US 11,838,952 B2
Method for performing random access procedure and device therefor
Jaehyung Kim, Seoul (KR); Joonkui Ahn, Seoul (KR); Suckchel Yang, Seoul (KR); Changhwan Park, Seoul (KR); Seokmin Shin, Seoul (KR); and Seunggye Hwang, Seoul (KR)
Assigned to LG Electronics Inc., Seoul (KR)
Appl. No. 16/610,597
Filed by LG Electronics Inc., Seoul (KR)
PCT Filed May 4, 2018, PCT No. PCT/KR2018/005182
§ 371(c)(1), (2) Date Nov. 4, 2019,
PCT Pub. No. WO2018/203698, PCT Pub. Date Nov. 8, 2018.
Claims priority of provisional application 62/542,804, filed on Aug. 9, 2017.
Claims priority of provisional application 62/501,698, filed on May 4, 2017.
Prior Publication US 2020/0068619 A1, Feb. 27, 2020
Int. Cl. H04W 74/08 (2009.01); H04W 74/00 (2009.01)
CPC H04W 74/0833 (2013.01) [H04W 74/004 (2013.01); H04W 74/006 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for performing a random access procedure by a user equipment (UE) in a wireless communication system supporting multiple preamble formats including a first type preamble format and a second type preamble format, the method comprising:
receiving, from a base station (BS) through a system information block (SIB), narrowband physical random access channel (NPRACH) configuration information for configuring one or more of the supported multiple preamble formats;
receiving, from the BS through a narrow band physical downlink control channel (NPDCCH) order, downlink control information (DCI) including a preamble format indicator indicating the first type preamble format or the second type preamble format; and
transmitting, to the BS, a random access preamble including a sequence part and a cyclic prefix (CP) part based on the NPRACH configuration information and the NPDCCH order,
wherein the first type preamble format includes a first sequence part and a first CP part, the first sequence part having 5 symbols and the first CP part being attached in front of the first sequence part,
wherein the second type preamble format includes a second sequence part and a second CP part, the second sequence part having 3 symbols and the second CP part being attached in front of the second sequence part,
wherein a ratio of the first CP part to the first sequence part in the first type preamble format is smaller than a ratio of the second CP part to the second sequence part in the second type preamble format,
wherein the first CP part attached to the first sequence part with 5 symbols is shorter than the second CP part attached to the second sequence part with 3 symbols,
wherein the UE determines, based on the NPRACH configuration information, whether only the first type preamble format is configured in the BS without the second type preamble format, or both the first type preamble format and the second type preamble format are configured in the BS, and
wherein the second type preamble format is transmitted by the UE based on that both conditions (a) and (b) are satisfied:
(a) the UE determined, based on the NPRACH configuration information, that both the first type preamble format and the second type preamble format are configured in the BS and
(b) the preamble format indicator of the NPDCCH order indicated the UE to transmit the second type preamble format.