JPH05284057A - Portable terminal equipment - Google Patents

Abstract

PURPOSE:To provide a compact portable terminal equipment facilitating switching by attaching/detaching a first unit enabling analog communication and a second unit enabling digital communication, and automatically switching to a digital communication system when the second unit is mounted. CONSTITUTION:A portable telephone set is composed of an analog communication system unit 11 and a digital communication system unit 20, and both of units 11 and 20 can be attached and detached through a connecting terminal 12. The input side of an amplifier 7a, the output side of an amplifier 7b, the input side of a demodulation part 5 and the output side of a modulation part 6 are switched to a circuit on the side of the digital communication system unit 20 by a switch 4. This switching is controlled by an analog communication system unit control circuit 10. When the digital communication system unit 20 is connected, the control circuit 10 connects the switch 4 to the side of digital modulation/demodulation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile terminal device capable of arbitrarily selecting an analog communication system or a digital communication system for mobile communication.

[0002]

2. Description of the Related Art In the present analog communication system, there is an advantage that a cover area is large and a terminal device can be downsized. On the other hand, in the current digital communication system, the cover area is small and the device is large, but it is expected that the cover area will be expanded and the device will be miniaturized due to the use of ICs in the future. By the way, the mobile terminal device with the fixed communication method has a drawback that it cannot receive services of other methods. Also,
A mobile terminal device compatible with a dual mode in which an analog communication system and a digital communication system are mixed can receive both the analog communication system service and the digital communication system service, but has a drawback that the device becomes large. ..

[0003]

As described above, in the conventional art, the demand for portable terminal devices that can use both the analog communication system and the digital communication system has been increasing. Therefore, it has been proposed to simply integrate a terminal of an analog communication system and a terminal of a digital communication system and use them by switching them.

However, in such a device, it is difficult for the user to arbitrarily select the communication system due to the difference in the communication systems and the difference in the coverage area, and in the portable terminal device compatible with all the communication systems. It is disadvantageous in terms of size.

The present invention has been made in order to solve such a conventional problem, and an object thereof is to provide a portable terminal device in which communication modes can be easily switched and which can be constructed in a small size. To do.

[0006]

In order to achieve the above object, the present invention provides a first unit capable of analog communication, and a second unit detachably attached to the first unit and capable of digital communication. It is characterized by having a unit and a switching means for automatically switching to the digital communication mode when the second unit is mounted.

[0007]

With the above-mentioned structure, it is possible to use as a small-sized analog communication type terminal device by using only the first unit. Also, the second unit
When the unit of No. 1 is attached, the modulation unit and demodulation unit of the first unit and the modulation unit and demodulation unit of the second unit are switched by the communication system switching unit, so that it can be used as a terminal device of the digital communication system. ..

Further, the communication system used by the analog and digital communication systems is detected depending on the switching status of each unit, and the base station is notified of the communication system being used.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a mobile phone as a mobile terminal device to which the present invention is applied.

As shown in the figure, this portable telephone is composed of an analog communication system unit 11 and a digital communication system unit 2.
It is roughly divided into 0 and both units 11, 20.
Is removable via the connection terminal 12.

The analog communication system unit 11 includes an antenna 1 and an RF section 2 for frequency conversion of a transmission / reception signal, an IF section 3 for detecting a signal, a demodulation section 5, and a modulation section 6.
And amplifiers 7a and 7b, a speaker 8 and a microphone 9. Further, the input side of the amplifier 7a, the output side of the amplifier 7b, the input side of the demodulation section 5, and the output side of the modulation section 6 are
The switch 4 switches to a circuit on the digital communication system unit 20 side, and this switching is controlled by the analog communication system unit control circuit 10.

The digital communication system unit 20 includes a demodulation section 13, a modulation section 14, a channel codec section 15 for switching a communication format for digital communication,
Speech codec unit 1 for digitizing voice signals
6, D / A converter 17, and A / D converter 18. In addition, the digital communication system unit control circuit 1
Reference numeral 9 adds a signal indicating that it is operating in the digital communication system to the voice signal and the control signal as shown in FIG. 3 to notify the base station of the communication system currently used.

The input side of the demodulation section 13, the output side of the modulation section 14, the output side of the D / A converter 17, and the input side of the A / D converter 18 are described above via the connection terminal 12. It is connected to each switch 4 of the analog communication system unit 11.

Next, the operation of this embodiment will be described.
The received signal received by the antenna 1 is the RF unit 2, I
It passes through the F section 3 and is converted into a low frequency band. When the digital communication system unit 20 is not connected, the signal from the analog communication system unit control circuit 10 causes
The switch 4 for selecting the communication method is connected to the analog modulation / demodulation side. Therefore, the frequency-converted received signal is demodulated into a voice signal and reaches the human ear through the amplifier 7 and the speaker 8. Also, the audio signal obtained by the microphone 9 is
The signal is modulated by the analog modulator 6, converted into a propagation frequency by passing through the IF section and the RF section, and transmitted from the antenna 1.

On the other hand, when the digital communication system unit 20 is connected, the analog communication system unit control circuit 1
0 connects the switch 4 to the digital modulation / demodulation side. The received signal received by the analog communication system unit 11 is
Digital demodulation unit 1 from IF unit 3 via connection terminal 12
3 is processed by a channel codec, a speech codec, etc., and then D / A converted into an audio signal. Conversely, the audio signal obtained by the microphone 9 is A / D
It is converted and subjected to processing such as speech codec and channel codec. At this time, the digital communication system unit control circuit 19 adds a signal indicating that the digital communication system is operating to the voice signal and other control signals in order to inform the base station of the communication system to be used (FIG. 3). .. After that, the transmission signal is digitally modulated, converted into a propagation frequency by the IF unit 3 and the RF unit 2 of the analog communication system unit 11 and transmitted.

FIG. 2 shows an example of a method of connecting each unit. The digital communication unit 23 is mounted on the rear surface of the analog communication system unit 21, and both units are connected by inserting the unit connection terminal 22. Here, the battery 24 is also equipped on the digital communication system unit 20 side, and this power source is mainly used on the digital circuit side. The control circuit in the analog communication unit 21 checks the voltage of each battery, and if either battery is discharged,
Connect to the other battery.

FIG. 3 is a conceptual diagram of transmission signal data. In addition to the frame synchronization signal and the control signal containing the destination telephone number, a model setting signal indicating the communication system is transmitted using a part of the area of the voice data signal. Thereby, the base station detects which communication method is used for communication.

FIG. 4 shows a modification of this embodiment. By replacing different types of digital communication system units 20 with analog communication system units, it is possible to support various communication systems such as FDMA, TDMA, and CDMA.

FIG. 5 corresponds to a communication carrier using a different communication system and replaces it with a digital communication system unit suitable for each system, thereby dealing with the difference in the coverage area depending on the communication system.

FIG. 6 shows an example of a frequency conversion unit for supporting different frequency bands. For example, if you want to perform communication in the 1.2 GHz band with an analog communication system unit compatible with the 900 MHz band, by installing the frequency conversion unit 25 corresponding to the input frequency,
An IF signal having a constant frequency can be obtained even for different input frequencies, and a desired operation is performed. Furthermore, by connecting a digital communication system unit to the analog communication system unit and the frequency conversion unit, it is possible to support digital communication systems of different frequencies.

FIG. 7 is a block diagram and connection diagram of the frequency conversion unit 25 and the analog communication system unit 11. The analog communication system unit control circuit 10 switches the frequency unit changeover switch 26 to the frequency conversion unit side by connecting the frequency conversion circuit. As a result, the analog communication system unit 11 can operate corresponding to different frequencies.

FIG. 8 shows that the unit connection terminal of the analog communication system unit can be used to connect a battery to the terminal, whereby the call time and the reception waiting time can be extended.

[0023]

As described above, according to the present invention,
The first unit capable of analog communication and the second unit capable of digital communication are detachably configured, and when the second unit is mounted, the digital communication system is automatically switched. Further, it is not necessary to mount the second unit when performing analog communication.

Therefore, it is possible to obtain a wide range of use corresponding to each communication system and to achieve miniaturization.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a mobile terminal device to which the present invention is applied.

FIG. 2 is a perspective view showing the external appearance of the mobile terminal device of this embodiment.

FIG. 3 is a conceptual diagram of a data format.

FIG. 4 is a connection diagram of units corresponding to different communication systems.

FIG. 5 is a unit connection diagram for coping with a telecommunications carrier having different coverage areas.

FIG. 6 is a connection diagram of a frequency conversion unit.

FIG. 7 is a block diagram showing a connection status of a frequency conversion unit.

FIG. 8 is a connection diagram of an external auxiliary power supply using a unit connection terminal.

[Explanation of symbols]

 1 antenna 2 RF part 3 IF part 4 communication method selection switch 5 analog demodulation part 6 analog modulation part 7 amplifier 8 speaker 9 microphone 10 analog communication system unit control circuit 11, 21 analog communication system unit 12, 22 connection terminal 13 digital demodulation part 14 digital modulation section 15 channel codec section 16 speech codec section 17 D / A converter 18 A / D converter 19 digital communication system unit control circuit 20, 23 digital communication system unit 24 battery 25 frequency conversion unit 26 frequency unit changeover switch

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04M 1/02 B 9077-5K

Claims (1)

[Claims] 1. A first unit capable of analog communication, a second unit detachably attached to the first unit and capable of digital communication, and digital communication automatically performed when the second unit is mounted. A mobile terminal device comprising: switching means for switching to a mode.