JPS63173427A - Radio selective calling system with voice information - Google Patents

Abstract

PURPOSE:To realize the privacy call by converting a selective call signal into a digital coding signal at the transmission system, applying digital signal conversion to a voice information signal, reducing the voice code length, storing the converted and reduced signal, and sending the result by an instruction code thereby increasing the subscriber capacity. CONSTITUTION:A selective call number inputted by a keyboard 1 is digital-coded by an ID encoder 3, stored tentatively in a memory 7 and displayed on an indicator 4. A voice signal from a microphone 8 is coded by an A/D converter 12 via a low frequency amplifier 9 and a filter 10, and subject to ADM conversion to obtain a digital voice signal. In such a case, the voice information transmission length is limited and controlled by a central processing unit 6 interlocking with a timer 5. The transmission time length of the digital voice signal is reduced by a data compression circuit 13 and stored in the memory 7 together with other call and voice information and outputted to a paging/ transmitter system 18 by badge processing according to a command outputted from the central processing unit 6, and transmitted in radio via a modulator 14, a high frequency amplifier 15 and a transmission antenna 16.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a wireless selective calling system with audio information in a paging system, and in particular modulates audio information from a voice band signal to a digital signal and outputs the modulated signal. The present invention relates to a wireless selective calling system with voice information that demodulates a signal into a voice band signal and reproduces voice information.

[Conventional technology]

Conventionally, this type of wireless selective calling system with voice information uses two components: a voice tone signal (selective call signal) and a voice band signal (
This is a so-called analog audio signal in which the input audio information) is FM modulated and transmitted, while the received signal is demodulated and synchronized with an audio tone signal lamechanical lead filter, and the audio band signal is amplified and output as audio information. There is a two-tone tone and voice method for transmitting.

[Problem that the invention seeks to solve]

The above-mentioned conventional wireless selective calling system with voice information requires only a small number of two-component combinations of voice tone signals that are used for prisoners.
The maximum number of subscribers (number of selective call receivers) per system using one frequency is over 3,500, and (B) the voice information signal length is long, 10 to 20 seconds per message and per subscriber.
The maximum number of subscribers mentioned above will further decrease to about 2,000, resulting in extremely poor transmission efficiency from the perspective of effective frequency utilization, and also cause mismatches in selective calling codes among selective calling receivers operating on the same frequency in the same system. However, it is a place where it is possible to monitor other people's voice information and there is no confidentiality.

Calls are received at any time, causing noise to others in quiet areas. In addition, you will be asked to hear audio information that you do not want to hear, and if you are in a noisy area, it will be difficult to hear the audio information even if you receive a call, and you will not be able to listen to it again.

[Failure to solve the problem]

In the wireless selective calling system with audio information of the present invention, the transmission system converts the selective calling signal into a digitally encoded signal and outputs it, while converting the audio information signal into a digital signal and shortening the audio code length. The shortened signal is stored and transmitted according to the command code.The 1-1 receiving system receives and detects the digitally encoded selective call signal, and after receiving and storing the digital audio signal, converts this digital audio signal into the original audio band signal. It demodulates and amplifies it and outputs it.

[Effect]

This invention can shorten the information transmission time required per unit subscriber, increase subscriber capacity, and make it impossible for each subscriber to monitor other people's voice information, allowing confidential information to be transmitted. can be made into a sex.

〔Example〕

Fig. 1 cA) and Fig. 1 middle) are block diagrams showing an embodiment of the wireless selective calling system with voice information according to the present invention. indicates the receiving side. In the figure, 1 is a keyboard for inputting a selective call number, etc., 2 is a digital oscillator, 3 is an ID encoder for digitally encoding a selective call signal, 4 is an indicator for displaying a selective call number, 5 is a timer, and 6 is this In conjunction with timer 5, the audio information transmission length is set to 8 seconds or 16 seconds, for example.
7 is a memory that temporarily stores the digitally encoded selective call signal, 8 is a microphone, 9 is a low frequency amplifier, 1° is a filter, 11
is a clock oscillator that is necessary for conversion and outputs a lock, 1
2 is an A/D converter, 13 is a data compression circuit for shortening the transmission time length of a digital audio signal, 14 is a modulator for FSK modulation, 15 is a high frequency amplifier, and 16 is a transmitting antenna. Note that 17 is the keyboard 1. Digital oscillator 2, ID encoder 3. Indicator 4° timer 5. Central processing unit6. Memory T, microphone 8. Low frequency amplifier9. Filter 10. clock generator 11,
A paging terminal base consisting of an A/D converter 12 and a data compression circuit 13; 18 is the modulator 1 described above;
4. A paging transmitter system consisting of a high frequency amplifier 15 and a transmitting antenna 16, 19 a receiving antenna, 20 a high frequency amplifier that amplifies a high frequency signal, 21 an intermediate frequency amplifier that amplifies an intermediate frequency, 22 a demodulator, and 23 a demodulator. A memory for temporarily storing the received digital voice signal and selective call signal, 24 a ROM in which a self ID number is recorded, and 25 a comparison between the received selective call signal and the recorded self ID number to detect a match. 26 is a central processing unit, 27 is, for example, 16 KHz.
2B is a D/A converter, 29 is a switch, 30 is a filter,
31 is a low frequency amplifier, and 32 is a speaker.

Next, the operation of the wireless selective calling system with audio information having the above configuration will be explained. First, the selective call number inputted on the keyboard 1 is inputted into the ID encoder 3. Therefore, this ID encoder 3 digitally encodes this selective call number using the clock signal generated from the digital oscillator 2 and outputs it to the memory T and to the indicator 4. Therefore, the selective call number is temporarily stored in the memory 7 and displayed on the indicator 4. Next, when the input of audio information is started using the microphone 8, this audio signal passes through a low frequency amplifier 9 and a filter 10, and then is encoded by an A/D converter 12 and ADM-converted into a digital audio signal.

At this time, the clock oscillator 11 is required for conversion and is locked.
On the other hand, the audio information transmission length is limited and controlled to, for example, about 8 seconds or 16 seconds by the central processing unit 6 that is linked to the timer 5. This digital audio signal is temporarily stored in the memory 7 after its transmission time length is shortened by the data compression circuit 13. Similarly, it is stored along with other call and voice information and output from memory 7 to paging/transmitter system 18 by badge processing in accordance with commands output from central processing unit 6. These selective call signals and digital voice signals are transmitted as outputs of the paging terminal system 11 to the next stage wireless transmission system either directly or via an approach line, and input to the modulator 14. Therefore, after the modulator 14 performs FSK modulation, the signal is high-frequency amplified by the high-frequency amplifier 15 and transmitted wirelessly from the transmitting antenna 16. On the other hand, a high frequency signal inputted by the receiving antenna 19 is received and amplified by a high frequency amplifier 20, further intermediate frequency amplified by an intermediate frequency amplifier 21, and then demodulated by a demodulator 22. One digital audio signal of the demodulated signal is temporarily recorded as it is in the memory 23, and the other selective call signal of the demodulated signal is input to the ID detector 25. Therefore, the ID detector 25 uses this demodulated selective calling signal and R
It compares and detects the own ID number recorded in the OM 24 and outputs a match signal to the central processing unit 26 when they match. Upon receiving this matching signal, the central processing unit 26 retains its own ID number temporarily recorded in the memory 23, and also transfers the temporarily stored digital audio signal to the D.
/A converter 28. Therefore, this D/
The A converter 28 inputs 1 from the clock generator 27.
Using a 6KHzbp♂ clock, this digital audio signal is converted back into an audio signal by digital-to-analog conversion. This audio signal passes through a filter 30 and is low-frequency amplified by a low-frequency amplifier 31, and then outputted as audio through a speaker 32. After the message ends, the device is automatically reset and enters the reception standby state.

Furthermore, if the holder (subscriber) wishes to hear the message again, by operating the switch 29, a command signal is sent from the central processing unit 26 to the memory 23, and the voice message is reproduced from the speaker 32 in the same manner as described above. can do. Moreover, desired audio information can be repeatedly reproduced at any time by the storage/reproduction means.

〔Effect of the invention〕

As explained in detail above, according to the wireless selective calling system with audio information according to the present invention, the selective calling signal is digitally encoded, the audio information signal is ADM converted, further packet-converted, and sent to the transmission system. By demodulating and reproducing the analog voice information signal after receiving the paging signal, it is possible to shorten the information transmission time required for each subscriber and relatively increase the subscriber capacity, making it possible to reach a large number of users. In addition to making effective use of frequencies, it is impossible to monitor other people's voice information, which makes communication confidential, and by choosing the place and time when receiving and monitoring the voice information, you can prevent crosstalk to neighbors. It has the effect of preventing noise.

[Brief explanation of the drawing]

FIG. 1 (2) and FIG. 1 (B) are block diagrams showing an embodiment of the wireless selective calling system with voice information according to the present invention. 2..Digital oscillator, 3.-φ.ID encoder, 6..Central processing unit, 7..Memo IJ, 8-
...Microphone, 12.Fist...A/D converter,
13... Reference data compression circuit, 14... Modulator, 1
6... Transmission antenna, 17... Φ paging terminal thread, 18... Fist e paging/transmitter system,
19... Reception antenna, 22... Demodulator, 2
3...Memory, 24...ROM, 25@...
ID detector, No. 26 central processing unit, No. 28...
D/A comparator, 32-...speaker.

Claims (1)

[Claims] In a wireless selective calling system with audio information that transmits and receives a selective calling signal and an audio information signal, means for digitally encoding the selective calling signal and digitally converting the audio information signal, and then shortening the audio signal length, and the converted and shortened signal. means for storing and outputting a digitally encoded selective call signal in accordance with an instruction code; a means for receiving and storing a digital voice signal while receiving and detecting a digitally encoded selective call signal; and demodulating and amplifying the digital voice signal into an original voice band signal. What is claimed is: 1. A wireless selective calling system with voice information, characterized in that it is equipped with means for outputting voice information.