Prach transmission power adjustment

Patent metadata

Field	Value
Publication number	US-2016100434-A1
Application number	US-201514861749-A
Country	US
Kind code	A1
Filing date	Sep 22, 2015
Priority date	Oct 6, 2014
Publication date	Apr 7, 2016
Grant date	—

Abstract

In a first configuration, a UE may determine a PRACH power ramp-up P ramp-up for the PRACH with respect to a previously unsuccessful PRACH transmission (e.g., a previously unsuccessful PRACH transmission with a highest transmission power). In a second configuration, when the UE is in a power-limited scenario, the UE drops/refrains from transmitting the PRACH transmission if P ramp-up −P scal <P drop , and transmits the PRACH otherwise, where P scal is the power scaling factor, P ramp-up is the configured ramp-up power value, and P drop is a threshold. In a third configuration, the UE determines whether to increment a Preamble_Transmission_Counter. In one sub-configuration, the UE increments the Preamble_Transmission_Counter when the PRACH transmission takes place, and does not increment the Preamble_Transmission_Counter otherwise. In another sub-configuration, the UE increments the Preamble_Transmission_Counter when the PRACH transmission takes place and P ramp-up −P scal ≧P count , where P count is a threshold, and does not increment the Preamble_Transmission_Counter otherwise.

First claim

What is claimed is:

1 . A method of wireless communication, comprising:
determining to scale a transmission power for a physical random access channel (PRACH) transmission of a plurality of concurrent PRACH transmissions; determining whether to send the PRACH transmission based on the scaled transmission power; and sending the PRACH transmission at the scaled transmission power upon determining to send the PRACH transmission.

2 . The method of claim 1 , further comprising determining whether to increment a preamble transmission counter based at least on the determination of whether to send the PRACH transmission.

3 . The method of claim 1 , further comprising:
incrementing a preamble transmission counter upon determining to send the PRACH transmission; and refraining from incrementing the preamble transmission counter upon determining not to send the PRACH transmission.

4 . The method of claim 1 , further comprising determining whether to increment a preamble transmission counter based on the power ramping stepsize and the power scaling factor.

5 . The method of claim 4 , wherein the determining whether to increment the preamble transmission counter is based on a difference between the power ramping stepsize and the power scaling factor.

6 . The method of claim 5 , wherein the determining whether to increment the preamble transmission counter comprises determining to increment the preamble transmission counter when the PRACH transmission is determined to be sent and the difference between the power ramping stepsize and the power scaling factor is greater than or equal to a threshold.

7 . The method of claim 5 , wherein the determining whether to increment the preamble transmission counter comprises determining to refrain from incrementing the preamble transmission counter upon determining not to send the PRACH transmission or when the difference between the power ramping stepsize and the power scaling factor is less than a threshold.

8 . The method of claim 1 , wherein:
the determining to scale the transmission power for the PRACH transmission is based on a power scaling factor, the transmission power for the PRACH transmission is based on a power ramping stepsize and the power scaling factor, and the determining whether to send the PRACH transmission is based on the power ramping stepsize and the power scaling factor.

9 . The method of claim 8 , wherein the determining whether to send the PRACH transmission is based on a difference between the power ramping stepsize and the power scaling factor.

10 . The method of claim 9 , wherein the determining whether to send the PRACH transmission is based on whether the difference between the power ramping stepsize and the power scaling factor is greater than or equal to a threshold.

11 . The method of claim 10 , wherein the determining whether to send the PRACH transmission comprises determining to send the PRACH transmission when the difference between the power ramping stepsize and the power scaling factor is greater than or equal to the threshold.

12 . The method of claim 10 , wherein the determining whether to send the PRACH transmission comprises refraining from sending the PRACH transmission when the difference between the power ramping stepsize and the power scaling factor is less than the threshold.

13 . The method of claim 1 , further comprising:
determining a transmission power for another PRACH transmission based at least on the power ramping stepsize and a transmission power of a previously unsuccessful PRACH transmission; and sending said another PRACH transmission at the determined transmission power for said another PRACH transmission.

14 . The method of claim 13 , wherein the transmission power of the previously unsuccessful PRACH transmission is a highest transmission power of previously sent unsuccessful PRACH transmissions.

15 . The method of claim 13 , wherein the transmission power of the previously unsuccessful PRACH transmission is a transmission power of an immediately previous sent unsuccessful PRACH transmission.

16 . A method of wireless communication, further comprising:
determining a transmission power for a physical random access channel (PRACH) transmission based at least on a power ramping stepsize and a previously determined transmission power of a previously sent unsuccessful PRACH transmission; and sending the PRACH transmission at the determined transmission power.

17 . The method of claim 16 , wherein the transmission power of the previously sent unsuccessful PRACH transmission is a highest transmission power of previously sent unsuccessful PRACH transmissions.

18 . The method of claim 16 , wherein the transmission power of the previously sent unsuccessful PRACH transmission is a transmission power of an immediately previous sent unsuccessful PRACH transmission.

19 . An apparatus for wireless communication, comprising:
a memory; and at least one processor coupled to the memory and configured to: determine to scale a transmission power for a physical random access channel (PRACH) transmission of a plurality of concurrent PRACH transmissions; determine whether to send the PRACH transmission based on the scaled transmission power; and send the PRACH transmission at the scaled transmission power upon determining to send the PRACH transmission.

20 . The apparatus of claim 19 , wherein the at least one processor is further configured to determine whether to increment a preamble transmission counter based at least on the determination of whether to send the PRACH transmission.

21 . The apparatus of claim 19 , wherein the at least one processor is further configured to:
increment a preamble transmission counter upon determining to send the PRACH transmission; and refrain from incrementing the preamble transmission counter upon determining not to send the PRACH transmission.

22 . The apparatus of claim 19 , wherein the at least one processor is further configured to determine whether to increment a preamble transmission counter based on the power ramping stepsize and the power scaling factor.

23 . The apparatus of claim 22 , wherein the at least one processor is configured to determine whether to increment the preamble transmission counter based on a difference between the power ramping stepsize and the power scaling factor.

24 . The apparatus of claim 23 , wherein the at least one processor is configured to determine whether to increment the preamble transmission counter by determining to increment the preamble transmission counter when the PRACH transmission is determined to be sent and the difference between the power ramping stepsize and the power scaling factor is greater than or equal to a threshold.

25 . The apparatus of claim 23 , wherein the at least one processor is configured to determine whether to increment the preamble transmission counter by determining to refrain from incrementing the preamble transmission counter upon determining not to send the PRACH transmission or when the difference between the power ramping stepsize and the power scaling factor is less than a threshold.

26 . The apparatus of claim 19 , wherein the at least one processor is configured to determine to scale the transmission power for the PRACH transmission based on a power scaling factor, the transmission power for the PRACH transmission being based on a power ramping ste

Assignees

• Qualcomm Inc

Inventors

• Chen Wanshi
• Gaal Peter
• Damnjanovic Jelena

Classifications

• H04W52/362 Primary

  Aspects of the step size · CPC title

• H04W74/0866 Primary

  using a dedicated channel for access · CPC title

• H04W52/50

  at the moment of starting communication in a multiple access environment · CPC title

• H04W52/228

  using past power values or information · CPC title

• H04W52/146

  Uplink power control · CPC title