US-12621864-B2 - Downlink initial access signal to random access channel occasion association

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, configuration information indicating a downlink initial access signal (IAS) to random access channel (RACH) occasion association pattern, wherein the downlink IAS to RACH occasion association pattern indicates at least one of switching gaps between downlink IAS occasions and between RACH occasions or guard bands between RACH occasions. The UE may transmit, to the base station, a RACH message using a RACH occasion according to the downlink IAS to RACH occasion association pattern. Numerous other aspects are described.

Inventors

• Iyab Issam SAKHNINI
• Tao Luo

Assignees

• QUALCOMM INCORPORATED

Dates

Publication Date

20260505

Application Date

20210316

Claims (20)

1. 1 . A user equipment (UE) for wireless communication, comprising: a memory; and one or more processors, coupled to the memory, configured to: receive, from a base station, configuration information indicating a downlink initial access signal (IAS) to random access channel (RACH) occasion association pattern that is based at least in part on a comparison between a length of a downlink to uplink switching time of the base station and a length of a beam switching time of the base station, wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between one or more of: at least two downlink IAS occasions, at least two RACH occasions corresponding to a plurality of synchronization signal blocks (SSBs), or at least one downlink IAS occasion and at least one RACH occasion; and transmit, to the base station, a RACH message in accordance with the downlink IAS to RACH occasion association pattern.
2. 2 . The UE of claim 1 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern includes: a plurality of downlink IAS occasions, the plurality of downlink IAS occasions including at least one first downlink IAS occasion for a first beam associated with the base station and at least one second downlink IAS occasion for a second beam associated with the base station that is different than the first beam, and a plurality of RACH occasions associated with the plurality of downlink IAS occasions, wherein the plurality of downlink IAS occasions are grouped together in a time domain and the plurality of RACH occasions are grouped together in the time domain.
3. 3 . The UE of claim 2 , wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least two downlink IAS occasions, wherein the plurality of downlink IAS occasions includes switching gaps between downlink IAS occasions included in the plurality of downlink IAS occasions, or wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least two RACH occasions, wherein the plurality of RACH occasions includes switching gaps between RACH occasions included in the plurality of RACH occasions.
4. 4 . The UE of claim 1 , wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least one downlink IAS occasion and at least one RACH occasion, and wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern includes a downlink IAS associated with a beam grouped with a RACH occasion associated with the beam in a time domain.
5. 5 . The UE of claim 4 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS and the RACH occasion are multiplexed in a time domain.
6. 6 . The UE of claim 4 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication of a downlink/uplink switching gap between the downlink IAS and the RACH occasion.
7. 7 . The UE of claim 1 , wherein the downlink IAS to RACH occasion association pattern is further based at least in part on: a number of downlink IAS occasions associated with the downlink IAS to RACH occasion association pattern, an amount of time associated with channel acquisition for the UE, or any combination thereof.
8. 8 . The UE of claim 1 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern includes a varied ordering of RACH occasions between a first association period and a second association period, the varied ordering comprising a first order of RACH occasions in a time domain for the first association period and a second order of RACH occasions in the time domain for the second association period.
9. 9 . The UE of claim 1 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern includes a first downlink IAS associated with a first number of RACH occasions and a second downlink IAS associated with a second number of RACH occasions, the first number of RACH occasions corresponding to a different number of RACH occasions relative to the second number of RACH occasions.
10. 10 . The UE of claim 1 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern includes a first RACH occasion frequency division multiplexed with a second RACH occasion and a guard band included between the first RACH occasion and the second RACH occasion in a frequency domain.
11. 11 . The UE of claim 10 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the downlink IAS to RACH occasion association pattern is associated with a single carrier waveform type.
12. 12 . The UE of claim 1 , wherein the one or more processors, to receive the configuration information, are configured to: receive an indication that the switching gaps include at least one of downlink to uplink switching gaps or beam switching gaps, wherein a switching gap includes: an explicit switching gap, a switching gap included in a cyclic prefix, a sub-symbol switching gap, an extended guard period switching gap, or any combination thereof.
13. 13 . The UE of claim 1 , wherein a downlink IAS associated with the downlink IAS to RACH occasion association pattern includes a system information block (SIB) signal.
14. 14 . The UE of claim 1 , wherein the configuration information includes an indication of whether the downlink IAS to RACH occasion association pattern is mapped in the time domain only or in both time and frequency domains.
15. 15 . A method of wireless communication performed by a user equipment (UE), comprising: receiving, from a base station, configuration information indicating a downlink initial access signal (IAS) to random access channel (RACH) occasion association pattern that is based at least in part on a comparison between a length of a downlink to uplink switching time of the base station and a length of a beam switching time of the base station, wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between one or more of: at least two downlink IAS occasions, at least two RACH occasions corresponding to a plurality of synchronization signal blocks (SSBs), or at least one downlink IAS occasion and at least one RACH occasion; and transmitting, to the base station, a RACH message in accordance with the downlink IAS to RACH occasion association pattern.
16. 16 . The method of claim 15 , wherein receiving the configuration information comprises: receiving an indication that the downlink IAS to RACH occasion association pattern includes: a plurality of downlink IAS occasions, the plurality of downlink IAS occasions including at least one first downlink IAS occasion for a first beam associated with the base station and at least one second downlink IAS occasion for a second beam associated with the base station that is different than the first beam, and a plurality of RACH occasions associated with the plurality of downlink IAS occasions, wherein the plurality of downlink IAS occasions are grouped together in a time domain and the plurality of RACH occasions are grouped together in the time domain.
17. 17 . The method of claim 16 , wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least two downlink IAS occasions, wherein the plurality of downlink IAS occasions includes switching gaps between downlink IAS occasions included in the plurality of downlink IAS occasions, or wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least two RACH occasions, wherein the plurality of RACH occasions includes switching gaps between RACH occasions included in the plurality of RACH occasions.
18. 18 . The method of claim 15 , wherein the downlink IAS to RACH occasion association pattern indicates switching gaps between at least one downlink IAS occasion and at least one RACH occasion, and wherein receiving the configuration information comprises: receiving an indication that the downlink IAS to RACH occasion association pattern includes a downlink IAS associated with a beam grouped with a RACH occasion associated with the beam in a time domain.
19. 19 . The method of claim 18 , wherein receiving the configuration information comprises: receiving an indication that the downlink IAS and the RACH occasion are multiplexed in a time domain.
20. 20 . The method of claim 18 , wherein receiving the configuration information comprises: receiving an indication of a downlink/uplink switching gap between the downlink IAS and the RACH occasion.

Description

FIELD OF THE DISCLOSURE Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for downlink initial access signal (IAS) to random access channel (RACH) occasion association. BACKGROUND Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, or the like). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP). A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs). A UE may communicate with a BS via the downlink and uplink. “Downlink” (or “forward link”) refers to the communication link from the BS to the UE, and “uplink” (or “reverse link”) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP), a radio head, a transmit receive point (TRP), a New Radio (NR) BS, a 5G Node B, or the like. The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. NR, which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the 3GPP. NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful. SUMMARY In some aspects, a user equipment (UE) for wireless communication includes a memory and one or more processors, coupled to the memory, configured to: receive, from a base station, configuration information indicating a downlink initial access signal (IAS) to random access channel (RACH) occasion association pattern, wherein the downlink IAS to RACH occasion association pattern indicates at least one of switching gaps between downlink IAS occasions and between RACH occasions or guard bands between RACH occasions; and transmit, to the base station, a RACH message using a RACH occasion according to the downlink IAS to RACH occasion association pattern. In some aspects, a base station for wireless communication includes a memory and one or more processors, coupled to the memory, configured to: transmit, to one or more UEs, configuration information indicating a downlink IAS to RACH occasion association pattern, wherein the downlink IAS to RACH occasion association pattern indicates at least one of switching gaps between downlink IAS occasions and between RACH occasions or guard bands between RACH occasions; and receive, from a UE of the one or more UEs, a RACH message using a RACH occasion according to the downlink IAS to RACH occasion association pattern. In some aspects, a method of wireless communication performed by a UE includes receiving, from a base station, configuration information indicating a downlink IAS to RACH occasion association pattern, wherein the downlink IAS to RACH occasion association pattern indicates at least one of switching gaps between downlink IAS occasions and between RACH occasions or guard bands between RACH occasions; and transmitting, to the base station, a RACH message using a RACH occasion according to the downlink IAS to RACH occasion association pattern. In some aspects, a method of wireless communication performed by a base station includes transmitting, to one or more UEs, configuration information indicating a downlink IAS to RACH occasion association pattern, wherein the downlink IAS to RACH occasion association pattern indicates at least one o