Modulated signal generating device and wireless device

• US 9,590,829 B2
• Filed: 10/14/2015
• Issued: 03/07/2017
• Est. Priority Date: 02/02/2015
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Egashira, Yoshimasa, Yamaguchi, Keiichi
• Primary Examiner(s): Aghdam, Freshteh N
• Application Number:
  US14/882,745
• Publication Number:
  US 20160226685A1
• Time in Patent Office: 510 Days
• Field of Search: 375/295, 375/297
• US Class Current: 1/1
• CPC Class Codes: H03C 1/00 Amplitude modulation H03C5/00, H03C7/00 take precedence
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04L 27/04 Modulator circuits; Transmitter circuits

Abstract

According to an embodiment, the modulated signal generating device modulates an input signal and generates an output signal. The modulated signal generating device includes a plurality of amplifiers, a combiner, a determining unit and a control signal generating unit. The plurality of amplifiers connects in parallel with one another and each configures to drive based on a control signal and to generate amplified signals. The combiner configures to combine the amplified signals and to obtain the output signal having a stepwise waveform. The determining unit configures to determine number of amplifiers to be driven based on a value of the input signal in a period shorter than a period of the input signal. The control signal generating unit configures to select zero or more amplifiers to be driven from among the amplifiers, based on the number of amplifiers determined by the determining unit, the value of the input signal, and a fluctuation in the value of the input signal, and to generate the control signal for driving the selected amplifier.

Claims

1. A modulated signal generating device that modulates an input signal and generates an output signal, the modulated signal generating device comprising:

a plurality of amplifiers connected in parallel with one another and each configured to drive based on a control signal and to generate amplified signals;

a combiner configured to combine the amplified signals and to obtain the output signal having a stepwise waveform;

a determining unit configured to determine a number of amplifiers to be driven based on a value of the input signal every period shorter than a period of the input signal; and

a control signal generating unit configured to select zero or more amplifiers to be driven from among the amplifiers, based on the number of amplifiers determined by the determining unit, the value of the input signal, and a fluctuation in the value of the input signal, and to generate the control signal for driving the selected amplifier.

2. The modulated signal generating device according to claim 1, further comprising:

a differential calculation unit configured to calculate a differential value of the input signal, wherein

the control signal generating unit selects the amplifier to be driven based on a priority corresponding to a combination of a sign of the value and a sign of the differential value of the input signal.

3. The modulated signal generating device according to claim 2, wherein a priority corresponding to the combination with the differential value in a plus sign has a reverse order to an order of another priority corresponding to the combination with the differential value in a minus sign.

4. The modulated signal generating device according to claim 2, wherein priorities corresponding to the respective combinations have orders different from one another.

5. The modulated signal generating device according to claim 3, wherein priorities corresponding to the respective combinations have orders different from one another.

6. The modulated signal generating device according to claim 2, wherein

the determining unit determines a plurality of numbers of amplifiers in terms defined by priorities corresponding to different combinations;

and

the control signal generating unit changes a start position of the priority corresponding to the combination in a current term according to a maximum number among the numbers of amplifiers determined in a last term.

7. The modulated signal generating device according to claim 3, wherein

the determining unit determines a plurality of numbers of amplifiers in terms defined by priorities corresponding to different combinations;

and

the control signal generating unit changes a start position of the priority corresponding to the combination in a current term according to a maximum number among the numbers of amplifiers determined in a last term.

8. The modulated signal generating device according to claim 4, wherein

the determining unit determines a plurality of numbers of amplifiers in terms defined by priorities corresponding to different combinations;

and

the control signal generating unit changes a start position of the priority corresponding to the combination in a current term according to a maximum number among the numbers of amplifiers determined in a last term.

9. The modulated signal generating device according to claim 5, wherein

the determining unit determines a plurality of numbers of amplifiers in terms defined by priorities corresponding to different combinations;

and

the control signal generating unit changes a start position of the priority corresponding to the combination in a current term according to a maximum number among the numbers of amplifiers determined in a last term.

10. A wireless device comprising:

a signal generating unit configured to generate a transmitted signal from transmitted data;

a modulating unit configured to modulate the transmitted signal and generate a first modulated signal;

a modulated signal generating device configured to modulate the first modulated signal and generate a second modulated signal; and

an antenna unit configured to transmit the second modulated signal, wherein

the modulated signal generating device includes;

a plurality of amplifiers connected in parallel with each other and each configured to generate amplified signals based on a control signal;

a combiner configured to combine the amplified signals and to obtain the second modulated signal having a stepwise waveform;

a determining unit configured to determine a number of amplifiers to be driven to generate amplified signals to be combined by the combiner according to a value of the first modulated signal every period shorter than a period of the first modulated signal; and

a control signal generating unit configured to select zero or more amplifiers to be driven from among the amplifiers, based on the number of the amplified signals determined by the determining unit, the value of the first modulated signal, and a fluctuation in the value of the first modulated signal, and to generate the control signal for driving the selected amplifier.