JPS593630Y2 - wireless transmitter/receiver - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a frequency-phase synchronized wireless transmitting/receiving device that is capable of transmitting and receiving communications on a specific channel after confirming signal tones of different frequencies transmitted on that specific channel.

For example, when a weather information service is provided using a wireless communication method, A, B)-tones with specific different frequencies are transmitted on a designated channel for a certain period of time, and then service information is announced. Emergency call systems are well known.

However, although the tone signal that is sent out prior to the transmission of the report content is affected by the strength of the electric field and the noise in the air, its discrimination limit is about 3 dB in terms of S/N, and the discrimination limit for the content of a call based on real voice is 5INAND. Although it is said to be about -12 dB, it is uneconomical to install a receiver with excellent sensitivity and selectivity just to capture and confirm the presence or absence of a tone signal. However, there are difficulties in accommodating it in a large occupied space.

In addition, manual switching to receive the transmission content following the tone signal is not required in addition to the driving operation on the mobile unit.
Vibrations and oscillations tend to cause misalignment, and operations such as switching are troublesome.

Therefore, in view of the above-mentioned difficulties, the present invention connects a simple discriminator circuit to the antenna terminal of a conventional radio transmitter/receiver for the mere identification of tone signals, and automatically controls the frequency through a control unit represented by a microcomputer. The purpose of the present invention is to obtain an economical, small-sized wireless transmitter/receiver that allows the user to listen to the contents of a transmitted message without switching the transceiver section including the transceiver system.

Embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is an electrical block diagram of a system implementing the present invention, in which 1 is a transceiver section, 2 is a tone discrimination circuit, and 3 is an electrical block diagram of a system implementing the present invention.
4 is a control unit, 4 is a channel display section, and 5 is a channel selection means.

Therefore, for example, 1350 Hz and 1900 Hz saws
The tone discriminator receives the 71,z tone transmitted for about 10 seconds on a specific channel, for example channel "16", confirms that the tone of the image frequency has arrived, and then transmits the subsequent transmitted information to the transceiver section. When a logic output appears in the signal tone discriminator circuit, the control unit selects a specific channel for the frequency phase synchronization circuit divider built into the transceiver section. A code for calling the station is sent, the receiving circuit of the transceiver section is switched to the specific channel, and the contents of the message following the call tone are heard.

Here is a keyboard switch as a channel selection method,
It can be either an up/down switch or a rotary switch, and the on/down switch sent to the control unit.
The off signal causes the control unit to send out a tuning code corresponding to a desired channel for changing the variable frequency division number of the frequency phase synchronization control system, and a display code required for displaying a channel number suitable for the selected channel. do.

Next, a specific example of the tone discrimination circuit will be explained with reference to FIG.

11 is a VHF band receiving section, 12.15.16 is an amplifier,
13 and 14 are, for example, ±lHz narrow band filters; 17.
1B is a detector, 19 is a gate switch, 20 is a time integration timer, and 21 is a bistable switch such as a flip-flop.

A detection stage (
Call tone signals of different frequencies are taken out from the call tone signals (not shown), applied to the amplifier 12, separated into respective frequency bands by the narrow band filters 13 and 14, and guided to the gate switch 19.

This gate switch applies one logic output to the timer 28 in response to the two forces separated in the narrow band filter.

At this point, the timer recognizes that the reception of continuous tone signals is confirmed by the output of the gate switch, and from this point on, the timer integrates the transmission and reception time in the transceiver section, and when a predetermined time is reached, the bistable switch 21 is activated. logic output AT
is sent to the control unit.

Then, the tone discrimination circuit 2 uses its logic output signal AT to cause the control unit 3 to send out a code signal C8 for switching to a specific channel.

Therefore, as long as the tone signal is continuously received, the output of the tone discriminator circuit will continue to issue a command to send out the channel selection code for a specific channel to the control unit. By pressing any button on, for example, a keyboard switch used as the station means, the control unit can send a noset signal R to the flip-flop at the final stage of the tone discrimination circuit to reset it.

As mentioned above, the present invention has high selectivity and high sensitivity in order to identify the tone signal in selective calling wireless communication, in which the tone signal sent out before the service information is identified first and then the call is started. Instead of a conventional receiver, we have installed a low-grade, inexpensive receiver and a tone discriminator circuit with high discrimination ability, and connected a control unit with microprocess function and a frequency phase synchronization system built into the transceiver to achieve high-performance transmission and reception. You can get the system.

The tone discrimination circuit, control unit, and frequency phase synchronization circuit can be integrated into an extremely small integrated circuit element using high-integration technology, making it suitable for reducing the size and weight of the entire device, and allowing the high-end receiver to be installed separately. Compared to the conventional method, mass productivity is high and it can be implemented economically.

[Brief explanation of the drawing]

FIG. 1 is a block diagram illustrating the circuit configuration of an embodiment of the present invention, and FIG. 2 is a specific circuit diagram of the tone discriminating circuit shown in FIG. 1. 1...Transceiver section, 2...Tone discrimination circuit, AT...Logic output signal to the control unit of the tone discrimination circuit, C3...Tone of the control unit. Tone signal to transceiver section, R...Reset signal to tone discrimination circuit of control unit, 3...
...Control unit, 5...Channel selection means.

Claims (1)

[Scope of utility model registration request] The input terminal of a tone discriminating circuit that receives multiple signal tones of different frequencies only on a specific channel to identify an emergency call is connected in parallel to the antenna terminal of a transceiver section that can transmit and receive through multiple assigned channels. Based on the output of the discrimination circuit, a setting code for a specific channel for preferentially transmitting/receiving the specific channel is sent to the transceiver unit via its frequency phase synchronization circuit, and the channel selection code and the tone are discriminated by operating the channel selection means. A frequency-phase synchronized wireless transmitting/receiving device characterized by comprising a control unit that issues a command to erase an output signal of a circuit.