METHOD AND APPARATUS FOR IMPROVING RANDOM ACCESS PREAMBLE TRANSMISSION IN A WIRELESS COMMUNICATION SYSTEM

• US 20150036617A1
• Filed: 07/28/2014
• Published: 02/05/2015
• Est. Priority Date: 07/30/2013
• Status: Active Grant

• Current Assignee: Innovative Sonic Limited
• Original Assignee: Innovative Sonic Limited
• Inventors: Guo, Yu-Hsuan, Lin, Ko-Chiang
• Granted Patent: US 10,813,131 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/38 TPC being performed in particular situations
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

Methods and apparatuses are disclosed for improving Random Access preamble transmission in a wireless communication system. The method includes receiving a configuration of an initial power and a power ramping step for a preamble transmission. The method also includes transmitting a first Preamble using a first power based on at least the initial power and the power ramping step, wherein the first Preamble is the last preamble transmission of a first Random Access procedure. The method includes determining whether the first Random Access procedure is successfully completed. The method also includes transmitting a second Preamble using a second power based on at least the first power, wherein the second Preamble is the first preamble transmission of a second Random Access procedure.

Claims

1. A method for a device to improve Random Access preamble transmission, the method comprising:

receiving a configuration of an initial power and a power ramping step for a preamble transmission;

transmitting a first Preamble using a first power based on at least the initial power and the power ramping step, wherein the first Preamble is the last preamble transmission of a first Random Access procedure;

determining whether the first Random Access procedure is successfully completed; and

transmitting a second Preamble using a second power based on at least the first power, wherein the second Preamble is the first preamble transmission of a second Random Access procedure.

2. The method of claim 1, wherein the second power is the same as the first power.

3. The method of claim 1, wherein the second power is calculated based on the first power.

4. The method of claim 1, wherein a location of the device and the configuration are not changed between the first Random Access procedure and the second Random Access procedure.

5. The method of claim 1, wherein the second power is used for the transmission of all preambles in the second Random Access procedure.

6. The method of claim 1, further comprising:

transmitting a third Preamble using a third power based on at least the second power and a power ramping step, wherein the third Preamble is not the first Preamble transmission of the second Random Access procedure.

7. The method of claim 1, further comprising:

transmitting a fourth Preamble using a fourth power based on at least an initial power if the second Random Access procedure was not successfully completed, wherein the fourth Preamble is the first preamble transmission of a third Random Access procedure.

8. A method for a device to improve Random Access preamble transmission, the method comprising:

having at least two different power ramping steps including a first power ramping step and a second power ramping step for preamble transmission, wherein the second power ramping step is larger than the first power ramping step; and

choosing one of the at least two different power ramping steps to be used to calculate transmission power for a Preamble of a Random Access procedure, wherein the choice is based on at least a cause triggering the Random Access procedure.

9. The method of claim 8, wherein the second power ramping step is chosen to calculate the transmission power for the Preamble when the cause is an emergency call or high priority access.

10. The method of claim 8, wherein the first power ramping step is chosen to calculate the transmission power for the Preamble when the cause is a mobile terminating call, mobile terminating access, mobile originating call, mobile originating signaling, mobile originating CS fallback, mobile originating data, or delay tolerant access.

11. The method of claim 8, wherein the first power ramping step is configured by a network via system information.

12. The method of claim 8, wherein the second power ramping step is configured by a network via system information or via dedicated signaling.

13. The method of claim 8, wherein the second power ramping step is a fixed value or calculated based on the first power ramping step.

14. The method of claim 8, wherein allowing the use of the second power ramping step is controlled by an indication provided by a network.

15. A communication device for improving Random Access preamble transmission in a wireless communication system, the communication device comprising:

a control circuit;

a processor installed in the control circuit;

a memory installed in the control circuit and operatively coupled to the processor, the memory having stored therein at least two different power ramping steps including a first power ramping step and a second power ramping step for preamble transmission,

wherein the second power ramping step is larger than the first power ramping step;

wherein the processor is configured to execute a program code stored in the memory to improve Random Access preamble transmission in a wireless communication system by;

choosing one of the at least two different power ramping steps to be used to calculate transmission power for a Preamble of a Random Access procedure, wherein the choice is based on at least a cause triggering the Random Access procedure.

16. The communication device of claim 15, wherein the second power ramping step is chosen to calculate the transmission power for the Preamble when the cause is an emergency call or high priority access.

17. The communication device of claim 15, wherein the first power ramping step is chosen to calculate the transmission power for the Preamble when the cause is a mobile terminating call, mobile terminating access, mobile originating call, mobile originating signaling, mobile originating CS fallback, mobile originating data, or delay tolerant access.

18. The communication device of claim 15, wherein the first power ramping step is configured by a network via system information.

19. The communication device of claim 15, wherein the second power ramping step is configured by a network via system information or via dedicated signaling.

20. The communication device of claim 15, wherein the second power ramping step is a fixed value or calculated based on the first power ramping step.