Propagation delay based transmit power control

• US 20080039128A1
• Filed: 08/09/2006
• Published: 02/14/2008
• Est. Priority Date: 08/09/2006
• Status: Abandoned Application

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Pettersson, Jan, Ostman, Leif Thomas
• Application Number:
  US11/501,242
• Publication Number:
  US 20080039128A1
• Time in Patent Office: Days
• US Class Current: 455/522
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/22 taking into account previous information or commands
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/54 Signalisation aspects of the TPC commands, e.g. frame structure

Abstract

The transmit power of a radio transmitter associated with a transmitting node communicating with a receiving node is controlled based on a propagation delay time associated with communication between the transmitting node and the receiving node. A power control loop is established for controlling a transmission power level for transmitting a signal from the transmitting node to the receiving node. A response time of the power control loop is reduced based on the propagation delay time.

Claims

1. A method for use in controlling transmit power of a radio transmitter associated with a transmitting node communicating with a receiving node, comprising:

transmitting a signal from the transmitting node to the receiving node at a transmission power level controlled by a power control loop;

determining a propagation delay time associated with communication between the transmitting node and the receiving node; and

reducing a response time of the power control loop based on the propagation delay time.

2. The method in claim 1, further comprising:

determining an adjustment value based on the propagation delay time, and

reducing the response time of the power control loop by adjusting the transmission power level using the adjustment value.

3. The method in claim 1, further comprising:

determining an adjustment time based on the propagation delay time, and

reducing the response time of the power control loop by adjusting the transmission power level at the adjustment time.

4. The method in claim 1, wherein the reducing step includes adjusting the transmission power level by an adjustment value no faster than the propagation delay time.

5. The method in claim 1, wherein the reducing step includes adjusting the transmission power level by an adjustment value substantially at or near the end of the propagation delay time.

6. The method claim 1, further comprising:

determining a number of timeslots associated with the propagation delay time; and

wherein the reducing step includes making a cumulative adjustment of the transmission power level over the number of timeslots.

7. The method in claim 6, wherein power adjustments are made incrementally with one of a power increase increment or a power decrease increment implemented each timeslot, the method further comprising:

reducing a size of one or both of the power increase increment and the power decrease increment.

8. The method in claim 6, wherein power adjustments are made incrementally with one of a power increase increment or a power decrease increment implemented each timeslot, the method further comprising:

determining a pattern of power increase and decrease increments that produces a net incremental power adjustment corresponding to the cumulative adjustment by the end of the number of timeslots.

9. The method in claim 6, wherein power adjustments associated with corresponding Transmit Power Control (TPC) commands are made incrementally in accordance with one of a power increase increment or a power decrease increment implemented each timeslot, and wherein the number of timeslots, x, corresponding to the propagation delay is a positive odd integer greater than one, the method further comprising:

generating a sequence of x−

1 power increase and decrease increments for x−

1 timeslots that cumulatively does not result in a net power increase or decrease, and

generating for the xth timeslot a power increment corresponding to the adjustment value.

10. The method in claim 6, wherein power adjustments associated with corresponding Transmit Power Control (TPC) commands are made incrementally with one of a power increase increment or a power decrease increment implemented each timeslot, and wherein the number of timeslots, x, corresponding to the propagation delay is a positive even integer, the method further comprising:

storing a first set of x TPC commands corresponding to a first set of x timeslots;

storing a second set of x TPC commands corresponding to a second set of x timeslots; and

generating a sequence of power increase and decrease increments for the 2x timeslots based on the first and second sets of TPC commands to implement the cumulative adjustment per x timeslots.

11. The method in claim 1, wherein the power control loop includes making power adjustments incrementally with one of a power increase increment or a power decrease increment implemented each timeslot, the method further comprising:

detecting that the propagation delay exceeds a predetermined threshold, and

in response, the reducing step includes making incremental power adjustments less frequently than every timeslot.

12. The method in clam 1 implemented in a radio base station.

13. The method in clam 1 implemented in a mobile station.

14. Apparatus in a transmitting node, comprising:

a transmitter for transmitting a signal from the transmitting node to the receiving node at a transmission power level controlled by a power control loop;

electronic circuitry configured to;

determine a propagation delay time associated with communication between the transmitting node and the receiving node, and

reduce a response time of the power control loop based on the propagation delay time.

15. The apparatus in claim 14, wherein the electronic circuitry is configured to:

determine an adjustment value based on the propagation delay time, and

reducing the response time of the power control loop by adjusting the transmission power level using the adjustment value.

16. The apparatus in claim 14, wherein the electronic circuitry is configured to:

determine an adjustment time based on the propagation delay time, and

reduce the response time of the power control loop by adjusting the transmission power level at the adjustment time.

17. The apparatus in claim 14, wherein the electronic circuitry is configured to adjust the transmission power level by an adjustment value no faster than the propagation delay time.

18. The apparatus in claim 14, wherein the electronic circuitry is configured to adjust the transmission power level by an adjustment value substantially at or near the end of the propagation delay time.

19. The apparatus in claim 14, wherein the electronic circuitry is configured to:

determine a number of timeslots associated with the propagation delay time; and

make a cumulative adjustment of the transmission power level over the number of timeslots.

20. The apparatus in claim 19, wherein the electronic circuitry is configured to:

make power adjustments incrementally with one of a power increase increment or a power decrease increment implemented each timeslot; and

reduce a size of one or both of the power increase increment and the power decrease increment.

21. The apparatus in claim 19, wherein the electronic circuitry is configured to:

make power adjustments incrementally with one of a power increase increment or a power decrease increment implemented each timeslot;

determine a pattern of power increase and decrease increments that will produce a net incremental power adjustment corresponding to the cumulative adjustment by the end of the number of timeslots; and

use the determined pattern to reduce a response time of the power control loop based on the propagation delay time.

22. The apparatus in claim 19, wherein the electronic circuitry is configured to:

make incremental power adjustments associated with corresponding Transmit Power Control (TPC) commands in accordance with one of a power increase increment or a power decrease increment implemented each timeslot,

wherein the number of timeslots, x, corresponding to the propagation delay is a positive odd integer greater than one, the electronic circuitry being further configured to;

generating a sequence of x−

1 power increase and decrease increments for x−

1 timeslots that cumulatively does not result in a net power increase or decrease, and

generate for the xth timeslot a power increment corresponding to the adjustment value.

23. The apparatus in claim 19, wherein the electronic circuitry is configured to:

make incremental power adjustments associated with corresponding Transmit Power Control (TPC) commands with one of a power increase increment or a power decrease increment implemented each timeslot, wherein the number of timeslots, x, corresponding to the propagation delay is a positive even integer;

store a first set of x TPC commands corresponding to a first set of x timeslots;

store a second set of x TPC commands corresponding to a second set of x timeslots; and

generate a sequence of power increase and decrease increments for the 2x timeslots based on the first and second sets of TPC commands to implement the cumulative adjustment per x timeslots.

24. The apparatus in claim 14, wherein the electronic circuitry is configured to:

make incremental making power adjustments with one of a power increase increment or a power decrease increment implemented each timeslot;

detect that the propagation delay exceeds a predetermined threshold, and

in response, the reducing step includes making incremental power adjustments less frequently than every timeslot.

25. The apparatus in claim 14 implemented in a radio base station.

26. The apparatus in claim 14 implemented in a mobile station.