Optical radio repeater with signal quality detection

• US 5,349,463 A
• Filed: 05/28/1993
• Issued: 09/20/1994
• Est. Priority Date: 08/17/1990
• Status: Expired due to Term

• Current Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation), NTT Data Communications Systems Corporation
• Original Assignee: Victor Company of Japan Limited (JVC Kenwood Corporation), NTT Data Communications Systems Corporation
• Inventors: Horii, Hiroshi, Shichijo, Shunichi, Fukasawa, Tetsuo, Katayama, Susumu, Iwasaki, Yoshiki, Nomoto, Takeshi, Koike, Hideo, Hirohashi, Kazutoshi, Yoshikawa, Akio, Takeda, Takaaki, Yunoki, Yoshiaki, Ushijima, Keishi, Kikuta, Michio
• Primary Examiner(s): Chilcot, Jr., Richard E.
• Assistant Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US08/068,572
• Time in Patent Office: 480 Days
• Field of Search: 359/172, 359/174, 359/175, 359/176-177, 375/3, 375/3.1, 455/20, 455/21
• US Class Current: 398/126
• CPC Class Codes: H04B 10/1149 Arrangements for indoor wireless networking of information

Abstract

An optical radio system includes a host device, an end device, and a repeater. The host device and the end device communicate with each other via the repeater by use of optical radio. The repeater includes a section for receiving a first light signal from one of the host device and the end device, a section for converting the received first light signal into a first electric signal, a section for frequency-converting the first electric signal into a second electric signal, and a section for generating a second light signal in response to the second electric signal and transmitting the generated second light signal. The repeater also includes a section for demodulating one of the first electric signal and the second electric signal into a baseband signal, a section for detecting a quality of the baseband signal, and a section for enabling transmission of the second light signal only when the detected quality of the baseband signal is equal to or greater than a predetermined quality.

Claims

1. An optical radio system comprising a host device, an end device and a repeater, wherein the host device and the end device communicate with each other via the repeater by use of light signals;

and wherein the repeater comprises;

first means for receiving a first light signal from the host device and the end device;

second means connected to the first means for converting the first light signal received by the first means into a first electric signal;

third means connected to the second means for frequency-converting the first electric signal into a second electric signal;

fourth means connected to the third means for generating a second light signal in response to the second electric signal and transmitting the generated second light signal when enabled;

fifth means connected to the second means and the third means for demodulating the first electric signal and the second electric signal into a baseband signal;

sixth means connected to the fifth means for detecting the quality of the baseband signal; and

seventh means connected to the fourth means and the sixth means for enabling transmission of the second light signal by the fourth means only when the baseband signal quality detected by the sixth means is equal to or greater than a predetermined quality.

2. The optical radio system of claim 1 wherein the sixth means comprises means for detecting a quality of the head portion of the baseband signal, the head portion having a predetermined start signal pattern.

3. The optical radio system of claim 2 wherein the repeater comprises means for detecting an amount of jitter of the baseband signal in the head portion, means for deciding whether the detected amount of jitter is equal to or less than a predetermined amount, and means for enabling transmission of the second light signal by the fourth means when the detected amount of the jitter is decided to be equal to or less than the predetermined amount.

4. The optical radio system of claim 2 wherein the repeater comprises means for detecting jitter of the baseband signal in the head portion, means for integrating the detected jitter into an integration jitter value for a predetermined time, means for deciding whether the integration jitter value is equal to or less than a predetermined value, and means for enabling transmission of the second light signal by the fourth means when the integration jitter value is decided to be equal to or less than the predetermined value.

5. The optical radio system of claim 2 wherein the repeater comprises means for detecting noise components of the baseband signal in the head portion, means for deciding whether a level of the detected noise components is equal to or less than a predetermined level, and means for enabling transmission of the second light signal by the fourth means when the level of the detected noise components is decided to be equal to or less than the predetermined level.

6. The optical radio system of claim 2 wherein the repeater comprises means for detecting noise components of the baseband signal in the head portion, means for integrating the detected noise components into an integration noise value for a predetermined time, means for deciding whether the integration noise value is equal to or less than a predetermined value, and means for enabling transmission of the second light signal by the fourth means when the integration noise value is decided to be equal to or less than the predetermined value.

7. The optical radio system of claim 1 wherein the repeater comprises means for detecting a predetermined pattern in a head portion of the baseband signal, and means for starting transmission of the second light signal by the fourth means when the predetermined pattern is detected.

8. The optical radio system of claim 1 wherein the repeater comprises means for detecting a predetermined pattern in an end portion of the baseband signal, and means for ending transmission of the second light signal by the fourth means when the predetermined pattern is detected.

9. The optical radio system of claim 1 wherein the host device and the repeater comprise respective light transmitting/receiving sections, wherein each of the light transmitting/receiving sections comprises a light transmission unit and a light reception unit, the light transmission unit including radially-arranged light emitting elements which are spaced at equal predetermined angular :

intervals smaller than a half-value angle of a directivity, the light reception unit including radially-arranged light receiving elements which are spaced at equal predetermined angular intervals smaller than a half-value angle of a directivity.

10. The optical radio system of claim 9 wherein each of the light transmitting/receiving sections comprises a light shielding member disposed between the light transmission unit and the light reception unit for providing an optical isolation between the light transmission unit and the light reception unit.

11. A repeater for an optical radio communication network, comprising:

means for receiving a first light signal, and converting the first light signal into a first electric signal;

means connected to the first means for generating a second electric signal in response to the first electric signal;

transmitting means connected to the generating means for converting the second electric signal into a second light signal, and transmitting the second light signal when enabled;

means connected to the receiving means and the generating means for detecting a condition of one of the first electric signal and the second electric signal; and

means connected to the transmitting means and the detecting means for selectively enabling and disabling the transmitting means in response to the condition of one of the first electric signal and the second electric signal which is detected by the detecting means.

12. The repeater of claim 11 wherein the detecting means comprises means for detecting a level of one of the first electric signal and the second electric signal as a condition of one of the first electric signal and the second electric signal.

13. The repeater of claim 11 wherein the detecting means comprises means for detecting a quality of one of the first electric signal and the second electric signal as a condition of one of the first electric signal and the second electric signal.

14. The repeater of claim 11 wherein the detecting means comprises means for detecting a noise component of one of the first electric signal and the second electric signal as a condition of one of the first electric signal and the second electric signal.

15. The repeater of claim 11 wherein the detecting means comprises means for detecting a jitter component of one of the first electric signal and the second electric signal as a condition of one of the first electric signal and the second electric signal.

16. The repeater of claim 11 wherein the generating means comprises means for doubling a frequency of the first electric signal to convert the first electric signal into the second electric signal.