Method of Handling Coverage Enhancement in Wireless Communication System

• US 20150117410A1
• Filed: 10/31/2014
• Published: 04/30/2015
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: HTC Corporation
• Inventors: Wu, Chih-Hsiang, Wu, Chih-Yao
• Granted Patent: US 9,961,595 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04W 36/0069 in case of dual connectivity, e.g. decoupled uplink/downlink

Abstract

A method of handling coverage enhancement for a user equipment (UE) of a wireless communication system includes determining whether the UE is in an enhanced coverage mode according to the number of repetitions of a downlink transmission based on which the UE successfully decodes a system information block (SIB); and performing an uplink transmission with repetitions or without repetitions based on whether the UE is in the enhanced coverage mode.

Claims

1. A method of handling coverage enhancement for a user equipment (UE) of a wireless communication system, the method comprising:

determining whether the UE is in an enhanced coverage mode according to the number of repetitions of a downlink transmission based on which the UE successfully decodes a system information block (SIB); and

performing an uplink transmission with repetitions or without repetitions based on whether the UE is in the enhanced coverage mode.

2. The method of claim 1, wherein the step of determining whether the UE is in the enhanced coverage mode comprises:

determining that the UE is in the enhanced coverage mode if the UE successfully decodes the SIB based on multiple repetitions of the downlink transmission; and

determining that the UE is not in the enhanced coverage mode if the UE successfully decodes different SIBs respectively based on once downlink transmission.

3. The method of claim 1, wherein the step of determining whether the UE is in the enhanced coverage mode comprises:

determining that the UE is in the enhanced coverage mode if the UE successfully decodes the SIB based on a first number of repetitions of the downlink transmission; and

determining that the UE is not in the enhanced coverage mode if the UE successfully decodes different SIBs respectively based on a second number of repetitions of the downlink transmission, wherein the first number is larger than the second number.

4. The method of claim 1, wherein the step of performing the uplink transmission with repetitions or without repetitions based on whether the UE is in the enhanced coverage mode comprises:

performing the uplink transmission with repetitions if the UE is in the enhanced coverage mode; and

performing the uplink transmission without repetitions if the UE is not in the enhanced coverage mode.

5. The method of claim 4, wherein the uplink transmission is a random access preamble in a random access procedure.

6. The method of claim 4, further comprising:

transmitting a physical uplink shared channel transmission with a first number of repetitions, wherein the first number is indicated by a random access response from a network of the wireless communication system in the random access procedure.

7. The method of claim 1, wherein the SIB is a master information block (MIB), SIB1, or SIB2.

8. The method of claim 1, wherein the step of determining whether the UE is in the enhanced coverage mode is periodically performed.

9. The method of claim 1, further comprising:

transmitting a first message to a network of the wireless communication system to indicate whether the UE is in the enhanced coverage mode.

10. The method of claim 1, further comprising:

after determining the UE is in the enhanced coverage mode, stopping measuring neighboring cells.

11. A method of handling coverage enhancement for a network of a wireless communication system, the method comprising:

in response to being informed by a user equipment (UE) of the wireless communication system that the UE is not in the enhanced coverage mode, stopping performing repetitions on a downlink transmission to the UE, wherein the UE informs of not being in the enhanced coverage mode by transmitting a random access preamble or a first message to the network.

12. The method of claim 11, further comprising:

transmitting a second message to the UE to indicate that the network releases a repetition configuration for the UE, in response to receiving the first message or the random access preamble, which indicates that the UE is not in the enhanced coverage mode.

13. The method of claim 11, further comprising:

enabling a mobility management function for the UE in response to receiving the first message or the random access preamble indicating that the UE is not in the enhanced coverage mode;

or

disabling the mobility management function for the UE in response to receiving the first message or the random access preamble indicating that the UE is in the enhanced coverage mode.

14. A method of handling coverage enhancement for a network of a wireless communication system, the method comprising:

transmitting a handover command including a random access configuration to a user equipment (UE) of the wireless communication system, wherein the random access configuration indicates the number of repetitions that the UE follows to transmit a random access preamble.

15. The method of claim 14, further comprising:

determining to include the random access configuration in the handover command when the network knows the UE is in an enhanced coverage mode.

16. The method of claim 14, wherein the UE determines whether the UE is in an enhanced coverage mode after the UE performs a handover according to the handover command.

17. The method of claim 14, wherein the UE receives repetitions of a physical broadcast channel transmission comprising a master information block (MIB) to decode the MIB and repetitions of a physical downlink shared channel transmission comprising a system information block (SIB) to decode the SIB after the UE performs a handover according to the handover command.

18. The method of claim 14, wherein the handover command comprises a T304 value which is large enough to cover a period of time during which the UE is able to transmit possible repetitions of the random access preamble.

19. The method of claim 14, further comprising:

transmitting a random access response with the number of repetitions in response to repetitions of the random access preamble.