DISTORTION COMPENSATOR APPARATUS, AMPLIFIER APPARATUS, TRANSMITTER, AND METHOD OF COMPENSATING DISTORTION

• US 20090195309A1
• Filed: 05/29/2007
• Published: 08/06/2009
• Est. Priority Date: 06/08/2006
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yamaoka, Atsushi, Yamaguchi, Keiichi
• Granted Patent: US 8,204,454 B2
• Time in Patent Office: Days
• US Class Current: 330/149
• CPC Class Codes: H03F 1/3288 to compensate phase shift as a function of the amplitude
• CPC Class Codes: H03F 1/3294 Acting on the real and imaginary components of the input signal
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2201/3233 Adaptive predistortion using lookup table, e.g. memory, RAM, ROM, LUT, to generate the predistortion

Abstract

This distortion compensator apparatus is a distortion compensator apparatus compensating nonlinearity of an amplifier and includes: a memory storing a compensation parameter used for correcting an input signal of the amplifier; a compensator correcting the input signal of the amplifier based on the compensation parameter; and an update controller updating the compensation parameter according to an operation state of the amplifier.

Claims

1. A distortion compensator apparatus compensating nonlinearity of an amplifier, comprising:

a memory storing a compensation parameter used for correcting an input signal of the amplifier;

a compensator correcting the input signal of the amplifier based on the compensation parameter; and

an update controller updating the compensation parameter according to an operation state of the amplifier.

2. The distortion compensator apparatus according to claim 1,

wherein said memory stores a first parameter used for correcting an amplitude component of the input signal and a second parameter used for correcting a phase component of the input signal,

wherein said compensator corrects the amplitude component and the phase component of the input signal based on the first and second parameters, and

wherein said update controller updates the first and second parameters.

3. The distortion compensator apparatus according to claim 2, wherein said compensator comprises:

a first amplitude calculator calculating an amplitude value of the input signal;

a real multiplier performing real multiplication processing on the first parameter stored in said memory and the input signal, based on the amplitude value calculated by said first amplitude calculator;

a second amplitude calculator calculating an amplitude value of a signal resulting from the real multiplication processing; and

a complex multiplier performing complex multiplication processing on the second parameter stored in said memory and the signal resulting from the real multiplication processing, based on the amplitude value calculated by said second amplitude calculator.

4. The distortion compensator apparatus according to claim 1, further comprising a monitor signal generator generating a monitor signal indicating a characteristic of the amplifier by monitoring the operation state of the amplifier,

wherein said update controller updates the compensation parameter based on the monitor signal.

5. The distortion compensator apparatus according to claim 4, wherein said monitor signal generator generates the monitor signal indicating at least one of output power of the amplifier, an adjacent channel leakage ratio of the amplifier, a gain occurring on a preceding stage of the amplifier, a phase difference occurring on the preceding stage of the amplifier, temperature of the amplifier, and a frequency of the input signal.

6. The distortion compensator apparatus according to claim 1, further comprising a timer outputting a timing signal indicating a timing for updating the compensation parameter, and

wherein said update controller updates the compensation parameter based on the timing signal outputted by said timer.

7. An amplifier apparatus comprising:

an amplifier;

a memory storing a compensation parameter used for correcting an input signal of said amplifier in order to compensate nonlinearity of said amplifier;

a compensator correcting the input signal of said amplifier based on the compensation parameter; and

an update controller updating the compensation parameter according to an operation state of said amplifier.

8. The amplifier apparatus according to claim 7 further comprising a monitor signal generator generating a monitor signal indicating a characteristic of said amplifier by monitoring the operation state of said amplifier,

wherein said update controller updates the compensation parameter based on the monitor signal.

9. A transmitter, comprising:

the amplifier apparatus according to claim 7; and

a modulator modulating the input signal corrected by said compensator to input the modulated input signal to said amplifier.

10. A method of compensating distortion for compensating nonlinearity of an amplifier, comprising:

storing in a memory a compensation parameter used for correcting an input signal of the amplifier;

correcting the input signal of the amplifier based on the compensation parameter; and

updating the compensation parameter according to an operation state of the amplifier.