MOBILE TELEPHONE HAVING SHORT-DISTANCE
VOICE/CHARACTER COMMUNICATION FUNCTION
Technical Field
The present invention relates in general to a mobile telephone having a short-distance voice/character communication function, and more particularly to a mobile telephone which is capable of performing a short-distance voice/character communication function not via a mobile switching center as well as a long-distance mobile telecommunication function via the mobile switching center.
Background Art
Mobile telephones are generally adapted to provide subscribers with a mobile telephone service and a personal communication service at a frequency band of 1.8GHz. Because mobile telephones are able to rapidly acquire information, the demand for them has recently been on a gradually increasing trend. Further, so far as a subscriber's personal telephone number is set in such a mobile telephone, the subscriber can conveniently and rapidly exchange messages with a different mobile telephone as well as a general telephone at any place or time or during his travels by establishing a telephone call connection between his mobile telephone and the general telephone or different mobile telephone. As a result, mobile telephones are now on a trend toward a great broadening in their utility and applications.
Such a conventional mobile telephone can conduct a long-distance conversation with a different mobile telephone only via a mobile switching center. In this case, the fee for the telephone call is charged to the subscriber number of the calling telephone. However, even in the case where subscribers, who work or live together within the range of a relatively short distance, for example, within the same building or in the employ of the same company, want to speak with one another
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Disclosure of the Invention
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a mobile telephone having a short-distance voice/character communication function, which is capable of performing radio communication with a different mobile telephone not via a mobile switching center within the range of a predetermined short-distance so that the fee for a telephone will not be charged.
In accordance with the present invention, the above and other objects can be accomplished by a provision of a mobile telephone with a short-distance voice/character communication function comprising a mobile telecommunication processing unit for allowing a subscriber to conduct a telephone conversation with a different subscriber on the basis of a subscriber telephone number during his travels, a character input unit for inputting a character message for transmission desired by the user, and a voice input unit for inputting the voice of the user, wherein the mobile telephone further comprises multi-high frequency generation means for generating a high frequency at any one of a plurality of predetermined frequency bands; signal modulation means for modulating the character message inputted by the character input unit and the voice inputted by the voice input unit respectively into an on-screen display signal and audio signal for transmission at the high frequency generated by the multi-high frequency generation means; transmission means for transmitting any one of the on-screen display signal and audio signal modulated by the signal modulation means over the air; reception means for receiving an external signal transmitted over the air at a predetermined high- frequency band and amplifying and filtering the received signal; on-screen display processing means for detecting an on-screen display signal from an output signal
from the reception means and performing an on-screen display process for the detected on-screen display signal: audio processing means for detecting an audio signal from the output signal from the reception means and processing the detected audio signal audibly; and indication means for providing any one of a visual indication of an output signal from the on-screen display processing means and an aural indication of an output signal from the audio processing means to the user.
The mobile telephone further comprises short-distance communication control means for selectively generating a plurality of control signals to the audio processing means, on-screen display processing means, multi-high frequency generation means and signal modulation means.
Preferably, the multi-high frequency generation means may include a multi- frequency setting unit for selecting any one of the plurality of predetermined frequency bands in response to a corresponding control signal from the short- distance communication control means, and a high frequency generator for generating the high frequency at the frequency band selected by the multi-frequency setting unit.
The signal modulation means may include an on-screen display modulator for modulating the user's character message inputted by the character input unit into the on-screen display signal for transmission at the high frequency generated by the high frequency generator, an audio modulator for modulating the user's voice inputted by the voice input unit into the audio signal for transmission at the high frequency generated by the high frequency generator; and a switch for selectively applying the high frequency generated by the high frequency generator to any one of the on-screen display modulator and audio modulator in response to a corresponding control signal from the short-distance communication control means.
The transmission means may include a power amplifier for receiving an output signal from any one of -he on-screen display modulator and audio modulator and amplifying the received signal to a predetermined power level, and a transmission antenna for transmitting an output signal from the power amplifier over the air.
The reception means may include a reception antenna for receiving the
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The on-screen display processing means may include an on-screen display detector for detecting an on-screen display signal from an output signal from the filter, an on-screen display demodulator for demodulating the on-screen display signal detected by the on-screen display detector into a digital character signal, and an on-screen display generator for converting the digital character signal from the on-screen display demodulator into an analog character signal.
The audio processing means may include an audio demodulator for detecting and demodulating an audio signal from the output signal from the filter, and an audio amplifier for amplifying the audio signal demodulated by the audio demodulator to a predetermined level.
The indication means may include a speaker for aurally outputting the audio signal amplified by the audio amplifier to the user, and a display for visually outputting the analog character signal from the on-screen display generator to the user.
Brief Description of the Drawings
The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a block diagram showing the construction of a mobile telephone having a short-distance voice/character communication function in accordance with the present invention.
Best Mode for Carrying Out the Invention
With reference to Fig. 1 , there is shown in block form the construction of a mobile telephone having a short-distance voice/character communication function in accordance with the present invention.
As shown in Fig. 1, the mobile telephone comprises a mobile telecommunication processing unit 1 and a short-distance communication processing unit. Although not shown, the mobile telecommunication processing unit 1 includes a radio frequency receiver having a duplexer, low-noise amplifier, band pass filter, mixer and automatic gain controller, and a radio frequency transmitter having the same components as those of the radio frequency receiver and a power amplifier at its final stage. The components of the radio frequency transmitter are arranged in the opposite order to those of the radio frequency receiver. The mobile telecommunication processing unit 1 further includes a base-band circuit for counting up/down radio frequency signals of the radio frequency transmitter/receiver to convert them into analog and digital signals corresponding to an intermediate frequency, respectively, a mobile station modulator/demodulator circuit for modulating and demodulating the analog and digital signals from the base-band circuit according to a code division multiple access (CDMA) protocol, time division multiple access (TDMA) protocol or frequency division multiple access (FDMA) protocol, respectively, a digital/analog (D/A) converter for converting the digital signal demodulated by the mobile station modulator/demodulator circuit into an analog signal and outputting the converted analog signal to a speaker, and an analog/digital (A D) converter for converting an analog audio signal from a microphone into a digital signal.
The short-distance communication processing unit, which is adapted to interact with the mobile telecommunication processing unit 1, includes an input unit 3 for inputting a character message and voice of the user, and a multi-high frequency generation circuit 5 for generating a high frequency at any one of a plurality of predetermined frequency bands. A signal modulation circuit 7 is adapted to modulate the character message and voice inputted by the input unit 3 respectively into an on-screen display (OSD) signal and audio signal for transmission at the high frequency generated by the multi-high frequency generation circuit 5. A
transmitter 9 is adapted to transmit any one of the OSD signal and audio signai modulated by the signal modulation circuit 7 over the air. and a receiver 1 1 is adapted to receive an external signai transmitted over the air at a predetermined high-frequency band and amplify and filter the received signai. An OSD processor 13 functions to detect an OSD signal from an output signal from the receiver 1 1 and peπurm an ϋ>n process for the detected OSD signal. An audio processor 15 functions to detect an audio signal from the output signal from the receiver 1 1 and process the detected audio signal audibly. An indicator 18 acts to provide any one of a visual indication of an output signal from the OSD processor 13 and an aural indication of an output signal from the audio processor 15 to the user. A short- distance communication controller 19 is provided to selectively generate a plurality of control signals to the multi-high frequency generation circuit 5, signal modulation circuit 7, audio processor 15, OSD processor 13 and mobile telecommunication processing unit 1 in response to an output signal from the input unit 3 to control them in an appropriate manner. The input unit 3 may preferably be partitioned into a character input part and a voice input part, not shown. More preferably, the character input part may additionally perform a key input operation based on the mobile telecommunication function of the present mobile telephone.
The multi-high frequency generation circuit 5 includes a multi-frequency setting unit 20 for selecting any one of the plurality of predetermined frequency bands in response to a corresponding control signal from the short-distance communication controller 19. and a high frequency generator 21 for generating the high frequency at the frequency band selected by the multi-frequency setting unit 20. The signal modulation circuit n includes an OSD modulator 23 for modulating the user's character message inputted by the input unit 3 into the OSD signal for transmission at the high frequency generated by the high frequency generator 21, an audio modulator 24 for modulating the user's voice inputted by the input unit 3 into the audio signal for transmission at the high frequency generated by the high frequency generator 21, and a switch 22 for selectively applying the high frequency generated by the high frequency generator 21 to am one of the OSD modulator 23 and audio modulator 24 in response to a corresponding control signal
from the short-distance communication controller 19. At this time, the short- distance communication controller 19 applies a different control signal to the switch 22 according to whether the input unit 3 inputs which one of the user's voice and character message. The transmitter 9 includes a power amplifier 25 for receiving an output signal from any one of the OSD modulator 23 and audio modulator 24 and amplifying the received signal to a predetermined power level, and a transmission antenna 26 for transmitting an output signal from the power amplifier 25 over the air. The receiver 11 includes a reception antenna 27 for receiving the external signal transmitted over the air on the basis of impedance matching and resonance functions, an amplifier 28 for amplifying the signal received by the reception antenna 27 to a predetermined processable level, and a filter 29 for filtering an output signal from the amplifier 28 to extract OSD signal or audio signal components therefrom.
The OSD processor 13 includes an OSD detector 30 for detecting an OSD signal from an output signal from the filter 29, an OSD demodulator 31 for demodulating the OSD signal detected by the OSD detector 30 into a digital character signal, and an OSD generator 32 for converting the digital character signal from the OSD demodulator 31 into an analog character signal.
The audio processor 15 includes an audio demodulator 33 for detecting and demodulating an audio signal from the output signal from the filter 29, and an audio amplifier 34 for amplifying the audio signal demodulated by the audio demodulator 33 to a predetermined level. The indicator 18 includes a speaker 35 for aurally outputting the audio signal amplified by the audio amplifier 34 to the user, and a display 36 for visually outputting the analog character signal from the OSD generator 32 to the user.
On the other hand, if the mobile telecommunication processing unit 1 detects an incoming call termination signal while the above-stated components are in operation, then it gives an alarm to the user through the display 36 or speaker 35 so that the user can conduct telephone conversation based on the mobile
telecommunication.
Now, a detailed description will be given of the operation of the mobile telephone with the above-stated construction in accordance with the present invention. The user can select a desired one of the short-distance radio communication function and long-distance mobile telecommunication function using the input unit 3. For example, in the case where the user selects the short-distance radio communication function through the input unit 3, the short-distance communication controller 19 selectively generates control signals to the multi-high frequency generation circuit 5, signal modulation circuit 7, OSD processor 13 and audio processor 15. If the user selects a desired one of a plurality of predetermined frequency bands through the input unit 3, then the short-distance communication controller 19 outputs a corresponding control signal to the multi-high frequency generation circuit 5 to generate a high frequency at the selected frequency band. That is, for the implementation of single-channel communication among a plurality of mobile telephones desiring the radio communication, a calling party can adjust its transmission frequency to a reception frequency of a called party and, similarly, the called party can adjust its reception frequency to the transmission frequency of the calling party. Thereafter, if the user enters a desired character or voice through the character input part or voice input part of the input unit 3, then the signal modulation circuit 7 modulates the entered character or voice at the high frequency generated by the multi-high frequency generation circuit 5 and transmits the resultant OSD signal or audio signal over the air through the transmitter 9. On the other hand, upon receiving an external signal transmitted over the air, the receiver 11 amplifies and filters the received signal. Then, the OSD processor 13 detects an OSD signal from an output signal from the receiver 11 or the audio processor 15 detects an audio signal from the output signal from the receiver 11. Upon detecting the OSD signal, the OSD processor 13 demodulates it into a character signal and displays the demodulated character signal on the display 36. Alternatively, upon detecting the audio signal, the audio processor 15 demodulates
and amplifies it and outputs the resultant voice through the speaker 35.
Industrial Applicability
As apparent from the above description, the present invention provides a mobile telephone having a short-distance voice/character communication function, which is capable of performing radio communication of a character message and voice with a different mobile telephone not via a mobile switching center within the range of a predetermined short-distance. Therefore, no fee for a telephone call is charged, thereby lessening an economic burden on the user. Further, the unification of the radio communication function and mobile telecommunication function results in a reduction in equipment purchasing cost and an increase in convenience to the user.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.