Radio communication apparatus

Abstract: A radio communication apparatus used for both digital communications and analog communications is disclosed which comprises a digital signal processor DSP (4) which processes many kinds of digital signals according to a plurality of signal procedures (55, 56, 57, 58) stored in a ROM (5). In the present invention, since the radio communication apparatus processes many kinds of procedures (55, 56, 57, 58) stored in the ROM (5) using one DSP (4), the size and the weight of the apparatus become small.

Description: The invention relates to a radio communication apparatus used for both digital communications and analog communications. FIG. 3 shows a block diagram of a conventional radio communication apparatus. In FIG. 3, a microphone 1 converts a human voice into a voice signal. A linear codec 3 converts the voice signal to a digital signal. A digital signal processor (DSP) 4 processes the digital signal. A ROM 52 stores instruction codes (voice coding procedures) used in the DSP 4. A digital modulation/demodulation portion 6 modulates the coded digital signal to form a modulated digital signal and demodulates a modulated signal to form a coded digital signal. An analog voice signal processing portion 12 modulates the voice signal to form a modulated voice signal and demodulates the modulated voice signal to form a voice signal. An FM modulation/demodulation portion 10 modulates the modulated voice signal to form an FM signal and demodulates an FM signal to form a modulated voice signal. A radio frequency transmitter/receiver 7 amplifies the signals which are received from the modulation/demodulation portion 6 or the FM modulation/demodulation portion 10 and supplies them to an antenna 8, and receives radio frequency signals from the antenna 8 and supplies them to the digital modulation/ demodulation portion 6 or the FM modulation/demodulation portion 10. A speaker 2 converts the voice signal which is received from the linear codec 3 or analog voice signal processing portion 12 into a sound or voice and outputs the voice. A control portion 11 controls the devices in the radio communication apparatus. The operation of the above conventional art is explained hereinafter. (1) A voice signal is processed in a digital manner. Firstly, the voice which is input to the microphone 1 is converted into an analog signal and is sent to the linear codec 3. The linear codec 3 converts the analog voice signal which is received from the microphone 1 into a digital signal and outputs it to the DSP 4. The DSP 4 processes the digital signal which is received from the linear codec 3 according to the voice coding procedure which is stored in the ROM 52 and sends the coded signal to the digital modulation/demodulation portion 6. The digital modulation/demodulation portion 6 modulates the carrier signal by the coded signal and outputs the digital modulated signal to the radio frequency transmitter/receiver 7. The radio transmitter/receiver 7 amplifies the received digital modulated signal and sends it to the base station via the antenna 8. When the radio frequency signal has been received from the base station via the antenna 8, the radio frequency transmitter/receiver 7 sends the radio signal to the digital modulation/demodulation portion 6. The digital modulation/ demodulation portion 6 demodulates the digital modulated signal and outputs the demodulated signal to the DSP 4. The DSP 4 decodes the demodulated signal according to the signal procedure stored in the ROM 52 and sends the decoded digital voice signal to the linear codec 3. The linear codec 3 converts the digital voice signal into an analog voice signal and sends it to the speaker 2 . The speaker 2 converts the analog voice signal into a voice output. (2) A voice signal is processed in an analog manner. Firstly, the voice which is input in the microphone 1 is converted into an analog signal and is sent to the analog voice signal processing portion 12. The analog voice signal processing portion 12 modulates the analog signal to a modulation tion voice signal for FM transmission and sends it to the FM modulation/demodulation portion 10. The FM modulation/ demodulation portion 10 modulates the carrier signal by the modulation voice signal and outputs the modulated FM signal to the radio frequency transmitter/receiver 7. The radio frequency transmitter/receiver 7 amplifies the received modulated FM signal and sends it to the base station from the antenna 8. When a radio frequency FM signal has been received from the base station via the antenna 8, the radio frequency transmitter/receiver 7 sends the radio frequency FM signal to the FM modulation/demodulation portion 10. The FM modulation/ demodulation portion 10 demodulates the radio frequency FM signal and outputs the demodulated signal to the analog voice signal processing portion 12 . The analog voice signal processing portion 12 demodulates the demodulated signal to form the analog voice signal and sends it to the speaker 2. The speaker 2 converts the analog voice signal to a voice output. The control portion 11 controls the devices in the radio communication apparatus and changes the control between digital communications and analog communications. In a conventional radio communication apparatus which is constructed as explained above, the signal goes through the linear codec 3 and DSP 4 during digital communications, and it goes through the analog voice signal processing portion 12 during analog communications. That is, since the voice processing portion for digital and analog communications are provided separately, the circuit configuration becomes large and also expensive. A further conventional radio communication arrangement is disclosed in the prior art document "38th IEEE Vehicular Technology Conference", Philadelphia, US, 15-17 June 1988, pages 543-547; R. FISHER: "Dual mode mobile unit for next generation digital narrow channel cellular telephone system". This arrangement shows a cellular telephone with two digital signal processors, one for transmitting and one for receiving. Each processor processes signals in both a digital communication mode and an analogue communication mode. It is a primary object of the present invention to provide a radio communication apparatus having a small size voice processing portion and thereby to provide an inexpensive and light weight radio communication apparatus. The radio communication apparatus of the present invention shows the features of appended claim 1. Such a radio communication apparatus includes a first linear codec for converting an analog signal into a digital signal, and for converting a digital signal into an analog signal, and a ROM for storing a plurality of signal procedures used for analog communications and digital communications. The radio communication apparatus also includes a digital signal processor for processing the digital signal which is received from the first linear codec and outputs a first coded digital signal to a digital modulation/ demodulation portion according to the corresponding signal procedure stored in the ROM, and for receiving and processing a second coded digital signal according to the said signal coding procedure stored in the ROM and outputs a digital signal to the first linear codec, in the case of digital communications; and for processing the digital signal which is received from the first linear codec 3 and outputs a third coded digital signal according to a voice procedure stored in the ROM to a second linear codec, and for receiving and processing a fourth coded digital signal according to said voice procedure stored in the ROM and outputs a digital signal, in the case of analog communications. The radio communication apparatus further includes a digital modulation/demodulation portion for generating a first digital modulated signal from the first coded digital signal, and for generating said second coded digital signal from a second digital modulated signal received from a transceiver. The radio communication apparatus also includes a second linear codec being placed between the DSP and a FM modulation/demodulation portion and generating an analog modulation signal from the third coded digital signal, and for generating said fourth coded digital signal from an analog demodulated signal. Moreover, the radio communication apparatus includes an FM modulation/demodulation portion for generating an analog FM modulated signal from the analog modulation signal, and for generating the analog demodulated signal from an analog radio frequency FM signal. The invention is described in detail below in connection with preferred embodiments and with reference to the accompanying drawings. FIG. 1 is a block diagram of a first embodiment of a radio communication apparatus in accordance with the present invention. FIG. 2 is a block diagram of a second embodiment of a radio communication apparatus in accordance with the present invention. FIG. 3 shows a block diagram of the conventional art. FIG. 1 shows a block diagram of a radio communication apparatus of a first embodiment of the present invention. A ROM 5 stores a voice coding procedure 55 for digital communication of the digitized voice signal and a voice procedure 56 for analog communication of the digitized voice signal. A linear codec 9 is placed between the DSP 4 and the FM modulation/demodulation portion 10 and generates an analog modulation signal from the digitized coded signal, and generates a digital demodulated signal from an analog demodulated signal. The reference numbers in FIG. 1 which are the same as in FIG. 3 are used for the same or corresponding portions. Therefore, the detailed explanation concerning the same reference numbers is abbreviated. The operation of the first embodiment of the present invention is explained hereinafter. (1) A voice signal is processed in a digital manner. In the first embodiment, when the voice signal is transmitted in a digital manner from the antenna, the control portion 11 sends the digital mode information to the DSP 4, activates the digital modulation/demodulation portion 6 and deactivates the FM modulation/demodulation portion 10. The DSP 4 also selects the voice coding procedure 55 stored in the ROM 5. Firstly, the voice which is input in the microphone 1 is converted into an analog signal and is sent to a first linear codec 3. The linear codec 3 converts the analog signal which is received from the microphone 1 into a digital signal and outputs it to the DSP 4. The DSP 4 processes the digital signal which is received from the linear codec 3 according to the signal voice procedure 55 which is stored in the ROM 5 and outputs a coded digital signal to the modulation/demodulation portion 6. The digital modulation/demodulation portion 6 modulates the carrier signal by the digital coded signal and outputs the digital modulated signal to the radio frequency transmitter/receiver 7. The radio frequency transmitter/receiver 7 amplifies the received digital modulated signal and sends it to the base station via the antenna 8. When the digital radio frequency signal has been received from the base station via the antenna 8, the radio frequency transmitter/receiver 7 sends the radio signal to the digital modulation/demodulation portion 6. The digital modulation/demodulation portion 6 demodulates the digital modulated signal and outputs a digital coded signal to the DSP 4. The DSP 4 decodes the digital coded signal to the decoded digital voice signal according to the signal coding procedure 55 stored in the ROM 5 and sends it to the linear codec 3. The linear codec 3 converts the digital voice signal into an analog voice signal and sends it to the speaker 2 . The speaker 2 converts the analog voice signal to a voice output. (2) A voice signal is processed in an analog manner. When the voice signal is sent in the analog manner, the control portion 11 sends the analog mode information to the DSP 4. Then the control portion 11 also activates the FM modulation/demodulation portion 10, and deactivates the digital modulation/demodulation portion 6. The DSP 4 also selects the voice procedure 56 stored in the ROM 5. Firstly, the voice which is input in the microphone 1 is converted into an analog voice signal and is sent to a first linear codec 3. The linear codec 3 converts the analog signal which is received from the microphone 1 into a digital voice signal and outputs it to the DSP 4. The DSP 4 converts the digital voice signal which is received from the linear codec 3 into a digitized coded signal according to the voice procedure 56 which is stored in the ROM 5 and sends it to the second linear codec 9. The second linear codec 9 converts the digitized coded signal into an analog modulation signal and sends it to the FM modulation/demodulation portion 10. The modulation/demodulation portion 10 modulates the carrier signal by the modulation signal and outputs an analog FM modulated signal to the radio transmitter/receiver 7. The radio frequency transmitter/receiver 7 amplifies the received FM modulated signal and sends it to the base station via the antenna 8. When the antenna 8 receives an analog radio signal from the base station, the antenna 8 sends it to the FM modulation/demodulation portion 10 via the radio frequency transmitter/receiver 7. The FM modulation/demodulation portion 10 demodulates the radio frequency FM signal and outputs the analog demodulated signal to the second linear codec 9. The second linear codec 9 converts the analog demodulated signal into a digital demodulated signal and sends it to the DSP 4. The DSP 4 converts the digital demodulated signal into a digital voice signal according to the voice procedure 56 stored in the ROM 5 and sends it to the linear codec 3. The linear codec 3 converts the digital voice signal into an analog voice signal and sends it to the speaker 2. The speaker 2 converts the analog voice signal into a voice output. In the above embodiment, it is to be noted that the DSP 4 processes the basic voice procedure of both the digital communication and the analog communication modes. Further, the DSP 4 can process other procedures in addition to the basic voice procedure such as a voice recognition procedure and an echo cancellation procedure. FIG. 2 shows a second embodiment of the present invention which processes additionally a voice recognition procedure and an echo cancellation procedure. In the second embodiment, the ROM 5 includes a voice recognition procedure 57 and an echo cancellation procedure 58 which are stored therein. In the second embodiment, the control portion 11 sends the mode information to the DSP 4. The DSP 4 selects one of the procedures and processes the selected procedure from the stored procedures 55 to 58. In the present embodiment, DSP 4 operates for each procedure selected from a number of procedures. Accordingly, only one DSP 4 is provided for the radio communication apparatus. As a result, the radio communication apparatus becomes small in size. The embodiments described above may be applied to an apparatus having functions for data transmission and facsimile transmission as well as voice transmission by providing the corresponding procedure for each function stored in the ROM 5.

Claims: A radio communication apparatus for both digital and analog communication comprising: a first linear codec (3) for analog-to-digital signal conversion and for digital-to-analog signal conversion; a ROM (5) for storing a plurality of signal procedures (55-58) used for analog and digital communication; a digital signal processor (4) adapted, in the case of digital communication, for processing a digital signal received from said first linear codec (3) and for outputting a first coded digital signal according to the corresponding signal procedure (55), and in addition, for receiving and processing a second coded digital signal according to the said signal procedure (55) and outputting a digital signal to said first linear codec (3), a digital modulation/demodulation portion (6) for generating a first digital modulated signal from the first coded digital signal, and in addition, for generating said second coded digital signal from a second digital modulated signal received from a transceiver (7); an FM modulation/demodulation portion (10); characterized in that said digital signal processor (4) is further adapted, in case of analog communication, for processing the digital signal received from the first linear codec (3) and outputting a third coded digital signal according to a voice procedure (56) stored in the ROM (5) and, in addition, for receiving and processing a fourth coded digital signal according to said voice procedure (56) and outputting a digital signal to said first linear codec (3), a second linear codec (9) is connected between said digital signal processor (4) and said FM modulation/ demodulation portion (10), said second linear codec (9) generating an analog modulation signal from said third coded digital signal and, in addition, generating said fourth coded digital signal, to be supplied to said digital signal processor (4), from an analog demodulated signal, said FM modulation/demodulation portion (10) is adapted for generating a first analog FM modulated signal from said analog modulation signal received from said second linear codec (9) and, in addition, for generating said analog demodulated signal, to be supplied to said second linear codec (9), from a second analog FM modulated signal received from said transceiver (7). The radio communication apparatus of Claim 1, wherein the ROM (5) includes a voice coding procedure (55) for processing signals supplied to and received from the digital modulation/demodulation portion (6). The radio communication apparatus of Claim 1 or 2, wherein the ROM (5) includes a voice procedure (56) for processing the signals supplied to and received from the FM modulation/ demodulation portion (10). The radio communication apparatus of any of claims 1 to 3, wherein the ROM (5) includes a data procedure for processing a digital data signal. The radio communication apparatus of any of claims 1 to 4, wherein the ROM (5) includes a voice recognition procedure (57) for processing a voice recognition signal. The radio communication apparatus of any of claims 1 to 5, wherein the ROM (5) includes an echo cancelling procedure (58) for processing an echo cancelling signal.

Inventors: NONAMI TAKAYUKI, NONAMI, TAKAYUKI, NONAMI, TAKAYUKI, C/O MITSUBISHI DENKI K.K.
Applicants: MITSUBISHI ELECTRIC CORP, MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1992
Main classification: H04B1
IPC codes: H04B7, H04M1, H04B1, H04B14