TELEPHONE SIGNAL CANCELLATION CIRCUIT, DIGITAL BROADCASTING RECEPTION CIRCUIT AND PORTABLE DIGITAL BROADCASTING RECEPTION APPARATUS

Abstract

A telephone signal cancellation circuit, a digital broadcasting reception circuit and a portable digital broadcasting reception apparatus is provided. The telephone signal cancellation circuit, includes a signal coupler for separating a part of a reception signal, a telephone signal selection filter for passing a telephone signal among signals from the signal coupler, a phase shifter for performing phase inversion on the telephone signal among the signals from the telephone signal selection filter, and a combiner for combining the signal from the phase shifter and the reception signal, and canceling the telephone signal included in the reception signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 is a conventional DVB-H GSM mobile phone;

FIG. 2 shows a spectrum of the DVB-H broadcasting frequency band, the GSM-TX frequency and a basic DVB-H broadcasting frequency band of the conventional DVB-H GSM mobile phone;

FIG. 3 is a graph illustrating the frequency characteristics of the conventional reception apparatus of FIG. 1;

FIG. 4 is a block diagram showing a portable digital broadcasting reception apparatus according to an embodiment of the present invention;

FIG. 5 shows a telephone signal cancellation circuit according to a first embodiment of the present invention;

FIG. 6 shows a telephone signal cancellation circuit according to a second embodiment of the present invention; and

FIG. 7 shows a graph illustrating frequency characteristics of the reception apparatus according to an embodiment of the present invention.

Claims

1. A telephone signal cancellation circuit, comprising: a signal coupler for separating a part of a reception signal;a telephone signal selection filter for passing a telephone signal among signals from the signal coupler;a phase shifter for performing phase inversion on the telephone signal among the signals from the telephone signal selection filter; anda combiner for combining the signal from the phase shifter and the reception signal, and canceling the telephone signal included in the reception signal.

2. The cancellation circuit of claim 1, further comprising: a noise cancellation controller for controlling the cancellation of the telephone signal included in the reception signal based on a pre-set transmission channel among telephone frequency bands.

3. The cancellation circuit of claim 2, wherein the telephone signal selection filter includes a variation filter for setting up a pass band having a frequency of the pre-set transmission channel as a mean frequency by control of the controller.

4. The cancellation circuit of claim 2, wherein the phase shifter performs phase inversion on a frequency signal corresponding to the pre-set transmission channel among the signals from the telephone signal selection filter by control of the controller.

5. The cancellation circuit of claim 2, further comprising: a power detector for detecting power of the telephone signal among output signals of the combiner.

6. The cancellation circuit of claim 5, further comprising: an automatic gain control (AGC) amplifier for amplifying the signal from the phase shifter based on the power of the telephone signal detected by the power detector and outputting the signal to the combiner.

7. The cancellation circuit of claim 5, wherein the noise cancellation controller controls phase shift in a frequency where a power value of the telephone signal is the minimum by changing a phase shift frequency of the phase shifter while monitoring the power of the telephone signal from the power detector.

8. The cancellation circuit of claim 1, wherein the telephone signal is a Global System for Mobile Communication (GSM) transmission signal that is a frequency band ranging about 880 MHz to 915 MHz.

9. A digital broadcasting reception circuit, comprising: a band-pass filter for passing a digital broadcasting signal among reception signals:a signal coupler for separating a part of a reception signal;a telephone signal selection filter for passing a telephone signal among signals from the signal coupler;a phase shifter for performing phase inversion on the telephone signal among the signals from the telephone signal selection filter;a combiner for combining a signal from the phase shifter and a reception signal from a band-pass filter and canceling the telephone signal included in the reception signal; anda Radio Frequency (RF) processor for receiving the digital broadcasting signal from the combiner.

10. The reception circuit of claim 9, further comprising: a noise cancellation controller for controlling the cancellation of the telephone signal included in the reception signal based on a pre-set transmission channel among telephone frequency bands.

11. The reception circuit of claim 10, wherein the telephone signal selection filter includes a variation filter for setting up a pass band having a frequency of the pre-set transmission channel as a mean frequency by control of the controller.

12. The reception circuit of claim 10, wherein the phase shifter performs phase inversion on a frequency signal corresponding to the pre-set transmission channel among the signals from the telephone signal selection filter by control of the controller.

13. The reception circuit of claim 9, further comprising: a power detector for detecting power of the telephone signal among output signals of the combiner.

14. The reception circuit of claim 13, further comprising: an automatic gain control (AGC) amplifier for amplifying the signal from the phase shifter based on the power of the telephone signal detected by the power detector and outputting the signal to the combiner.

15. The reception circuit of claim 13, further comprising: a noise cancellation controller for controlling phase shift in a frequency where a power value of the telephone signal is the minimum by changing a phase shift frequency of the phase shifter while monitoring power of the telephone signal from the power detector.

16. The circuit of claim 9, wherein the telephone signal is a Global System for Mobile Communication (GSM) transmission signal that is a frequency band ranging about 880 MHz to 915 MHz.

17. The reception circuit of claim 9, wherein the digital broadcasting signal is a digital video broadcasting handheld (DVB-H) signal which is a frequency band ranging about 470 MHz to 860 MHz.

18. A portable digital broadcasting reception apparatus, comprising: a main control unit for controlling a telephone call and digital broadcasting reception;a telephone circuit for transmitting/receiving a telephone signal through a first antenna by control of the controller; anda telephone signal cancellation circuit including a telephone signal cancellation circuit for receiving a digital broadcasting signal through a second antenna by control of the controller, performing phase inversion on the telephone signal flowing through the second antenna, combining the telephone signal with a reception signal through the second antenna, and canceling the telephone signal.

19. The apparatus of the claim 18, wherein the digital broadcasting reception circuit further includes: a band-pass filter for passing a digital broadcasting signal among the reception signals from the second antenna to the telephone signal cancellation circuit; anda Radio Frequency (RF) processor for receiving the digital broadcasting signal from the band-pass filter.

20. The apparatus of the claim 19, wherein the telephone signal cancellation circuit includes: a signal coupler for separating a part of the reception signal through the second antenna;a telephone signal selection filter for passing the telephone signal among the signals from the signal coupler;a phase shifter for performing phase inversion on the telephone signal among the signals from the telephone signal selection filter; anda combiner for combining the signal from the phase shifter and the reception signal from the band-pass filter, and canceling the telephone signal included in the reception signal.

21. The apparatus of the claim 19, further comprising: a noise cancellation controller for controlling the cancellation of the telephone signal included in the reception signal based on a pre-set transmission channel among the telephone frequency bands.

22. The apparatus of the claim 21, wherein the telephone signal selection filter includes a variation filter for setting up a pass band having a frequency of the pre-set transmission channel as a mean frequency by control of the controller.

23. The apparatus of the claim 21, wherein the phase shifter performs phase inversion on a frequency signal corresponding to the pre-set transmission channel among the signals from the telephone signal selection filter by control of the controller.

24. The apparatus of claim 20, further comprising: a power detector for detecting power of the telephone signal among output signals of the combiner.

25. The apparatus of claim 24, further comprising: an automatic gain control (AGC) amplifier for amplifying the signal from the phase shifter based on power of the telephone signal detected by the power detector and outputting the signal to the combiner.

26. The apparatus of claim 21, wherein the noise cancellation controller controls phase shift in a frequency where a power value of the telephone signal is the minimum by changing a phase shift frequency of the phase shifter while monitoring the power of the telephone signal from the power detector.

27. The apparatus of claim 20, wherein the telephone signal is a Global System for Mobile Communication (GSM) transmission signal that is a frequency band ranging about 880 MHz to 915 MHz.

28. The apparatus of claim 20, wherein the digital broadcasting signal is a digital video broadcasting handheld (DVB-H) signal which is a frequency band ranging about 470 MHz to 860 MHz.