Wireless communication apparatus

• US 7,120,202 B2
• Filed: 03/14/2002
• Issued: 10/10/2006
• Est. Priority Date: 03/16/2001
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Sasabata, Akihiro
• Primary Examiner(s): Ha, Dac
• Assistant Examiner(s): Wong, Linda
• Application Number:
  US10/275,112
• Publication Number:
  US 20030147475A1
• Time in Patent Office: 1,671 Days
• Field of Search: None
• US Class Current: 375/271
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453

Abstract

In a wireless communication apparatus which has the functions of both ASK modulation and QPSK modulation, which can be manufactured at a low cost, and which is small in size, an output terminal of a QPSK modulator is connected to a carrier wave input terminal of an ASK modulator via a switch. Also, an antenna is connected to an output terminal of the ASK modulator via a switch. Furthermore, a mixer is provided between the switches and. The switch connects the QPSK modulator and the ASK modulator at the time of a transmission, whereas it connects the QPSK modulator and the mixer at the time of a reception. The switch connects the ASK modulator and the antenna at the time of a transmission, whereas it connects the antenna and the mixer at the time of a reception. Thus, at the time of a transmission, an ASK-modulated wave or a QPSK-modulated wave is output using the ASK modulator and the QPSK modulator. At the time of a reception, a sine wave is output by the QPSK modulator and a data signal is down-converted, detected, or demodulated by the mixer.

Claims

1. A wireless communication apparatus comprising:

an amplitude shift keying modulator (ASK modulator) for amplitude shift key-modulating (ASK-modulating) a carrier wave using a data signal; and

a quadrature phase shift key modulator (QPSK modulator) for quadrature phase shift key-modulating (QPSK-modulating) a carrier wave using an in-phase signal (I-signal) and a quadrature signal (Q-signal);

wherein an output terminal of said QPSK modulator is connected to an input terminal for said carrier wave of said ASK modulator.

3. A wireless communication apparatus according to claim 1,

wherein when the wireless communication apparatus outputs a QPSK-modulated wave at the time of a transmission, said QPSK modulator QPSK-modulates a carrier wave using an I-signal and a Q-signal to output the QPSK-modulated wave, and said ASK modulator amplifies the QPSK-modulated wave by a constant gain, and

when the wireless communication apparatus outputs an ASK-modulated wave at the time of a transmission, said QPSK modulator outputs a sine wave, and said ASK modulator ASK-modulates the sine wave using a data signal.

4. A wireless communication apparatus according to claim 3,

wherein when the wireless communication apparatus outputs the QPSK-modulated wave at the time of a transmission, said QPSK modulator receives input of data signals respectively as an I-signal and a Q-signal and outputs the QPSK-modulated wave, and said ASK modulator receives input of a signal having a constant voltage as a data signal and amplifies the QPSK-modulated wave by a constant gain.

5. A wireless communication apparatus according to claim 3,

wherein when the wireless communication apparatus outputs the ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of signals having the same fixed phases and fixed amplitudes respectively as an I-signal and a Q-signal and outputs a sine wave, and said ASK modulator receives input of a data signal and ASK-modulates the sine wave to output the ASK-modulated wave.

6. A wireless communication apparatus according to claim 3,

wherein when the wireless communication apparatus outputs the ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of signals based on a QPSK data signal “

00”

as an I-signal and a Q-signal and performs a π

/4 shift QPSK operation to output a sine wave, and said ASK modulator receives input of a data signal and ASK-modulates the sine wave to output the ASK-modulated wave.

7. A wireless communication apparatus according to claim 6,

wherein said QPSK modulator receives input of a carrier wave having a frequency which is lower than a predetermined frequency by R/4·

Hz and performs a π

/4 shift QPSK operation to output a sine wave having the predetermined frequency, wherein R is a transmission rate of the QPSK data signal.

8. A wireless communication apparatus according to claim 1,

wherein when the wireless communication apparatus outputs a QPSK-modulated wave at the time of a transmission, said QPSK modulator QPSK-modulates a carrier wave using an I-signal and a Q-signal to output the QPSK-modulated wave, and said ASK modulator amplifies the QPSK-modulated wave by a constant gain, and

wherein when the wireless communication apparatus outputs an ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of data signals having the same fixed phases and amplitudes thereof changing identically in time respectively as an I-signal and a Q-signal and outputs the ASK-modulated wave, and said ASK modulator receives input of a signal having a constant voltage as a data signal and amplifies the ASK-modulated wave by a constant gain.

9. A wireless communication apparatus according to claim 1, further comprising an up-mixer for raising frequency, connected between said ASK modulator and said QPSK modulator.

12. A wireless communication apparatus according to claim 4,

wherein when the wireless communication apparatus outputs the ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of signals having the same fixed phases and fixed amplitudes respectively as an I-signal and a Q-signal and outputs a sine wave, and said ASK modulator receives input of a data signal and ASK-modulates the sine wave to output the ASK-modulated wave.

13. A wireless communication apparatus according to claim 4,

wherein when the wireless communication apparatus outputs the ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of signals based on a QPSK data signal “

00”

as an I-signal and a Q-signal and performs a π

/4 shift QPSK operation to output a sine wave, and said ASK modulator receives input of a data signal and ASK-modulates the sine wave to output the ASK-modulated wave.

2. A wireless communication apparatus comprising:

an amplitude shift keying modulator (ASK modulator) for amplitude shift key-modulating (ASK-modulating) a carrier wave using a data signal; and

a quadrature phase shift key modulator (QPSK modulator) for quadrature phase shift key-modulating (QPSK-modulating) a carrier wave using an in-phase signal (I-signal) and a quadrature signal (Q-signal), wherein an output terminal of said QPSK modulator is connected to an input terminal for said carrier wave of said ASK modulator;

a mixer; and

a switch provided between said QPSK modulator and each of said mixer and said ASK modulator, said switch connecting said ASK modulator and said QPSK modulator at the time of a transmission, and connecting said mixer and said QPSK modulator at the time of a reception;

wherein said QPSK modulator outputs a sine wave as a carrier wave to said mixer at the time of a reception.

10. A wireless communication apparatus according to claim 2,

wherein said ASK modulator, said mixer, and said switch are integrated as an RF block.

11. A wireless communication apparatus according to claim 2,

wherein when the wireless communication apparatus outputs a QPSK-modulated wave at the time of a transmission, said QPSK modulator QPSK-modulates a carrier wave using an I-signal and a Q-signal to output the QPSK-modulated wave, and said ASK modulator amplifies the QPSK-modulated wave by a constant gain, and

when the wireless communication apparatus outputs an ASK-modulated wave at the time of a transmission, said QPSK modulator outputs a sine wave, and said ASK modulator ASK-modulates the sine wave using a data signal.

14. A wireless communication apparatus according to claim 2,

wherein when the wireless communication apparatus outputs a QPSK-modulated wave at the time of a transmission, said QPSK modulator QPSK-modulates a carrier wave using an I-signal and a Q-signal to output the QPSK-modulated wave, and said ASK modulator amplifies the QPSK-modulated wave by a constant gain, and

when the wireless communication apparatus outputs an ASK-modulated wave at the time of a transmission, said QPSK modulator receives input of data signals having the same fixed phases and amplitudes thereof changing identically in time respectively as an I-signal and a Q-signal and outputs the ASK-modulated wave, and said ASK modulator receives input of a signal having a constant voltage as a data signal and amplifies the ASK-modulated wave by a constant gain.