Apparatus and method for handling bandwidth part configuration for random access channel procedure in wireless communication system

Patent metadata

Field	Value
Publication number	US-2019104554-A1
Application number	US-201816148841-A
Country	US
Kind code	A1
Filing date	Oct 1, 2018
Priority date	Sep 29, 2017
Publication date	Apr 4, 2019
Grant date	—

Abstract

The present disclosure relates to a pre-5 th -Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4 th -Generation (4G) communication system such as Long Term Evolution (LTE). Embodiments herein disclose a method of handling BWP configurations for a RACH procedure in a wireless network. The method includes configuring, by a BS, a BWP configuration comprising RACH resource for each BWP in a set of BWPs for the RACH procedure. Further, the method includes indicating, by the BS, the RACH resource for each of the BWPs in the set of BWPs to a UE in the wireless network.

First claim

What is claimed is:

1 . A method for operating a user equipment (UE) in a wireless communication system, the method comprising:
receiving a bandwidth part (BWP) configuration comprising a random access channel (RACH) resource for each BWP in a set of BWPs for a RACH procedure from a base station (BS); performing the RACH procedure on a selected BWP from the set of BWPs using the RACH resource for the selected BWP indicated in the BWP configuration; and receiving a random access response message on the selected BWP from the BS.

2 . The method of claim 1 , wherein the RACH resource for each of the BWPs is received by the UE using at least one of a remaining minimum system information (RMSI), a BWP configuration procedure via a radio resource control (RRC) indication, and a BWP activation mechanism via a downlink control information (DCI).

3 . The method of claim 1 , wherein each of the BWPs in the set of BWPs is associated with one of same numerology and different numerology.

4 . The method of claim 1 , wherein, when the UE does not perform the RACH on all BWPs, a timing advance (TA) value used on different BWPs is one of:
same as a TA value of an initial active BWP; zero for all the BWPs other than an initial active BWP; a pre-configured max TA value that accounts for a cell size and a frequency variations across various BWPs; same TA value for all the BWPs supported within a same transceiver unit (TXRU) and a different TA value for the BWPs belonging to other TXRUs as indicated by the BS; a TA value indicated in the BWP configuration; and same TA value for all the BWPs associated with one SS block.

5 . The method of claim 4 , wherein a granularity of the TA value is determined in a random access response based on a numerology of an uplink shared channel.

6 . The method of claim 4 , wherein the TA value is derived based on a quasi co-location relationship (QCL) between multiple TXRUs.

7 . The method of claim 1 , wherein the random access response message is received in at least one of:
a current active BWP on a primary cell; initial active BWP on the primary cell; a default BWP configured to the UE on the primary cell; and one of multiple active BWPs when the UE supports multiple active BWPs, wherein indexes of the supported multiple active BWPs are provided to the UE by the BS, and the index of BWP is related to the RACH resource or preamble chosen by the UE.

8 . The method of claim 1 , further comprising:
establishing a radio resource control (RRC) connection on an active BWP, wherein the selected BWP comprises the active BWP.

9 . The method of claim 8 , wherein the performing the RACH procedure comprises, performing the RACH procedure on the active BWP when the RACH resource is available.

10 . The method of claim 8 , further comprising:
switching to a default BWP or initial active BWP from a set of BWPs, when the RACH resource is not available in the active BWP.

11 . A base station (BS) in a wireless communication system, the BS comprising:
a transceiver; and a processor coupled to the transceiver and configured to:
configure a bandwidth part (BWP) configuration comprising a random access channel (RACH) resource for each BWP in a set of BWPs for an RACH procedure; and
indicate the RACH resource for each of the BWPs in the set of BWPs to a user equipment (UE).

12 . The BS of claim 11 , wherein the processor is further configured to indicate a timing advance (TA) value to the UE upon completion of the RACH procedure, wherein the TA value is indicated to the UE with reference to a granularity of a numerology used by one of:
a random access preamble numerology of a preamble format used by the UE and configured in a BWP configuration; a scheduled Transmission numerology configured for the UE in a remaining minimum system information (RMSI); an ongoing uplink (UL) data transmission numerology in a primary cell in case of a contention free RACH in the primary cell; an ongoing UL data transmission numerology in a secondary cell; a numerology configured for a supplementary uplink (SUL) carrier; and a numerology commonly chosen among multiple bandwidth parts in a case of multiple simultaneously active bandwidth parts.

13 . The BS of claim 11 , wherein the processor is further configured to indicate, by the BS, a TA value to the UE used by one of a lowest numerology among multiple active BWPs and a highest numerology among multiple active BWPs, when multiple BWP with different numerologies are involved.

14 . The BS of claim 13 , wherein a granularity of the TA value depends on the numerology of a first UL transmission after receiving a random access response.

15 . A user equipment (UE) in a wireless communication system, the UE comprising:
a transceiver; and a processor coupled to the transceiver and configured to:
receive a bandwidth part (BWP) configuration comprising a random access channel (RACH) resource for each BWP in a set of BWPs for a RACH procedure from a base station (BS);
perform the RACH procedure on a selected BWP from the set of BWPs using the RACH resource for the selected BWP indicated in the BWP configuration; and
receive a random access response message on the selected BWP from the BS.

16 . The UE of claim 15 , wherein the RACH resource for each of the BWPs is received by the UE using at least one of a remaining minimum system information (RMSI), a BWP configuration procedure via a radio resource control (RRC) indication, and a BWP activation mechanism via a downlink control information (DCI).

17 . The UE of claim 16 , wherein each of the BWPs in the set of BWPs is associated with one of same numerology and different numerology.

18 . The UE of claim 16 , wherein the transceiver is further configured to receive a Random access response message on the selected BWP.

19 . The UE of claim 16 , wherein, when the UE does not perform the RACH on all BWPs, a timing advance (TA) value used on different the BWPs is one of:
the same as a TA value of an initial active BWP; zero for all the BWPs other than an initial active BWP; a pre-configured max TA value that accounts for a cell size and frequency variations across the BWPs; same TA value for all the BWPs supported within a same transceiver unit (TXRU) and a different TA value for the BWPs belonging to other TXRUs as indicated by the BS; a TA value indicated in the BWP configuration; and a same TA value for all the BWPs associated with one SS block.

20 . The UE of claim 16 , wherein the processor is further configured to receive the random access response message on the selected BWP from the BS in at least one of:
a current active BWP on a primary cell; initial active BWP on a primary cell; a default BWP configured to the UE on a primary cell; and one of multiple active BWPs when the UE supports multiple active BWP, wherein an index of the supported multiple active BWP is provided to the UE by the BS, and the index of BWP is related to the RACH resource or preamble chosen by the UE.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Amuru Saidhiraj
• Agiwal Anil
• Nigam Anshuman

Classifications

• H04W74/0833 Primary

  Random access procedures, e.g. with 4-step access · CPC title

• H04W72/23

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04B7/0617

  for beam forming · CPC title