Method and user equipment for transmitting random access preamble, and method and base station for receiving random access preamble

Patent metadata

Field	Value
Publication number	US-10587447-B2
Application number	US-201916274008-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Mar 20, 2017
Publication date	Mar 10, 2020
Grant date	Mar 10, 2020

Abstract

A UE transmits a random access channel (RACH) preamble and a BS receives the RACH channel. The BS configures the RACH preamble to align boundaries of the RACH preamble with boundaries of OFDM symbols on which the RACH preamble is configured in the time domain. The UE generates/transmits the RACH preamble to align the boundaries of the RACH preamble with the boundaries of OFDM symbols on which the RACH preamble is configured in the time domain.

First claim

What is claimed is:

1. A method of transmitting a random access channel (RACH) preamble by a user equipment in a wireless communication system, the method comprising:
receiving, from a base station, random access information, and
transmitting, to the base station, the RACH preamble based on the random access information,
wherein the RACH preamble has a first length that is equal to a total length of 2 or more orthogonal frequency division multiplexing (OFDM) symbols,
wherein the RACH preamble consists of a cyclic prefix (CP) and a sequence part, the sequence part generated based on a Zadoff-Chu sequence,
wherein the RACH preamble is accompanied by no guard time,
wherein the sequence part has a second length and the CP has a third length so that a sum of the second and third lengths is equal to the first length, and
wherein the start and end of the RACH preamble are aligned with the start and end of the 2 or more OFDM symbols in a time domain.

2. The method of claim 1 , wherein the first length is equal to a total length of two OFDM symbols.

3. The method of claim 1 , wherein the first length is equal to a total length of four OFDM symbols.

4. The method of claim 1 , wherein the first length is equal to a total length of six OFDM symbols.

5. The method of claim 1 , wherein the third length of the CP varies according to a number of the 2 or more OFDM symbols such that the sum of the second and third lengths is equal to the first length.

6. A user equipment (UE) configured to transmit a random access channel (RACH) preamble in a wireless communication system, the UE comprising:
a transceiver; and
a processor operatively configured to control the transceiver and configured to:
control the transceiver to receive, from a base station, random access information, and
control the transceiver to transmit, to the base station, the RACH preamble based on the random access information,
wherein the RACH preamble has a first length that is equal to a total length of 2 or more orthogonal frequency division multiplexing (OFDM) symbols,
wherein the RACH preamble consists of a cyclic prefix (CP) and a sequence part, the sequence part generated based on a Zadoff-Chu sequence,
wherein the RACH preamble is accompanied by no guard time,
wherein the sequence part has a second length and the CP has a third length so that a sum of the second and third lengths is equal to the first length, and
wherein the start and end of the RACH preamble are aligned with the start and end of the 2 or more OFDM symbols in a time domain.

7. The UE of claim 6 , wherein the third length of the CP varies according to a number of the 2 or more OFDM symbols such that the sum of the second and third lengths is equal to the first length.

8. A device configured to control transmission of a random access channel (RACH) preamble in a wireless communication system, the device comprising:
at least one processor; and
at least one memory that is operably connectable to the at least one processor and that has stored thereon instructions which, when executed, cause the at least one processor to perform operations comprising:
controlling a transceiver to receive, from a base station, random access information, and
controlling the transceiver to transmit, to the base station, the RACH preamble based on the random access information,
wherein the RACH preamble has a first length that is equal to a total length of 2 or more orthogonal frequency division multiplexing (OFDM) symbols,
wherein the RACH preamble consists of a cyclic prefix (CP) and a sequence part, the sequence part generated based on a Zadoff-Chu sequence,
wherein the RACH preamble is accompanied by no guard time,
wherein the sequence part has a second length and the CP has a third length so that a sum of the second and third lengths is equal to the first length, and
wherein the start and end of the RACH preamble are aligned with the start and end of the 2 or more OFDM symbols in a time domain.

9. The device of claim 8 , wherein the third length of the CP varies according to a number of the 2 or more OFDM symbols such that the sum of the second and third lengths is equal to the first length.

Assignees

• Lg Electronics Inc

Inventors

• Yoon Sukhyon
• Ko Hyunsoo
• Kim Kijun
• Kim Eunsun
• Yang Suckchel

Classifications

• H04W74/0841

  with collision treatment · CPC title

• H04B7/086 Primary

  using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming · CPC title

• H04L5/00

  Arrangements affording multiple use of the transmission path · CPC title

• H04L27/2646

  using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length · CPC title

• H04W74/08

  Non-scheduled access, e.g. ALOHA (hybrid access H04W74/02) · CPC title