Methods and apparatus for determining, communicating and using information which can be used for interference control purposes

• US 20060083161A1
• Filed: 10/14/2005
• Published: 04/20/2006
• Est. Priority Date: 02/24/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Laroia, Rajiv, Li, Junyi, Rangan, Sundeep, Hande, Prashanth, Srinivasan, Murari
• Granted Patent: US 8,514,692 B2
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 1/7103 the interference being multiple access interference
• CPC Class Codes: H04B 17/24 with feedback of measurements to the transmitter
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

Methods and apparatus for collecting, measuring, reporting and/or using information which can be used for interference control purposes. Wireless terminals measure signals transmitted from one or more base stations, e.g., base station sector transmitters. The measured signals may be, e.g., beacon signals and/or pilot signals. From the measured signals, the wireless terminal generates one or more gain ratios which provide information about the relative gain of the communications channels from different base station sectors to the wireless terminal. This information represents interference information since it provides information about the signal interference that will be caused by transmissions from other base station sectors relative to transmissions made by the base station sector to which the wireless terminal is attached. Based on the signal energy measurements and relative gains generated from the energy measures, reports are generated in accordance with the invention and sent to one or more base stations.

Claims

1. A method of operating a wireless terminal comprising:

receive a first signal from a first base station with which the wireless terminal has a connection;

receive a second signal from a second base station;

measure the power of the first received signal;

measure the power of the second received signal; and

transmit a report indicating a ratio of a first value to a second value, the first and second values being a function of the measured power of the first received signal and the measured power of the second received signal, respectively.

2. The method of claim 1, wherein at least the first value different from, but determined from, the measured power of the first signal or wherein the second value is different from but determined from the measured power of the second signal.

3. The method of claim 1, wherein the first received signal is one of a beacon signal and a pilot signal received from the first base station.

4. The method of claim 3, wherein the second received signal is one of a beacon signal and a pilot signal received from the second base station, each of the first and second signals being single tone signals having a duration less than 3 OFDM symbol transmission time periods long.

5. The method of claim 4, wherein the second signal is a signal that was transmitted at a higher per tone power level than any user data transmitted during the duration of the second signal by the base station which transmitted said second signal.

6. The method of claim 1, wherein the first value is equal to the measured power of the first received signal.

7. The method of claim 6, wherein the second value is equal to the measured power of the second received signal.

8. The method of claim 1, wherein the first value is equal to the measured power of the first received signal multiplied by a gain factor where the gain factor is a function of the relative transmission power of the first and second signals.

9. The method of claim 1, wherein the second value is equal to the measured power of the second received signal multiplied by a gain factor where the gain factor is a function of the relative transmission power of the first and second signals.

10. The method of claim 1, wherein the first and second signals are reference signals, said reference signals being transmitted at a first and a second fixed power level, respectively, the method further comprising:

receiving one or more additional beacon signals form one or more additional base stations respectively,

measuring the power of the received one or more additional beacon signals;

wherein the method includes determining the second value from the measured power of the second signal and the measured power of the one or more additional beacon signals; and

wherein the first value is equal to measured power of the first signal.

11. The method of claim 8, wherein determining the second value includes:

setting said second value to the maximum of the measured power of the second signal and the one or more additional beacon signals.

12. The method of claim 10, wherein determining the second value includes:

setting said second value to the sum of the measured power of the second signal and the one or more additional beacon signals.

13. The method of claim 3, further comprising:

prior to receiving said first signal, receiving an additional beacon signal from said first base station;

measuring the power of the additional received beacon signal; and

wherein first value is a function of an average of the measured power of the first signal and the measured power of said additional received signal.

14. The method of claim 13, wherein the first value is equal to an average of the measured power of the first received signal and the measured power of said additional received signal multiplied by a gain factor where the gain factor is a function of the relative transmission power of the first and second signals.

15. The method of claim 13, further comprising,

prior to receiving said second signal, receiving a second additional beacon signal from said second base station;

measuring the power of the second additional received beacon signal; and

wherein second value is a function of an average of the measured power of the second signal and the measured power of said second additional received beacon signal.

16. A wireless terminal comprising:

a receiver module for receiving a first signal from a first base station with which the wireless terminal has a connection and a second signal from a second base station;

a power measurement module for the power of the first and second received signals; and

a report generation module for generating a report indicating a ratio of a first value to a second value, the first and second values being a function of the measured power of the first received signal and the measured power of the second received signal, respectively.

17. The wireless terminal of claim 16, wherein at least the first value different from, but determined from, the measured power of the first signal or wherein the second value is different from but determined from the measured power of the second signal.

18. The wireless terminal of claim 16, wherein the first received signal is one of a beacon signal and a pilot signal received from the first base station.

19. The wireless terminal of claim 18, wherein the second received signal is one of a beacon signal and a pilot signal received from the second base station, each of the first and second signals being single tone signals having a duration less than 3 OFDM symbol transmission time periods long.

20. The wireless terminal of claim 19, wherein the second signal is a signal that was transmitted at a higher per tone power level than any user data transmitted during the duration of the second signal by the base station which transmitted said second signal.

21. The wireless terminal of claim 16, wherein said report generation module sets the first value equal to the measured power of the first received signal.

22. The wireless terminal of claim 21, wherein the second value is equal to the measured power of the second received signal.

23. The wireless terminal of claim 16, wherein the first value is equal to the measured power of the first received signal multiplied by a gain factor where the gain factor is a function of the relative transmission power of the first and second signals.

24. The wireless terminal of claim 16, wherein the second value is equal to the measured power of the second received signal multiplied by a gain factor where the gain factor is a function of the relative transmission power of the first and second signals.