JP2630864B2 - Wireless telephone equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio telephone apparatus having a base unit connected to a general subscriber's telephone line unit and a slave unit capable of communicating with the base unit through a radio line unit, for example, a cordless telephone. It concerns a telephone.

[0002]

2. Description of the Related Art In a wireless telephone device, for example, a cordless telephone, it is common to use a noise reduction circuit to remove noise coming from a wireless system. Generally, a circuit using a signal compression / expansion (compander) IC is the most popular noise reduction circuit. Needless to say, the principle of this noise reduction circuit is to reduce the noise by compressing and transmitting the signal on the transmitting side and expanding the signal on the receiving side. In the case of a set adopting a noise reduction circuit using a compander IC, a DTMF (Dual T) which is a network control signal is used.
One Multi Frequency) signal was created on the master unit side and sent to the telephone line unit. On the other hand, communication data was sent from the slave unit to the master unit.

[0003]

In the above-mentioned cordless telephone, when the dial button of the slave unit is operated to transmit the DTMF signal generated on the master unit side to the telephone line unit, the slave unit cannot be used. It is necessary to continuously send communication data from the machine to the master machine. In this process, communication data may be disturbed by noise or the like, and a data transmission error may occur to cause a malfunction. In order to prevent this, it is necessary to read at least two frames instead of just reading one frame of data. By the way, one frame (18
Bit), it takes 130 to 150 ms for two frames, and 260 to 300 ms for two frames.
When sending digit data, 260-300
This would take a time of m seconds. DTMF signal is 50m
It is sufficient that the transmission time is not less than seconds, and the design value is usually set to 80 ms to 150 ms. Therefore, when it takes 260 to 300 msec to read communication data as described above, when the dial key is pressed at a fast speed, the DTMF signal transmission speed is transmitted to the speed of pressing the dial key. After the dial key was pressed, the DTMF signal was sent out after the dial key was pressed, resulting in a problem that the user was very uncomfortable.

In a conventional cordless telephone, a DTMF signal is generated by a microcomputer of the master unit and transmitted to the telephone line. In this case, however, the microcomputer of the master unit is used as the microcomputer. Must perform DTMF signal generation and transmission to the telephone line unit while performing data communication with the slave unit. Therefore, a high processing speed of the microcomputer is required, and there is a disadvantage that an expensive microcomputer must be used in view of cost. Therefore, it is conceivable to create the DTMF signal on the slave unit side to eliminate the above-mentioned disadvantages.

By the way, the DTMF signal [FIG.
(A)], the DTMF signal must be sent through a signal compression circuit constituting a noise reduction circuit because the DTMF signal is an analog signal. On the other hand, the DTMF signal received and demodulated by the master unit passes through a signal expansion circuit constituting a noise reduction circuit.
As shown in (b), the rise time of the DTMF signal is delayed, and the DOC standard (Canadian standard 90% within 5 ms)
Have to rise up to the level).

[0006]

Therefore, the present invention comprises a master unit connected to a general subscriber telephone line unit, and a slave unit capable of communicating with the master unit via a wireless line unit. A wireless telephone having a noise reduction circuit of a signal compression / expansion system in each of the slave units, a DTMF signal generation means provided on the slave side, and a DTMF signal from the DTMF signal generation means being transmitted to the master side. In the device,
The slave unit is provided with mute data generation means, and when transmitting a DTMF signal from the slave unit side to the master unit side, mute data from the mute data generation unit is also transmitted to the master unit side, and the master unit has A mute signal generating means for receiving the mute data and generating a mute signal, wherein the DTMF signal, which is demodulated on the master unit side and then sent to the telephone line unit through the noise reduction circuit, It is characterized in that it is configured to mute for a predetermined time by a signal from the generating means.

[0007]

According to the present invention, the DTMF signal generation means is provided on the slave unit side, and the DTMF signal from the DTMF signal generation means is transmitted to the master unit side. There is no need to send communication data for creating a DTMF signal from the slave unit to the master unit. Further, according to the present invention, the mute signal generating means is provided on the master unit side to mute the DTMF signal sent to the telephone line for a predetermined time, that is, the delay of the rise of the DTMF signal is reduced. Since the mute is applied for the time of occurrence, the DTMF signal rises to a predetermined level in a short time when the mute is released.

[0008]

1 and 2 show a radio telephone according to the present invention, for example, a telephone.
FIG. 2 is a diagram showing one embodiment of a slave unit A and a master unit B constituting a dress telephone.

In FIG. 1 showing a slave unit A, reference numeral 1 denotes a transmission / reception antenna constituting a radio line unit, reference numeral 2 denotes a duplexer (DPX) circuit for separating transmission waves and reception waves by frequency, and reference numeral 3 denotes a reception high frequency. (RF) amplifier, 4 is a reception mixer circuit, 5 is an intermediate frequency (IF) amplifier, and 6 is a detection (DE)
T) circuit, 7 is a preamplifier, 8 is a signal expansion (expander) circuit constituting a noise reduction circuit, 9 is a power amplifier, and 10 is a speaker provided in the handset.
F, 11 is a data amplifier, 12 is a data shaper circuit, 13 is a PLL frequency oscillating circuit section, and a PLL circuit 1
4. Low pass filters 15 and 16 for reception and transmission, and voltage controlled oscillators 17 and 18 for reception and transmission are provided. 19 is a transmission high frequency (TX) amplifier. Numeral 20 denotes arithmetic control means, which is constituted by, for example, a microcomputer. The microcomputer is operated by software processing so that a DTM can be operated when a keyboard switch described later is operated.
It is configured to generate an F signal and a mute data signal. That is, the microcomputer 20 includes DTMF signal generation means and mute data signal generation means. Further, the microcomputer 20 has a reception data input terminal 21 and a control signal output terminal 2 of the PLL circuit 14.
2, transmission data output terminal 23, DTMF signal output terminal 2
Four terminals (ports) are provided. 25 is a keyboard switch, 26 is a low-pass filter for DTMF signal,
27 is a DTMF signal amplifier, 28 is a microphone provided in the handset, 29 is a microphone preamplifier, 30 is a signal compression (compressor) circuit constituting a noise reduction circuit, and 31 is a microphone amplifier.

In FIG. 2 showing a master unit B, 101 is a transmitting / receiving antenna constituting a radio line unit, 102 is a duplexer circuit, 103 is a receiving high frequency (RF) amplifier, 1
04 is a reception mixer circuit, 105 is an intermediate frequency (IF) amplifier, 106 is a detection (DET) circuit, 107 is a preamplifier, 108 is a signal expansion (expander) circuit constituting a noise reduction circuit, and 111 is a data amplifier. , 1
12 is a data shaper circuit, 113 is a PLL frequency oscillating circuit section, and a PLL circuit 114, a receiving and transmitting low circuit.
It has pass filters 115 and 116 and voltage control oscillators 117 and 118 for reception and transmission. 119 is a transmitting high frequency (TX) amplifier. Numeral 120 denotes arithmetic control means which is constituted by a microcomputer, for example, and has terminals (ports) such as a reception data input terminal 121, a control signal output terminal 122 of the PLL circuit 114, and a transmission data output terminal 123. ). 124 is a general subscriber telephone line section, 125 is a line connection socket, 126 is a hook switch relay, 127 is a telephone line interface transformer, 128 is a hybrid circuit, 129 is a transmission signal preamplifier, and 130 is a transmission signal preamplifier. A signal compression (compressor) circuit constituting the noise reduction circuit, and 131 is a transmission signal amplifier. 132 is a mute data amplifier,
Reference numeral 133 denotes a mute circuit which constitutes mute signal generation means, for example, a well-known mute circuit including a time constant circuit of a capacitor and a resistor and a transistor, and 134 denotes an amplifier for a transmission signal to the telephone line section 124. It is.

Next, the operation of the radio telephone constructed as described above will be described with reference to the waveform diagram of FIG.

When the dial switch is operated by operating the keyboard switch 25 of the slave unit A, a transmission data output terminal (TX data port) 23 of the microcomputer 20 of the slave unit A is transmitted. The mute data b shown in FIG. 3B is transmitted for a time d (for example, about 40 ms), and then the DTMF signal a shown in FIG. 3A is transmitted. These signals are respectively modulated by the PLL frequency oscillation circuit section 13, passed through the transmission high-frequency amplifier 19, the duplexer circuit 2 and the antenna 1.
Is sent to master unit B.

The signal sent from the slave unit A to the master unit B is
From the antenna 101 of the base unit B, the duplexer of the base unit B
Circuit 102, high frequency amplifier 103, mixer circuit 10
4. The signal is demodulated through the intermediate frequency amplifier 105 and the detection circuit 106. The mute data shown in FIG. 3B demodulated by the detection circuit 106 is sent to the mute data amplifier 132 and functions as a trigger signal for the mute circuit 133 at the next stage. On the other hand, the DTMF signal demodulated by the detection circuit 106 is supplied to a preamplifier 107, a signal expansion circuit 108, a transmission signal amplifier 13
4, hybrid circuit 128, transformer 127, relay
126, and transmitted to the telephone line section 124 via the socket 125.

When the DTMF signal passes through the signal expansion circuit 108, the peak value of the rising portion gradually increases. However, this rising part [Fig. 3 (c)
The broken line portion in FIG. 7 shows the time e in the transmission signal amplifier 134 due to the mute signal generated by the mute circuit 133.
(For example, about 10 msec), the signal is muted and transmitted to the telephone line unit 124 side. Therefore,
The time delay at the rise of the DTMF signal transmitted to the telephone line unit 124 is eliminated. That is, the DTMF signal sent to the telephone line section 124 rises to a level of 90% or more within 5 ms after the end of the time e.

[0015]

According to the present invention, the DTMF signal generation means is provided on the slave unit side, and the DTMF signal generation means receives the DTMF signal from the DTMF signal generation means.
Since the MF signal is sent to the master unit, there is no need to send communication data for creating a DTMF signal on the master unit side from the slave unit side to the master unit side as in the related art. Date
This eliminates the need for time and expensive microcomputers for reading the data. Further, according to the present invention, the mute signal generating means is provided on the master unit side to mute the DTMF signal sent to the telephone line for a predetermined time, that is, DT
Since the mute is applied for the time during which the rise of the MF signal is delayed, the DTMF signal rises to a predetermined level in a short time when the mute is released. Therefore, it can satisfy the Canadian DOC standard which specifies that the DTMF signal must rise to a level of 90% within 5 ms.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a cordless telephone handset constituting a wireless telephone apparatus of the present invention.

FIG. 2 is a block diagram showing one embodiment of a base unit of a cordless telephone constituting the wireless telephone device of the present invention.

FIGS. 3A and 3B are waveform charts at predetermined points of the cordless telephone shown in FIGS. 1 and 2, wherein (a) and (b) are DTMF signal waveforms and mute data waveforms produced on the handset side; () Is a waveform diagram of a DTMF signal transmitted from the master unit to the telephone line unit.

FIG. 4 is a diagram for explaining the wireless telephone device of the present invention, that is, a diagram showing an example in which a mute is not applied to a rising portion of a DTMF signal. The DTMF signal waveform (b) is sent to the base unit side, passed through the noise reduction circuit, and then sent out to the telephone line unit.
FIG. 4 is a waveform chart showing a waveform of a TMF signal.

[Explanation of symbols]

 A slave unit B master unit 8,108 signal expansion circuit 30,130 signal compression circuit 20,120 microcomputer 124 telephone line unit 133 mute circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Ejima 2--18 Keihanhondori, Moriguchi-shi Sanyo Electric Co., Ltd. 56) References JP-A-57-15560 (JP, A) JP-A-2-222256 (JP, A) JP-A-63-83838 (JP, U)

Claims (1)

(57) [Claims] 1. A base unit connected to a general subscriber's telephone line unit, and a slave unit capable of communicating with the master unit via a wireless line unit, wherein each of the master unit and the slave unit uses a signal compression / expansion method. In a wireless telephone device comprising a noise reduction circuit, DTMF signal generation means provided on the slave unit side, and transmitting a DTMF signal from the DTMF signal generation means to the master unit side, Mute data generating means is provided, and when transmitting a DTMF signal from the slave unit to the master unit, mute data from the mute data generating unit is also sent to the master unit, and the mute data is transmitted to the master unit. And a mute signal generating means for generating a mute signal in response to the DTMF signal which is demodulated on the master unit side and then sent to the telephone line unit through a noise reduction circuit.
A wireless telephone device characterized in that a signal is muted for a predetermined time by a signal from the mute signal generating means when the signal rises.