Signal measurement on component carriers in wireless communication systems

• US 8,666,321 B2
• Filed: 02/21/2011
• Issued: 03/04/2014
• Est. Priority Date: 02/21/2011
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Narasimha, Murali, Krishnamurthy, Sandeep H., Kuchibhotla, Ravi
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Mathew, Max
• Application Number:
  US13/031,401
• Publication Number:
  US 20120214541A1
• Time in Patent Office: 1,107 Days
• Field of Search: 455/436, 455/442, 455/507, 455/521, 455/524, 455/525
• US Class Current: 455/67.11
• CPC Class Codes: H04L 25/0202 Channel estimation
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 36/38 by fixed network equipment

Abstract

A method in a wireless communication terminal including generating a first averaged signal measurement on a first carrier frequency, wherein the first averaged signal measurement is based on a first averaging period, 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, wherein the second averaged signal measurement is based on a second averaging period, 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, wherein the first weight is less than the second weight if the second averaging period is greater than a threshold.

Claims

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

generating a first averaged signal measurement on a first carrier frequency, wherein the first averaged signal measurement is based on a first averaging period;

producing a first filter output based on the first averaged signal measurement weighted by a first weight, wherein the first weight is based on a parameter received from a base station;

generating a second averaged signal measurement on the first carrier frequency, wherein the second averaged signal measurement is based on a second averaging period; 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;

wherein the first weight is different from the second weight if the second averaging period is greater than a threshold.

2. The method of claim 1 wherein the first weight is less than the second weight if the second averaging period is greater than the threshold.

3. The method of claim 1 further comprising producing a third filter output subsequent to producing the second filter output wherein the third filter output is based on the first weight.

4. The method of claim 1 further comprising reporting the second filter output to a serving base station.

5. The method of claim 3, receiving a handover command from the serving base station in response to the reporting.

6. The method of claim 4 further comprising handing over to a second base station serving a different coverage area than the serving base station in response to receiving the handover command.

7. The method of claim 5, wherein a first serving cell on the first carrier frequency is a deactivated serving cell, the method further comprising configuring the first serving cell as a primary serving cell in response to receiving the handover command.

8. The method of claim 1 further comprising:

producing the first filter output by using a first filter coefficient;

producing the second filter output using a second filter coefficient if the second averaging period is greater than the threshold,

wherein the second filter coefficient is different than the first filter coefficient.

9. The method of claim 1 wherein the second filter coefficient has a value that negates the first filter output component of the second filter output.

10. The method of claim 8,

wherein the first averaged signal measurement and the second averaged signal measurement are averaged layer 1 signal measurements, and

wherein the first filter output and the second filter output are layer 3 filtered measurements.

11. The method of claim 1, wherein the first filter output and second filter output are infinite impulse response filter outputs.

12. The method of claim 1, wherein the wireless communication terminal is configured for carrier aggregation, and wherein the first carrier frequency is a deactivated carrier.

13. The method of claim 1 further comprising receiving a message ordering the terminal to perform the signal measurements on the first carrier frequency using the second averaging period.