Signal measurement on component carriers in wireless communication systems

• US 9,319,914 B2
• Filed: 05/02/2013
• Issued: 04/19/2016
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Inventors: Narasimha, Murali, Krishnamurthy, Sandeep H., Kuchibhotla, Ravi
• Primary Examiner(s): LEE, JUSTIN YE
• Application Number:
  US13/875,462
• Publication Number:
  US 20130242789A1
• Time in Patent Office: 1,083 Days
• Field of Search: 455/438, 370/252
• US Class Current: 1/1
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/302 due to low signal strength

Abstract

A method in a wireless communication device includes performing measurements of a first serving cell on a first carrier frequency at a first rate, determining whether a signal level of a second serving cell on a second carrier frequency exceeds a threshold, and performing measurements of the first serving cell at a second rate if the signal level of the second serving cell is below the threshold, wherein the second rate is higher than the first rate.

Claims

1. A method in a wireless communication device, the method comprising:

measuring a signal of a primary serving cell carrier signal;

measuring a signal of a deactivated component carrier of a secondary serving cell at a first rate;

determining a difference between the primary serving cell carrier signal and a neighboring cell carrier signal;

if the determined difference between the primary serving cell carrier signal and the neighboring cell carrier signal is higher than a threshold value, measuring the signal of the deactivated secondary component carrier of the secondary serving cell at a second rate, the second rate being higher than the first rate;

receiving a measurement reporting offset from a base station; and

if the determined difference is higher than the measurement reporting offset, reporting the measured signal to the base station.

2. The method of claim 1 further comprising receiving, in response to the reporting step, a handover command from the base station.

3. The method of claim 2 wherein the handover command is a command for the wireless communication device to handover from the primary serving cell to the neighboring cell.

4. The method of claim 2:

wherein the secondary cell becomes activated; and

wherein the handover command is a command for the wireless communication device to handover from the primary serving cell to the activated secondary serving cell.

5. The method of claim 1 further comprising:

determining, based on the measured deactivated secondary component carrier signal, that the wireless communication device should handover from the primary serving cell; and

performing a handover from the primary serving cell based on the handover determination.

6. The method of claim 1, wherein the signal of the primary serving cell carrier signal is measured by:

generating a first averaged signal measurement on a first carrier frequency;

producing a first filter output based on the first averaged signal measurement weighted by a first weight;

generating a second averaged signal measurement on the first carrier frequency; and

producing a second filter output based on the first filter output and based on the second averaged signal measurement weighted by a second weight.

7. The method of claim 6, wherein the first averaged signal measurement is based on a first averaging period, the second averaged signal measurement is based on a second averaging period, and the first weight is less than the second weight if the second averaging period is greater than a threshold.

8. The method of claim 1, wherein the primary serving cell and the secondary serving cell are provided by a same base unit.

9. The method of claim 1 wherein the measured signal is reported to the base station at the second rate when the determined difference is higher than the measurement reporting offset.