Apparatus for controlling signal-transmission power, mobile station, method of controlling signal-transmission power, and program

• US 8,554,263 B2
• Filed: 08/10/2012
• Issued: 10/08/2013
• Est. Priority Date: 03/15/2006
• Status: Expired due to Fees

• Current Assignee: Lenovo Innovations Ltd Hong Kong (Lenovo Group Ltd.)
• Original Assignee: NEC Corporation
• Inventors: Murata, Yoshitaka
• Primary Examiner(s): Rego, Dominic E
• Application Number:
  US13/572,309
• Publication Number:
  US 20120307664A1
• Time in Patent Office: 424 Days
• Field of Search: 455/522, 455/67.11, 455 68- 70, 455/115.3, 455/126, 455/127.1, 455/127.2, 455/135, 455/226.3, 455/277.2, 455/296, 370/318
• US Class Current: 455/522
• CPC Class Codes: H04B 2201/70706 with means for reducing the peak-to-average power ratio
• CPC Class Codes: H04W 52/22 taking into account previous information or commands
• CPC Class Codes: H04W 52/225 Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/226 using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]
• 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

Abstract

The peak-index calculator calculates a peak index as an indication of PAR in accordance with gain factors β of channels. The coefficient selector includes a lookup table storing therein fitting coefficients X and Y each categorized in accordance with a combination of β, and selects coefficients X and Y each having a value determined in accordance with a combination of the gain factors β. The power-reduction calculator calculates a reduction in maximum signal-transmission power in accordance with both the peak index and the selected coefficients X and Y. The TXAGC calculator controls maximum signal-transmission power in accordance with the calculated reduction.

Claims

1. A signal-transmission power-controlling apparatus for controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, comprising:

a reduction-calculator for calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controller for controlling said maximum signal-transmission power in accordance with said reduction calculated by said reduction-calculator,

wherein said reduction-calculator includes a peak-index calculator which selects, as an average power indication, a square root of a sum of squares of each of said value to determine an amplitude, and, as a peak power indication, a square root of a sum of (a) square of a sum of gain factors of channels assigned to I-phase among said gain factors, and (b) square of a sum of gain factors of channels assigned to Q-phase among said factors, and calculates, as said peak index, a ratio between said peak power indication and said average power indication.

2. A signal-transmission power controlling apparatus for controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, comprising:

a reduction-calculator for calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controller for controlling said maximum signal-transmission power in accordance with said reduction calculated by said reduction-calculator,

wherein said reduction-calculator calculates said reduction in accordance with an equation;

Reduction=Y×

(20×

log₁₀(C))^X

where C indicates said peak index, and each of X and Y indicates said coefficient.

3. A mobile station, comprising:

a signal-transmission power controlling apparatus for controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, including;

a reduction-calculator for calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controller for controlling said maximum signal-transmission power in accordance with said reduction calculated by said reduction-calculator;

wherein said reduction-calculator includes a peak-index calculator which selects, as an average power indication, a square root of a sum of squares of each of said value to determine an amplitude, and, as a peak power indication, a square root of a sum of (a) square of a sum of gain factors of channels assigned to I-phase among said gain factors, and (b) square of a sum of gain factors of channels assigned to Q-phase among said factors, and calculates, as said peak index, a ratio between said peak power indication and said average power indication.

4. A mobile station, comprising:

including a signal-transmission power controlling apparatus for controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, comprising;

a reduction-calculator for calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controller for controlling said maximum signal-transmission power in accordance with said reduction calculated by said reduction-calculator,

wherein said reduction-calculator calculates said reduction in accordance with an equation;

Reduction=Y×

(20×

log₁₀(C))^X

where C indicates said peak index, and each of X and Y indicates said coefficient.

5. A method of controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, comprising:

a reduction-calculating step of calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controlling step of controlling said maximum signal-transmission power in accordance with said reduction calculated in said reduction-calculating step;

wherein said reduction-calculating step includes a step of selecting, as an average power indication, a square root of a sum of squares of each of said value to determine an amplitude, and, as a peak power indication, a square root of a sum of (a) square of a sum of gain factors of channels assigned to I-phase among said gain factors, and (b) square of a sum of gain factors of channels assigned to Q-phase among said factors, and calculating, as said peak index, a ratio between said peak power indication and said average power indication.

6. A method of controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, comprising:

a reduction-calculating step of calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controlling step of controlling said maximum signal-transmission power in accordance with said reduction calculated in said reduction-calculating step;

wherein said reduction-calculating step includes a step of calculating said reduction in accordance with an equation;

Reduction=Y×

(20×

log₁₀(C))^X

where C indicates said peak index, and each of X and Y indicates said coefficient.

7. A non-transitory computer-readable storage medium storing therein a program for causing a computer to carry out a method of controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, steps executed by said computer in accordance with said program, including:

a reduction-calculating step of calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controlling step of controlling said maximum signal-transmission power in accordance with said reduction calculated in said reduction-calculating step;

wherein said reduction-calculating step includes a step of selecting, as an average power indication, a square root of a sum of squares of each of said value to determine an amplitude, and, as a peak power indication, a square root of a sum of (a) square of a sum of gain factors of channels assigned to I-phase among said gain factors, and (b) square of a sum of gain factors of channels assigned to Q-phase among said factors, and calculating, as said peak index, a ratio between said peak power indication and said average power indication.

8. A non-transitory computer-readable storage medium storing therein a program for causing a computer to carry out a method of controlling maximum signal-transmission power among power for transmitting a plurality of signals multiplexed with one another, steps executed by said computer in accordance with said program, including:

a reduction-calculating step of calculating a reduction in said maximum signal-transmission power in accordance with a peak index and a coefficient, said peak index being calculated based on a value to determine an amplitude of each of said signals, said peak index providing an indication of a ratio between peak power and average power in a signal to be transmitted, said coefficient being predetermined in accordance with a combination of said the value to determine an amplitude; and

a controlling step of controlling said maximum signal-transmission power in accordance with said reduction calculated in said reduction-calculating step;

wherein said reduction-calculating step includes a step of calculating said reduction in accordance with an equation;

Reduction=Y×

(20×

log₁₀(C))^X

where C indicates said peak index, and each of X and Y indicates said coefficient.