Spread spectrum modulation communication apparatus for narrow band interference elimination

• US 5,974,101 A
• Filed: 06/05/1995
• Issued: 10/26/1999
• Est. Priority Date: 04/28/1992
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Nago, Hidetada
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Gluck, Jeffrey
• Application Number:
  US08/461,239
• Time in Patent Office: 1,604 Days
• Field of Search: 375/206, 375/350, 375/200, 375/346, 375/349, 455/307
• US Class Current: 375/350
• CPC Class Codes: H04B 1/1036 with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters H04B1/123 takes precedence; filter circuits H03H
• CPC Class Codes: H04B 1/7102 with transform to frequency domain
• CPC Class Codes: H04B 2001/1063 using a notch filter
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference

Abstract

A wireless communication apparatus employing spread spectrum modulation which detects and eliminates interference waves and temporarily stops and restarts communication for maintaining fine communication status. If the interference wave frequency band is known, a reception signal of the frequency band is eliminated. Communication is temporarily halted and restarted corresponding to interference occurrence period and/or radiowave propagation condition, and communication status is notified to a user. Further, if the interference wave occurrence period is unknown, the frequency of the interference wave is detected and a signal of the detected frequency is eliminated. In a case where communication is performed in packet form, the number of packets which can be transmitted sequentially without receiving reception confirmation is controlled based on the radiowave propagation condition. Moreover, a reception signal can be divided into a plurality of frequency band signals and interference wave detection can be performed in band signal units.

Claims

1. A reception apparatus comprising:

receiving means for receiving a signal;

detecting means for detecting reception results of a plurality of frequency bands received by said receiving means;

storing means for storing reference data corresponding to the plurality of frequency bands;

comparing means for comparing the reception results with the reference data; and

elimination means for eliminating, from the reception results, a signal of a frequency band obtained from comparison results by said comparing means.

2. The apparatus according to claim 1, wherein said detecting means detects first reception results of the plurality of frequency bands in accordance with a first signal received by said receiving means at a first timing and second reception results of the plurality of frequency bands in accordance with a second signal received by said receiving means at a second timing, and said storing means stores the first reception results.

3. The apparatus according to claim 2, wherein said comparing means compares the second reception results with the first reception results, and said eliminating means eliminates, from the second reception results, the signal of the frequency band obtained from comparison results by said comparing means.

4. The apparatus according to claim 1, wherein said detecting means comprises transform means for performing Fourier Transform on the reception results;

and

said comparing means compares results from the Fourier Transform with the reference data.

5. The apparatus according to claim 1, wherein said eliminating means comprises:

a plurality of serial-connected filter means; and

selecting means for selecting at least one of the plurality of the serial-connected filter means in accordance with the comparison results by said comparing means.

6. A reception method comprising the steps of:

receiving a signal;

detecting reception results of a plurality of frequency bands received in said receiving step;

storing reference data corresponding to the plurality of frequency bands;

comparing the reception results with the reference data; and

eliminating from the reception results, a signal of a frequency band obtained from comparison results in said comparing step.

7. The method according to claim 6, wherein said detecting step detects first reception results of the plurality of frequency bands in accordance with a first signal received in said receiving step at a first timing and second reception results of the plurality of frequency bands in accordance with a second signal received in said receiving step at a second timing;

and

said storing step stores the first reception results.

8. The method according to claim 7, wherein said comparing step compares the second reception results with the first reception results, and said eliminating step eliminates, from the second reception result, the signal of the frequency obtained from the comparison results in said comparing step.

9. The method according to claim 6, wherein said detecting step comprises a step of performing Fourier transform on the reception results;

and

said comparing step compares results from the Fourier Transform with the reference data.

10. The method according to claim 6, wherein said eliminating step comprises a step of selecting at least one of a plurality of serial-connected filters in accordance with the comparison results in said comparing step.