Power level convergence in a communications system

• US 6,718,180 B1
• Filed: 10/24/2000
• Issued: 04/06/2004
• Est. Priority Date: 10/24/2000
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Almgren, Magnus, Lundh, Peter
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): NGUYEN, DAVID Q
• Application Number:
  US09/696,334
• Time in Patent Office: 1,260 Days
• Field of Search: 455/522, 455/127, 455/69, 370/342
• US Class Current: 455/522
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

Methods, systems, and arrangements enable balanced base station transmitter output power levels with respect to a receiving mobile station in a macro-diversity communication by adjusting a base station transmitter output power level responsive to power control command(s) sent by the mobile station and the (current) transmitter output power level of the base station. In a fixed adjustment step embodiment, power level convergence is enabled by adjusting the transmitter output power level of a given base station by a greater amount (e.g., than the nominal amount) when a power control command orders a power adjustment of the transmitter output power level towards a reference level and by adjusting the transmitter output power level by a lesser amount when a power control command orders a power adjustment of the is transmitter output power level away from the reference level. A continuous adjustment step embodiment is also disclosed.

Claims

1. A method for adjusting power in a base station, comprising the steps of:

receiving a power instruction from a mobile station that is engaged in a macro-diversity communication with the base station;

ascertaining a current power of the base station;

determining a power adjustment amount responsive to the power instruction from the mobile station that is engaged in the macro-diversity communication with the base station and the current power of the base station; and

adjusting the current power of the base station based on the power adjustment amount,

wherein said step of determining a power adjustment amount responsive to the power instruction and the current power of the base station comprises the steps of;

comparing the current power of the base station to a predetermined threshold; and

setting the power adjustment amount equal to a first amount that is less than a first nominal amount if the power instruction corresponds to an increase command and the current power of the base station is greater than the predetermined threshold;

setting the power adjustment amount equal to a second amount that is greater than a second nominal amount if the power instruction corresponds to an increase command and the current power of the base station is not greater than the predetermined threshold;

setting the power adjustment amount equal to a third amount that is less than a third nominal amount if the power instruction corresponds to a decrease command and the current power of the base station is less than the predetermined threshold;

or

setting the power adjustment amount equal to a fourth amount that is greater than a fourth nominal amount if the power instruction corresponds to a decrease command and the current power of the base station is not less than the predetermined threshold.

2. The method according to claim 1, wherein said step of receiving a power instruction comprises the step of receiving a transmission output power command.

3. The method according to claim 2, wherein said step of receiving a transmission output power command comprises the step of receiving at least one transmission power control (TPC) command bit.

4. The method according to claim 1, wherein said step of ascertaining a current power of the base station comprises the step of ascertaining a current transmission output power level of the base station.

5. The method according to claim 1, wherein said step of determining a power adjustment amount responsive to the power instruction and the current power of the base station comprises the step of determining a fixed power adjustment step responsive to the power instruction and the current power of the base station.

6. The method according to claim 1, wherein said step of determining a power adjustment amount responsive to the power instruction and the current power of the base station comprises the step of determining a continuous power adjustment step responsive to the power instruction and the current power of the base station.

7. The method according to claim 1, wherein said step of adjusting the currant power of the base station based on the power adjustment amount comprises the step of at least one of decreasing or increasing the current power of the base station by the power adjustment amount in accordance with the power instruction.

8. The method according to claim 1, wherein said step of determining a power adjustment amount responsive to the power instruction and the current power of the base station comprises the step of determining the power adjustment step based, at least partly, on at least one of an active set of a mobile station, a mean value, a parameter of a wireless communications system of the base station, and a weather or services-related condition.

9. The method according to claim 1, wherein respective absolute values of the first, second, third, and fourth nominal amounts are equal.

10. The method according to claim 1, wherein said step of determining a power adjustment amount responsive to the power instruction and the current power of the base station comprises the step of applying information from the power instruction and the current power of the base station to at least one function to extract the power adjustment amount.

11. The method according to claim 10, wherein the at least one function comprises at least one continuous, smoothly varying function.