METHOD AND SYSTEM FOR MANAGING TRANSMIT POWER ON A WIRELESS COMMUNICATION NETWORK

• US 20140018123A1
• Filed: 07/16/2012
• Published: 01/16/2014
• Est. Priority Date: 07/16/2012
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility LLC (Lenovo Group Ltd.)
• Inventors: Frank, Colin D., Krishnamurthy, Sandeep H., Brown, Tyler A.
• Granted Patent: US 8,868,123 B2
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04L 25/03821 Inter-carrier interference cancellation [ICI]
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 52/00 Power management, e.g. TPC [Transmission Power Control], power saving or power classes gain control in transmitters or power amplifiers H03G3/3042
• CPC Class Codes: H04W 52/10 Open loop power control
• CPC Class Codes: H04W 52/146 Uplink power control
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

The present disclosure sets forth multiple embodiments of the invention. Among those embodiments is a method for managing the power of an uplink signal (e.g., an LTE PUSCH or PUCCH). The method involves determining a convolution of a first function and a second function (which may be power density functions) of the uplink signal and determining the power of the uplink signal based on the convolution. The uplink signal comprises one or both of a data signal (transmitted over a PUSCH, for example) and a control signal (transmitted over a PUSCH or PUCCH, for example). The uplink signal is transmitted over one or more subcarriers (which may be carried by resource blocks, for example).

Claims

1. A method for managing the power of an uplink signal to be transmitted on a carrier, wherein the carrier has a carrier frequency the method comprising:

determining a convolution of a first function of S_Z(f) and a second function of S_Z(f), wherein S_Z(f) is the power spectral density of the uplink signal at frequency f and wherein the uplink signal comprises one or both of a data signal and a control signal to be carried by one or more subcarriers of the carrier;

estimating a power spectral density of the uplink signal over a range of frequencies based on the convolution;

determining a power of the uplink signal based on the estimated power spectral density of the uplink signal over a range of frequencies; and

transmitting the uplink signal over the one or more subcarriers.

2. The method of claim 1 wherein,

the range of frequencies includes the carrier frequency;

the first function is S_Z(f);

the second function is the convolution of S_Z(f) with S_Z(−

f).

3. The method of claim 1 wherein,

the range of frequencies includes the carrier frequency;

the first function is S_Z(−

f);

the second function is the convolution of S_Z(f) with S_Z(f).

4. The method of claim 1 wherein,

the range of frequencies includes a frequency that is three times the carrier frequency of the uplink signal;

the first function is S_Z(f);

the second function is the convolution of S_Z(f) with S_Z(f).

5. The method of claim 1 wherein,

the range of frequencies includes a frequency that is two times the carrier frequency of the uplink signal;

the first function is S_Z(f);

the second function is S_Z(f).

6. The method of claim 1, further comprising:

determining a power reduction of the uplink signal based on the estimated power spectral density of the uplink signal over the range of frequencies;

determining a maximum transmit power of the uplink signal based on the determined power reduction;

wherein determining a power of the uplink signal comprises determining the power of the uplink signal based on the determined maximum transmit power, and

wherein transmitting the uplink signal comprises transmitting the uplink signal at the determined power.

7. The method of claim 1, wherein determining a power of the uplink signal comprises:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers, wherein the first set of subcarriers is within an in-band frequency range for the uplink signal, wherein the first set of subcarriers are allocated to carry at least one of the data signal and the control signal;

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the second set of subcarriers is within the in-band frequency range, wherein the first set of subcarriers is not allocated to carry either the data signal or the control signal; and

determining a power reduction of the uplink signal based on a ratio of the determined first power and the determined second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

8. The method of claim 1, wherein determining a power of the uplink signal comprises:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers. wherein the first set of subcarrier is not in an in-band frequency range of the uplink signal, wherein the first set of subcarriers is are at frequencies that are adjacent to the in-band frequency range,

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the second set of subcarriers are within the in-band frequency range and that are allocated to carry at least one of the data signal and the control signal; and

determining a power reduction based on a ratio of the determined first power and the determined second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at the power that is based at least in part on the determined power reduction.

9. The method of claim 1, wherein determining a power of the uplink signal comprises:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers, wherein the frequencies of the first set of subcarriers are higher than or lower than frequencies of regions that are adjacent to an in-band region of the uplink signal;

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the frequencies of the second set of subcarriers are in the in-band region, wherein the second set of subcarriers are allocated to carry at least one of the data signal and the control signal; and

determining a power reduction based on a ratio of the first power and the second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

10. The method of claim 1, wherein determining a power of the uplink signal comprises:

calculating a first ratio, wherein the first ratio is the ratio of

the power spectral density of a set of subcarriers that are in a region that is in-band with respect to the uplink signal, and that are allocated to carry at least one of a data signal and a control signal, and

the power spectral density of a set of subcarriers that are in the in-band region, and that are allocated to carry neither a data signal nor a control signal;

calculating a second ratio, wherein the second ratio is the ratio of

the power spectral density of the set of subcarriers that are in the in-band region, and that are allocated to carry at least one of a data signal and a control signal;

the power spectral density of at least one of a first and a second frequency region that are out-of-band, wherein the first and the second frequency regions are adjacent to the in-band region, and wherein the first and the second frequency regions are at frequencies that are higher than or lower than the in-band region;

calculating a third ratio, wherein the third ratio is the ratio of

the power spectral density of the set of subcarriers that are in the in-band region, and that are allocated to carry at least one of a data signal and a control signal;

the power spectral density of at least one of a third and a fourth frequency region that are out-of-band and that are not in the first or second frequency regions, wherein the third and the fourth frequency regions are adjacent to the first and second frequency regions, and wherein the third and the fourth frequency regions are at frequencies that are higher than or lower than the first and second frequency regions;

determining a power reduction based on the first, second and third ratios;

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

11. The method of claim 1 wherein the uplink signal comprises a physical uplink shared channel (PUSCH).

12. The method of claim 1 wherein the uplink signal comprises a physical uplink control channel (PUCCH).

13. A wireless terminal for managing the power of an uplink signal to be transmitted on a carrier, wherein the carrier has a carrier frequency the wireless terminal comprising a controller that performs steps comprising:

determining a convolution of a first function of S_Z(f) and a second function of S_Z(f), wherein S_Z(f) is the power spectral density of the uplink signal at frequency f and wherein the uplink signal comprises one or both of a data signal and a control signal to be carried by one or more subcarriers of the carrier;

estimating a power spectral density of the uplink signal over a range of frequencies based on the convolution;

determining a power of the uplink signal based on the estimated power spectral density of the uplink signal over a range of frequencies; and

transmitting the uplink signal over the one or more subcarriers.

14. The wireless terminal of claim 13 wherein,

the range of frequencies includes the carrier frequency;

the first function is S_Z(f);

the second function is the convolution of S_Z(f) with S_Z(−

f).

15. The wireless terminal of claim 13 wherein,

the range of frequencies includes the carrier frequency;

the first function is S_Z(−

f);

the second function is the convolution of S_Z(f) with S_Z(f).

16. The wireless terminal of claim 13 wherein,

the range of frequencies includes a frequency that is three times the carrier frequency of the uplink signal;

the first function is S_Z(f);

the second function is the convolution of S_Z(f) with S_Z(f).

17. The wireless terminal of claim 13 wherein,

the range of frequencies includes a frequency that is two times the carrier frequency of the uplink signal;

the first function is S_Z(f);

the second function is S_Z(f).

18. The wireless terminal of claim 13, wherein the controller performs further steps comprising:

determining a power reduction of the uplink signal based on the estimated power spectral density of the uplink signal over the range of frequencies;

determining a maximum transmit power of the uplink signal based on the determined power reduction;

wherein determining a power of the uplink signal comprises determining the power of the uplink signal based on the determined maximum transmit power, and

wherein transmitting the uplink signal comprises transmitting the uplink signal at the determined power.

19. The wireless terminal of claim 13, wherein the controller performs the step of determining a power of the uplink signal by performed steps comprising:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers, wherein the first set of subcarriers is within an in-band frequency range for the uplink signal, wherein the first set of subcarriers are allocated to carry at least one of the data signal and the control signal;

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the second set of subcarriers is within the in-band frequency range, wherein the first set of subcarriers is not allocated to carry either the data signal or the control signal; and

determining a power reduction of the uplink signal based on a ratio of the determined first power and the determined second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

20. The wireless terminal of claim 13, wherein the controller performs the step of determining a power of the uplink signal by performing steps comprising:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers. wherein the first set of subcarrier isis not in an in-band frequency range of the uplink signal, wherein the first set of subcarriers is are at frequencies that are adjacent to the in-band frequency range,

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the second set of subcarriers are within the in-band frequency range and that are allocated to carry at least one of the data signal and the control signal; and

determining a power reduction based on a ratio of the determined first power and the determined second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at the power that is based at least in part on the determined power reduction.

21. The wireless terminal of claim 13, wherein the controller performs the step of determining a power of the uplink signal by performing steps comprising:

determining a first power based on the estimated power spectral density of the uplink signal over frequencies that include a first set of subcarriers, wherein the frequencies of the first set of subcarriers are higher than or lower than frequencies of regions that are adjacent to an in-band region of the uplink signal;

determining a second power based on the estimated power spectral density of the uplink signal over frequencies that include a second set of subcarriers, wherein the frequencies of the second set of subcarriers are in the in-band region, wherein the second set of subcarriers are allocated to carry at least one of the data signal and the control signal; and

determining a power reduction based on a ratio of the first power and the second power,

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

22. The wireless terminal of claim 13, wherein the controller performs the step of determining a power of the uplink signal by performing steps comprising:

calculating a first ratio, wherein the first ratio is the ratio of

the power spectral density of a set of subcarriers that are in a region that is in-band with respect to the uplink signal, and that are allocated to carry at least one of a data signal and a control signal, and

the power spectral density of a set of subcarriers that are in the in-band region, and that are allocated to carry neither a data signal nor a control signal;

calculating a second ratio, wherein the second ratio is the ratio of

the power spectral density of the set of subcarriers that are in the in-band region, and that are allocated to carry at least one of a data signal and a control signal;

the power spectral density of at least one of a first and a second frequency region that are out-of-band, wherein the first and the second frequency regions are adjacent to the in-band region, and wherein the first and the second frequency regions are at frequencies that are higher than or lower than the in-band region;

calculating a third ratio, wherein the third ratio is the ratio of

the power spectral density of the set of subcarriers that are in the in-band region, and that are allocated to carry at least one of a data signal and a control signal;

the power spectral density of at least one of a third and a fourth frequency region that are out-of-band and that are not in the first or second frequency regions, wherein the third and the fourth frequency regions are adjacent to the first and second frequency regions, and wherein the third and the fourth frequency regions are at frequencies that are higher than or lower than the first and second frequency regions;

determining a power reduction based on the first, second and third ratios;

wherein transmitting the uplink signal comprises transmitting the uplink signal at a power that is based at least in part on the determined power reduction.

23. The wireless terminal of claim 13, wherein the uplink signal comprises a physical uplink shared channel (PUSCH).

24. The wireless terminal of claim 13, wherein the uplink signal comprises a physical uplink control channel (PUCCH).