JP2983829B2 - Digital mobile phone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital portable telephone device capable of wirelessly communicating voice and data, and more particularly, to determining whether a voice signal is sound or not, and determining that the sound signal is sound. A digital portable telephone device that performs so-called VOX (Voice Operated Transmitter) control, which transmits only data and stops transmission by turning off the power amplifier and the like of the transmitter in a silent period to propose power consumption of the transmitter. It is about.

[0002]

2. Description of the Related Art Today, a cellular system that connects a portable terminal wirelessly to a general telephone network to make a telephone call has been remarkably spread. In this cellular system, the analog system was initially adopted and the 800 MHz band was allocated, but since demand is expected to increase in the future,
Recently, more efficient wireless telephone systems employing digital methods have been introduced. In the digital cellular system (hereinafter referred to as PDC system), in addition to the 800 MHz band,
A 1.5 GHz band is newly assigned and digitization is being carried out to improve the frequency use efficiency and communication quality, as well as to enhance the secret function and communication contents.

[0003] Such a PDC system is standardized by a standard standard [STD-27B] for a digital car telephone system. According to this standard, a π / 4 shift QPSK is used as a modulation system, and a TDMA system (time division multiple access) is used as a communication system. Connection method), and (vector sum excitation linear predictive coding method (VSELP)) as a speech coding method.

On the other hand, in a mobile communication device such as a mobile phone, conventionally, as described in Japanese Patent Application Laid-Open No. 4-114520 (H04B 7/26), the power consumption of a transmitter is reduced. Next, VOX control is generally performed. The above-mentioned standard [STD-27B] of the digital car telephone system is also standardized as an optional function.

[0005]

By the way, a so-called hold function for temporarily stopping a call during a call is conventionally known. When a call is put on hold during a call, a device on the holding side executes the hold function. At the same time as generating a melody sound indicating a hold, the melody sound is transmitted as voice from the side that executed the hold to the other party, and the other party recognizes the melody sound.

However, in a system using VSELP as a speech encoding method like the above-mentioned PDC system, V
When the OX control is executed, there is a problem that the held melody sound is not correctly transmitted. That is, since the melody sound is formed by sequentially generating a single sound electrically, unlike a normal conversational voice, the melody sound is discontinuous between the sounds, and the VOX control operates at the discontinuous portion. The head of the sound is interrupted, making it very hard to hear as a melody.

Further, in order to prevent malfunction of VOX control due to noise, there is a case where a noise determination circuit is used. In such a case, a continuous sound is determined as noise, and the VOX operates erroneously. There was also.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has a codec circuit for encoding audio input from a microphone, and an apparatus for detecting the presence or absence of audio input. A VOX control circuit for performing VOX control based on a judgment result of the sound judgment circuit which is inputted as a sound judgment circuit, and a codec which outputs a melody signal from a melody generating unit in place of a sound from a microphone by a user's holding operation. In a digital portable telephone device configured to input to a circuit, when a hold is instructed, a hold sound from a melody generating unit is input to a codec circuit instead of a voice signal from a microphone and VOX control is turned off. It is characterized by having done.

[0009]

When the hold is instructed even if the VOX control is in operation, a hold melody is sent out and the VOX is controlled.
Control is forcibly turned off.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a digital portable telephone device according to the present invention. A speech voice signal input from a microphone 1 is transmitted to a VSELP codec circuit 4 via a voice processing circuit 2 and a changeover switch 3. V
SELP encoding is performed. And then TDMA /
After a scramble process and a CRC code process are performed by the VOX control circuit 5, the data is formatted into a prescribed data sequence, subjected to π / 4 shift QPSK modulation processing by the modulation circuit 7, and transmitted from the antenna 8 via the transmission circuit 7. Is done.

On the other hand, reference numeral 9 denotes a hold mode setting switch. When the user presses this switch during a call and instructs to set the hold mode, the system control circuit 10 switches the changeover switch 3, and as a result,
Instead of the audio signal from the microphone 1, the melody generator 1
The melody sound of a single sound generated by 1 is selected and transmitted from the antenna 8 via the VSELP codec circuit 4, the TDMA / VOX control circuit 4, the modulation circuit 6, and the transmission circuit. At this time, a melody sound is also generated from the speaker 12 for confirmation.

The signal encoded by the VSELP codec circuit 4 is determined by a sound determination circuit 13 as to whether the signal is voiced or unvoiced.
It is determined whether the signal input from is noise. The noise determination circuit 14 determines whether or not a signal of a constant frequency is noise by determining whether or not the signal has continued for a predetermined time. When the VOX function is turned on by the user's setting, the judgment results of the sound judgment circuit 13 and the noise judgment circuit 14 are transmitted to the TDMA / VOX control circuit 5 via the OR gate 15, The following VO
X processing is performed.

That is, FIG. 2 shows a signal format in a communication physical channel.
(B) shows a signal format when the OX function is off or when the VOX function is on and there is sound, and (B) shows a signal format when the VOX function is on and there is no sound. The signal format is 28 slots per slot (6.6 mS).
0 bit is arranged.

When the VOX is off or VOX shown in FIG.
When turned on and having sound, the audio data encoded by the VSELP codec circuit 4 is formatted into a total of 224 bits in two TCH areas. On the other hand, when the VOX function is set to ON and the sound determination circuit 13 determines that there is no sound or the noise determination circuit 14 determines that the signal input from the microphone 1 is noise, As shown in FIG. 1B, the transmission of the TCH for transmitting the encoded audio data is not performed, and the number of data is reduced during that period, so that the transmission power is reduced.

On the other hand, during a call, the hold mode setting switch 9
Is turned on, the changeover switch 3 is turned on by the hold instruction signal from the system control unit 10 so that the melody sound generating unit 1 is turned on.
Switch to melody sound output signal from VSELP
It is sent to the codec circuit 4.

At this time, if the VOX function is set to ON, the sound determination circuit unit 13 makes a judgment on the melody sound by executing the hold, and as described above, there is a melody depending on the type of the melody sound. In some cases, a part of the melody sound may be determined to be silent, and part of the encoded data of the melody sound may not be transmitted. As a result, the melody sound may be interrupted at the other party. When a noise having a single frequency is continuously input for a predetermined period of time as in this embodiment, a melody is determined to be a single frequency when a noise determination circuit 14 is used to determine that noise has been input. In general, the melody is determined to be noise, and VOX control is performed.

In order to cope with this problem, a hold instruction signal from the system control unit 10 is input to the OR gate 15, and if a hold is executed when the VOX function is turned on, a sound determination is forcibly performed. . When the hold mode setting switch 9 is released, the setting returns to the setting of the VOX function before execution of the hold.

[0018]

As described above, in the digital portable telephone device according to the present invention, when the hold is instructed, the hold sound from the melody generating unit is input to the codec circuit instead of the voice signal from the microphone, and the VOX control is performed. Is turned off, the hold is instructed when the VOX function is set to ON, and the correct melody sound is transmitted without the VOX control malfunctioning even if the hold melody is input instead of the voice signal. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a digital mobile phone device according to the present invention.

FIG. 2 is a diagram showing a transmission format of the digital portable telephone device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microphone 3 Changeover switch 4 Codec circuit 5 VOX control circuit 9 Hold mode setting switch 10 System control circuit 11 Melody generating section 13 Sound judgment circuit 14 Noise judgment circuit 15 OR gate

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takahisa Uchimoto 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Kazuyoshi Kamiyoshi 2-5-5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Inside Sanyo Electric Co., Ltd. (56) References JP-A-7-79486 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H04B 7/24-7/26 102 H04Q 7/00-7/38

Claims (2)

(57) [Claims] A VOX control is performed based on a codec circuit that encodes a voice input from a microphone, a sound determination circuit that detects the presence or absence of a voice input, and a determination result of the voice determination circuit that is input. A VOX control circuit and a digital mobile phone device configured to input a melody signal from a melody generating unit to the codec circuit in place of voice from a microphone by a user's holding operation, the microphone being used when a hold is instructed. A digital mobile telephone device characterized in that a hold tone from a melody generating unit is input to a codec circuit in place of a voice signal from the melody generator and VOX control is turned off. 2. The digital portable telephone device according to claim 1, further comprising noise determination means for determining that noise has been input when a predetermined frequency is continuously input for a predetermined time.