Method and apparatus for performing random access procedure for coverage enhancement user equipments in wireless communication system

• US 9,955,508 B2
• Filed: 12/01/2014
• Issued: 04/24/2018
• Est. Priority Date: 12/04/2013
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Jaewook, Park, Sungjun, Lee, Youngdae, Jung, Sunghoon
• Primary Examiner(s): Cho, Hong
• Application Number:
  US15/034,644
• Publication Number:
  US 20160262186A1
• Time in Patent Office: 1,240 Days
• Field of Search: None
• CPC Class Codes: H04L 1/00 Arrangements for detecting or preventing errors in the information received correcting synchronisation H04L7/00
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/189 Transmission or retransmission of more than one copy of a message
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A method and apparatus for performing a random access procedure in a wireless communication system is provided. In one embodiment, a user equipment (UE) determines a required amount of repetitions for uplink transmissions during a random access procedure, and performs repetitions for uplink transmissions based on the determined required amount of repetitions for uplink transmissions. The uplink transmissions may include transmission of preambles which are grouped. In another embodiment, a UE configures a communication windows for lost-cost machine-type communication (MTC) UE, and performs a random access procedure through the configured communication window.

Claims

1. A method for performing, by a user equipment (UE), a random access procedure in a wireless communication system, the method comprising:

receiving a mapping table between a number of repetitions required for correct reception of a downlink message and an estimated number of repetitions for uplink transmissions from a network;

determining a required amount of repetitions for uplink transmissions during a random access procedure based on the number of repetitions required for correct reception of the downlink message according to the mapping table; and

performing repetitions for uplink transmissions based on the determined required amount of repetitions for uplink transmissions.

2. The method of claim 1, wherein the downlink message is one of system information or a paging message.

3. The method of claim 1, wherein the uplink transmissions include transmission of preambles which are grouped.

4. The method of claim 3, wherein the preambles are grouped based on the number of repetitions for correct reception of downlink message.

5. A user equipment (UE) in a wireless communication system, the UE comprising:

a radio frequency (RF) transceiver; and

a processor that is coupled to the RF transceiver and that;

controls the RF transceiver to receive a mapping table between a number of repetitions required for correct reception of a downlink message and an estimated number of repetitions for uplink transmissions from a network,

determines a required amount of repetitions for uplink transmissions during a random access procedure based on the number of repetitions required for correct reception of the downlink message according to the mapping table, and

controls the RF transceiver to perform repetitions for uplink transmissions based on the determined required amount of repetitions for uplink transmissions.

6. The UE of claim 5, wherein the downlink message is one of system information or a paging message.

7. The UE of claim 5, wherein the uplink transmissions include transmission of preambles which are grouped.

8. The UE of claim 7, wherein the preambles are grouped based on the number of repetitions for correct reception of downlink message.