WIRELESS COMMUNICATION APPARATUS

• US 20070098047A1
• Filed: 10/27/2006
• Published: 05/03/2007
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: 138 East LCD Advancements Limited (Vector Capital Corporation)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: IIDA, Izumi
• Granted Patent: US 7,706,494 B2
• Time in Patent Office: Days
• US Class Current: 375/141
• CPC Class Codes: H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
• CPC Class Codes: H04B 2215/067 by modulation dispersion

Abstract

A wireless communication apparatus includes: a transmitter which sends transmitted data while mixing it with a carrier; a receiver which receives the transmitted data sent from the transmitter while mixing it with the carrier; a spreading waveform generator which generates a spread clock resulting from a reference clock for generating the carrier being spread in a PN pattern; a wired sender which, by sending the spread clock by wire, causes both the transmitter and the receiver to share it; and a carrier reproducer which reproduces the carrier based on a result of a phase comparison with the spread clock.

Claims

1. A wireless communication apparatus comprising:

a transmitter which sends transmitted data while mixing it with a carrier;

a receiver which receives the transmitted data sent from the transmitter while mixing it with the carrier;

a spreading waveform generator which generates a spread clock resulting from a reference clock for generating the carrier being spread in a PN pattern;

a wired sender which, by sending the spread clock by wire, causes both the transmitter and the receiver to share it; and

a carrier reproducer which reproduces the carrier based on a result of a phase comparison with the spread clock.

2. A wireless communication apparatus according to claim 1, comprising:

a local oscillator which generates a local clock;

a transmitter which sends transmitted data wirelessly while mixing it with the local clock;

a first frequency divider which generates a first divided clock resulting from the local clock being divided;

a spreading waveform generator which generates a spread clock resulting from the first divided clock being spread in the PN pattern;

a wired sender which, by sending the spread clock by wire, causes both the transmitter and the receiver to share it;

a voltage controlled oscillator which generates a multiplied clock based on a control voltage;

a receiver which receives the transmitted data sent from the transmitter while mixing it with the multiplied clock;

a second frequency divider which generates a second divided clock resulting from the multiplied clock being divided;

a phase comparator which detects a phase difference between the spread clock sent by the wired sender and the second divided clock; and

a charge pump circuit which transmits a control voltage corresponding to the phase difference detected by the phase comparator.

3. A wireless communication apparatus according to claim 2, wherein the spreading waveform generator includes:

an edge detector which detects an edge of the PN pattern;

an exclusive OR circuit which carries out an exclusive OR operation of the first divided clock and the spread clock; and

a switch which, based on a result of the detection of the edge of the PN pattern, switches between a doubled clock resulting from the first divided clock being doubled and an output from the exclusive OR circuit.

4. A wireless communication apparatus according to claim 2, wherein the phase comparator includes:

a first flip flop which, after the second divided clock decays, by applying a reset at a timing of a change in level of the second divided clock sampled in the spread clock, transmits an up signal, which corresponds to a phase lag of the second divided clock with respect to the spread clock, to the charge pump circuit; and

a second flip flop which, after the second divided clock rises, by applying a reset based on a level of the second divided clock sampled in the spread clock, transmits a down signal, which corresponds to a phase advance of the second divided clock with respect to the spread clock, to the charge pump circuit.

5. A wireless communication apparatus according to claim 2, comprising:

a mixer which superimposes the first divided clock generated by the first frequency divider on a power supply line; and

a separator which separates an alternating current component from the first divided clock superimposed on the power supply line.

6. A wireless communication apparatus according to claim 1, wherein

the spreading waveform generator changes a clock duty ratio in such a way that a high level section between symbol changing points of the PN pattern occupies 50% or more.

8. A wireless communication apparatus according to claim 1, including a first and second circuit block formed on an identical semiconductor chip, wherein

the transmitter is formed on the first circuit block;

the receiver is formed on the second circuit block;

the spreading waveform generator and the wired sender are mounted on the first or second circuit block; and

the carrier reproducer is mounted on the second circuit block.

9. A wireless communication apparatus according to claim 1, including a first and second semiconductor chip mounted on a mounting board, wherein

the transmitter is formed on the first semiconductor chip;

the receiver is formed on the second semiconductor chip;

the spreading waveform generator and the wired sender are mounted on the first or second semiconductor chip; and

the carrier reproducer is mounted on the second semiconductor chip.

7. A wireless communication apparatus comprising:

a first casing portion;

a second casing portion connected to the first casing portion;

a connector which connects the first casing portion and the second casing portion in such a way that a positional relationship between the first casing portion and the second casing portion can be changed;

an external wireless communication unit which, being mounted on the first casing portion, carries out an external wireless communication;

a display which is mounted on the second casing portion;

a transmitter which, being mounted on the first casing portion, sends transmitted data wirelessly while mixing it with a carrier;

a receiver which, being mounted on the second casing portion, receives the transmitted data transmitted from the transmitter while mixing it with the carrier;

a spreading waveform generator which, being mounted on the first casing portion or the second casing portion, generates a spread clock resulting from a clock for generating the carrier being spread in a PN pattern;

a wired sender which, being mounted on the first casing portion or the second casing portion, by sending the spread clock by wire, causes both the transmitter and the receiver to share it; and

a carrier reproducer which, being mounted on the second casing portion, reproduces the carrier based on a result of a phase comparison with the spread clock.

10. A wireless communication apparatus according to claim 7, wherein

the spreading waveform generator, by changing a position of a trailing edge of the PN pattern, while changing a clock duty ratio in such a way as to prevent two or more clocks for generating the carrier from existing in a section ranging from a trailing edge to a next leading edge of the PN pattern, generates the spread clock resulting from the clocks being spread in the PN pattern.