JPH026698Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radio telephone device that can transmit accurate dialing pulses and prevent unnecessary signals from being generated at the end of a call.

In general, in wireless telephone equipment such as cordless telephones, distortion occurs due to variations in the characteristics of the wireless line while the dial pulse is transmitted from the wireless telephone to the subscriber line via the fixed connection equipment, and this causes distortion of the dial pulse. The rate has fluctuated. For this reason, conventionally, on the fixed connection device side, the dial pulse that has been received, demodulated, and waveform-shaped is guided to a monostable multivibrator (hereinafter abbreviated as monomulti), and this monomulti is used as the leading edge of the dial pulse, that is, the make The trigger is driven at the edge of transition from to break, and the output is used as the dial pulse output of the fixed connection device, thereby improving the make rate.

On the other hand, in general, radio telephone devices transmit signals by setting the dial pulse and the end-of-call signal to the same tone frequency in order to simplify the configuration of the radio telephone. Therefore, if this signal transmission method and the method for improving the make rate using the monomultiple are combined, the signal will be transmitted as follows.

That is, as shown in FIG.
A call-end signal (pulse) B having a pulse width longer than one break period of is generated, and each of these pulses A and B
is converted into a tone signal using the same tone frequency as shown in FIG. 1b. Then, the carrier wave is modulated by this tone signal and sent to the wireless line.

On the other hand, the fixed connection device receives the modulated carrier wave, demodulates and rectifies it, shapes the waveform as shown in Figure 1c, and guides this waveform-shaped output to a monomultiple as shown in Figure 1d. Correct (improve) the make rate. Further, the fixed connection device integrates and compares the waveform shaped output (FIG. 1c) as shown in FIG. 1E to detect the end-of-call pulse (FIG. 1F). Then, at this detection timing, the call memory that was set at the start of the call is reset. Further, the fixed connection device performs a logical product between the output of the above-mentioned call memory (FIG. 1g) and the reproduction dial pulse from the monomulti (FIG. 1d),
This allows the DC loop of the subscriber line to be controlled intermittently,
It sends dial pulses to the exchange.

However, the output of the monochrome multiplier includes not only the reproduction dial pulse but also a pulse corresponding to one break generated at the leading edge (rising edge) of the end pulse. Therefore, a pulse corresponding to the dial "1" is sent to the subscriber line as shown in FIG. 1h even though the call is over. This pulse is undesirable because it causes noise.

On the other hand, in order to avoid such inconveniences, there is a method in which the dial signal and the end-of-call signal are set to different tone frequencies and are received and reproduced separately. However, in such a method, an oscillator must be prepared for each tone frequency, which causes another problem such as complicating the configuration of the radio telephone.

The present invention was developed in view of the above circumstances, and its purpose is to transmit an accurate dialing signal without generating unnecessary signals at the end of a call, and to provide a wireless system with a simple configuration. The purpose of the present invention is to provide telephone equipment.

Hereinafter, the present invention will be described with reference to an embodiment shown in the drawings. FIG. 2 is a schematic configuration diagram showing only the portions related to the present invention of the radio telephone device in the same embodiment. In the figure, 1 indicates the radio telephone, and 2 indicates a fixed connection device connected to the subscriber line 3.

The radio telephone 1 includes a signal generation circuit 11 that converts a dial pulse generated in response to a dial operation and a call termination signal (pulse) generated in response to an on-hook operation into tone signals of the same wave number.
and a transmitter 12 that modulates the carrier wave with the tone signal and sends it to the wireless line 4 via the antenna 13.
It is composed of. Note that the output time (pulse width) of the call termination signal is set to be longer than one break period T _B of the dial pulse.

On the other hand, the fixed connection device 2 includes a receiver 22 that receives and demodulates the modulated carrier wave from the wireless telephone 1 via an antenna 21, extracts the tone signal component, and then rectifies it, and converts the output of the receiver 22 into a waveform. A dial pulse reproducing circuit 24 regenerates dial pulses from the output of the waveform shaping circuit 23 (hereinafter referred to as demodulated pulses for convenience of explanation), and detects an end-of-call signal from the demodulated pulses. A call memory ((S-R flip-flop) 2 which is set by the end of call signal detection circuit 25 and an off-hook signal and reset by the detection output of the end of call signal detection circuit 25 is set.
6 each.

The dial pulse regeneration circuit 24 includes a delay circuit 27 that delays the demodulated pulse by a predetermined time T _D ;
A monostable multivibrator (mono multi) 28 that is triggered at the leading edge of each demodulated pulse delayed by this delay circuit 27 and generates a signal having a pulse width equal to one break period T _B
and a signal sending circuit 29 which inputs the output of this monomulti 28. The end-of-call signal detection circuit 25 also includes an integrating circuit 30 that integrates the demodulated pulse from the waveform shaping circuit 23 based on an appropriate time constant, and a predetermined threshold for the output of the integrating circuit 30. The period in which the threshold level is higher than the threshold level is a predetermined time longer than the dial pulse 1 break cycle T _B
It is comprised of a comparison circuit 31 that detects a call termination signal when the connection is continued for a length of _T1 . In addition,
The signal sending circuit 29 performs an AND operation between the output of the monomulti 28 and the Q output of the communication memory 26 mentioned above, and controls the DC loop of the subscriber line 3 intermittently based on this AND output. .

Therefore, in the above configuration, when a carrier wave modulated by the dial pulse and the tone signal of the end call signal (A, B in FIG. 3a) is transmitted from the radio telephone 1, the modulated carrier wave is After being received and demodulated by the receiver 22 of the fixed connection device 2, the waveform is shaped by the waveform shaping circuit 23 as shown in FIG. 3b. This waveform shaped output (demodulated pulse) is
After the signal is integrated by the integrating circuit 30 as shown in FIG. 3e, it is compared with a predetermined threshold level ○i in the comparator circuit 31, and components exceeding this threshold level ○i are extracted. As a result, the end of call signal is detected as shown in FIG. 3f.
As a result, the call memory 26, which was set at the start of the call (off-hook), is reset at the detection timing of the end of call signal, as shown in FIG. 3g.

On the other hand, the demodulated pulse (FIG. 3b) of the waveform shaping circuit 23 is delayed by a predetermined time T _D as shown in FIG. 3c by the delay circuit 27, and then by the monomulti 28 as shown in FIG. The dial pulse make rate is corrected. and,
This correction signal is ANDed by the signal sending circuit 29 with the Q output of the communication memory 26 (FIG. 3g) as shown in FIG. controlled.

In this way, in the apparatus of this embodiment, when reproducing the demodulated pulse, the make rate is corrected by the monomulti 28 after the delay circuit 27 delays it by a predetermined time T _D. Therefore, the signal sending circuit 2
Signal after make rate correction in 9 and Q of call memory 26
When performing logical AND with the output, unnecessary pulses are not generated as in the conventional case, so only dial pulses are sent to the exchange and ultimately to the other party's telephone, which results in the generation of noise. can be definitely prevented.

Next, other embodiments of the present invention will be described with reference to FIGS. 4 and 5 a to i. Note that the same parts as in FIG. 2 are given the same reference numerals and detailed explanations will be omitted. This embodiment differs in configuration from the previous embodiment in that the output of the waveform shaping circuit 23, that is, the demodulated pulse, is delayed by a predetermined time T _D in the delay circuit 27, and then the make-up is performed by the monomulti 28. The main part of the dial pulse regeneration circuit 24 is the demodulation pulse (fifth pulse).
By providing a monomulti 32 that is triggered at the trailing edge of each pulse as shown in Figure d) and correcting the make rate through this monomulti 32, one break period of the dial pulse as shown in Figure 5E results. The make rate is now corrected after a delay of T _D. Incidentally, FIG. 5c shows the threshold level ○i when waveform shaping the output of the receiver 22.

Therefore, according to the device configured in this way, the monomulti 32 is triggered at the trailing edge of each pulse of the demodulated pulse (FIG. 5d), and the make rate of the dial pulse is corrected. As in the first embodiment, the demodulated pulses are delayed as if they were delayed, and as a result, the conventional problem of generating unnecessary pulses as shown in FIG. be able to. Therefore, no noise is generated at the other party's telephone. Further, in this embodiment, since the delay of the demodulated pulse and the correction of the make rate are performed only by the monomulti 32, the configuration of the dial pulse regeneration circuit 24 and, by extension, the configuration of the fixed connection device can be simplified. can.

Note that the present invention is not limited to the above embodiments. For example, in FIG.
may be provided between the monomulti 28 and the signal sending circuit 29, and may also be provided between the receiver 22 and the waveform shaping circuit 23.
It may be provided between. Furthermore, the dial pulse regeneration circuit in other embodiments of the present invention can obtain the same effect by using a shift register instead of a monomulti, or by using a microcomputer for processing. In addition, the configuration of the end-of-call signal detection circuit, the function of the waveform shaping circuit 23, etc. can be modified in various ways without departing from the gist of the present invention.

As detailed above, according to the present invention, the timing of supplying the dial pulse reproduction output to the signal sending circuit is delayed by a predetermined period of time or more, so that unnecessary pulses are not generated at the end of a call and accurate It is possible to provide a wireless telephone device that can transmit diamond pulses and has a simple configuration.

[Brief explanation of drawings]

Figures 1a to 1h are timing diagrams showing the conventional method;
FIG. 2 is a schematic configuration diagram of a radio telephone device according to an embodiment of the present invention, FIGS. 3a to 3h are timing diagrams used to explain the operation of the embodiment, and FIGS. 4 and 5 are FIG. 4 is a schematic configuration diagram of a radio telephone, and FIGS. 5 a to 5 i are timing diagrams showing another embodiment of the present invention. 1...Wireless telephone, 2...Fixed connection device, 3...
...Subscriber line, 4...Radio line, 24...Dial pulse regeneration circuit, 25...Call end signal detection circuit, 26
...Call memory (S-R flip-flop), 2
7...Delay circuit, 28, 32...Mono multi, 2
9...Signal sending circuit, 30...Integrator circuit, 31...
...comparison circuit.

Claims (1)

[Scope of claim for utility model registration] (1) Consisting of a wireless telephone and a fixed connection device connected to a subscriber line, when transmitting dial pulses and call termination signals from the wireless telephone to the fixed connection device, the dial pulse In a radio telephone device that modulates and transmits a carrier wave with the same tone signal as a break period and end signal, a receiving unit that receives and demodulates a modulated carrier wave from the radio telephone;
End-of-call signal detection means for detecting a time corresponding to the presence of a tone signal in the signal obtained by the receiving section as a end _{-of-call signal when the time corresponding to the presence of a tone signal is longer than the break period of the dial pulse by a predetermined time T1} ; dial pulse reproducing means for reproducing a dial pulse whose break period start point is a time point at which the tone signal changes from absent to present from the signal obtained by the receiving section by at least the predetermined time _T1 ; Each of the fixed connection devices is provided with a signal sending means for sending the dial pulse regenerated by the dial pulse reproducing means to the exchange via the subscriber line before the signal detecting means detects the end-of-call signal. wireless telephone equipment. (2) The dial pulse reproducing means is a monostable multi-channel pulse generator whose metastable time is set equal to the break period of the dial pulse, and which is triggered in response to the transition from the presence of the tone signal to the absence of the tone signal of the signal obtained by the receiving section. The wireless telephone device according to claim 1, characterized in that it comprises a vibrator.