JPH0326031A - Relay system and repeater - Google Patents

Abstract

PURPOSE:To utilize a radio wave resource effectively and to reduce the installation cost by utilizing the shielding performance of a ground face existing between an on-ground radio station and an underground radio station and making the frequency of the on-ground radio station identical to the frequency of the underground radio station. CONSTITUTION:A repeater is provided with an on-ground radio station 1 installed at the on-ground, a leakage coaxial cable 2 installed in an underground cavity 5, an underground radio station 3 connected to the leakage coaxial cable 2 and an inter-base station cable 4 connecting the underground radio station 3 and the on-ground radio station 1. Then the on-ground side 6 and the underground cavity 5 are isolated completely electromagnetically with the shielding effect of the ground face 14 and no radio wave interference is caused between the on-ground side 6 and the underground cavity 5. Thus, the communication between an on-ground radio station 12 and an underground radio station 12 is relayed by one frequency to promote the effective utilization of the radio wave resource, thereby reducing the installation cost.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a relay system and relay device for relaying between a terrestrial radio station and an underground radio station. (Prior Art) A system shown in FIG. 3 has been known as a method for communicating between a radio station on the ground-L side and a radio station on the ground-F side.

This system includes a base station 101 installed on the ground side, a leaky coaxial cable l02 installed on the ground F side, and a distributor 103 that connects this leaky coaxial cable +02 and the base station lot. .

The base station lot includes a J construction station antenna 104 and a first base station transceiver l05 connected to this base station antenna 104.
and the 2nd base station transmitting/receiving unit 106 connected to the 2mI distributor +03, and the receiving section f1 of the 1J engineering station transmitting/receiving unit 3 +05]07 and the second base station transmitting/receiving unit 106 connected to the 2mI distributor +03. (In addition to connecting the transmitter 108 of the base station transceiver +06, the transmitter +09 of the first base station transceiver +05 and the second base station transceiver 10
and a connecting section II1 that connects to the receiving section 110 of No. 6.

When the bear line signal of frequency r1 is transmitted from the ground radio station +15, the antenna of the other station +04 is transmitted from the E bear line station 115.
The first base station transmitter/receiver receives the non-&Q signal from 1. 0 5 receiver {'ilj unit +07 is supplied.

The receiving section 107 demodulates this {ri e-, generates an audio signal and a receiving A3-3, and sends this to the second J,!, via the connecting section 111. , to the transmitter 108 of the base station transceiver 106.

The transmitting unit 108 generates a high frequency signal with a frequency f2 using these audio signals {a and the received signal as modulation signals, and
This high frequency signal is passed through the distributor 103 to the distributor l0.
It radiates into the underground cavity from the leaky coaxial cable 102 connected to 3 and transmits it to the underground radio station 116.

Furthermore, when radio I3 of frequency f2 is transmitted from the underground radio station +16, the leaky coaxial cable 102 receives the radio I12 from the underground radio station 116 and sends it to the second radio via the distributor 103. Receiving section of base station transceiver 106! Supply to 10. The transmitter/receiver 110 demodulates this signal, generates the audio 4g signal and the received signal, and transmits it to the transmitter 1 of the l-th base station transceiver 105 via the connection unit Il+.
Transfer to 09.

The transmitter 109 modulates these audio signals and received signals {2
To generate a signal with frequency dispersion 11 as a signal, this signal is emitted from the base station antenna 104 to the ground]; wireless station 1
Tell 15.

In this way, this system uses a radio signal with frequency ``1'' on the ground L side, and uses a radio signal with frequency f2 on the underground side to prevent the occurrence of oscillation phenomena caused by radio wave T-crossing. ”-Relays communication between radio station 115 and underground radio station +16.

However, in such a conventional relay system, 2
Because it requires two frequencies, the result is contrary to the requirement for efficient use of radio wave sources.

Also. In order to use different frequencies above ground and underground, the ground L radio station +15 and the ground F radio station l16 are used as ground radio stations.
It is necessary to prepare a two-frequency switching type radio that has both the frequency of the second side and the frequency of the ground F side, which causes problems such as increased capital investment and complicated operation and management of the radio. (Objective of the Invention) The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional technology, and is capable of relaying between a two-way radio station and a ground-based radio station using t frequencies. By this, "K"
It is possible to promote the effective use of i-wave resources, and
The purpose is to provide a relay method that can reduce equipment costs.

(Summary of the Invention) In order to solve the problem mentioned above, the relay system according to the present invention utilizes the shielding property of the ground between the terrestrial radio station and the underground radio station to The present invention is characterized in that the frequency of the station and the frequency of the ground-based radio station are made the same. (Embodiments) The present invention will be described in detail below based on embodiments shown in the drawings.

No.! The figure is a block diagram showing one embodiment of the present invention.

The relay device shown in this figure includes an underground base station 1 installed on the ground side, a leaky coaxial cable 2 laid in an underground cavity 5, an underground base station 3 connected to this leaky coaxial cable 2, and an underground base station 1 installed on the ground side. It is provided with an inter-base station cable 4 that connects the underground base station 3 and the above-mentioned terrestrial base station I.

Earth [6 ground due to the shield effect that 7i14 has]
The ground side and the ground F cavity 5 side are electromagnetically completely separated to prevent radio wave interference from occurring between the ground side 6 and the ground F cavity 5 side.

The ground L base station l has a base station antenna 7 and a base station antenna 7 as shown in FIG. A place with a receiving section 8 and a transmitting section 9! −． Station transceiver 1
0 and. Transmitting the antenna 7 in liii to the receiving unit 8 in rI
A changeover switch 1.1 is provided to connect either of the parts 8 and 9.

+1ii Note - The receiving unit 8 of the L station transmitting/receiving IO includes a high frequency bandpass filter 15 connected to the antenna 7 like a normal receiver, and a high frequency bandpass filter 15 that amplifies the output signal.
A mixing circuit 2 that mixes the output of the amplifier with a local signal transmitted from a terrestrial base station and obtained via a low-pass filter 20 and a local amplifier 19, which will be described later.
1 and the intermediate frequency f3 of the difference between the two batches is extracted from the output of this mixing circuit 2l! It is equipped with an F-band bus filter 16, an IF amplifier 22 that amplifies the output of the F-band bus filter 16, and a second IP band bus filter 17 that removes high frequencies generated by the amplifier and is connected to a cable that connects to the underground base station. The base station Andena 7 connects 2 terrestrial radio stations +
When the signal (f1) from 2 (see Figure 1) is received, this signal and the local oscillation signal (f1) supplied from the underground base station via the inter-base station cable 4 are amplified to the required level.
f2), an intermediate frequency signal of frequency <1-n! is generated, amplified to a required level while removing high frequencies, and sent to the base station 3 via the inter-base station cable 4.
Send to. Furthermore, the transmission f/s unit 9 of the terrestrial base station 10 is an IP
An amplifier 25 and an IF bandpass filter 23 that removes distortion components from its output, the filter output signal being used as one input, and the signal obtained by amplifying the output (fL) of the local oscillator 28 by the local amplifier 27 as the other input. A mixing circuit 29 as an input, a high frequency amplifier 30 that amplifies the output of this mixing circuit to a required level, and fl+rL from the output.
A high frequency bandpass filter 24 extracts a signal from the local oscillator 28, and a local amplifier 26 amplifies the output of the local oscillator 28 and sends it to a local station. +1Q When an intermediate frequency signal (f1) of frequency (fl-fL) is supplied via the inter-base station cable 4, after amplifying it to a required level and removing distortion, the local signal obtained by the oscillation circuit 28 is While mixing with the oscillation signal to generate a signal of frequency rl. The signal is increased to a required level while removing distortion, and is outputted from the base station antenna 7 via the changeover switch 11 and transmitted to the ground 42 radio station +2.

Also. +fiJ underground base station 3 includes a land station transceiver 34 having a receiving section 32 and a transmitting section 33, and 1γj3[:!
It is provided with a distributor 35 connected to the leaky coaxial cable 2, and a changeover switch 36 for connecting the distributor 35 and the ifl recording f station transceiver 34.

The transmitting unit 33 of the base station transmitter/receiver 34 has almost the same configuration as the transmitting unit of the above-mentioned base station, and includes two bandpass filters 37 and 38, three amplifiers 39 to 4l, and an oscillation circuit 42. , mixing circuit 43, and power amplifier 44
When an intermediate frequency signal of frequency (1-rL) is supplied from the receiving unit 8 via the inter-base station cable 4, this intermediate frequency signal and the local frequency signal obtained by the oscillation circuit 42 A signal of frequency f1 is generated based on the oscillation signal, and the signal is emitted from the leaky coaxial cable 2 via the changeover switch 36 and the distributor 35 to the ground F.
The information is transmitted to the wireless station 13 (see FIG. 1).

In addition, the underground station transmitting/receiving F! The receiving unit 32 of the J34 has the same configuration as that of the terrestrial base station No. 12, and includes three punt bass filters 45 to 47, two amplifiers 48 and 49, a low bass filter 50, a mixing circuit 5l, and one punt bass filter. ′
When a signal from the underground radio station 13 is received by the leaky coaxial cable 2, the distributor 3
5. Receive this signal via the changeover switch 36, and generate an intermediate frequency signal of frequency (fl-fL) based on this signal and the local oscillation signal supplied via the inter-base station cable 4. is sent to the Oii-ki transmitter 9 via the inter-base station cable 4.

In this embodiment, a local oscillator is provided in the transmitter 4A section of each of the ground station and the ground-to-station of the repeater, and the output of the local oscillator is mixed with the signal transmitted from the correspondingly connected receiving section. At the same time, the receiver connected to the receiver derives the local oscillator output of the correspondingly connected transmitter via a cable, and combines this signal with the received signal. They are mixed and the difference between the two is extracted to produce an intermediate frequency signal.

Therefore, the frequency of the signal transmitted to the receiver via one antenna and the signal generated by the corresponding transmitter and output from the other antenna will soon be the same. Even if the frequency of the local oscillator fluctuates, it is characteristic that the change in both signal frequencies is very slight.

This is because the local oscillation frequency signal to be subtracted in one receiver and the local oscillation frequency to be added in the other transmitter are supplied from the same oscillator.

Furthermore, as in this example, the frequency of the signal transmitted between the aboveground and underground base stations is different from the transmitting and receiving frequency, and moreover, it is converted to an intermediate frequency and has a lower frequency. Even if the amplification degree is increased, troubles due to input/output loopback can be prevented, and by using a relatively low frequency, even if the distance between the ground and underground base stations becomes long, the cables between them can be prevented. Reduces high frequency signal loss and prevents S/N drop.
Even two is convenient. Further, if the frequencies of the two local oscillators shown in L are set to be the same as each other, the intermediate frequencies of the two local oscillators will be different from each other, so troubles due to interference from the residence can be prevented.

Next, the operation of this embodiment will be explained with reference to FIG.

Now, when the terrestrial L radio station 12 transmits at the frequency f1, the base station antenna 7 receives the signal No.&Q{3 from the terrestrial radio station l2 and supplies it to the receiving section 8 of the ground station transceiver 10.

The receiving section 8 converts this signal into an intermediate frequency signal and transmits it to the transmitting section 33 of the underground base station transceiver 34 via the inter-base station cable 4.

The transmitter 33 generates a signal of frequency fl from this intermediate frequency signal, and also transmits this No. 3 to the leaky coaxial cable 2.
qr L underground radio station broadcasting from underground cavity 5! 3.

Furthermore, when the underground radio station l3 transmits at frequency f+, the leaky coaxial cable 2 receives the radio signal from the underground radio station l3 and supplies it to the receiving section 32 of the underground station transceiver 34.

The receiving section 32 converts this signal into an intermediate frequency signal and transmits it to the transmitting section 9 of the ground station transceiver 10 via the inter-base station cable 4.

The transmitter 9 receives the frequency [!] from this intermediate frequency signal. This signal is emitted from the base station antenna 7 and transmitted to the ground radio station I2. In this way, in this embodiment, the conductivity of the ground 14 between the ground 1-6 and the underground cavity 5 is utilized to use the other surface 14 as a shielding member, so that the oscillation phenomenon caused by radio wave interference can be avoided. One frequency f1 while preventing the occurrence of
can relay communication between the terrestrial radio station 12 and the underground radio station I3.

This makes it possible to promote effective use of radio wave resources and reduce equipment costs.

It should be noted that in carrying out the present invention, there is no reason to be limited to the embodiments described in L. and send it as it is to the other transmitter, and the transmitter is simply a high frequency amplifier, or one receiver demodulates the received signal and the other transmitter sends the demodulated f3 signal,
In addition to transmitting the frequency (or frequency and phase) information of the received signal, the other transmitter receives this information and controls the VCXO etc. based on this information to create radio waves that are exactly the same as the received frequency. It's okay. According to this method, the signal line connecting both base stations can be used for low frequency (audio), and it is inexpensive and does not cause deterioration of S/N.

(9. Effects of light) As explained above, according to the present invention, it is possible to relay between a ground radio station and a ground radio radio station using one frequency, thereby making effective use of radio wave resources. It is possible to promote this and reduce equipment costs.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a relay system according to the present invention. FIG. 2 is a detailed block diagram of the same embodiment, and FIG. 3 is a block diagram showing an example of a conventional relay system. l...Ground base station, 2...Leaky coaxial cable, 3.
... Underground base station, 7... Base station antenna, l2...
Earth To Mκ line station! 3-...Underground radio station.

Claims (1)

[Claims] (1) In a relay method that relays between a terrestrial radio station and an underground radio station, the frequency of the terrestrial radio station and the frequency of the underground radio station are A relay method characterized by making the frequencies the same.