WO2024093323A1

WO2024093323A1 - Determination of rach occasion groups

Info

Publication number: WO2024093323A1
Application number: PCT/CN2023/105076
Authority: WO
Inventors: Yuantao Zhang; Ruixiang MA; Zhi YAN
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2024-05-10

Abstract

Various aspects of the present disclosure relate to determination of RACH occasion (RO) groups. In an aspect, a user equipment determines a set of RO groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. Each RO of the plurality of ROs is associated with a frequency index and a time index. By allocating a RO with two indexes, i.e., a frequency index and a time index, the user equipment may easily determine the RO groups that can be used for the transmission of physical random access channel (PRACH) repetitions. In this way, the RO determination rules may be enhanced.

Description

DETERMINATION OF RACH OCCASION GROUPS

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to determination of random access channel occasion (RO) groups.

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) ) .

In 5G new radio (NR) systems, the random-access procedure is utilized for various purposes. For example, the random-access procedure may be utilized by a UE in initial access to find a cell to camp on; or utilized by a radio resource control (RRC) IDLE/INACTIVE UE to switch to a RRC Connected mode to start data transmission/reception; or utilized by a RRC Connected UE to re-establish the lost uplink (UL) synchronization, etc. Enhancements on the random-access procedure are still needed.

SUMMARY

The present disclosure relates to methods, apparatuses, and systems that support determining RO groups.

In a first aspect of the solution, a user equipment determines a set of RO groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. Each RO of the plurality of ROs is associated with a frequency index and a time index. By allocating a RO with two indexes, i.e., a frequency index and a time index, the user equipment may easily determine the RO groups that can be used for the transmission of physical random access channel (PRACH) repetitions. In this way, the RO determination rules may be enhanced.

In some implementations of the method and apparatuses described herein, the frequency index of a RO may be determined based on a frequency position of the RO in at least one RO that is multiplexed in a frequency domain in a same time occasion. The time index of a RO may be determined based on a time position of the RO in a set of ROs that have a same frequency index.

Some implementations of the method and apparatuses described herein may further include determining that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid. The set of RO groups may be determined from valid ROs in the plurality of ROs.

In some implementations of the method and apparatuses described herein, the set of ROs may be valid for a physical random access channel (PRACH) repetition in the case that a following condition is met: the number of ROs in the set of ROs is the same as the number of ROs in the plurality of ROs having a lowest frequency index. The set of ROs may be invalid for the PRACH repetitions in the case that the condition is not met.

In some implementations of the method and apparatuses described herein, determining that a set of ROs in the plurality of ROs are valid or invalid may comprise: determining at least one RO group for a configured number of PRACH repetitions from the set of ROs; determining that the set of ROs are valid for PRACH repetitions in the case that a following condition is met: the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions; or determining that the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.

In some implementations of the method and apparatuses described herein, the set of ROs may be valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: the number of ROs in the set of ROs is equal to or larger than the configured number. The set of ROs may be invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

In some implementations of the method and apparatuses described herein, the set of ROs may be valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: a RO group can be determined from the set of ROs for the configured number of PRACH repetitions. The set of ROs may be invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

In some implementations of the method and apparatuses described herein, the frequency index associated with the set of ROs may be an invalid frequency index for PRACH repetitions in the case that a following condition is met: the set of ROs are invalid for PRACH repetitions. The frequency index associated with the set of ROs may be a valid frequency index for the PRACH repetitions in the case that the condition is not met.

In some implementations of the method and apparatuses described herein, the number of at least one SSB to RO association pattern periods is determined such that the number is a minimum integer fulfilling one of the following: at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions; or at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.

In some implementations of the method and apparatuses described herein, RO groups among the set of RO groups may be indexed by: indexing RO groups in a first subset of RO groups among the set of RO groups with a lowest frequency index; and indexing RO groups in a second subset of RO groups among the set of RO groups with a second lowest frequency index after the indexing of the RO groups in the first subset of RO groups is completed.

In some implementations of the method and apparatuses described herein, ROs in a RO group in the set of RO groups may be associated with the same frequency index.

In some implementations of the method and apparatuses described herein, ROs in a RO group in the set of RO groups may be determined at least based on a configured frequency index offset.

In some implementations of the method and apparatuses described herein, the set of RO groups may be determined for a configured number of PRACH repetitions.

In some implementations of the method and apparatuses described herein, the set of RO groups may be determined based on at least one set of ROs. A set of ROs among the at least one set of ROs may be determined based on a maximum configured number for PRACH repetitions and the number of ROs, among the plurality of ROs, with a same valid frequency index.

In some implementations of the method and apparatuses described herein, in the case that the configured number is a first configured number, the set of ROs may comprise a first set of ROs. In the case that the configured number is a second configured number, the set of ROs may comprise a second set of ROs which are the same as the first set of ROs.

In some implementations of the method and apparatuses described herein, the set of RO groups may be determined based on at least one set of ROs. A set of ROs among the at least one set of ROs may be determined based on the configured number and the number of ROs, among the plurality of ROs, with a same valid frequency index.

In some implementations of the method and apparatuses described herein, in the case that the configured number is a first configured number, the set of ROs may comprise a first set of ROs. In the case that the configured number is a second configured number, the set of ROs may comprise a second set of ROs different from the first set of ROs.

Some implementations of the method and apparatuses described herein may further include transmitting, to a base station, PRACH repetitions in a RO group in the set of RO groups.

In a second aspect of the solution, a base station determines a set of RO groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. Each RO of the plurality of ROs is associated with a frequency index and a time index. By allocating a RO with two indexes, i.e., a frequency index and a time index, the base station may easily determine the RO groups that can be used for the transmission of the PRACH repetitions. In this way, the RO determination rules may be enhanced.

Some implementations of the method and apparatuses described herein may further include monitoring PRACH repetitions in a RO group in the set of RO groups.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an example of a wireless communications system that supports determination of RO groups in accordance with aspects of the present disclosure.

FIG. 1B illustrates an example of an NR 4-step random-access procedure that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIG. 1C illustrates an example of a structure of overall random access channel (RACH) resources that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIGS. 1D through 1F illustrate examples of associations between ROs and SSBs that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIG. 2 illustrates an example signaling chart of a communication process that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIGS. 3A through 3C illustrate examples of RACH resource structures that support determination of valid ROs in accordance with some example embodiments of the present disclosure.

FIG. 4 illustrates an example of a RACH resource structure that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIG. 5 illustrates an example of a RACH resource structure that supports frequency hopping in a RO group in accordance with some example embodiments of the present disclosure.

FIG. 6 illustrates an example of a RACH resource structure that supports determination of RO groups in accordance with some example embodiments of the present disclosure.

FIGS. 7 through 8 illustrate examples of devices that support determination of RO groups in accordance with aspects of the present disclosure.

FIGS. 9 through 10 illustrate examples of processors that support determination of RO groups in accordance with aspects of the present disclosure.

FIGS. 11 through 14 illustrate flowcharts of methods that support determination of RO groups 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 may 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.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example 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, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as, 5G NR, long term evolution (LTE) , LTE-advanced (LTE-A) , wideband code division multiple access (WCDMA) , high-speed packet access (HSPA) , narrow band internet of things (NB-IoT) , and so on. Further, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will also be future type communication technologies and systems in which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned systems.

As used herein, the term “network device” generally refers to a node in a communication network via which a terminal device can access the communication network and receive services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , a radio access network (RAN) node, an evolved NodeB (eNodeB or eNB) , an NR NB (also referred to as a gNB) , a remote radio unit (RRU) , a radio header (RH) , an infrastructure device for a V2X (vehicle-to-everything) communication, a transmission and reception point (TRP) , a reception point (RP) , a remote radio head (RRH) , a relay, an integrated access and backhaul (IAB) node, a low power node such as a femto BS, a pico BS, and so forth, depending on the applied terminology and technology.

As used herein, the term “terminal device” generally refers to any end device that may be capable of wireless communications. By way of example rather than a limitation, a terminal device may also be referred to as a communication device, a user equipment (UE) , an end user device, a subscriber station (SS) , an unmanned aerial vehicle (UAV) , a portable subscriber station, a mobile station (MS) , or an access terminal (AT) . The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet, a wearable terminal device, a personal digital assistant (PDA) , a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback appliance, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , a USB dongle, a smart device, wireless customer-premises equipment (CPE) , an internet of things (loT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device (for example, a remote surgery device) , an industrial device (for example, a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. In the following description, the terms: “terminal device, ” “communication device, ” “terminal, ” “user equipment” and “UE, ” may be used interchangeably.

In an NR 4-step random-access procedure, the UE firstly transmits a PRACH preamble in Msg1 to the BS, and then receives a Random-Access Response (RAR) in Msg2, indicating reception of the preamble. A PRACH preamble transmission is associated with a downlink (DL) RS. This association can help a serving BS to identify an uplink spatial reception filter or beam to receive a PRACH preamble and can help a UE to identify an uplink spatial transmission filter or beam to transmit a PRACH preamble. The PRACH preamble transmission takes place in RACH occasions (ROs) , each of which occupies multiple consecutive resource blocks.

It has been identified in 3GPP that PRACH might be the bottleneck channel if short PRACH format (e.g., PRACH format B4 as defined in TS38.211) is used. One solution to enhance the PRACH detection performance is to use repeated PRACH transmissions with same beam. For example, the BS might configure one or multiple number of PRACH repetitions to the UEs. {2, 4, 8} PRACH repetitions are supported for configuration. From the point of view of a UE, the UE shall determine a configured number of PRACH repetitions from the configured set of PRACH repetitions and transmit the PRACH repetition in a corresponding RO group. The RO group contains a set of valid ROs, the number of which is the same as the corresponding number of PRACH repetitions.

A set of RO group (s) for a configured number of PRACH repetitions is determined/configured within a time period X, starting from frame 0. The determined/configured set of RO groups repeats every time period X. The time period X contains K SSB to RO association pattern period (s) . One issue to be resolved is how the value K of the K SSB to RO association pattern period (s) is determined, e.g., whether it is explicitly configured or implicitly determined.

The ROs in a RO group for PRACH repetition cannot be frequency-division-multiplexed (FDMed) ROs in a same time occasion. This is because using FDMed ROs in a same time occasion would lead to power division among the ROs, therefore erasing the gain from PRACH repetition.

In view of the above, embodiments of the present disclosure provide a solution for determining RO groups. In an aspect of the solution, a user equipment determines a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. Each RO of the plurality of ROs is associated with a frequency index and a time index. By allocating a RO with two indexes, i.e., a frequency index and a time index, the user equipment may easily determine the RO groups that can be used for the transmission of the PRACH repetitions. In this way, the RO determination rules may be enhanced.

Aspects of the present disclosure are described in the context of a wireless communications system.

FIG. 1A illustrates an example of a wireless communications system 100 that supports determination of RO groups 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) ) , 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 server 118. In some implementations, one or more UEs 104 may communicate with the application server 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 server 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 an example of an NR 4-step random-access procedure 120 that supports determination of RO groups in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the procedure 120 will be described with reference to FIG. 1A. The procedure 120 may involve a UE 104 and a BS 102 as illustrated in FIG. 1A. It is noted that the 4-step random-access procedure is merely for illustration, and not for limitation. Embodiments of the present disclosure may apply to other random-access procedures.

In the random-access procedure 120, the UE 104 may firstly transmit 122 a Msg1 including a preamble to the BS 102. After receiving the Msg1, the BS 102 may transmit 124 a Random-Access Response (RAR) in Msg2 to the UE 104, indicating the reception of the preamble and providing necessary information for the transmission of Msg3. The RAR may be received by the UE 104 in a RAR window, which starts after a time gap after the UE 104 transmits the Msg1. The UE 104 may then transmit 126 a Msg3 to the BS 102. The BS 102 may transmit 128 a Msg4 to the UE 104. The Msg3 and Msg4 may be used to solve potential collisions due to simultaneous transmissions of the same preamble from different UEs to the BS 102.

The PRACH Msg1 transmission takes place in ROs, each of which occupies multiple consecutive resource blocks. A RACH configuration can include ROs in indicated/configured RACH slots and indicated/configured frequency resource blocks that repeat with an indicated/configured periodicity. A configuration of ROs in time domain can include a periodicity for RACH configuration, a configuration for the slots within a PRACH configuration period that can be used for PRACH transmission, and a corresponding PRACH preamble format.

In the time domain, ROs may be configured in every PRACH configuration period, which contains a set of radio frames. Within a PRACH configuration period, a subset of subframes may be indicated to contain a set of PRACH slots, and within each PRACH slot, there might be a set of ROs available for PRACH Msg1 transmission. Besides, in the frequency domain, the BS may configure FDMed ROs. A parameter msg1-FDM may indicate the number of FDMed ROs in the frequency domain.

FIG. 1C illustrates an example of a structure 130 of overall RACH resources that supports determination of RO groups in accordance with some example embodiments of the present disclosure. In the example structure 130, a PRACH configuration period may contain 10 subframes, e.g., subframe #0 to subframe #9. Within the PRACH configuration period, subframe #0 and subframe #6 are indicated to contain a set of PRACH slots. A PRACH slot is configured with two ROs in the time domain and four ROs (i.e., msg1-FDM = 4) in the frequency domain. As shown in FIG. 1C, RO#0 to RO#7 are available for PRACH Msg1 transmission in a PRACH slot in subframe #0, and RO#8 to RO#15 are available for PRACH Msg1 transmission in a PRACH slot in subframe #6.

The ROs are associated with SSBs that may be transmitted with different beams. The SSBs consist of a primary synchronization signal (PSS) /asecondary synchronization signal (SSS) and physical broadcast channel (PBCH) signal for the UE to sync. to the DL, to obtain the cell ID, and to acquire the system information. The UE will measure the channel status of each SSB, select the one with a 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.

An association between SSBs (i.e., beams) and ROs can be identified by a SSB-to-RO association rule and a SSB-to-RO association period as well as a SSB-to-RO association pattern period. The association between SSBs and ROs can be one-to-one (1-to-1) , many-to-one (1-to-N) , or one-to-many (N-to-1) depending on the network configuration. This may be determined by a parameter SSB-PerRACH-Occasion.

FIGS. 1D through 1F illustrate examples of associations 140A, 140B and 140C between ROs and SSBs that supports determination of RO groups in accordance with some example embodiments of the present disclosure. As shown in FIGS. 1D through 1F, eight SSBs, e.g., SSB#0 to SSB#7, are assumed.

In the example association 140A, there is one RO in the frequency domain. The parameter SSB-PerRACH-Occasion = 1 for the association 140A. In other words, each RO among the RO#0 to RO#7 is mapped to one corresponding SSB. For example, RO#0 is mapped to SSB#0 and RO#1 is mapped to SSB#1.

In the example association 140B, there is one RO in the frequency domain. The parameter SSB-PerRACH-Occasion = 2 for the association 140B. In other words, each RO among the RO#0 to RO#7 is mapped to two corresponding SSBs. For example, RO#0 is mapped to SSB#0 and SSB#1 and RO#1 is mapped to SSB#2 and SSB#3.

In the example association 140C, there is one RO in the frequency domain. The parameter SSB-PerRACH-Occasion = 1/2 for the association 140C. In other words, two RO among the RO#0 to RO#15 are mapped to one corresponding SSBs. For example, RO#0 and RO#1 are mapped to SSB#0 and RO#2 and RO#3 are mapped to SSB#1.

The association is performed periodically in each SSB to RO association period. The SSB to RO association period is an integer times of the PRACH configuration period and contains one or multiple SSB-to-RO mapping cycles. The duration of the SSB to RO association period is the minimum period such that within the SSB to RO association period, each SSB is associated with at least one RO. Besides, a SSB to RO association pattern period was specified and a same SSB to RO association pattern is repeated in each SSB to RO association pattern period. One SSB to RO association pattern period contains at least one SSB to RO association period.

Reference is now made to FIG. 2, which illustrates an example signaling chart of a communication process that supports determination of RO groups in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to FIG. 1A. The process 200 may involve the UE 104 and the BS 102. It is to be understood that the steps and the order of the steps in FIG. 2 are merely for illustration, and not for limitation. It is to be understood that process 200 may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

As shown in FIG. 2, the UE 104 determines 202 a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. The SSB may be associated with a same set of preambles. Each RO of the plurality of ROs is associated with a frequency index and a time index. In some embodiments, the UE 104 may transmit 206 PRACH repetitions 208 in a RO group in the set of RO groups. By allocating a RO with two indexes, i.e., a frequency index and a time index, the user equipment may easily determine the RO groups that can be used for the transmission of the PRACH repetitions. In this way, the RO determination rules may be enhanced.

For example, after receiving SSBs from the BS 102, the UE 104 may measure the channel status of each SSB and select a SSB with a good channel quality. After selecting a SSB, the UE 104 may determine a set of RO groups associated with the selected SSB, select one RO group from the determined set of RO groups and transmit PRACH repetitions in the selected RO group to the BS 102. In some embodiments, the UE 104 may be configured with several PRACH repetition numbers, e.g., {2, 4, 8} . In other words, the UE 104 may determine to transmit a 2-PRACH repetition, or a 4-PRACH repetition, or an 8-PRACH repetition. If the UE 104 determines to transmit a 4-PRACH repetition, the UE 104 may determine a set of RO groups in a time period X which consists of K SSB to RO association pattern period (s) . Each RO group includes four ROs associated with the selected SSB. As mentioned above, a set of RO group (s) for a configured number of PRACH repetitions repeats every time period X. The UE 104 may select one RO group for transmitting a 4-PRACH repetition.

Similarly, the BS 102 determines 204 a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period. The plurality of ROs are associated with a same SSB or a same set of SSBs. Each RO of the plurality of ROs is associated with a frequency index and a time index. In some embodiments, the BS 102 may monitor 210 PRACH repetitions 208 in a RO group in the set of RO groups. By allocating a RO with two indexes, i.e., a frequency index and a time index, the base station may easily determine the RO groups that can be used for the transmission of the PRACH repetitions. In this way, the RO determination rules may be enhanced.

For example, the BS 102 may broadcast several SSBs corresponding to different beams. The BS 102 may determine corresponding ROs associated with the transmitted SSBs and determine corresponding RO groups. The BS 102 may monitor PRACH repetitions in the RO groups and identify a SSB associated with the RO group in which the PRACH repetitions are received.

In some embodiments, the frequency index of a RO may be determined based on a frequency position of the RO in at least one RO that is multiplexed in a frequency domain in a same time occasion. In some embodiments, the time index of a RO may be determined based on a time position of the RO in a set of ROs that have a same frequency index.

In other words, the configuration of ROs according to some example embodiments of the present disclosure may be based on a concept of layered ROs for PRACH repetitions. A RO for PRACH repetition may have two indexes, one in frequency domain and one in time domain. The frequency domain index may indicate the order of the RO in the set of ROs that are associated with a same SSB or a same set of SSBs and multiplexed in frequency domain in a same time occasion. The time domain index may indicate the index of the RO in the set of ROs that have same frequency domain index. In the following description, the terms “frequency domain index” and “frequency index” may be used interchangeably, and the terms “time domain index” and “time index” may be used interchangeably.

In an example implementation, the frequency indexing for the ROs that are associated with the same SSB or the same set of SSBs and multiplexed in frequency domain in a same time occasion may be performed in an order of low frequency to high frequency. The indexing of ROs in time domain may be performed per time period X. In other words, in each time period X, the time index starts from 0.

One specific aspect of the determination of RO groups is how to determine the valid ROs for PRACH repetitions. In some embodiments, the UE 104 may determine that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid. Correspondingly, the BS 102 may determine that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid. The set of RO groups may be determined from valid ROs in the plurality of ROs. For example, for ROs associated with a same SSB or a same set of SSBs and with a same frequency index, the UE 104 may determine whether the ROs are valid or invalid for PRACH repetitions based on the number of such ROs in one SSB to RO association pattern period or in the time period X consisting of K SSB to RO association pattern period (s) .

In one example implementation, the set of ROs may be valid for PRACH repetitions if the number of ROs in the set of ROs is the same as the number of ROs in the plurality of ROs having a lowest frequency index; otherwise, the set of ROs may be invalid for the PRACH repetitions. For example, in one SSB to RO association pattern period or in the time period X, if the number of ROs with a specific frequency index is the same as the number of ROs with frequency index 0, then these ROs may be used for PRACH repetitions. Otherwise, these ROs with the specific frequency index cannot be used for PRACH repetitions. The rational of this embodiment comes from the fact that the number of ROs with frequency index 0 is always no less than the number of ROs with any other frequency index and could anyway be used for PRACH repetitions. In this way, only those frequency indexes that provide the maximum number of ROs (i.e., same with the number of ROs with frequency index 0) can be used for PRACH repetitions.

In some embodiments, the frequency index associated with the set of ROs may be a valid frequency index for PRACH repetitions if the set of ROs are valid for PRACH repetitions; otherwise, the frequency index associated with the set of ROs may be an invalid frequency index for PRACH repetitions. For example, a frequency index that has same number of ROs as frequency index 0 is a valid frequency index for PRACH repetition, otherwise, it is an invalid frequency index for PRACH repetitions. For the case that shared ROs are used for all the configured numbers of PRACH repetitions, the valid frequency indexes are the same for all the configured numbers of PRACH repetitions. For example, if the configured numbers of PRACH repetitions are {2, 4, 8} , the valid frequency indexes are the same for 2-PRACH repetitions, 4-PRACH repetitions and 8-PRACH repetitions.

Reference is now made to FIGS. 3A and 3B, which illustrate examples of RACH resource structures 300A and 300B that support determination of valid ROs in accordance with some example embodiments of the present disclosure. In the following description, the reference numerals “RO#n (SSB#m) ” , “#n (#m) ” and “n (m) ” may be used interchangeably and indicate a RO with a time index n and associated with SSB#m. As mentioned above, in some implementations, one RO may be associated with multiple SSBs. The reference numerals “RO#n (SSB#m1, m2) ” , “#n (#m, m2) ” and “n (m, m2) ” may be used interchangeably and indicate a RO with a time index n and associated with SSB#m1 and SSB#m2.

In the structure 300A, the system has four configured SSBs {#0, #1, #2, #3} . The SSB-PerRACH-Occasion is configured as 1/2, i.e., two ROs are associated with a same SSB. Msg1-FDM is configured as 2, so there are two FDMed ROs in a same time occasion. Totally 16 ROs are configured in a SSB to RO association pattern period. For each SSB, there are four associated ROs within the SSB to RO association pattern period.

FIG. 3A takes SSB#0 as the target SSB and shows the frequency indexing and time indexing of ROs associated with SSB#0. It is to be understood that this is merely for purpose of illustration. The indexing also applies to other SSBs. In the SSB to RO association period, ROs 301, 302, 311 and 312 are associated with SSB#0. ROs 301 and 311 are multiplexed in frequency domain in a same time occasion. Based on a frequency indexing in an order of low frequency to high frequency, the RO 301 may be indexed with a frequency index 0 and the RO 311 may be indexed with a frequency index 1. Similarly, ROs 302 and 312 are multiplexed in frequency domain in a same time occasion. Based on a frequency indexing in an order of low frequency to high frequency, the RO 302 may be indexed with a frequency index 0 and the RO 312 may be indexed with a frequency index 1. The ROs 301 and 302 have the same frequency index and are indexed in the time domain, starting from 0. The ROs 311 and 312 have the same frequency index and are indexed in the time domain, starting from 0.

As shown in FIG. 3A, for SSB#0 (and for each of any other SSB) , there are two ROs with frequency index 0 and two ROs with frequency index 1. The number of ROs with frequency index 1 is the same as the number of ROs with frequency index 0. Thus, these two ROs with each of the frequency indexes may be used for PRACH repetitions. Both frequency indexes are valid for PRACH repetitions.

FIG. 3B shows another example, where the system has six configured SSBs {#0, #1, #2, …, #5} . The SSB-PerRACH-Occasion is configured as 2, i.e., one RO is associated with two SSBs. Msg1-FDM is configured as 4, so there are two FDMed ROs in a same time occasion. Totally 16 ROs are configured in a SSB to RO association pattern period. For each SSB, there are five associated ROs within the SSB to RO association pattern period.

FIG. 3B takes SSB#0 as the target SSB and shows the frequency indexing and time indexing of ROs associated with SSB#0. It is to be understood that this is merely for purpose of illustration. The indexing also applies to other SSBs. In the SSB to RO association period, five ROs 321-324 and 331 are associated with SSB#0. ROs 321 and 331 are multiplexed in frequency domain in a same time occasion. Based on a frequency indexing in an order of low frequency to high frequency, the RO 321 may be indexed with a frequency index 0 and the RO 331 may be indexed with a frequency index 1. The ROs 321, 322, 323 and 324 have the same frequency index and are indexed in the time domain, starting from 0.

As shown in FIG. 3B, for SSB#0 (and for each of any other SSB) , there are four ROs with frequency index 0 and one RO with frequency index 1. The number of ROs with frequency index 1 is different from the number of ROs with frequency index 0. Thus, the ROs with frequency index 0 are valid for PRACH repetition, while the RO with frequency index 1 is invalid for PRACH repetitions. Frequency index 0 is a valid frequency index for PRACH repetitions while frequency index 1 is an invalid frequency index for PRACH repetitions.

In some embodiments, in order to determine that a set of ROs in the plurality of ROs are valid or invalid, the UE 104 may determine at least one RO group for a configured number of PRACH repetitions from the set of ROs. The UE 104 may determine that the set of ROs are valid for PRACH repetitions if the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions. Otherwise, the UE 104 may determine that the set of ROs are invalid for the PRACH repetitions.

Correspondingly, in order to determine that a set of ROs in the plurality of ROs are valid or invalid, the BS 102 may determine at least one RO group for a configured number of PRACH repetitions from the set of ROs. The BS 102 may determine that the set of ROs are valid for PRACH repetitions if the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions. Otherwise, the BS 102 may determine that the set of ROs are invalid for the PRACH repetitions.

For example, in one SSB to RO association pattern period or in the time period X, if the determined number of RO groups for the ROs with a specific frequency index for a configured number of PRACH repetitions is same as the number of RO groups for the same number of PRACH repetitions determined for frequency index 0, then ROs with this specific frequency index may be used for PRACH repetitions. Otherwise, the ROs cannot be used for PRACH repetitions. The rational of this embodiment comes from the fact that for frequency index 0, the determined RO groups for a configured number of PRACH repetitions is always no less than the number of RO groups determined for other frequency indexes and could anyway be used for PRACH repetitions. In this way, only those frequency indexes that provide the maximum number of ROs can be used for PRACH repetitions.

In some embodiments, the frequency index associated with the set of ROs may be a valid frequency index for PRACH repetitions if the set of ROs are valid for PRACH repetitions; otherwise, the frequency index associated with the set of ROs may be an invalid frequency index for PRACH repetitions. For example, a frequency index that has same number of RO groups as frequency index 0 is a valid frequency index for PRACH repetitions; otherwise, it is an invalid frequency index for PRACH repetitions. For the case that shared ROs are used for all the configured numbers of PRACH repetitions, the valid frequency indexes are the same for all the configured numbers of PRACH repetitions. For example, if the configured numbers of PRACH repetitions are {2, 4, 8} , the valid frequency indexes are the same for 2-PRACH repetitions, 4-PRACH repetitions and 8-PRACH repetitions.

Still taking FIGS. 3A and 3B as examples, in the structure 300A in FIG. 3A, for SSB#0 (and for each of any other SSB) , one RO group with frequency index 1 may be determined for 2-PRACH repetitions and one RO group with frequency index 0 may be determined for 2-PRACH repetitions. Thus, these two ROs with each of the frequency indexes may be used for PRACH repetitions. Both frequency indexes are valid for PRACH repetitions.

In the structure 300B in FIG. 3B, for SSB#0 (and for each of any other SSB) , no RO group with frequency index 1 can be determined for 2-PRACH repetitions and two RO group with frequency index 0 may be determined for 2-PRACH repetitions. Thus, the ROs with frequency index 0 are valid for PRACH repetition, while the RO with frequency index 1 is invalid for PRACH repetitions. Frequency index 0 is a valid frequency index for PRACH repetitions while frequency index 1 is an invalid frequency index for PRACH repetitions.

In some embodiments, the set of ROs may be valid for PRACH repetitions for a configured number of PRACH repetitions if the number of ROs in the set of ROs is equal to or larger than the configured number; otherwise, the set of ROs may be invalid for the PRACH repetitions. For example, in the time period X, for a configured number of PRACH repetitions R, if the number of ROs with a frequency index is smaller than R, then the ROs with this frequency index cannot be used for PRACH repetitions with R repetitions. Otherwise, the ROs can be used for PRACH repetitions with R repetitions.

Reference is now made to FIG. 3C, which illustrate an example of RACH resource structure 300C that supports determination of valid ROs in accordance with some example embodiments of the present disclosure.

In the structure 300C, assuming K = 2, indicating that the time period X includes two SSB to RO association pattern periods. The system has six configured SSBs {#0, #1, #2, …, #5} . SSB-PerRACH-Occasion is configured as 2, i.e., one RO is associated with two SSBs. Msg1-FDM is configured as 4, so there are two FDMed ROs in a same time occasion. Totally 48 ROs are configured in a SSB to RO association pattern period. For each SSB, there are 16 associated ROs within the SSB to RO association pattern period.

FIG. 3C takes SSB#0 as the target SSB and shows the frequency indexing and time indexing of ROs associated with SSB#0. It is to be understood that this is merely for purpose of illustration. The indexing also applies to other SSBs. As shown in FIG. 3B, for SSB#0 (and for each of any other SSB) , there are 12 ROs 341-352 with frequency index 0 and four ROs 361-364 with frequency index 1. If the configured number of PRACH repetitions is 2, then frequency index 0 and the frequency index 1 are both valid for 2-PRACH repetitions since the number of ROs with frequency index 0 is 12 and the number of ROs with frequency index 1 is 4, larger than the configured number {2} . If the configured number of PRACH repetitions is 4, then frequency index 0 and the frequency index 1 are both valid for 4-PRACH repetitions since the number of ROs with frequency index 0 is larger than the configured number {4} and the number of ROs with frequency index 1 is equal to the configured number {4} . If the configured number of PRACH repetitions is 8, then frequency index 0 is valid for 8-PRACH repetitions and the frequency index 1 is invalid for 8-PRACH repetitions since the number of ROs with frequency index 0 is larger than the configured number {8} while the number of ROs with frequency index 1 is smaller than the configured number {8} . In other words, frequency index 0 with 12 ROs is a valid for {2, 4, 8} PRACH repetitions, while frequency index 1 with four ROs is valid for {2, 4} repetitions, and is invalid for {8} PRACH repetitions.

In some embodiments, the set of ROs may be valid for PRACH repetitions for a configured number of PRACH repetitions if a RO group can be determined from the set of ROs for the configured number of PRACH repetitions; otherwise, the set of ROs may be invalid for the PRACH repetitions for the configured number of PRACH repetitions. For example, in the time period X, for a configured number of PRACH repetitions R, if at least one RO group for a frequency index could be determined, then the PRACH repetition with R repetitions can be transmitted in the determined at least one RO group. Otherwise, the ROs cannot be used for PRACH repetitions with R repetitions.

Still taking FIG. 3C as an example, in the structure 300C, if the configured number of PRACH repetitions is {2, 4, 8} , then at least one RO group for frequency index 0 could be determined for {2, 4, 8} PRACH repetitions and thus the PRACH repetitions with {2, 4, 8} repetitions can be transmitted in the determined at least one RO group for frequency index 0. At least one RO group for frequency index 1 could be determined for {2, 4} PRACH repetitions and thus the PRACH repetitions with {2, 4} repetitions can be transmitted in the determined at least one RO group for frequency index 1; while no RO group for frequency index 1 could be determined for {8} PRACH repetitions and thus the PRACH repetitions with {8} repetitions cannot be transmitted in ROs with frequency index 1. Accordingly, frequency index 0 is a valid for {2, 4, 8} PRACH repetitions, while frequency index 1 is valid for {2, 4} repetitions, and is invalid for {8} PRACH repetitions.

As mentioned above, the RO groups may be determined within a time period X containing K SSB to RO association pattern period (s) . One specific aspect of the determination of RO groups is how to determine the K SSB to RO association pattern periods for PRACH repetitions.

In some embodiments, the number of at least one SSB to RO association pattern periods may be determined such that the number is a minimum integer fulfilling that at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions.

Alternatively, the number of at least one SSB to RO association pattern periods may be determined such that the number is a minimum integer fulfilling that at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions.

Alternatively, the number of at least one SSB to RO association pattern periods may be determined such that the number is a minimum integer fulfilling that at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.

Alternatively, the number of at least one SSB to RO association pattern periods may be determined such that the number is a minimum integer fulfilling that at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.

In other words, the K SSB to RO association pattern periods may be determined such that K is the minimum integer fulfilling that there is at least one RO group of frequency index 0 or at least one RO group of any valid frequency index can be determined for the maximum (or each) configured number of PRACH repetitions. Alternatively, the K SSB to RO association pattern periods are determined such that K is the minimum integer fulfilling that the number of ROs with frequency index 0 or the number of ROs with any valid frequency index is larger than the maximum configured number of PRACH repetitions.

For example, the UE 104 may firstly determine the number of ROs with frequency index 0 or the number of ROs with a valid frequency index in a SSB to RO association pattern period. Then the K SSB to RO association pattern periods are determined as follows: K = 1, if the number of ROs is larger than the configured maximum number of PRACH repetitions; K = ceil (number of configured maximum number of PRACH repetitions/number of the ROs in one association pattern period) , otherwise.

In some embodiments, the K SSB to RO association pattern periods are determined for the configured maximum number of PRACH repetitions and are applicable to other configured number of PRACH repetitions, if any. In other words, if K is determined as 2 for the configured maximum number of PRACH repetitions {8} , the time period X containing 2 SSB to RO association pattern periods may also apply to other configured number of PRACH repetitions, e.g., {2, 4} .

For example, for a specific frequency index, the number of RO groups for a specific number of PRACH repetitions R could be determined as floor (N_ROs, R) , where N_ROs is the number of ROs with this frequency index in the time period X. Still taking FIG. 3A and FIG. 3B as examples, assuming the BS 102 configures {2, 4, 8} PRACH repetitions.

In the structure 300A in FIG. 3A, the number of the ROs in one association pattern period is 2. Assuming the number of configured maximum number of PRACH repetitions is 8, then K = ceil (number of configured maximum number of PRACH repetitions/number of the ROs in one association pattern period) = ceil (8/2) = 4. RO groups for PRACH repetition may thus be defined within 4 SSB to RO association pattern periods. Thus, N_ROs = 4*2 = 8. For 2/4/8 PRACH repetitions, there are floor (N_ROs, R) = 4/2/1 RO groups within the 4 SSB to RO association pattern periods for each valid frequency index.

In the structure 300B in FIG. 3B, the number of the ROs in one association pattern period is 4. Assuming the number of configured maximum number of PRACH repetitions is 8, then K = ceil (number of configured maximum number of PRACH repetitions/number of the ROs in one association pattern period) = ceil (8/4) = 2. RO groups for PRACH repetition may thus be defined within 2 SSB to RO association pattern periods. Thus, N_ROs = 2*4 = 8. For 2/4/8 PRACH repetitions, there are floor (N_ROs, R) = 4/2/1 RO groups within the 2 SSB to RO association pattern periods for each valid frequency index.

FIG. 4 illustrates an example of a RACH resource structure 400 that supports determination of RO groups in accordance with some example embodiments of the present disclosure. In the structure 400, assuming K = 2, indicating that the time period X includes two SSB to RO association pattern periods. The system has six configured SSBs {#0, #1, #2, …, #5} . FIG. 4 takes SSB#0 as the target SSB and shows the RO group determination associated with SSB#0. It is to be understood that this is merely for purpose of illustration. The determination also applies to other SSBs.

Assuming the configured number of PRACH repetition is 4. As shown in FIG. 4, for SSB#0 (and for each of any other SSB) , there are eight valid ROs 401-408 for PRACH repetitions. The ROs 401-408 may form 2 RO groups for the 4-PRACH repetitions for frequency index 0 for SSB#0. One RO group, e.g., RO group#0, contains ROs 401-404 with time indexes {#0, #1, #2, #3} . Another RO group, e.g., RO group#1, contains ROs 405-408 with time indexes {#4, #5, #6, #7} .

In some embodiments, RO groups among the set of RO groups may be indexed in various manners. For example, RO groups in a first subset of RO groups among the set of RO groups can be indexed with a lowest frequency index. Then, RO groups in a second subset of RO groups among the set of RO groups can be indexed with a second lowest frequency index after the indexing of the RO groups in the first subset of RO groups is completed. In other words, for ROs associated with a same SSB and are valid for PRACH repetitions, the RO groups may be indexed within the K SSB to RO association pattern period. The indexing may be performed in an order of time first, frequency second manner, i.e., firstly indexing the RO groups with the lowest frequency index, and then move to the second lowest frequency index and continue the indexing.

In an example implementation, ROs in a RO group in the set of RO groups may be associated with the same frequency index. For example, the determination of RO groups for PRACH repetitions may be performed when frequency hopping is not configured/supported, in which case each RO group contains ROs that have a same frequency index.

In an example, when frequency hopping is configured for PRACH repetitions, each RO group may contain the ROs that might have different frequency indexes. For instance, ROs in a RO group in the set of RO groups may be determined at least based on a configured frequency index offset. As one example implementation, for R PRACH repetitions, the first R/2 ROs may be associated with one frequency index f1 and the remaining R/2 ROs may be associated with another frequency index f2. The index f2 may be determined based on a configured offset, e.g., f2 = mod (f1+offset, f_t) , where f_t is the total number of valid frequency indexes for PRACH repetitions, and the offset is the indicated frequency index offset.

FIG. 5 illustrates an example of a RACH resource structure 500 that supports frequency hopping in a RO group in accordance with some example embodiments of the present disclosure. FIG. 5 takes SSB#0 as the target SSB and shows how RO groups associated with SSB#0 are determined when frequency hopping is configured. It is to be understood that this is merely for purpose of illustration. The determination also applies to other SSBs.

As shown in FIG. 5, for SSB#0 (and for each of any other SSB) , there are eight ROs 501-508 with time indexes {#0, #1, #2, #3, #4, #5, #6, #7} and frequency index 0 and another eight ROs 511-518 with time indexes {#0, #1, #2, #3, #4, #5, #6, #7} and frequency index 1. The ROs 501-508 with frequency index 0 and ROs 511-518 with frequency index 1 can be used for PRACH repetitions. If a frequency offset index is indicated as 1, assuming the configured number of PRACH repetition is 8, then for 8-PRACH repetitions, one RO group, e.g., RO group#0, contains ROs 501-504 with time indexes {#0, #1, #2, #3} and frequency index 0 and ROs 515-518 with time indexes {#4, #5, #6, #7} and frequency index 1. Another RO group, e.g., RO group#1, contains RO 505-508 with time indexes {#4, #5, #6, #7} and frequency index 0 and ROs 511-514 with time indexes {#0, #1, #2, #3} with frequency index 1.

In some embodiments, the set of RO groups may be determined for a configured number of PRACH repetitions. For example, within the K SSB to RO association pattern periods, the UE could determine a set of RO groups for each configured number of PRACH repetitions. One specific aspect of the determination of RO groups is how to determine the RO groups on the determined ROs for a configured number of PRACH repetitions.

In some example implementations, the set of RO groups may be determined based on at least one set of ROs. A set of ROs among the at least one set of ROs may be determined based on a maximum configured number for PRACH repetitions and the number of ROs, among the plurality of ROs, with a same valid frequency index. Different sets of ROs among the at least one set of ROs may be associated with different valid frequency indexes. In some embodiments, the BS 102 may configure several PRACH repetition numbers. The UE 104 may transmit PRACH repetitions with one of the configured numbers. If the configured number is a first configured number, the set of ROs may comprise a first set of ROs. If the configured number is a second configured number, the set of ROs may comprise a second set of ROs which are the same as the first set of ROs. In other words, the RO groups for each number of PRACH repetitions may be determined over a same set of ROs (i.e., determined for the maximum configured number of PRACH repetitions) with a same valid frequency index.

For example, the RO groups for each number of PRACH repetitions may be determined on top of the first N_valid ROs with a same valid frequency index, where N_valid is determined such that the N_valid ROs contain a maximum number of RO groups for the configured maximum number of PRACH repetitions within the K SSB to RO association pattern periods, i.e., N_valid=N_groups*R_max, where R_max is the configured maximum number of PRACH repetitions, N_groups = floor (N_ROs/R_max) , and N_ROs is the number of ROs with the same valid frequency index in the K association pattern periods. The rest (N_ROs –N_valid) ROs in the K SSB to RO association pattern periods, if exist, would not be used for PRACH repetitions for any number of PRACH repetitions.

FIG. 6 illustrates an example of a RACH resource structure 600 that supports determination of RO groups in accordance with some example embodiments of the present disclosure. FIG. 6 takes SSB#0 as the target SSB and shows how RO groups from valid ROs. It is to be understood that this is merely for purpose of illustration. The determination also applies to other SSBs.

As shown in FIG. 6, for SSB#0 (and for each of any other SSB) , there are 12 ROs 601-612 with time indexes {#0, #1, #2, …, #11} and frequency index 0 and four ROs 621-624 with time indexes {#0, #1, #2, #3} and frequency index 1. Taking the following rule as an example of determining valid frequency indexes: the number of ROs associated with the frequency index is the same as the number of ROs having a lowest frequency index for the same SSB, the ROs 601-612 with frequency index 0 are valid for PRACH repetitions, while the ROs 621-624 with frequency index 1 are invalid for PRACH repetitions. It should be understood that other rules for determining valid frequency indexes may also be applied.

In the structure 600, the number of ROs with the same valid frequency index 0 in the K association pattern periods N_ROs is 12 Assuming the configured number of PRACH repetitions is {2, 4, 8} , then R_max = 8. N_groups = floor (N_ROs/R_max) =floor (12/8) =1. N_valid = N_groups*R_max = 1*8 = 8. For 2-PRACH repetitions, 4- PRACH repetitions or 8-PRACH repetitions, the RO groups for PRACH repetitions may be defined in the first N_valid = 8 ROs, i.e., ROs 601-608 with time indexes {#0, #1, #2, …, #7} . For example, one, two and four RO groups can be determined for 8-PRACH repetitions, 4-PRACH repetitions and 2-PRACH repetition, respectively. The last four ROs 609-612 with time indexes {#8, #9, #10, #11} would not be used for PRACH repetitions.

In some example implementations, the set of RO groups may be determined based on at least one set of ROs. A set of ROs among the at least one set of ROs may be determined based on the configured number and the number of ROs, among the plurality of ROs, with a same valid frequency index. Different sets of ROs among the at least one set of ROs may be associated with different valid frequency indexes. In some embodiments, the BS 102 may configure several PRACH repetition numbers. The UE 104 may transmit PRACH repetitions with one of the configured numbers. If the configured number is a first configured number, the set of ROs may comprise a first set of ROs. If the configured number is a second configured number, the set of ROs may comprise a second set of ROs different from the first set of ROs. In other words, for different configured numbers of PRACH repetitions, the RO groups can be determined over different sets of ROs.

For example, different with the above example implementation where the rest (N_ROs –N_valid) ROs in the K SSB to RO association pattern periods cannot be used for PRACH repetitions for other number of PRACH repetitions, in this example implementation, these rest ROs can be used for a configured number of PRACH repetitions R1, if the number of these ROs (N_ROs –N_valid) is larger than R1, i.e., at least one RO group can be determined for PRACH repetitions with R1 repetitions.

Still taking FIG. 6 as an example, in the structure 600, the ROs 601-612 with frequency index 0 are valid for PRACH repetitions. For 8-PRACH repetitions, the RO groups may be determined in the first N_valid = 8 ROs. One RO group can be determined. For 4-PRACH repetitions, the RO groups may be determined in the 12 ROs, and three RO groups can be determined. The N_RO –N_valid = 4 ROs can construct one RO group for a 4-PRACH repetition and therefore could be used for a 4-PRACH repetition. For 2-PRACH repetitions, the RO groups may be determined in the 12 ROs, six RO groups can be determined. The N_RO –N_valid = 4 ROs can construct two RO groups for 2-PRACH repetitions and therefore could be used for 2-PRACH repetitions.

In a further example implementation, the UE 104 may determine whether the rest (N_ROs –N_valid) ROs can be used for PRACH repetition with R1 repetitions based on configuration.

Based on some example embodiments of the present disclosure, the UE 104 and the BS 102 may make the same determination when determining RO groups associated with the same SSB for the same configured number of PRACH repetitions. Thus, signaling overhead may be reduced.

FIG. 7 illustrates an example of a device 700 that supports determination of RO groups in accordance with aspects of the present disclosure. The device 700 may be an example of a UE 104 as described herein. The device 700 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 700 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 702, a memory 704, a transceiver 706, and, optionally, an I/O controller 708. 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 702, the memory 704, the transceiver 706, 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 702, the memory 704, the transceiver 706, 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 702, the memory 704, the transceiver 706, 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 702 and the memory 704 coupled with the processor 702 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 702, instructions stored in the memory 704) .

For example, the processor 702 may support wireless communication at the device 700 in accordance with examples as disclosed herein. The processor 702 may be configured to operable to support a means for determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

The processor 702 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 702 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 702. The processor 702 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 704) to cause the device 700 to perform various functions of the present disclosure such that the device 700 may perform any process of the disclosure as discussed with reference to FIGS. 2 to 6.

The memory 704 may include random access memory (RAM) and read-only memory (ROM) . The memory 704 may store computer-readable, computer-executable code including instructions that, when executed by the processor 702 cause the device 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. In some implementations, the code may not be directly executable by the processor 702 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 704 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 708 may manage input and output signals for the device 700. The I/O controller 708 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 708 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 708 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 708 may be implemented as part of a processor, such as the processor 706. In some implementations, a user may interact with the device 700 via the I/O controller 708 or via hardware components controlled by the I/O controller 708.

In some implementations, the device 700 may include a single antenna 710. However, in some other implementations, the device 700 may have more than one antenna 710 (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 706 may communicate bi-directionally, via the one or more antennas 710, wired, or wireless links as described herein. For example, the transceiver 706 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 706 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 710 for transmission, and to demodulate packets received from the one or more antennas 710. The transceiver 706 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 710 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 710 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. 8 illustrates an example of a device 800 that supports determination of RO groups in accordance with aspects of the present disclosure. The device 800 may be an example of a network entity 102 as described herein. The device 800 may support wireless communication with one or more network entities 102, UEs 104, or any combination thereof. The device 800 may include components for bi-directional communications including components for transmitting and receiving communications, such as a processor 802, a memory 804, a transceiver 806, and, optionally, an I/O controller 808. 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 802, the memory 804, the transceiver 806, 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 802, the memory 804, the transceiver 806, 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 802, the memory 804, the transceiver 806, 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 802 and the memory 804 coupled with the processor 802 may be configured to perform one or more of the functions described herein (e.g., executing, by the processor 802, instructions stored in the memory 804) .

For example, the processor 802 may support wireless communication at the device 800 in accordance with examples as disclosed herein. The processor 802 may be configured to operable to support a means for determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

The processor 802 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 802 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 802. The processor 802 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 804) to cause the device 800 to perform various functions of the present disclosure such that the device 800 may perform any process of the disclosure as discussed with reference to FIGS. 2 to 6.

The memory 804 may include random access memory (RAM) and read-only memory (ROM) . The memory 804 may store computer-readable, computer-executable code including instructions that, when executed by the processor 802 cause the device 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. In some implementations, the code may not be directly executable by the processor 802 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some implementations, the memory 804 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 808 may manage input and output signals for the device 800. The I/O controller 808 may also manage peripherals not integrated into the device M02. In some implementations, the I/O controller 808 may represent a physical connection or port to an external peripheral. In some implementations, the I/O controller 808 may utilize an operating system such as or another known operating system. In some implementations, the I/O controller 808 may be implemented as part of a processor, such as the processor 806. In some implementations, a user may interact with the device 800 via the I/O controller 808 or via hardware components controlled by the I/O controller 808.

In some implementations, the device 800 may include a single antenna 810. However, in some other implementations, the device 800 may have more than one antenna 810 (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 806 may communicate bi-directionally, via the one or more antennas 810, wired, or wireless links as described herein. For example, the transceiver 806 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 806 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 810 for transmission, and to demodulate packets received from the one or more antennas 810. The transceiver 806 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 810 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 810 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. 9 illustrates an example of a processor 900 that supports determination of RO groups in accordance with aspects of the present disclosure. The processor 900 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 900 may be implemented in a device or its components as described herein. For example, the device may be an example of a UE 104 as described herein. The processor 900 may include a controller 902 configured to perform various operations in accordance with examples as described herein. The processor 900 may optionally include at least one memory 904, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 900 may optionally include one or more arithmetic-logic units (ALUs) 900. 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) .

The processor 900 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 900) 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 902 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 900 to cause the processor 900 to support various operations in accordance with examples as described herein. For example, the controller 902 may operate as a control unit of the processor 900, generating control signals that manage the operation of various components of the processor 900. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 902 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 904 and determine subsequent instruction (s) to be executed to cause the processor 900 to support various operations in accordance with examples as described herein. The controller 902 may be configured to track memory address of instructions associated with the memory 904. The controller 902 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 902 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 900 to cause the processor 900 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 902 may be configured to manage flow of data within the processor 900. The controller 902 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 900.

The memory 904 may include one or more caches (e.g., memory local to or included in the processor 900 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 904 may reside within or on a processor chipset (e.g., local to the processor 900) . In some other implementations, the memory 904 may reside external to the processor chipset (e.g., remote to the processor 900) .

The memory 904 may store computer-readable, computer-executable code including instructions that, when executed by the processor 900, cause the processor 900 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 902 and/or the processor 900 may be configured to execute computer-readable instructions stored in the memory 904 to cause the processor 900 to perform various functions. For example, the processor 900 and/or the controller 902 may be coupled with or to the memory 904, and the processor 900, the controller 902, and the memory 904 may be configured to perform various functions described herein. In some examples, the processor 900 may include multiple processors and the memory 904 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 900 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 900 may reside within or on a processor chipset (e.g., the processor 900) . In some other implementations, the one or more ALUs 900 may reside external to the processor chipset (e.g., the processor 900) . One or more ALUs 900 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 900 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 900 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 900 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 900 to handle conditional operations, comparisons, and bitwise operations.

The processor 900 may support wireless communication in accordance with examples as disclosed herein. The processor 900 may be configured to or operable to support a means for determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

FIG. 10 illustrates an example of a processor 1000 that supports determination of RO groups in accordance with aspects of the present disclosure. The processor 1000 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 1000 may be implemented in a device or its components as described herein. For example, the device may be an example of a network entity 102 as described herein. The processor 1000 may include a controller 1002 configured to perform various operations in accordance with examples as described herein. The processor 1000 may optionally include at least one memory 1004, such as L1/L2/L3 cache. Additionally, or alternatively, the processor 1000 may optionally include one or more arithmetic-logic units (ALUs) 1000. 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) .

The processor 1000 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 1000) 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 1002 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 1000 to cause the processor 1000 to support various operations in accordance with examples as described herein. For example, the controller 1002 may operate as a control unit of the processor 1000, generating control signals that manage the operation of various components of the processor 1000. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 1002 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 1004 and determine subsequent instruction (s) to be executed to cause the processor 1000 to support various operations in accordance with examples as described herein. The controller 1002 may be configured to track memory address of instructions associated with the memory 1004. The controller 1002 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 1002 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 1000 to cause the processor 1000 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 1002 may be configured to manage flow of data within the processor 1000. The controller 1002 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 1000.

The memory 1004 may include one or more caches (e.g., memory local to or included in the processor 1000 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementation, the memory 1004 may reside within or on a processor chipset (e.g., local to the processor 1000) . In some other implementations, the memory 1004 may reside external to the processor chipset (e.g., remote to the processor 1000) .

The memory 1004 may store computer-readable, computer-executable code including instructions that, when executed by the processor 1000, cause the processor 1000 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 1002 and/or the processor 1000 may be configured to execute computer-readable instructions stored in the memory 1004 to cause the processor 1000 to perform various functions. For example, the processor 1000 and/or the controller 1002 may be coupled with or to the memory 1004, and the processor 1000, the controller 1002, and the memory 1004 may be configured to perform various functions described herein. In some examples, the processor 1000 may include multiple processors and the memory 1004 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 1000 may be configured to support various operations in accordance with examples as described herein. In some implementation, the one or more ALUs 1000 may reside within or on a processor chipset (e.g., the processor 1000) . In some other implementations, the one or more ALUs 1000 may reside external to the processor chipset (e.g., the processor 1000) . One or more ALUs 1000 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 1000 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 1000 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 1000 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 1000 to handle conditional operations, comparisons, and bitwise operations.

The processor 1000 may support wireless communication in accordance with examples as disclosed herein. The processor 1000 may be configured to or operable to support a means for determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

FIG. 11 illustrates a flowchart of a method 1100 that supports determination of RO groups in accordance with aspects of the present disclosure. The operations of the method 1100 may be implemented by a device or its components as described herein. For example, the operations of the method 1100 may be performed by a UE 104 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 1105, the method may include determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index. The operations of 1105 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1105 may be performed by a device as described with reference to FIG. 1A.

FIG. 12 illustrates a flowchart of a method 1200 that supports determining that a set of ROs in the plurality of ROs are valid or invalid in accordance with aspects of the present disclosure. The operations of the method 1200 may be implemented by a device or its components as described herein. For example, the operations of the method 1200 may be performed by a UE 104 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.

The method 1200 may be deemed as a specific example of the step 1105 in the method 1100. In particular, the set of RO groups determined in step 1105 in the method 1100 may be determined from valid ROs in the plurality of ROs. With the method 1200, the UE 114 may determine that a set of ROs in the plurality of ROs are valid or invalid.

At 1205, the method may include determining at least one RO group for a configured number of PRACH repetitions from the set of RO. The operations of 1205 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1205 may be performed by a device as described with reference to FIG. 1A.

At 1210, the method may include determining whether the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions. The operations of 1205 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1210 may be performed by a device as described with reference to FIG. 1A.

If yes, at 1215, the method may include determining that the set of ROs are valid for PRACH repetitions. The operations of 1215 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1215 may be performed by a device as described with reference to FIG. 1A.

If no, at 1220, the method may include determining that the set of ROs are invalid for the PRACH repetitions. The operations of 1220 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1220 may be performed by a device as described with reference to FIG. 1A.

FIG. 13 illustrates a flowchart of a method 1300 that supports determination of RO groups in accordance with aspects of the present disclosure. The operations of the method 1300 may be implemented by a device or its components as described herein. For example, the operations of the method 1300 may be performed by a network entity 102 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 1305, the method may include determining a set of RO groups from a plurality of ROs in at least one SSB to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index. The operations of 1105 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1305 may be performed by a device as described with reference to FIG. 1A.

FIG. 14 illustrates a flowchart of a method 1400 that supports determining that a set of ROs in the plurality of ROs are valid or invalid in accordance with aspects of the present disclosure. The operations of the method 1400 may be implemented by a device or its components as described herein. For example, the operations of the method 1400 may be performed by a network entity 102 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.

The method 1400 may be deemed as a specific example of the step 1305 in the method 1300. In particular, the set of RO groups determined in step 1305 in the method 1300 may be determined from valid ROs in the plurality of ROs. With the method 1400, the network entity 112 may determine that a set of ROs in the plurality of ROs are valid or invalid.

At 1405, the method may include determining at least one RO group for a configured number of PRACH repetitions from the set of RO. The operations of 1405 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1405 may be performed by a device as described with reference to FIG. 1A.

At 1410, the method may include determining whether the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions. The operations of 1405 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1410 may be performed by a device as described with reference to FIG. 1A.

If yes, at 1415, the method may include determining that the set of ROs are valid for PRACH repetitions. The operations of 1415 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1415 may be performed by a device as described with reference to FIG. 1A.

If no, at 1420, the method may include determining that the set of ROs are invalid for the PRACH repetitions. The operations of 1420 may be performed in accordance with examples as described herein. In some implementations, aspects of the operations of 1420 may be performed by a device as described with reference to FIG. 1A.

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.

In summary, embodiments of the present disclosure may provide the following solutions.

Clause 1. A user equipment comprising: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: determine a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

Clause 2. The user equipment of clause 1, wherein the frequency index of a RO is determined based on a frequency position of the RO in at least one RO that is multiplexed in a frequency domain in a same time occasion, and wherein the time index of a RO is determined based on a time position of the RO in a set of ROs that have a same frequency index.

Clause 3. The user equipment of clause 1, wherein the processor is further configured to: determine that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid, wherein the set of RO groups are determined from valid ROs in the plurality of ROs.

Clause 4. The user equipment of clause 3, wherein: the set of ROs are valid for a physical random access channel (PRACH) repetition in the case that a following condition is met: the number of ROs in the set of ROs is the same as the number of ROs in the plurality of ROs having a lowest frequency index; or the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.

Clause 5. The user equipment of clause 3, wherein determining that a set of ROs in the plurality of ROs are valid or invalid comprises: determining at least one RO group for a configured number of PRACH repetitions from the set of ROs, determining that the set of ROs are valid for PRACH repetitions in the case that a following condition is met: the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions; or determining that the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.

Clause 6. The user equipment of clause 3, wherein: the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: the number of ROs in the set of ROs is equal to or larger than the configured number; or the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

Clause 7. The user equipment of clause 3, wherein: the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: a RO group can be determined from the set of ROs for the configured number of PRACH repetitions; and the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

Clause 8. The user equipment of any of clauses 3-7, wherein: the frequency index associated with the set of ROs is an invalid frequency index for PRACH repetitions in the case that a following condition is met: the set of ROs are invalid for PRACH repetitions; or the frequency index associated with the set of ROs is a valid frequency index for the PRACH repetitions in the case that the condition is not met.

Clause 9. The user equipment of any of clauses 1-8, wherein the number of at least one SSB to RO association pattern periods is determined such that the number is a minimum integer fulfilling one of the following: at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions; or at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.

Clause 10. The user equipment of clause 1, wherein RO groups among the set of RO groups are indexed by: indexing RO groups in a first subset of RO groups among the set of RO groups with a lowest frequency index; and indexing RO groups in a second subset of RO groups among the set of RO groups with a second lowest frequency index after the indexing of the RO groups in the first subset of RO groups is completed.

Clause 11. The user equipment of clause 1, wherein ROs in a RO group in the set of RO groups are associated with the same frequency index.

Clause 12. The user equipment of clause 1, wherein ROs in a RO group in the set of RO groups are determined at least based on a configured frequency index offset.

Clause 13. The user equipment of clause 1, wherein the set of RO groups are determined for a configured number of PRACH repetitions.

Clause 14. The user equipment of clause 13, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on a maximum configured number for PRACH repetitions and the number of ROs, among the plurality of ROs, with a same valid frequency index.

Clause 15. The user equipment of clause 14, wherein: in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs which are the same as the first set of ROs.

Clause 16. The user equipment of clause 13, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on the configured number and the number of ROs, among the plurality of ROs, with a same valid frequency index.

Clause 17. The user equipment of clause 16, wherein: in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs different from the first set of ROs.

Clause 18. The user equipment of clause 1, wherein the processor is further configured to: transmit, via the transceiver to a base station, PRACH repetitions in a RO group in the set of RO groups.

Clause 19. A base station comprising: a processor; and a transceiver coupled to the processor, wherein the processor is configured to: determine a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

Clause 20. The base station of clause 19, wherein the frequency index of a RO is determined based on a frequency position of the RO in at least one RO that is multiplexed in a frequency domain in a same time occasion, and wherein the time index of a RO is determined based on a time position of the RO in a set of ROs that have a same frequency index.

Clause 21. The base station of clause 19, wherein the processor is further configured to: determine that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid, wherein the set of RO groups are determined from valid ROs in the plurality of ROs.

Clause 22. The base station of clause 21, wherein: the set of ROs are valid for a physical random access channel (PRACH) repetition in the case that a following condition is met: the number of ROs in the set of ROs is the same as the number of ROs in the plurality of ROs having a lowest frequency index; or the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.

Clause 23. The base station of clause 21, wherein determining that a set of ROs in the plurality of ROs are valid or invalid comprises: determining at least one RO group for a configured number of PRACH repetitions from the set of ROs, determining that the set of ROs are valid for PRACH repetitions in the case that a following condition is met: the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions; or determining that the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.

Clause 24. The base station of clause 21, wherein: the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: the number of ROs in the set of ROs is equal to or larger than the configured number; or the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

Clause 25. The base station of clause 21, wherein: the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: a RO group can be determined from the set of ROs for the configured number of PRACH repetitions; and the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.

Clause 26. The base station of any of clauses 21-25, wherein: the frequency index associated with the set of ROs is an invalid frequency index for PRACH repetitions in the case that a following condition is met: the set of ROs are invalid for PRACH repetitions; or the frequency index associated with the set of ROs is a valid frequency index for the PRACH repetitions in the case that the condition is not met.

Clause 27. The base station of any of clauses 19-26, wherein the number of at least one SSB to RO association pattern periods is determined such that the number is a minimum integer fulfilling one of the following: at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions; at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions; or at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.

Clause 28. The base station of clause 19, wherein RO groups among the set of RO groups are indexed by: indexing RO groups in a first subset of RO groups among the set of RO groups with a lowest frequency index; and indexing RO groups in a second subset of RO groups among the set of RO groups with a second lowest frequency index after the indexing of the RO groups in the first subset of RO groups is completed.

Clause 29. The base station of clause 19, wherein ROs in a RO group in the set of RO groups are associated with the same frequency index.

Clause 30. The base station of clause 19, wherein ROs in a RO group in the set of RO groups are determined at least based on a configured frequency index offset.

Clause 31. The base station of clause 19, wherein the set of RO groups are determined for a configured number of PRACH repetitions.

Clause 32. The base station of clause 31, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on a maximum configured number for PRACH repetitions and the number of ROs, among the plurality of ROs, with a same valid frequency index.

Clause 33. The base station of clause 32, wherein: in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs which are the same as the first set of ROs.

Clause 34. The base station of clause 31, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on the configured number and the number of ROs, among the plurality of ROs, with a same valid frequency index.

Clause 35. The base station of clause 34, wherein: in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs different from the first set of ROs.

Clause 36. The base station of clause 19, wherein the processor is further configured to: monitor PRACH repetitions in a RO group in the set of RO groups.

Clause 37. A method performed by a user equipment, the method comprising: determining a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

Clause 38. A method performed by a base station, the method comprising: determining a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

Clause 39. 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: determine a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period, wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and wherein each RO of the plurality of ROs is associated with a frequency index and a time index.

Claims

A user equipment comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

determine a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period,

wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and

wherein each RO of the plurality of ROs is associated with a frequency index and a time index.
The user equipment of claim 1, wherein the frequency index of a RO is determined based on a frequency position of the RO in at least one RO that is multiplexed in a frequency domain in a same time occasion, and

wherein the time index of a RO is determined based on a time position of the RO in a set of ROs that have a same frequency index.
The user equipment of claim 1, wherein the processor is further configured to:

determine that a set of ROs with a same frequency index in the plurality of ROs are valid or invalid, wherein the set of RO groups are determined from valid ROs in the plurality of ROs.
The user equipment of claim 3, wherein:

the set of ROs are valid for a physical random access channel (PRACH) repetition in the case that a following condition is met: the number of ROs in the set of ROs is the same as the number of ROs in the plurality of ROs having a lowest frequency index; or

the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.
The user equipment of claim 3, wherein determining that a set of ROs in the plurality of ROs are valid or invalid comprises:

determining at least one RO group for a configured number of PRACH repetitions from the set of ROs,

determining that the set of ROs are valid for PRACH repetitions in the case that a following condition is met: the number of RO groups in the at least one RO group is the same as the number of RO groups associated with a lowest frequency index for the configured number of PRACH repetitions; or

determining that the set of ROs are invalid for the PRACH repetitions in the case that the condition is not met.
The user equipment of claim 3, wherein:

the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: the number of ROs in the set of ROs is equal to or larger than the configured number; or

the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.
The user equipment of claim 3, wherein:

the set of ROs are valid for PRACH repetitions for a configured number of PRACH repetitions in the case that a following condition is met: a RO group can be determined from the set of ROs for the configured number of PRACH repetitions; and

the set of ROs are invalid for the PRACH repetitions for the configured number of PRACH repetitions in the case that the condition is not met.
The user equipment of any of claims 3-7, wherein:

the frequency index associated with the set of ROs is an invalid frequency index for PRACH repetitions in the case that a following condition is met: the set of ROs are invalid for PRACH repetitions; or

the frequency index associated with the set of ROs is a valid frequency index for the PRACH repetitions in the case that the condition is not met.
The user equipment of any of claims 1-8, wherein the number of at least one SSB to RO association pattern periods is determined such that the number is a minimum integer fulfilling one of the following:

at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions;

at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for a maximum configured number of PRACH repetitions;

at least one RO group of a lowest frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions; or

at least one RO group of any valid frequency index in the at least one SSB to RO association pattern periods can be determined for each configured number of PRACH repetitions.
The user equipment of claim 1, wherein RO groups among the set of RO groups are indexed by:

indexing RO groups in a first subset of RO groups among the set of RO groups with a lowest frequency index; and

indexing RO groups in a second subset of RO groups among the set of RO groups with a second lowest frequency index after the indexing of the RO groups in the first subset of RO groups is completed.
The user equipment of claim 1, wherein ROs in a RO group in the set of RO groups are associated with the same frequency index.
The user equipment of claim 1, wherein ROs in a RO group in the set of RO groups are determined at least based on a configured frequency index offset.
The user equipment of claim 1, wherein the set of RO groups are determined for a configured number of PRACH repetitions.
The user equipment of claim 13, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on a maximum configured number for PRACH repetitions and the number of ROs, among the plurality of ROs, with a same valid frequency index.
The user equipment of claim 14, wherein:

in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and

in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs which are the same as the first set of ROs.
The user equipment of claim 13, wherein the set of RO groups are determined based on at least one set of ROs, wherein a set of ROs among the at least one set of ROs are determined based on the configured number and the number of ROs, among the plurality of ROs, with a same valid frequency index.
The user equipment of claim 16, wherein:

in the case that the configured number is a first configured number, the set of ROs comprise a first set of ROs; and

in the case that the configured number is a second configured number, the set of ROs comprise a second set of ROs different from the first set of ROs.
A base station comprising:

a processor; and

a transceiver coupled to the processor,

wherein the processor is configured to:

determine a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period,

wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and

wherein each RO of the plurality of ROs is associated with a frequency index and a time index.
A method performed by a user equipment, the method comprising:

determining a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period,

wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and

wherein each RO of the plurality of ROs is associated with a frequency index and a time index.
A method performed by a base station, the method comprising:

determining a set of random access channel occasion (RO) groups from a plurality of ROs in at least one synchronization signal and physical broadcast channel (PBCH) block (SSB) to RO association pattern period,

wherein the plurality of ROs are associated with a same SSB or a same set of SSBs, and

wherein each RO of the plurality of ROs is associated with a frequency index and a time index.