s) of a RO group corresponding to the PRACH group. Alternatively, the RA-RNTI may be determined simply based on the RO of the last or first PRACH repetition in the PRACH group.

In the example illustrated in FIG. 4G, UE 210 attempts to detect a DCI format 0_0 with CRC scrambled by M RA-RNTI during the M windows, and for each window, the RNTI (for example, RA-RNTI) among the multiple RNTIs 400G is determined by the RO of the last (or first) PRACH repetition in the RO group. Or, for each window, PA-RNTI is determined by a new parameter which represents the beam index or group index. More specifically, the 4 monitoring windows (for example, window 1, window 2, window 3 and window 4 as illustrated in FIG. 4C) may be determined as in FIG. 4C. In each monitoring window, a RA-RNTI corresponding to the monitoring window is detected. More specifically, window 1, window 2, window 3 and window 4 correspond to the 4 PRACH groups as illustrated in FIGS. 4G and 4C, RNTI1, RNTI2, RNTI3 and RNTI4 also correspond to the 4 PRACH groups, and are detected in their corresponding monitoring windows, respectively. For example, RNTI1 as shown in FIG. 4G is to be detected in window 1 as shown in FIG. 4C, RNTI2 as shown in FIG. 4G is to be detected in window 2 as shown in FIG. 4G, RNTI3 as shown in FIG. 4G is to be detected in window 3 as shown in FIG. 4G, and RNTI4 as shown in FIG. 4G is to be detected in window 4 as shown in FIG. 4G. For the example shown in FIG. 4G, similar to the example shown in FIG. 4F, RA-RNTI may be determined by a new parameter which represents the beam index, or group index. Alternatively, RA-RNTI may be determined by the RO (s) of a RO group corresponding to the PRACH group. Alternatively, the RA-RNTI may be determined simply based on the RO of the last or first PRACH repetition in the PRACH group.

As mentioned above, after reception of the DCI 202, UE 210 transmits, to the base station 220, the PUSCH transmission 203 based on a RAR UL grant scheduled by the DCI 202. In doing so, the PUSCH transmission 203 and one PRACH groups (for example, one of the 4 PRACH groups as illustrated in FIGS. 4A –4G) may use a same beam. Same beam means, the DMRS of the PUSCH transmission and PRACH repetition have same DM-RS antenna port quasi co-location properties or have same spatial domain information. For example, if UE 210 receives a random access response (RAR) UL grant according to the DCI format 0_0 with CRC scrambled by a RA-RNTI in a monitoring window, then UE 210 transmits a PUSCH transmission (for example, PUSCH transmission 203 as illustrated in FIG. 2) according to the RAR UL grant. Here, the PUSCH transmission and one PRACH group among the M PRACH groups corresponding to the RA-RNTI or monitoring window in which the DCI 202 is received use same beam. Alternatively, if UE 210 receives random access response (RAR) UL grant according to the DCI format 0_0 in a monitoring window, then transmits a PUSCH transmission according to the RAR UL grant. Here, the PUSCH transmission and one PRACH group among the M PRACH groups corresponding to the monitoring window use same beam. In this case, if the window is overlapped, assuming the PDCCH (or, put it another way, the DCI, for example, DCI 202 as illustrated in FIG. 2) is received from the monitoring window with smaller starting symbol (or ending symbol) . For example, in the example shown in FIG. 4G, if the PDCCH (i.e., Msg2 illustrated in FIG. 1B or DCI 202 as shown in FIG. 2) is received in an overlapped period of window 2 and window 3, then it is assumed that the PDCCH is received from the window 2, because it has smaller starting symbol or ending symbol as compared with window 3.

For indication of the best beam for PUSCH transmission 203, a plurality of bits in the RAR UL grant in the DCI 202 may be (re) used. The number of bits needed to indicate the best beam may be determined by the number of the PRACH groups, i.e., the value of M. More specifically, the plurality of bits may be in at least one field of: a TDRA information field, an MCS information field, a TPC information field, a CSI request information field, or an FDRA information field.

In some example embodiments, UE 210 may retransmit the PUSCH transmission 203 (i.e., perform PUSCH transmission repetitions) based on the received DCI format 0_0 scrambled by TC-RNTI. The beam for the PUSCH retransmission may be same as the PUSCH transmission 203 or may be indicated by a plurality of bits in the DCI format 0_0 scrambled by TC-RNTI, the number of the plurality of bits is determined by the number of the PRACH groups, i.e., the value of M. These bits may be in at least one field of: a TDRA information field, an MCS information field, a TPC information field, a CSI request information field, an FDRA information field, or an HPN field.

In some example embodiments, UE 210 may detect another DCI format 0_0 with CRC scrambled by C-RNTI scheduling another PUSCH transmission, and UE 210 may decide the resource for the another PUSCH transmission according to the SS set where the UE 210 receives the another DCI. If the resource is in UE specific search space for the UE 210, then UE 210 may determine the PUSCH repetition according the number of repetition number configured by RRC signaling. In this case, if the repetition number for the another PUSCH transmission is configured, then the PUSCH transmission may be repeated according to the repetition number. Otherwise, if the repetition number is not configured, then the PUSCH is not repeated. Alternatively, if the resource is in common search space for the UE 210, UE 210 may determine whether the PUSCH transmission should be repeated or not according to the repetition number configured by SIB1. Or, the UE 210 may determine that the another PUSCH transmission should not be repeated.

If the determined repetition number is K (K is an integer) , the PUSCH may be transmitted in K continuous physic slot or K continuous available slot. For different SS set, the available slot is different. More specifically, for UE specific SS set, a slot is not an available slot if the SLIV in the slot is overlapped with a flexible symbol. While for CSS, a slot is an available slot if the SLIV in the slot is overlapped with a flexible symbol.

For UE specific Search Space (USS) , it is configured by RRC signaling whether joint channel estimation (JCE) is supported or not, but for CSS, it is decided based one SIB1 whether JCE is supported. More specifically, if UE 210 receives the another DCI in UE specific search space, UE 210 may determine whether the PUSCH repetitions in the K continuous slots are to be used for JCE or not based on RRC signaling. Alternatively, if UE 210 receives the another DCI in the common search space, UE 210 may determine whether the PUSCH repetitions in the K continuous slots are to be used for JCE or not based on SIB1, or determine the PUSCH repetition in the K continuous slots are not to be used for JCE.

FIG. 5 illustrates an example of a device 500 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The device 500 may be an example of a UE 210 as described herein. The device 500 may support wireless communication with one or more network entities 102, UEs 104, core networks 106 or any combination thereof. The device 500 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 502, a memory 504, a transceiver 506, and, optionally, an I/O controller 508. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 502, the memory 504, the transceiver 506, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 502, the memory 504, the transceiver 506, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 502, the memory 504, the transceiver 506, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 502 and the memory 504 coupled with the processor 502 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 502, instructions stored in the memory 504) .

For example, the processor 502 may support wireless communication at the device 500 in accordance with examples as disclosed herein. The processor 502 may be configured to operable to support a means for transmitting, to a base station (for example, the base station 220 as illustrated in FIG. 2) , PRACH transmission repetitions (for example, PRACH transmission repetitions 201 as illustrated in FIG. 2) using a plurality of beams; in response to the PRACH transmission repetitions, receiving, from the base station, DCI (for example, DCI 202 as illustrated in FIG. 2) with CRC scrambled by at least one RA-RNTI during at least one monitoring window; and transmitting, to the base station, a PUSCH transmission (for example, PUSCH transmission 203 as illustrated in FIG. 2) based on a RAR UL grant scheduled by the DCI..

The processor 502 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 502 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 502. The processor 502 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 504) to cause the device 500 to perform various functions of the present disclosure.

The memory 504 may include random access memory (RAM) and read-only memory (ROM) . The memory 504 may store computer-readable, computer-executable code including instructions that, when executed by the processor 502 cause the device 500 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 502 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 504 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 508 may manage input and output signals for the device 500. The I/O controller 508 may also manage peripherals not integrated into the device 500. In some implementations, the I/O controller 508 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 508 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 508 may be implemented as part of a processor, such as the processor 506. In some implementations, a user may interact with the device 500 via the I/O controller 508 or via hardware components controlled by the I/O controller 508.

In some implementations, the device 500 may include a single antenna 510. However, in some other implementations, the device 500 may have more than one antenna 510 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 506 may communicate bi-directionally, via the one or more antennas 510, wired, or wireless links as described herein. For example, the transceiver 506 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 506 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 510 for transmission, and to demodulate packets received from the one or more antennas 510. The transceiver 506 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 510 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 510 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 6 illustrates an example of a device 600 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The device 600 may be an example of a base station 220 as described herein. The device 600 may support wireless communication with one or more network entities 102, UEs 104, core networks 106 or any combination thereof. The device 600 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 602, a memory 604, a transceiver 606, and, optionally, an I/O controller 608. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 602, the memory 604, the transceiver 606, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. For example, the processor 602, the memory 604, the transceiver 606, or various combinations or components thereof may support a method for performing one or more of the operations described herein.

In some implementations, the processor 602, the memory 604, the transceiver 606, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some implementations, the processor 602 and the memory 604 coupled with the processor 602 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 602, instructions stored in the memory 604) .

For example, the processor 602 may support wireless communication at the device 600 in accordance with examples as disclosed herein. The processor 602 may be configured to operable to support a means for receiving, from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams; in response to the PRACH transmission repetitions, transmitting, to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and receiving, from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

The processor 602 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some implementations, the processor 602 may be configured to operate a memory array using a memory controller. In some other implementations, a memory controller may be integrated into the processor 602. The processor 602 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 604) to cause the device 600 to perform various functions of the present disclosure.

The memory 604 may include random access memory (RAM) and read-only memory (ROM) . The memory 604 may store computer-readable, computer-executable code including instructions that, when executed by the processor 602 cause the device 600 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some implementations, the code may not be directly executable by the processor 602 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 604 may include, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The I/O controller 608 may manage input and output signals for the device 600. The I/O controller 608 may also manage peripherals not integrated into the device 600. In some implementations, the I/O controller 608 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 608 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 608 may be implemented as part of a processor, such as the processor 606. In some implementations, a user may interact with the device 600 via the I/O controller 608 or via hardware components controlled by the I/O controller 608.

In some implementations, the device 600 may include a single antenna 610. However, in some other implementations, the device 600 may have more than one antenna 610 (i.e., multiple antennas) , including multiple antenna panels or antenna arrays, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 606 may communicate bi-directionally, via the one or more antennas 610, wired, or wireless links as described herein. For example, the transceiver 606 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 606 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 610 for transmission, and to demodulate packets received from the one or more antennas 610. The transceiver 606 may include one or more transmit chains, one or more receive chains, or a combination thereof.

A transmit chain may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmit chain may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmit chain may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmit chain may also include one or more antennas 610 for transmitting the amplified signal into the air or wireless medium.

A receive chain may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receive chain may include one or more antennas 610 for receive the signal over the air or wireless medium. The receive chain may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receive chain may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receive chain may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

FIG. 7 illustrates an example of a processor 700 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The processor 700 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 700 may include a controller 702 configured to perform various operations in accordance with examples as described herein. The processor 700 may optionally include at least one memory 704, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 700 may optionally include one or more arithmetic-logic units (ALUs) 706. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) . In some example embodiments of the present disclosure, the processor 700 may be included in the user equipment (UE) (for example, UE 210 as illustrated in FIG. 2) .

The processor 700 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 700) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 702 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 700 to cause the processor 700 to support various operations of a UE 210 in accordance with examples as described herein. For example, the controller 702 may operate as a control unit of the processor 700, generating control signals that manage the operation of various components of the processor 700. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 702 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 704 and determine subsequent instruction (s) to be executed to cause the processor 700 to support various operations in accordance with examples as described herein. The controller 702 may be configured to track memory address of instructions associated with the memory 704. The controller 702 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 702 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 700 to cause the processor 700 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 702 may be configured to manage flow of data within the processor 700. The controller 702 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 700.

The memory 704 may include one or more caches (e.g., memory local to or included in the processor 700 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 704 may reside within or on a processor chipset (e.g., local to the processor 700) . In some other implementations, the memory 704 may reside external to the processor chipset (e.g., remote to the processor 700) .

The memory 704 may store computer-readable, computer-executable code including instructions that, when executed by the processor 700, cause the processor 700 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 702 and/or the processor 700 may be configured to execute computer-readable instructions stored in the memory 704 to cause the processor 700 to perform various functions. For example, the processor 700 and/or the controller 702 may be coupled with or to the memory 704, and the processor 700, the controller 702, and the memory 704 may be configured to perform various functions described herein. In some examples, the processor 700 may include multiple processors and the memory 704 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 706 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 706 may reside within or on a processor chipset (e.g., the processor 700) . In some other implementations, the one or more ALUs 706 may reside external to the processor chipset (e.g., the processor 700) . One or more ALUs 706 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 706 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 706 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 706 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 706 to handle conditional operations, comparisons, and bitwise operations.

The processor 700 may support wireless communication in accordance with examples as disclosed herein. The processor 700 may be configured to or operable to support a means for transmitting, to a base station (for example, the base station 220 as illustrated in FIG. 2) , PRACH transmission repetitions (for example, PRACH transmission repetitions 201 as illustrated in FIG. 2) using a plurality of beams; in response to the PRACH transmission repetitions, receiving, from the base station, DCI (for example, DCI 202 as illustrated in FIG. 2) with CRC scrambled by at least one RA-RNTI during at least one monitoring window; and transmitting, to the base station, a PUSCH transmission (for example, PUSCH transmission 203 as illustrated in FIG. 2) based on a RAR UL grant scheduled by the DCI.

FIG. 8 illustrates an example of a processor 800 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The processor 800 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 800 may include a controller 802 configured to perform various operations in accordance with examples as described herein. The processor 800 may optionally include at least one memory 804, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 800 may optionally include one or more arithmetic-logic units (ALUs) 806. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) . In some example embodiments of the present disclosure, the processor 800 may be included in a base station (for example, BS 220 as illustrated in FIG. 2) .

The processor 800 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 800) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 802 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 800 to cause the processor 800 to support various operations of the base station 220 in accordance with examples as described herein. For example, the controller 802 may operate as a control unit of the processor 800, generating control signals that manage the operation of various components of the processor 800. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 802 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 804 and determine subsequent instruction (s) to be executed to cause the processor 800 to support various operations in accordance with examples as described herein. The controller 802 may be configured to track memory address of instructions associated with the memory 804. The controller 802 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 802 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 800 to cause the processor 800 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 802 may be configured to manage flow of data within the processor 800. The controller 802 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 800.

The memory 804 may include one or more caches (e.g., memory local to or included in the processor 800 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 804 may reside within or on a processor chipset (e.g., local to the processor 800) . In some other implementations, the memory 804 may reside external to the processor chipset (e.g., remote to the processor 800) .

The memory 804 may store computer-readable, computer-executable code including instructions that, when executed by the processor 800, cause the processor 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 802 and/or the processor 800 may be configured to execute computer-readable instructions stored in the memory 804 to cause the processor 800 to perform various functions. For example, the processor 800 and/or the controller 802 may be coupled with or to the memory 804, and the processor 800, the controller 802, and the memory 804 may be configured to perform various functions described herein. In some examples, the processor 800 may include multiple processors and the memory 804 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 806 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 806 may reside within or on a processor chipset (e.g., the processor 800) . In some other implementations, the one or more ALUs 806 may reside external to the processor chipset (e.g., the processor 800) . One or more ALUs 806 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 806 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 806 may be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 806 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 806 to handle conditional operations, comparisons, and bitwise operations.

The processor 800 may support wireless communication in accordance with examples as disclosed herein. The processor 800 may be configured to or operable to support a means for receiving, from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams; in response to the PRACH transmission repetitions, transmitting, to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and receiving, from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

FIG. 9 illustrates a flowchart of a method 900 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The operations of the method 900 may be implemented by a device or its components as described herein. For example, the operations of the method 900 may be performed by a UE 210 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 910, the method may include transmitting, to a base station (for example, the base station 220 as illustrated in FIG. 2) , PRACH transmission repetitions (for example, PRACH transmission repetitions 201 as illustrated in FIG. 2) using a plurality of beams. At 920, the method may include in response to the PRACH transmission repetitions, receiving, from the base station, DCI (for example, DCI 202 as illustrated in FIG. 2) with CRC scrambled by at least one RA-RNTI during at least one monitoring window. At 930, the method may include transmitting, to the base station, a PUSCH transmission (for example, PUSCH transmission 203 as illustrated in FIG. 2) based on a RAR UL grant scheduled by the DCI.

FIG. 10 illustrates a flowchart of a method 1000 that supports PRACH repetitions using different beams and PUSCH repetition using a beam among the different beams in accordance with aspects of the present disclosure. The operations of the method 1000 may be implemented by a device or its components as described herein. For example, the operations of the method 1000 may be performed by a BS 220 as described herein. In some implementations, the device may execute a set of instructions to control the function elements of the device to perform the described functions. Additionally, or alternatively, the device may perform aspects of the described functions using special-purpose hardware.

At 1010, the method may include receiving, from a user equipment (UE) , physical random access channel (PRACH) transmission repetitions by the UE using a plurality of beams. At 1020, the method may include in response to the PRACH transmission repetitions, transmitting, to the UE, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window. At 1020, the method may include receiving, from the UE, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.

It should be noted that the methods described herein describes possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor.

As used herein, including in the claims, an article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. Further, as used herein, including in the claims, a “set” may include one or more elements.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

transmit, via the transceiver and to a base station, physical random access channel (PRACH) transmission repetitions using a plurality of beams;

in response to the PRACH transmission repetitions, receive, via the transceiver and from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access -radio network temporary identifier (RA-RNTI) during at least one monitoring window; and

transmit, via the transceiver and to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.
The UE of claim 1, wherein the PUSCH transmission is transmitted using a first beam among the plurality of beams, wherein the first beam is indicated by the DCI.
The UE of claim 2, wherein the number of PRACH transmission repetitions is N, the N PRACH transmission repetitions comprise M PRACH groups, and wherein

one of the M PRACH groups comprises PRACH transmission repetitions associated with one of: a same beam, a same synchronization signal and physical broadcast channel (PBCH) block (SSB) , a same channel state information reference signal (CSI-RS) , or a same spatial filter, or

one of the M PRACH groups comprises one PRACH transmission.
The UE of claim 3, wherein the processor is configured to perform one of the following:

indicating, via the transceiver and to the base station, a value of M,

receiving, via the transceiver and from the base station, the value of M, or

determining, as the value of M, the number of used SSBs for the N PRACH transmission repetitions.
The UE of claim 4, wherein the indicating a value of M is by a PRACH resource for the PRACH transmission repetitions, and the PRACH resource comprises a preamble and a random access channel (RACH) occasion.
The UE of claim 3 or 4, wherein:

every N/M continuous PRACH repetitions among the PRACH transmission repetitions belong to one group among the M PRACH groups, or

each M continuous PRACH repetitions among the N PRACH transmission repetitions belong to the M PRACH groups.
The UE of claim 3 or 4, wherein in the case that the value of M is larger than N, the processor is further configured to set M as N.
The UE of claim 3, wherein the at least one monitoring window comprises one monitoring window determined based on one of the following:

one PRACH repetition among the N PRACH transmission repetitions, or

one PRACH group among the M PRACH groups.
The UE of claim 3, wherein the at least one monitoring window comprises M monitoring windows, and the processor is further configured to:

determine M monitoring windows based on the M PRACH groups, wherein each monitoring window among the M monitoring windows is corresponding to each PRACH group among the M PRACH groups.
The UE of claim 9, wherein the processor is further configured to:

determine a second monitoring window with a configured length based on one PRACH repetition among the PRACH transmission repetitions or one PRACH group among the M PRACH groups; and

divide the second monitoring window into the M monitoring windows, and each monitoring window among the M monitoring windows is corresponding to one of the M PRACH groups.
The UE of claim 10, wherein the second monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition among the N PRACH transmission repetitions or the last or first PRACH group among the M PRACH groups.
The UE of claim 9, wherein the processor is further configured to:

determine each monitoring window among the M monitoring window based on each group among the M PRACH groups,

wherein one monitoring window starts at the first symbol of the earliest control resource set (CORESET) the UE is configured to receive physical downlink control channel (PDCCH) for Type1-PDCCH common search space (CSS) set that is at least one symbol, after the last symbol of the last or first PRACH repetition of each corresponding PRACH group among the M PRACH groups.
The UE of claim 9, wherein a first monitoring window among the plurality of monitoring windows starts from the one PRACH repetition in the first PRACH group among the M PRACH groups, and the other monitoring windows among the M monitoring window are continuous in time domain following the first monitoring window,

wherein the length of each of the M monitoring windows is the same.
The UE of claim 9, wherein the processor is further configured to determine a RA-RNTI based on one of the following:

a first PRACH repetition among the N PRACH transmission repetitions,

a last PRACH repetition among the N PRACH transmission repetitions,

a first PRACH repetition of the first or last PRACH group among the M PRACH groups,

a last PRACH repetition of the first or last PRACH group among the M PRACH groups,

a beam index of the first or last PRACH group among the M PRACH groups, or

a group index of the first or last PRACH group among the M PRACH groups.
The UE of claim 9, wherein the processor is configured to transmit the PUSCH transmission by:

in response to receiving the DCI in a monitoring window, transmitting the PUSCH transmission using same beam as the PRACH group corresponding to the monitoring window.
The UE of claim 8 or 9, wherein the processor is configured to receive the DCI by:

receiving the DCI with CRC scrambled by M RA-RNTIs corresponding to the M PRACH groups during at least one monitoring window,

wherein for one PRACH group of the M PRACH groups, the processor is configured to determine a RA-RNTI corresponding to the one PRACH group based on one of the following:

the RO of the last or first PRACH repetition in the one RRACH group,

a beam index indicating a beam among the plurality of beams, the beam being associated with the one PRACH group, or

a group index of the one PRACH group.
The UE of claim 16, wherein the processor is configured to determine the first beam by:

in response to receiving the DCI with CRC scrambled by a RA-RNTI in a monitoring window, determining the first beam is same as a beam among the plurality of beams associated the one PRACH groups corresponding to the RA-RNTI.
A processor for wireless communication, comprising:

at least one memory; and

a controller coupled with the at least one memory and configured to cause the controller to:

transmit, to a base station, physical random access channel (PRACH) transmission repetitions associated using a plurality of beams;

in response to the PRACH transmission repetitions, receive, from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and

transmit, to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.
A method performed by a user equipment (UE) , the method comprising:

transmitting, to a base station, physical random access channel (PRACH) transmission repetitions associated using a plurality of beams;

in response to the PRACH transmission repetitions, receiving, from the base station, downlink control information (DCI) with cyclic redundancy check (CRC) scrambled by at least one random access –radio network temporary identifier (RA-RNTI) during at least one monitoring window; and

transmitting, to the base station, a physical uplink shared channel (PUSCH) transmission based on a random access response (RAR) uplink (UL) grant scheduled by the DCI.