Communication apparatus

• US 5,199,045 A
• Filed: 04/13/1992
• Issued: 03/30/1993
• Est. Priority Date: 06/09/1987
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kato, Ichiro
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/866,271
• Time in Patent Office: 351 Days
• Field of Search: 375/1, 380/34, 455/69, 455/88, 455/92
• US Class Current: 375/141
• CPC Class Codes: H04B 1/707 using direct sequence modulation

Abstract

A spread communication system comprising a receiver, a diffusion convertor for converting a signal from the receiver, a control signal generator for generating a control signal representing an output level of the diffusion convertor, another diffusion convertor for converting data to be transmitted, a transmitter for transmitting data from the another diffusion convertor and a transmission controller for controlling a transmission level of the transmitter in accordance with the control signal from the control signal generator.

Claims

1. A communication apparatus comprising:

receiving means for receiving a signal including a signal from a partner station;

conversion means for converting the signal received by said receiving means in accordance with a diffusion code, wherein the diffusion code is determined in accordance with a diffusion code used in transmission by the partner station;

control signal generating means coupled to the conversion means for generating a control signal corresponding to an output level of said conversion means;

transmission means for transmitting data to the partner station; and

transmission control means coupled to the transmission means for controlling a transmission level of a signal output of said transmission means in accordance with the control signal generated by said control signal generating means.

2. A communication apparatus according to claim 1, wherein said receiving means receives a radio signal.

3. A communication apparatus according to claim 1, wherein said transmission means transmits a radio signal.

4. A communication apparatus according to claim 1, wherein said transmission control means controls the transmission level of the signal output of said transmission means such that the transmission level of the signal output of said transmission means is inversely proportional to the output level of said conversion means.

5. A communication apparatus according to claim 1, further comprising:

demodulation means for demodulating the signal received by said receiving means; and

demodulation control means for controlling the level of the demodulated signal of said demodulation means in accordance with the control signal generated by said control signal generating means.

6. A communication apparatus according to claim 5, wherein said demodulation control means controls said demodulation means to keep the level of the demodulated signal output therefrom constant.

7. A communication apparatus according to claim 1, further comprising:

amplifier means for amplifying the signal received by said receiving means; and

amplification control means for controlling an amplification factor of said amplifier means in accordance with the control signal generated by said control signal generating means.

8. A communication apparatus according to claim 7, wherein said amplification control means controls the amplification factor of said amplifier means to keep the output level thereof constant.

9. A communication apparatus according to claim 1, wherein said transmission means includes transmission data input means and transmits the data input by said transmission data input means after spectrum diffusion.

10. A communication apparatus according to claim 1, wherein said receiving means receives a spectrum-diffused signal.

11. A communication system for allowing a plurality of sub-stations to communicate with each other through a main station, each of said sub-stations comprising:

data transmitting means for transmitting data to the main station; and

control means coupled to the data transmitting means for controlling a data transmission level of data transmitted from said data transmitting means to the main station at the start of data transmission to the main station in accordance with a level of a pilot signal received from said main station before the start of data transmission from said data transmission means to the main station.

12. A communication apparatus according to claim 11, wherein said data transmission means transmits spectrum diffused data.

13. A communication apparatus according to claim 11, wherein said control means receives a pilot signal from said main station, said pilot signal being a signal converted on the basis of a pilot diffusion code.

14. A communication apparatus according to claim 13, wherein said control means comprising receiving means for receiving a signal, converting means for converting the signal received by said receiving means in accordance with the pilot diffusion signal and level control means for controlling a transmission level of said data transmission means in accordance with an output level of said converting means.

15. A communication apparatus according to claim 11, wherein said control means controls the transmission level of said data transmission means to be inversely proportional to the received pilot signal.

16. A system according to claim 11, wherein said main station transmits the pilot signal repeatedly.

17. A spectrum diffusion communication system for allowing a plurality of sub-stations to communicate with each other through a main station, each of said sub-stations comprising:

data transmitting means for transmitting spectrum diffusion data to the main station; and

control means coupled to the data transmitting means for controlling a transmission level of the spectrum diffusion data transmitted by said data transmitting means to the main station at the start of transmission of spectrum diffusion data to the main station in accordance with a level of a pilot signal received from the main station before the start of transmission of spectrum diffusion data from the data transmitting means to the main station.

18. A communication apparatus according to claim 17, wherein said control means receives a pilot signal from a main station, said pilot signal being a signal converted on the basis of a pilot diffusion code.

19. A communication apparatus according to claim 18, wherein said control means comprises receiving means for receiving a signal, converting means for converting the signal received by said receiving means in accordance with the pilot diffusion signal and level control means for controlling a transmission level of said data transmission means in accordance with an output level of said converting means.

20. A communication apparatus according to claim 17, wherein said control means controls the transmission level of said data transmission means to be inversely proportional to the received pilot signal.

21. A system according to claim 17, wherein said main station transmits the pilot signal repeatedly.

22. A communication apparatus comprising:

receiving means for receiving a signal including a signal from a partner station through first and second channels, wherein said signal is a spectrum-diffused signal and diffusion codes are different for the first channel and the second channel;

demodulating means coupled to the receiving means for demodulating the signal received from the partner station through the first channel to obtain original data;

detecting means coupled to the receiving means, for detecting a level of the signal from the partner station received through the second channel; and

transmitting means coupled to the detecting means for transmitting a signal with a signal level corresponding to the signal level detected by said detecting means.

23. An apparatus according to claim 22, wherein said transmitting means transmits a spectrum diffused signal.

24. An apparatus according to claim 22, wherein said transmitting means comprises control means for controlling a transmission level to be in inverse proportion to the level detected by said detecting means.

25. An apparatus according to claim 22, wherein said demodulating means demodulates received data amplified according to a level detected by said detecting means to obtain original data.

26. A communication apparatus, comprising:

transmitting means for transmitting data to a main station;

receiving means for receiving a reference signal from the main station; and

control means coupled to the receiving means for controlling a transmission level of the data transmitted by said transmitting means to the main station at the start of data transmission to the main station in accordance with a reception level of the reference signal before the start of data transmission from said transmitting means to the main station.

27. An apparatus according to claim 26, wherein said receiving means comprising demodulating means for demodulating an information signal from the main station.

28. An apparatus according to claim 27, wherein said demodulating means comprises amplifying means for amplifying an information signal in accordance with a reception level of the reference signal.

29. An apparatus according to claim 26, wherein said control means controls a transmission level of said transmission means to be in inverse proportion to a reception level of the reference signal.

30. An apparatus according to claim 26, wherein said transmission means transmits spectrum-diffused data.

31. An apparatus according to claim 26, wherein said receiving means receives a spectrum-diffused signal.

32. An apparatus according to claim 26, wherein the main station transmits the reference signal repeatedly.