JP3147107B2 - Communication terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an appropriate simultaneous call while suppressing echo between a speaker and a microphone. SOLUTION: This equipment is provided with a PDC reception part 31 and a PDC transmission part 33 which deal with a PDC system, and a PHS reception part 32 and a PHS transmission part 34 which deal with a PHS system. Reception signals outputted from the reception part 31 and the reception part 32 through reception signal output lines 31a and 32a are composed and outputted to a speaker 26. Transmission signals inputted from a microphone 25 are inputted to the transmission part 33 and the transmission part 34 through transmission signal input lines 33a and 34a. A PDC echo cancellor 38 is provided between the reception signal output line 31a and the transmission signal input line 33a, and a PDC echo cancellor 39 is provided between the reception signal output line 32a and the transmission signal input line 34a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device such as a so-called dual mode portable terminal which can be selectively connected to any of a plurality of communication networks having different communication systems.

[0002]

As shown schematically in FIG. 4, a communication terminal device, for example, a cellular phone, generally includes a transmitting / receiving section 1 for transmitting / receiving and processing a radio signal, and a transmitting / receiving section for transmitting / receiving the signal. A control circuit 2 for controlling the unit 1 is provided. The transmitting and receiving unit 1 is connected to an antenna 3 and a speaker 4 and a microphone 5. The control circuit 2 includes a key operation unit 6.
And the display unit 7 are connected. And the speaker 4
An echo canceller 8 is provided between the reception signal output line and the transmission signal input line in order to remove an echo component generated when the sound output from the microphone is input to the microphone 5. . Note that a simplified portable telephone system (PHS) terminal has a similar configuration.

[0003] Conventionally, however, both cellular type portable telephones and PHS terminals have been provided as dedicated machines for the communication system. In contrast,
In recent years, what is called a dual mode portable terminal that can be used for both the cellular system and the PHS system has been considered.

As shown in FIG. 5, this dual mode portable terminal uses a PD instead of the transmitting / receiving section 1 shown in FIG.
P compatible with C (personal digital cellular) system
DC receiving section 9 and PDC transmitting section 10, and PH
The hardware configuration includes a PHS receiver 11 and a PHS transmitter 12 compatible with the S system. The antenna 3, the speaker 4, the microphone 5, the echo canceller 8, the key operation unit 6, and the display unit 7 are shared.

[0005] In this type of communication terminal apparatus, a three-party call service that allows three persons to talk at the same time is provided by some communication carriers. Such a three-party call has the advantage that it is not necessary to make a number of telephone calls at the time of a meeting or a schedule check by three persons, and the demand is expected to increase. However, since this type of three-party call service is effective only between users subscribing to the same carrier, it lacks flexibility. Since this is realized, there is a problem that the equipment needs to be changed in order to newly provide a three-party call service.

Therefore, if the above-mentioned dual-mode portable terminal is used, the center (exchange) of the telecommunications carrier can be used.
A three-way call can be realized without changing the function of. That is, for example, Mr. A possessing a dual-mode portable terminal makes a telephone call to Mr. B possessing a mobile phone in a cellular system, and in his circuit connection state, further communicates with Mr. C possessing a PHS terminal. This is to make a call using the PHS method. According to this, even between different types of communication terminals, Mr. A can talk with both Mr. B and Mr. C at the same time.

However, in the dual mode portable terminal having the configuration shown in FIG. 5, the voice of Mr. A can be heard by both Mr. B and Mr. C, and the voice of Mr. B and the voice of Mr. C can be heard by Mr. A, respectively. , B's voice is muted by the echo canceller 8 and cannot be heard by Mr. C. Similarly, the voice of Mr. C has been muted by the echo canceller 8 and cannot be heard by Mr. B. In this case, from the original purpose of the three-way call, the voice of Mr. B output from the speaker 4 of the dual-mode portable terminal is:
It is desirable to reach Mr. C through the microphone 5, but if the function of the echo canceller 8 does not exist, an echo or howling will occur and a satisfactory call cannot be made.

The present invention has been made in view of the above circumstances, and an object of the present invention is to enable simultaneous communication with a plurality of communication partners while simultaneously establishing communication lines for a plurality of communication networks. Accordingly, it is an object of the present invention to provide a communication terminal device that enables appropriate simultaneous communication while suppressing echo between a speaker and a microphone.

[0009]

SUMMARY OF THE INVENTION A communication terminal device according to the present invention is capable of simultaneously communicating with a plurality of communication partners while simultaneously establishing communication lines for a plurality of communication networks. In each of a plurality of communication systems, an echo canceller is provided between a reception signal output line that outputs a reception signal from a reception unit to a speaker and a transmission signal input line that inputs a transmission signal from a microphone to a transmission unit. The present invention is characterized in that it is provided (the invention of claim 1).

The echo canceller estimates a transfer characteristic of an echo path, creates a pseudo echo from a received signal, and subtracts the pseudo echo from a transmitted signal to remove an echo component. According to the present invention, an echo canceller is provided between a reception signal output line and a transmission signal input line for each of a plurality of communication systems, so that even when a call is made using any communication system, An echo component generated due to the sound output from the speaker by the reception signal from the receiving means being input to the microphone is removed by a corresponding echo canceller and then input to the transmitting means. That is, a clear call can be made.

In the case where a telephone line is simultaneously established with a plurality of communication partners while a communication line is simultaneously established with a plurality of communication networks, a reception signal output from one receiving means relating to one communication system is received. When a sound is output from the speaker by the signal, the sound is input to the microphone. At this time, in the transmission signal input to one transmission unit according to the communication method, the echo component is reduced by the echo canceller. The audio output from the speaker is removed and input as a transmission signal as it is without being canceled to the transmission means according to another communication method.

Therefore, according to the first aspect of the present invention, it is possible to simultaneously make a call with a plurality of communication partners, and while receiving a function as an echo canceller, receiving a speaker by one communication method. Is transmitted by another communication method through a microphone, and an excellent effect of enabling appropriate simultaneous communication can be achieved.

[0013] In this case, as the plurality of communication systems, more specifically, two types of mobile communication systems, a cellular system and a PHS system, can be included (the invention of claim 2). A three-party call can be made between different types of communication terminals of the cellular system and the PHS system.

Further, if a display means for displaying which communication network is connected among a plurality of communication networks is provided (the invention of claim 3), which communication network (communication system) is currently displayed to the user. It is easy to know if you are using Further, a plurality of operation keys for selecting which of the plurality of communication networks to connect to at the time of calling may be provided corresponding to each communication network (the invention of claim 4). As a result, the user can easily select a communication network to be connected, and the operability at that time can be improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a so-called dual mode portable terminal which can be used in two types of communication systems, a PDC (cellular) system and a PHS system, will be described below with reference to FIG. This will be described with reference to FIG. First, FIG. 2 shows a dual mode portable terminal 21 (hereinafter simply referred to as “portable terminal 2”) as a communication terminal device according to the present embodiment.
1 ").

The main body 22 of the portable terminal 21 has a vertically long shape which is portable and has a key operation section 23 located on the lower side on the surface thereof and a key operation section 23 on the upper side. A display unit 24 composed of an LCD is provided. Further, a microphone 25 for inputting a transmission sound is provided at a lower end portion, and a speaker 26 for outputting voice is provided above the display portion 24. Further, an antenna 2 serving as a transmission unit for transmitting a transmission / reception signal via a communication network is provided at an upper end portion of the main body 22.
7 is provided so as to be able to be pulled out.

The key operation section 23 has keys such as an end / power key 23a, a menu key 23b, a cursor key 23c, a plurality of dial keys 23d corresponding to numbers and characters, and a function key 23e. , Two start keys 28 and 29 are provided. These two start keys 28 and 29 are operated at the time of calling and receiving, and correspond to the PDC communication network and the PHS communication network, respectively, and determine which communication network the user connects to at the time of calling. It functions as an operation key for selection.

Although not shown, LEDs are arranged on the back side of the two start keys 28 and 29, respectively, to correspond to the communication network connected at the time of communication (line connection). The LED is turned on and the key is bright. Further, when a call is received, a ringing tone and an LED corresponding to the corresponding communication network are provided.
Is blinking. Therefore, by operating the blinking start key 28 or 29, a call can be received.

The start keys 28 and 29 (LE
D) also functions as display means for displaying which of the plurality of communication networks is connected. The display unit 24 displays a telephone number, various messages, and the like.
The connected communication network (PDC or PHS) is also displayed in characters on the display unit 24, and this also functions as a display unit.

FIG. 1 schematically shows an electric configuration of the portable terminal 21. Here, in the main body 22, a control circuit 30 mainly configured by a microcomputer and performing overall control is provided, and as a receiving unit controlled by the control circuit 30 to process a received signal. A PDC receiving unit 31, a PHS receiving unit 32, and a PDC transmitting unit 33 and a PH as transmitting means controlled by the control circuit 30 to process a transmission signal.
An S transmitting section 34 is provided.

The receiving units 31 and 32 and the transmitting unit 33
And 34 are connected to the antenna 27 via a duplexer 35. Then, as described later, the receiving unit 3
1 and 32 are connected to the speaker 26, respectively, and the transmission units 33 and 34 are connected to the microphone 25, respectively.
The control circuit 30 receives an operation signal from the key operation unit 23, and controls display on the display unit 24 and lighting control of the LED.

The PDC receiving unit 31 and the PDC transmitting unit 33 correspond to the PDC system, and the PDC receiving unit 31 receives a 1.5 GHz band radio wave received signal from the antenna 27. The reception signal is converted into a reception signal and output to the speaker 26.
When a transmission signal is input from the microphone 25, the PDC transmission unit 33 converts the transmission signal into a transmission signal and outputs it as a 1.5 GHz band radio wave from the antenna 27. PD via 36 (see FIG. 3)
C-mode communication (communication) is enabled.

On the other hand, the PHS receiver 32 and the PHS
The transmitting unit 34 for the PHS system
When a reception signal of a radio wave in the 1.9 GHz band is input from the antenna 27, the reception unit 32 converts the reception signal into a reception signal and outputs the reception signal to the speaker 26. Further, the PHS transmission unit 34 is provided with the microphone 25.
When the transmission signal is input from the PHS communication system, the transmission signal is converted into a transmission signal and output from the antenna 27 as a radio wave of a 1.9 GHz band. Communication (call) is made possible.

At this time, the PDC receiving unit 31 and P
The receiving signals output from the receiving section 32 for HS via the receiving signal output lines 31a and 32a are synthesized and output to the speaker 26. The transmission signal input from the microphone 25 is transmitted to the PDC transmission unit 3 via transmission signal input lines 33a and 34a.
3 and the PHS transmission section 34.

In this embodiment, a PDC echo canceller 38 is provided between the PDC reception signal output line 31a and the transmission signal input line 33a.
A PHS echo canceller 39 is provided between the HS reception signal output line 32a and the transmission signal input line 34a. These echo cancellers 38 and 39
Includes an adaptive filter that, as is well known, estimates a transfer characteristic of an echo path and creates a pseudo echo from a received signal.
By subtracting the pseudo echo from the transmission signal, the echo component is removed.

Now, with the above configuration, the portable terminal 21
Can be used for both a call using the PDC system connected to the PDC communication network 36 and a communication call using the PHS system connected to the PHS communication network 37, respectively. In the present embodiment, simultaneous three-party communication using both of these two types of communication networks 36 and 37 is possible. In addition, the portable terminal 21 has
Both a PDC phone number and a PHS phone number are assigned.

Next, the operation of the above configuration will be described with reference to FIG. The user of the portable terminal 21 can selectively connect to either the PDC communication network 36 or the PHS communication network 37 when establishing a communication line with a communication partner. The PDC method and the PHS method can be selectively used depending on the model of the terminal device, the difference in communication fee and service for each communication carrier, and the like.

In this case, during a call using the PDC system, an echo component generated due to the sound output from the speaker 26 due to the reception signal from the PDC receiving unit 31 being input to the microphone 25 is PDC
After being removed by the echo canceller 38, it is input to the PDC transmission unit 33, and a clear call can be made. At this time, the LED of the PDC start key 28 lights up, and the display unit 24 displays “PD
The character "C" is displayed.

On the other hand, during a call using the PHS system, an echo component generated by the sound output from the speaker 26 by the reception signal from the PHS receiving unit 32 being input to the microphone 25 is a PHS signal. After being removed by the echo canceller 39, the signal is input to the PHS transmitter 34, so that a clear call can be made. At this time, the LED of the PHS start key 29 is turned on, and the characters “PHS” are displayed on the display unit 24.

Then, as described above, this portable terminal 2
By using 1, the simultaneous three-party communication can be performed using both the PDC communication network 36 and the PHS communication network 37. FIG. 3 schematically shows a state of the three-way call. In the three-way call, Mr. A who owns the dual-mode portable terminal 21 is, for example, a portable terminal of a PDC system (or a dual-mode portable terminal). Terminal) 4
PDC communication network 36 for the communication partner (Mr. B) having 0
In addition, in the line connection state according to the above, furthermore, for example, the line is simultaneously connected to the communication partner (Mr. C) having the PHS type portable terminal (or dual mode portable terminal) 41 by the PHS communication network 37. .

As a specific procedure, when Mr. A wants to make a three-way call with Mr. B and Mr. C, first, for example, he inputs the telephone number of Mr. B (portable terminal 40), and The call is transmitted by the start key 28, and the line with Mr. B is connected by the PDC communication network 36. At this time,
The LED of the start key 28 is lit. Then, in that state, enter the phone number of Mr. C (portable terminal 41),
The unlit PHS start key 29 is operated to make a call, and the line is connected by the PHS communication network 37. At this time, both LEs of the start keys 28 and 29 are
D comes on. In this case, it is needless to say that a call may be made from Mr. B (or Mr. C) to Mr. A.

At the time of the three-party call, as shown in FIG. 1, when the voice of Mr. A is input from the microphone 25, the transmission signal is transmitted to the BDC by the PDC transmission unit 33 and the PHS transmission unit 34. Sent to both his portable terminal 40 and his portable terminal 41, Mr. B and Mr. C can hear their voices. Also, the portable terminal 40 (B
The reception signal from the user is output from the speaker 26 via the PDC receiving unit 31, and the portable terminal 41 (C
) Is output from the speaker 26 via the PHS receiving unit 32, and Mr. A can hear both of Mr. B and Mr. C.

Thus, in order to perform an appropriate simultaneous three-party call, Mr. B's voice reaches Mr. C, and Mr. C's voice reaches B
Need to reach Mr. In the present embodiment, the PDC receiving unit 3
1 from the speaker 26 according to the reception signal output from
When his voice is output, the voice is input to the microphone 25. At this time, in the transmission signal input to the PDC transmitting unit 33, the echo component is removed by the PDC echo canceller 38, The voice of Mr. B from the speaker 26 is directly input to the PHS transmission unit 34 as a transmission signal without being canceled.

Similarly, when the voice of Mr. C is output from the speaker 26 by the reception signal output from the PHS receiving unit 32, the voice is input to the microphone 25. At this time, the PHS transmitting unit The echo component is removed from the transmission signal input to 34 by the PHS echo canceller 39, and the voice of Mr. C from the speaker 26 is input to the PDC transmission unit 33 as it is without being canceled. Will be done. Therefore, it is possible to send Mr. B's voice to Mr. C, and also to send Mr. C's voice to Mr. B, while securing the function of echo cancellation by the echo cancellers 38 and 39 and making a clear call. Therefore, it is possible to enable appropriate simultaneous three-party communication.

As described above, according to the present embodiment, simultaneous communication by three parties can be made in a state where communication lines are simultaneously established for both the PDC communication network 36 and the PHS communication network 37. Unlike the three-party calling service, three-way calling is possible even between different types of communication terminals, and the flexibility is increased. Moreover, the mobile terminal can be used independently of the function at the center (exchange) of the communication carrier. Since this is realized by the function of the switching device 21, it is possible to suffice without a significant change of the switching equipment.

The receiving signal output line 3 for PDC
1a and the transmission signal input line 33a;
Receiving signal output line 32a and transmitting signal input line 3
4a, the PDC echo canceller 38 and the PHS echo canceller 39 are provided, respectively.
This makes it possible to solve the problem that the sound cannot be heard by Mr. C, and it is possible to perform an appropriate simultaneous call while suppressing the echo between the speaker 26 and the microphone 25. It is effective.

Furthermore, in the present embodiment, in particular, for the respective communication systems (communication networks) of the PDC system and the PHS system, individual start keys 28 and 29 are provided, so that the user can easily select the communication network to be connected. Since the operability at that time can be improved, and which communication network is connected, the start keys 28 and 29 are turned on and the display unit 24 is displayed. It is also possible to obtain an advantage that the user can easily know which communication network (communication system) is currently used.

In the above embodiment, the PDC system and the PH
Although the two types of communication systems called the S system have been described as examples, the communication system may be an analog cellular system, a CDMA system, or the like. The present invention can also be applied to communication using a general public line. Furthermore, a configuration in which three or more types of communication schemes can be used may be employed, thereby realizing simultaneous communication of four or more parties.

In addition, the present invention may be applied to, for example, a device which has a function of making a voice call so as to enable a so-called hands-free call, and various modifications of a hardware configuration such as a key operation unit are possible. Yes, for example, the start keys 28 and 29 may be composed of one switching key.
The present invention can be implemented with appropriate modifications without departing from the gist.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically illustrating an electrical configuration of a dual mode portable terminal according to an embodiment of the present invention.

FIG. 2 is a front view showing the appearance of the dual mode portable terminal.

FIG. 3 is a diagram schematically illustrating a three-party call;

FIG. 4 is a diagram corresponding to FIG. 1 showing a conventional example.

FIG. 5 is a diagram corresponding to FIG. 1 showing another conventional example.

[Explanation of symbols]

In the drawing, 1 is a dual mode portable terminal (communication terminal device), 23 is a key operation unit, 24 is a display unit, 25 is a microphone, 26 is a speaker, 27 is an antenna (transmission means), and 28 and 29 are start keys ( Operation keys), 30 is a control circuit, 31 is a PDC receiving unit (receiving means), 32 is a PH
S receiving unit (receiving unit), 33 is a PDC transmitting unit (transmitting unit), 34 is a PHS transmitting unit (transmitting unit), 36 is P
A DC communication network, 37 is a PHS communication network, and 38 and 39 are echo cancellers.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-79479 (JP, A) JP-A-10-9680 (JP, A) JP-A-11-4183 (JP, A) JP-A-5-79 218957 (JP, A) JP-A-6-284464 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04M 1/00 H04M 1/58-1/62 H04M 11/00- 11/10 H04B 7/24-7/26 113 H04Q 7/00-7/38

Claims (4)

(57) [Claims] 1. A microphone for inputting a transmission signal, a speaker for outputting a reception signal, transmission means for transmitting a transmission / reception signal via a communication network, and a plurality of communication systems provided corresponding to a plurality of communication systems, respectively. A plurality of transmission means for converting a transmission signal input from a microphone into a transmission signal and outputting the transmission signal to the transmission means, and converting a reception signal from the transmission means provided for each of a plurality of communication systems into a reception signal And a plurality of receiving means for outputting to the speaker, and when establishing a communication line with a communication partner, communication of one communication method and another communication method which are different from each other is established.
A communication terminal device capable of selectively connecting to a communication network, wherein the communication terminal device is connected to a communication network of one communication method and further connected to another communication network.
Is provided so that it can be connected to a communication
And while simultaneously establishing a communication line for a plurality of communication networks in other communication systems, it is configured to be able to simultaneously talk with a plurality of communication partners, and for each of the plurality of communication systems, An echo canceller is provided between a reception signal output line for outputting a reception signal from a reception unit to a speaker and a transmission signal input line for inputting a transmission signal from the microphone to a transmission unit. Communication terminal device. 2. The communication terminal device according to claim 1, wherein the plurality of communication systems include two types of mobile communication systems, a cellular system and a PHS system. 3. The communication terminal device according to claim 1, further comprising a display unit that displays which of the plurality of communication networks is connected. 4. A plurality of operation keys for selecting which one of the plurality of communication networks to connect to at the time of outgoing call are provided for each communication network. 4. The communication terminal device according to any one of 1 to 3.