JPH09307466A - Hybrid receiving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely receive the transmitted signals by a receiving device which is mounted on a mobile object despite a millimeter wave communication system or an optical space communication system of a transmitter device. SOLUTION: The optical signal sent from a transmitting device of an optical space communication system is condensed by a main reflector 5 of a parabolic antenna and received by an optical signal receiving part 11 including a photodetector 12, a preamplifier 13, a band limit filter 14 and a limiter/demodulator 15. The millimeter wave signal sent from a transmitting device of a millimeter wave communication system is converged by the reflector 5 and a secondary reflector 6 of the parabolic antenna and received by a primary radiator 7. Then the received millimeter wave is amplified and demodulated at a millimeter wave signal receiving part 21 including a down-converter 22, an intermediate frequency amplifier 23, a band limit filter 24 and a demodulator 25. An automatic signal selection circuit 31 detects the presence or absence of the output signals of both parts 11 and 21 and selects the signal of the receiving part of the signal detection side to output it to an external output terminal 33 via a video amplifier part 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid receiver capable of receiving a signal on the mobile side regardless of whether the millimeter wave communication system or the optical space communication system is used as the transmitter installed on the fixed body side. Regarding

[0002]

2. Description of the Related Art Conventionally, in transportation facilities such as railways, a monitor is installed near the driver's seat of a train to improve safety,
A system is considered in which, for example, a transmitter installed at predetermined intervals along the track transmits information such as the situation in front of the train and the state of railroad crossings to the receiver on the train side and displays it on the monitor in the driver's seat. . In this case, the information is transmitted using the millimeter wave communication method on the ground, which is less affected by fog and sunlight.
Since a multipath failure occurs when the train enters the tunnel, an optical signal is transmitted to the train side by the optical space communication transmitter in the tunnel.

In the communication system using the millimeter wave communication or the optical space communication, the millimeter wave communication requires a millimeter wave transmitter / receiver and the optical space communication needs an optical space transmitter / receiver. That is, it is necessary to install both the millimeter wave signal receiver and the optical signal receiver on the train side.

[0004]

Conventionally, in consideration of the communication environment as described above, consideration has been given to a mixture of transmitters in which a millimeter wave transmission type or optical space communication type transmitter is installed depending on the installation environment. In this case, both the millimeter wave signal receiver and the optical signal receiver must be installed on the mobile side, and which receiver on the mobile side depends on whether the transmitter is for the millimeter wave signal or the optical signal. There is a problem that communication cannot be performed unless the use of is switched manually.

The present invention has been made in order to solve the above-mentioned problems, and the optical / millimeter wave circuit is manually operated regardless of whether the transmitter is a millimeter wave communication transmitter or an optical space communication light transmitter. An object of the present invention is to provide a hybrid receiver that can reliably receive a signal without switching by operation.

[0006]

A hybrid receiver according to the present invention includes a parabolic antenna for receiving a millimeter wave signal transmitted from a transmitter by a millimeter wave communication system and an amplifier for amplifying the millimeter wave signal received by the parabolic antenna. The millimeter wave signal receiving unit to be processed, a part or all of the reflecting surface of the parabolic antenna is a mirror surface, and means for reflecting and condensing the optical signal transmitted from the transmitting device by the optical space communication method, and reflecting by this means The optical signal receiving unit that receives the collected optical signal and performs amplification processing, and the receiving unit that outputs the signal by detecting the presence / absence of output signals from the millimeter wave signal receiving unit and the optical signal receiving unit. An automatic selection circuit for selecting is provided, and the millimeter wave signal reception unit and the optical signal reception unit are integrally configured.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a hybrid receiver 1 according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a Cassegrain parabola antenna unit 3, and FIG. 3 is a block diagram showing an internal configuration.

In FIG. 1, reference numeral 2 denotes a main body of the hybrid receiver 1, which comprises a Cassegrain parabolic antenna section 3 and a light receiving section 4 installed in the Cassegrain parabolic antenna section 3.

The Cassegrain type parabolic antenna section 3
2 comprises a main reflecting mirror 5, a sub-reflecting mirror 6, a primary radiator 7 and a support fitting 8. A part or all of the anti-slope of the main reflecting mirror 5 is mirror-finished, and both the millimeter wave and the light are reflected so that they are focused at the focal point 9 of the main reflecting mirror 5. Further, the light receiving section 4 is installed in the sub-reflecting mirror 6 so as to be at the focal position 9, and a light transmitting hole 10 is provided in a part of the anti-slope of the sub-reflecting mirror 6 for transmitting light to the light receiving section 4. There is.

Further, in FIG. 3, reference numeral 11 denotes an optical signal receiving section, which comprises a light receiving element 12, a preamplifier 13, a band limiting filter 14, and a limiter / demodulator 15. The light receiving element 1
2 and the preamplifier 13 are integrated and installed in the sub-reflecting mirror 6 as the light receiving unit 4. Further, reference numeral 21 denotes a millimeter wave signal receiving unit, which includes a down converter 22, an intermediate frequency amplifier 23, a band limiting filter 24, and a demodulator 25, and is configured integrally with the optical signal receiving unit 11.

The signal demodulated by the limiter / demodulator 15 of the optical signal receiver 11 and the signal demodulated by the demodulator 25 of the millimeter wave signal receiver 21 are the optical signal /
It is input to the millimeter wave signal automatic selection circuit 31. This optical signal / millimeter wave signal automatic selection circuit 31 includes a limiter / demodulator 1
5 and the presence or absence of the output signal of the demodulator 25, and based on the detected signal, one of the demodulators 15 and 25 is automatically selected by, for example, a diode switch or the like, and the selected demodulated signal is an optical signal / millimeter wave. Signal common video amplifier 32
After being amplified by, the signal is output from the external output terminal 33 to the outside.

In the hybrid receiver configured as described above, whether a signal is sent from a fixed transmitter by an optical space communication system or a millimeter wave communication system,
The transmitted signal can be automatically selected and received.

For example, if an optical signal is sent from a transmitter of the optical space communication system, this optical signal is condensed by the main reflecting mirror 5 and is provided in the sub-reflecting mirror 6 for transmitting light.
The light enters the light receiving portion 4 via 0 and is converted into an electric signal by the light receiving element 12. The electric signal converted by the light receiving element 12 is amplified by a preamplifier 13, and then a signal in a predetermined band is taken out through a band limiting filter 14, and a limiter
It is input to the demodulator 15. This limiter / demodulator 15
Input the input signal to the optical signal / millimeter wave signal automatic selection circuit 31 by limiting the input signal to a constant amplitude and demodulating. The optical signal / millimeter wave signal automatic selection circuit 31 detects the output signal of the limiter / demodulator 15 in the absence of the signal from the demodulator 25, and selects the signal from the limiter / demodulator 15 to amplify the video. It is output to the unit 32. The video amplifier 32 amplifies the signal from the limiter / demodulator 15 selected by the optical signal / millimeter wave signal automatic selection circuit 31 and outputs the amplified signal to the outside from the external output terminal 33.

Further, when a millimeter wave signal is sent in place of the above-mentioned optical signal from a transmitter using the millimeter wave communication system,
The millimeter wave signal is converged by the main reflection mirror 5 and the sub reflection mirror 6 and received by the primary radiator 7. Further, the down converter 22 converts the intermediate frequency signal. The intermediate frequency signal is amplified by the intermediate frequency amplifier 23, and then sent to the demodulator 25 via the band limiting filter 24. The demodulator 25 demodulates the signal in the predetermined band output from the band limiting filter 24, and the optical signal / millimeter wave signal automatic selection circuit 3
Output to 1. This optical signal / millimeter wave signal automatic selection circuit 3
1 indicates that there is no signal from the limiter / demodulator 15,
When the output signal of the demodulator 25 is detected, the output signal of the demodulator 25 is selected and output to the outside via the video amplifier 32 and the external output terminal 33.

As described above, the hybrid receiver 1 is
Regardless of whether the signal is sent from the transmitter by the optical space communication method or the millimeter wave communication method, the signal sent is selected and output to the outside.

Next, a specific example of use will be described with reference to FIG. FIG. 4 shows an example in which the hybrid receiver 1 is installed in a train 42 that passes through a tunnel (or an underground tunnel) 40 and a ground 41. The hybrid receiver 1 is installed at the forefront of the train 42. Then, a light transmitter 43 is provided near the exit in the tunnel 40.
Is installed to send an optical signal toward the forefront of the train 42 traveling in the tunnel 40, and a millimeter wave transmitter 44 is installed on the ground 41 so that the millimeter wave can be transmitted to the train 42 running on the ground. I am trying to send a signal.

When the train 42 enters the tunnel 40, the signal transmitted from the millimeter wave transmitter 44 is cut off, and instead the optical signal from the light transmitter 43 is transmitted to the train 42.
In the hybrid receiver 1 mounted on the train 42, the optical signal from the light transmitter 43 is received by the optical signal receiver 11, demodulated, and input to the optical signal / millimeter wave signal automatic selection circuit 31.
When the demodulated signal output from the optical signal receiving unit 11 is input, the optical signal / millimeter wave signal automatic selection circuit 31 selects the signal from the limiter / demodulator 15 of the optical signal receiving unit 11 to perform video amplification. For example, it is output to a monitor or the like in the driver's seat via the unit 32 and the external output terminal 33. The driver can confirm the content of the information sent from the light transmitter 43 by the display on this monitor.

When the train 42 exits from the tunnel 40 to the ground 41, the hybrid receiver 1 sends the light transmitter 43.
The millimeter wave signal receiving section 21 receives the millimeter wave signal sent from the millimeter wave transmitter 44 instead of the optical signal from the. The millimeter wave signal received by the millimeter wave signal receiving section 21 is demodulated by the demodulator 25 and input to the optical signal / millimeter wave signal automatic selection circuit 31. When the demodulated signal is input from the millimeter wave signal reception unit 21, the optical signal / millimeter wave signal automatic selection circuit 31 receives the demodulator 25 of the millimeter wave signal reception unit 21.
The signal from is selected and is output to a driver's seat monitor or the like via the video amplifier 32 and the external output terminal 33.

As described above, the communication system suitable for the communication environment is used inside the tunnel 40 or on the ground 41, but the hybrid receiver 1 mounted on the train 42 is
When the transmission signal is received, the reception signal is automatically selected and output to a monitor or the like, so that the driver may enter the train 42 into the tunnel 40 or from the tunnel 40 to the ground 4
Even in the case of 1, the receiving circuit does not need to be manually switched and the driver can concentrate on the driving operation.

[0020]

As described above in detail, according to the present invention, the optical signal receiving unit and the millimeter wave can be used regardless of whether the transmitter uses the millimeter wave communication system or the optical space communication system. The transmission signal can be reliably received without switching the signal receiving unit by manual operation.

[Brief description of drawings]

FIG. 1 is a diagram showing an external configuration of a hybrid receiver according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a Cassegrain parabolic antenna unit in the same embodiment.

FIG. 3 is a block diagram showing an internal circuit configuration in the same embodiment.

FIG. 4 is a diagram showing an example of use in the same embodiment.

[Explanation of symbols]

 1 Hybrid receiver 2 Main body 3 Cassegrain parabolic antenna section 4 Light receiving section 5 Main reflecting mirror 6 Sub-reflecting mirror 7 Primary radiator 8 Support metal fitting 9 Focus position 10 Light transmission hole 11 Optical signal receiving section 12 Light receiving element 13 Preamplifier 14 Band Limiting filter 15 Limiter / demodulator 21 Millimeter wave signal receiving section 22 Down converter 23 Intermediate frequency amplifier 24 Band limiting filter 25 Demodulator 31 Optical signal / millimeter wave signal automatic selection circuit 32 Video amplifying section 33 External output terminal

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location H04B 10/105 H04B 9/00 R 10/10 10/22 (72) Inventor Katsuya Ueno Saitama Omiya 1406 Hasunuma, Ichi, Yagi Antenna Co., Ltd. Omiya Factory

Claims (1)

[Claims] 1. A parabolic antenna for receiving a millimeter wave signal transmitted from a transmitting device using a millimeter wave communication system, a millimeter wave signal receiving section for amplifying a millimeter wave signal received by the parabolic antenna, and the parabolic antenna. Part or all of the reflecting surface is a mirror surface, and means for reflecting and condensing the optical signal transmitted from the transmitting device by the optical space communication method, and the optical signal reflected and condensed by this means is received and amplified. The millimeter wave signal receiving unit, and an automatic selection circuit for detecting the presence or absence of the output signal of the millimeter wave signal receiving unit and the optical signal receiving unit, and selecting the receiving unit on the side outputting the signal, the millimeter wave signal A hybrid receiver comprising a signal receiving unit and an optical signal receiving unit integrally formed.