Communication device and communication method

• US 6,564,040 B1
• Filed: 05/18/2000
• Issued: 05/13/2003
• Est. Priority Date: 05/25/1999
• Status: Expired due to Term

• Current Assignee: Optis Wireless Technology, LLC (Brevet Capital)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Fujiwara, Yoji
• Primary Examiner(s): Congle, Thanh
• Assistant Examiner(s): TRINH, TAN H
• Application Number:
  US09/573,325
• Time in Patent Office: 1,090 Days
• Field of Search: 455/260, 455/264, 455/75, 455/76, 375/376, 375/375
• US Class Current: 455/76
• CPC Class Codes: H04B 15/06 by local oscillators of receivers

Abstract

A communication device and a communication method, which is capable of reducing noises due to higher harmonic components and avoiding disturbance over a receiving function or a transmitting function by setting an oscillation frequency of an operation clock easily at a high speed and with high precision. The oscillation frequency of the operation clock is calculated by a microcomputer 109 such that higher harmonics of the operation frequency of the operation clock CLK1 can be positioned farthest from the receiving frequency, and a frequency dividing ratio of a variable frequency divider 105 of a PLL frequency synthesizer is set by a control signal CTL1 according to the operation frequency of the calculated operation clock CLK1, and then the operation clock CLK1 is generated by the PLL frequency synthesizer and then supplied to the microcomputer 109.

Claims

1. A communication device comprises:

a clock generating means for generating a clock;

a processing means which operates based on the clock; and

a radio portion for processing a radio signal at a predetermined frequency;

an operation frequency controlling means for calculating an operation frequency of the clock such that higher harmonics of the operation frequency of the clock is positioned farthest from the radio frequency,

wherein the clock generating means generates the clock having the operation frequency calculated by the operation frequency controlling means.

2. A communication device as claimed in claim 1, wherein said radio portion is a receiver portion for receiving a signal transmitted from another communication device at a predetermined receiving frequency and demodulating it, and

said operation frequency controlling means calculates an operation frequency of the clock such that higher harmonics of the operation frequency of the clock is positioned farthest from the receiving frequency.

3. A communication device as claimed in claim 1, wherein said radio portion is a transmitter portion for transmitting a transmit signal modulated at a predetermined transmitting frequency, and

the operation frequency controlling means calculates an operation frequency of the clock such that higher harmonics of the operation frequency of the clock is positioned farthest from the transmitting frequency.

4. A communication device as claimed in claim 1, wherein said radio portion include a receiver portion for receiving a signal transmitted from another communication device at a predetermined receiving frequency and demodulating it, and a transmitter portion for transmitting a transmit signal modulated at a predetermined transmitting frequency, and

said operation frequency controlling means calculates an operation frequency of the clock such that higher harmonics of the operation frequency of the clock can be positioned farthest from the receiving frequency or the transmitting frequency.

5. A communication device according to claim 1, wherein said clock generating means comprises a PLL frequency synthesizer which comprises a reference oscillator, a phase comparator, a low pass filter, a voltage controlled oscillator, and a variable frequency divider, and which varies the operation frequency of the clock by programmably changing a frequency dividing ratio of the variable frequency divider.

6. A communication device according to claim 1 further comprising:

a storing means for holding calculation results of the operation frequency of the clock whose higher harmonics is positioned farthest from the radio frequency every radio frequency.

7. A communication method for a communication device including a clock generating means for generating a clock, a processing means which operates based on the clock, and a radio portion for processing a radio signal at a predetermined frequency, said communication method comprising:

an operation frequency controlling step of calculating an operation frequency of the clock such that higher harmonics of the operation frequency of the clock can be positioned farthest from the radio frequency,

wherein the clock generating means generates the clock having the operation frequency calculated by the operation frequency controlling step.

8. A communication method as claimed in claim 7, wherein said radio portion is a receiver portion for receiving a signal transmitted from another communication device at a predetermined receiving frequency and demodulating it, and an operation frequency of the clock is calculated such that higher harmonics of the operation frequency of the clock can be positioned farthest from the receiving frequency.

9. A communication method as claimed in claim 7, wherein said radio portion is a transmitter portion for transmitting a transmit signal modulated at a predetermined transmitting frequency, and an operation frequency of the clock is calculated such that higher harmonics of the operation frequency of the clock is positioned farthest from the transmitting frequency.

10. A communication method as claimed in claim 7, wherein, said radio portion include a receiver portion for receiving a signal transmitted from another communication device at a predetermined receiving frequency and demodulating it, and a transmitter portion for transmitting a transmit signal modulated at a predetermined transmitting frequency, an operation frequency of the clock is calculated such that higher harmonics of the operation frequency of the clock is positioned farthest from the receiving frequency or the transmitting frequency.

11. A communication method according to claim 7, wherein said clock generating means includes a PLL frequency synthesizer which comprises a reference oscillator, a phase comparator, a low pass filter, a voltage controlled oscillator, and a variable frequency divider, and

the operation frequency controlling step has a varying step of varying the operation frequency of the clock by setting a frequency dividing ratio into the variable frequency divider in accordance with a calculated operation frequency.

12. A communication method according to claim 7, further comprising:

a calculating step of calculating the operation frequency of the clock whose higher harmonics can be positioned farthest from the receiving frequency or the transmitting frequency every receiving frequency or every transmitting frequency; and

a storing step of holding results calculated in the calculating step in a storing means.

13. A communication method according to claim 7, the operation frequency controlling step or the calculating step includes:

a first calculating step of calculating frequency difference between the higher harmonics, which can be positioned nearest to the receiving frequency or the transmitting frequency, out of the higher harmonics of the operation frequency of the clock and the receiving frequency or the transmitting frequency every operation frequency of the clock, which can be set in the clock generating means, and

a second calculating step of identifying the higher harmonics, which has a maximum frequency difference out of frequency differences between higher harmonics which are calculated by the first calculating step and the receiving frequency or the transmitting frequency and then calculating the operation frequency of the clock corresponding to an identified higher harmonics.

14. A computer readable recording medium for recording, as a program, a communication method for a communication device including a clock generating means for generating a clock, a processing means which operates based on the clock, and a radio portion for processing a radio signal at a predetermined frequency, wherein said program causes a computer to carry out the communication method, wherein the communication method comprises:

an operation frequency controlling step of calculating an operation frequency of the clock such that higher harmonics of the operation frequency of the clock can be positioned farthest from the radio frequency;

wherein the clock generating means generates the clock having the operation frequency calculated by the operation frequency controlling step.