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EP-4736564-A1 - RO GROUP FOR MULTIPLE PRACH TRANSMISSIONS

EP4736564A1EP 4736564 A1EP4736564 A1EP 4736564A1EP-4736564-A1

Abstract

Methods, systems, apparatuses, and computer programs for multiple Physical Random Access Channel (PRACH) transmissions are disclosed. In one aspect, operations are performed by a UE and can include identifying the number of RACH occasions (ROs) M associated with a particular Synchronization Signal Block (SSB) in a single SSB-to-RO association pattern period P;obtaining a particular PRACH repetition number N, wherein the particular PRACH repetition number N is equal to or less than a maximum PRACH repetition number L; and determining the number of SSB-to-RO association pattern periods K within a time period X as a function of the number of ROs M associated with the particular SSB in a single SSB-to-RO association pattern period P and the particular PRACH repetition number N.

Inventors

  • YE, CHUNXUAN
  • ZHANG, DAWEI
  • SUN, HAITONG
  • HE, HONG
  • FAKOORIAN, SEYED ALI AKBAR
  • ZENG, WEI
  • YAO, CHUNHAI

Assignees

  • Apple Inc.

Dates

Publication Date
20260506
Application Date
20230809

Claims (19)

  1. One or more processors of a user equipment (UE) , the one or more processors configured to perform operations for multiple Physical Random Access Channel (PRACH) transmissions, the operations comprising: identifying the number of RACH occasions (ROs) M associated with a particular Synchronization Signal Block (SSB) in a single SSB-to-RO association pattern period P; obtaining a particular PRACH repetition number N, wherein the particular PRACH repetition number N is equal to or less than a maximum PRACH repetition number L; and determining the number of SSB-to-RO association pattern periods K within a time period X as a function of the number of ROs M associated with the particular SSB in a single SSB-to-RO association pattern period P and the particular PRACH repetition number N.
  2. The one or more processors of claim 1, wherein and X = K × P.
  3. The one or more processors of claim 1, the operations further comprising: obtaining one or more RO groups within the time period X, wherein at least one RO group is associated with the particular PRACH repetition number N, wherein the number of ROs in the at least one RO group is the same as the particular PRACH repetition number N.
  4. The one or more processors of claim 1, wherein the particular PRACH repetition number N is the maximum PRACH repetition number L, the operations further comprising: obtaining a single RO group within the time period X, wherein the number of ROs in the single RO group is the maximum PRACH repetition number L.
  5. The one or more processors of claim 1, wherein the particular PRACH repetition number N is 1/2 × the maximum PRACH repetition number L, the operations further comprising: obtaining two RO groups within the time period X, wherein the number of ROs in each RO group is 1/2 × L.
  6. The one or more processors of claim 1, wherein the particular PRACH repetition number N is 1/4 × the maximum PRACH repetition number L, the operations further comprising: obtaining four RO groups within the time period X, wherein the number of ROs in each RO group is 1/4 × L.
  7. The one or more processors of claim 3, wherein when the single SSB-to-RO association pattern period P includes at least L ROs, K = 1.
  8. The one or more processors of claim 7, when K = 1, the number of RO groups within the time period X is
  9. The one or more processors of claim 3, the operations further comprising: determining a first starting RO position in a first time period X, wherein the first starting RO position is aligned with a radio frame 0; and determining a second starting RO position in a subsequent time period X, wherein the second starting RO position is the first starting RO position + K× association pattern period ×C, where C is a natural number.
  10. The one or more processors of claim 9, wherein the particular PRACH repetition number N is 1/2 × the maximum PRACH repetition number L, the operations further comprising: providing two RO groups within the time period X, wherein the number of ROs in each RO group is 1/2 × L; and determining a third starting RO position in a second RO group in the first time period X, wherein the third starting RO position is the first starting RO position + 1/2 × L× RO.
  11. The one or more processors of claim 9, wherein the particular PRACH repetition number N is 1/4 × the maximum PRACH repetition number L, the operations further comprising: providing four RO groups within the time period X, wherein the number of ROs in each RO group is 1/4 × L; and determining a third starting RO position in a subsequent RO group in the first time period X, wherein the third starting RO position is the first starting RO position + 1/4 × L × RO × m, where m=1, 2, or 3.
  12. The one or more processors of claim 3, wherein the number of SSB-to-RO association pattern periods K is the same for any particular PRACH repetition number.
  13. The one or more processors of claim 3, wherein the number of SSB-to-RO association pattern periods K is associated with the particular PRACH repetition number N, wherein a different N corresponds to a different K.
  14. The one or more processors of claim 3, wherein ROs associated with the particular SSB in each RO group have the same frequency position.
  15. The one or more processors of claim 3, the operations further comprising: obtaining one or more ROs configured with Frequency Division Multiplexing (FDM) ; and enabling frequency hopping within the ROs configured with FDM.
  16. The one or more processors of claim 15, wherein the number of ROs configured with FDM and associated with the particular SSB is the same at different time instances.
  17. The one or more processors of claim 16, the operations further comprising: dropping a RO having a larger index at a particular time instance, so that the number of ROs configured with FDM and associated with the particular SSB is the same.
  18. A method of performing operations of any one of claims 1-17.
  19. A user equipment (UE) , comprising: one or more processors; and one or more memory devices storing instructions that, when executed, cause the one or more processors to perform operations of any one of claims 1-17.

Description

RO GROUP FOR MULTIPLE PRACH TRANSMISSIONS BACKGROUND Wireless communication networks, such as fourth generation (4G) , fifth generation (5G) , etc., provide integrated communication platforms and telecommunication services to wireless user devices. The wireless communication networks have wireless access nodes that exchange wireless signals with the wireless user devices using wireless network protocols, such as protocols described in various telecommunication standards promulgated by the Third Generation Partnership Project (3GPP) . Example wireless communication networks include time-division multiple access (TDMA) networks, frequency-division multiple access (FDMA) networks, orthogonal frequency-division multiple access (OFDMA) networks, Long Term Evolution (LTE) , and Fifth Generation New Radio (5G NR) . Random Access Channel (RACH) Occasion refers to a specific time window within a frame when user devices (UEs) can initiate random access procedures to establish initial communication with the base station. During a RACH Occasion (RO) , UEs can transmit random access preambles via the Physical Random Access Channel (PRACH) to request access to the network. The RO defines a time window within which UEs are allowed to transmit their preambles for random access. SUMMARY According to one innovative aspect of the present disclosure, one or more processors of a user equipment (UE) configured to perform operations for multiple Physical Random Access Channel (PRACH) transmissions are disclosed. In one aspect, the operations can include identifying the number of RACH occasions (ROs) M associated with a particular Synchronization Signal Block (SSB) in a single SSB-to-RO association pattern period P; obtaining a particular PRACH repetition number N, wherein the particular PRACH repetition number N is equal to or less than a maximum PRACH repetition number L; and determining the number of SSB-to-RO association pattern periods K within a time period X as a function of the number of ROs M associated with the particular SSB in a single SSB-to-RO association pattern period P and the particular PRACH repetition number N. Other aspects include methods, apparatuses, systems, and computer programs for performing the aforementioned operations. The innovative operations can include other optional features. For example, in some implementations, and X = K × P. In some implementations, the operations further include obtaining one or more RO groups within the time period X, wherein at least one RO group is associated with the particular PRACH repetition number N, wherein the number of ROs in the at least one RO group is the same as the particular PRACH repetition number N. In some implementations, the particular PRACH repetition number N is the maximum PRACH repetition number L, and the operations further include obtaining a single RO group within the time period X, wherein the number of ROs in the single RO group is the maximum PRACH repetition number L. In some implementations, the particular PRACH repetition number N is 1/2 × the maximum PRACH repetition number L, and the operations further include obtaining two RO groups within the time period X, wherein the number of ROs in each RO group is 1/2 × L. In some implementations, the particular PRACH repetition number N is 1/4 × the maximum PRACH repetition number L, and the operations further include obtaining four RO groups within the time period X, wherein the number of ROs in each RO group is 1/4 × L. In some implementations, when the single SSB-to-RO association pattern period P includes at least L ROs, K = 1. In some implementations, when K = 1, the number of RO groups within the time period X is In some implementations, the operations further include determining a first starting RO position in a first time period X, wherein the first starting RO position is aligned with a radio frame 0;and determining a second starting RO position in a subsequent time period X, wherein the second starting RO position is the first starting RO position + K× association pattern period ×C, where C is a natural number. In some implementations, the particular PRACH repetition number N is 1/2 × the maximum PRACH repetition number L, and the operations further include providing two RO groups within the time period X, wherein the number of ROs in each RO group is 1/2 × L; and determining a third starting RO position in a second RO group in the first time period X, wherein the third starting RO position is the first starting RO position + 1/2 × L× RO. In some implementations, the particular PRACH repetition number N is 1/4 × the maximum PRACH repetition number L, and the operations further include providing four RO groups within the time period X, wherein the number of ROs in each RO group is 1/4 × L; and  determining a third starting RO position in a subsequent RO group in the first time period X, wherein the third starting RO position is the first starting RO position + 1/4 × L × RO × m, w