JPH0936797A - Radio call receiver with optical communication function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit information between radio calling receivers. SOLUTION: After a subcarrier is subject to on/off modulation by a digital signal at a modulation section 22, the signal applies on/off control to the light and it is sent. A receiver side applies photoelectric conversion to the received light and the converted signal is given to a band pass filter 20 whose center frequency is a frequency of subcarrier to eliminate noise and a demodulation section 21 eliminates the subcarrier to regenerate the digital signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio paging receiver with an optical communication function, and more particularly, between a paging receiver and a ROM writer,
Alternatively, the present invention relates to a radio paging receiver with an optical communication function having a function of transmitting information by optical communication between two radio paging receivers.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing a configuration example of a conventional radio paging receiver with an optical communication function. A high frequency signal from a base station received from an antenna is transmitted to a radio section 1, a demodulation section 2,
Also, the call signal is extracted by being processed by the decoder unit 3 and input to the control unit 6. The control unit 6 executes the program stored in the ROM 14 and uses the RAM 13 as a work area. When the destination address of the calling signal from the decoder unit 6 and the own station address assigned to the radio calling receiver and stored in the ROM 14 in advance match, a speaker and a vibrator are driven via the driving unit 7. Alternatively, a call notification unit using an LED or the like is operated to notify the user that there is a call, and the message transmitted at the same time as the call signal is transmitted via the display drive unit 5 to the L level.
It is displayed on the CD display unit 4.

An optical interface consisting of a light emitting section 11, an electric / optical converting section (E / O converting section) 12, a light receiving section 9, and an optical / electrical converting section 10 is used for information by optical communication with an adapter of a ROM writer. It is used for transmission and is used for address writing by the ROM writer.

[0004]

In the above-mentioned optical interface of the conventional radio paging receiver with optical communication function, light (infrared light) is directly turned on / off by the pulse of the digital signal to be transmitted, and is turned on / off. The received light was directly converted into a digital signal by optical / electrical conversion.
However, optical noise from the outside enters the light receiving unit 9,
Also, when it is necessary to reduce the power consumption as in a radio paging receiver, the light emitting unit 13 cannot be made to have a high output. For this reason, when trying to transmit information such as an address book between the radio calling receivers, the distance between the light emitting part and the light receiving part of the two radio calling receivers must be extremely short, 8 mm or less, and the S /
Accurate information transmission was not possible due to N deterioration, which was virtually impossible. An object of the present invention is to provide a radio paging receiver with an optical communication function capable of transmitting information between radio paging receivers.

[0005]

According to the present invention, there is provided optical transmitting means for converting digital information stored in its internal storage means into an optical signal and transmitting the optical signal, and digital information extracted from the received optical signal. In a radio paging receiver with an optical communication function, which is provided with an optical receiving means for storing it in an internal storage means, the optical transmitting means includes a subcarrier generating means and the subcarrier output from the means. The optical receiving unit includes a modulating unit for performing on / off modulation by a pulse of digital information, and an electro-optical converting unit for transmitting on-off light by a modulated signal output from the unit, wherein the optical receiving unit receives the received optical signal. An optical / electrical converting means for converting into an electric digital signal, and a bandpass filter having the output of the means as an input and having its center frequency set to be equal to the frequency of the subcarrier. Discloses a radio paging receiver with an optical communication function, characterized in that a demodulating means for generating a digital baseband signal by removing the sub-carrier from the output signal of the band-pass filter.

[0006]

[Function] After the sub-carrier is turned on / off by the transmission signal, light is turned on / off at the output to be transmitted, and at the receiving side, the optical signal is converted into an electric signal and then passed through a band pass filter to be added in accordance with the transmission. Most of the noise components generated can be removed, and the reception S / N can be improved. Therefore, information transmission between the radio paging receivers also becomes easy. Further, by using a subcarrier band filter, size and weight can be reduced.

[0007]

The present invention will be described below with reference to examples. FIG.
2 is a block diagram showing an embodiment of a radio paging receiver with an optical communication function according to the present invention, and the configuration other than the optical interface is the same as that of FIG. The optical interface is characterized in that the modulator 22 is provided in the transmission system and the filter 20 and the demodulator 21 are provided in the reception system.

The modulator 22 has a pulse oscillator as a subcarrier, and in the present embodiment, this is a pulse train having a frequency of 38 KHz, which is a frequency sufficiently higher than the frequency of the digital signal. In the modulator 22, the digital signal CD for transmitting the pulse train is on-off modulated as shown in FIG. 3 to generate a modulated signal MD. However, in FIG. 3, the fine pulse of the modulation signal MD shows a pulse of 38 KHz repetition. The electric / optical conversion unit 12 turns on / off the infrared light according to the modulation signal MD. Therefore, the output light level has a waveform similar to that of the signal MD in FIG.

When the optical signal optically modulated as described above is received and the electrical signal corresponding to the modulation signal MD of FIG. 3 is taken out by the optical / electrical conversion section 10, this is inputted to the filter 20. Let f be the repetition frequency of the digital signal
_S , that of the subcarrier pulse is f _SUB (38K in this embodiment)
Hz), the modulated signal MD is a signal having a frequency band of about f _SUB −f _S to f _SUB + f _S.
The filter 20 is a bandpass filter that passes this frequency band. Then, since the noise component of the light entering the light receiving unit 9 has its spectrum spread over a very wide frequency range, most of the energy is removed by the filter 20 as described above, and almost only the signal component is demodulated. It is input to the section 21. The demodulation unit 21 removes the subcarrier component from this input and reproduces and outputs a digital signal corresponding to the digital signal SD in FIG.

In this way, according to this embodiment, most of the noise components are removed, and the reception S / N is improved. Therefore, the transmission distance can be extended even with the same transmission energy as the conventional one, and it becomes possible to transmit information such as an address book between the radio paging receivers, which was impossible in the past.

When the optical transmission between the two radio paging receivers having the optical communication function becomes possible as described above, the information transmission using this transmission line is performed by the key provided in each radio paging receiver. Information transmission can be actually performed by executing a program prepared for information transmission / reception by operation. And such a program or key operation procedure can be easily realized by using a well-known technique. Moreover, the address writing by the ROM writer that has been used conventionally is
This can be performed by setting the transmission / reception system of the ROM writer adapter to the same configuration as that of the radio paging receiver of FIG. Moreover, in this case as well, there is an effect that writing can be performed without installing the ROM writer adapter so as to contact the radio paging receiver. However, when writing to the ROM, it is necessary to first read the relevant information from the ROM and send it to the ROM writer in order to check whether the address stored in the radio paging receiver is normal. For this reason, since a transmission line from the radio paging receiver to the ROM writer is also used, it is necessary to provide a transmission / reception system similar to that shown in FIG. 1 on the adapter side of the ROM writer.

Further, in the above embodiment, the subcarrier modulation and the bandpass processing in the frequency band are performed to remove the optical transmission line noise component. However, this configuration is used. Thus, the filter 20 can be configured as a bandpass filter having a relatively high frequency band. This makes it easier to reduce the size and weight of the filter,
The configuration is suitable for a portable device such as a radio paging receiver.

[0013]

According to the present invention, there is an effect that information can be transmitted by a radio paging receiver.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a radio paging receiver with an optical communication function according to the present invention.

FIG. 2 is a block diagram showing a configuration example of a conventional radio paging receiver with an optical communication function.

FIG. 3 is a diagram showing a modulation example of a subcarrier pulse.

[Explanation of symbols]

 6 control section 20 filter 21 demodulation section 22 modulation section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical indication H04B 10/152 10/142 10/04 10/06

Claims (1)

[Claims] 1. An optical transmitting means for converting digital information stored in its internal storage means into an optical signal for transmission, and for extracting digital information from the received optical signal and storing it in its internal storage means. In the radio paging receiver with an optical communication function, the optical transmitting means on-off modulates the sub-carrier generating means and the sub-carrier output from the means by the pulse of the digital information. For converting the received optical signal into an electrical digital signal, the optical receiving unit including: Optical / electrical conversion means, a bandpass filter having the output of the means as an input, the center frequency of which is set to be equal to the frequency of the subcarrier, and the bandpass filter And a demodulation means for generating a baseband digital signal by removing the subcarrier from the output signal of the radio paging receiver.