JPS6221294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] Regarding a set backup wireless relay system, it is described how to obtain low power consumption performance by using two direct relay devices with the same shift frequency.

[Industrial application field]

The present invention relates to a set-preparation wireless relay system. The wireless relay system according to the present invention is used for a set backup type wireless line, especially a wireless line that requires a low-consumption type relay station.

[Prior art and problems to be solved by the invention]

The conventional set backup method wireless relay method has been replaced with the fourth one.
As shown in FIG. FIG. 4 shows the case of unidirectional communication, and FIG. 5 shows the case of bidirectional communication. In FIG. 3, first, in the preceding station A , baseband input 1 is given to a branch circuit (BR) 2, which is connected to a working transmitter circuit (T) 3, a backup transmitter circuit (T) 4, and a transmission changeover switch ( SW) 5 and then transmitted from the antenna 6. At relay station B , antenna 7
The signals received in the hybrid circuit (H) 8 are branched and sent to the receiving circuits (R) 9 and 10, and the signal is synthesized or selected in the signal combining circuit (CB) 11. The signal is transmitted from the antenna 16 via the circuit (T) 13, the backup transmitter circuit (T) 14, and the transmission selector switch (SW) 15. At receiving station C , antenna 1
The signal received at 7 is branched by a hybrid circuit (H) 18 and sent to receiving circuits (R) 19 and 20, and the signal is combined or selected by a signal combining circuit (CB) 21 to obtain a baseband output 22. The signal combining circuit performs signal combining when the two receiving circuits are normal, and selects to disconnect the output of the abnormal side when one becomes abnormal. This is because when the two receiving circuits are operating normally, the signal increases by 6 dB due to the combination using the signal combiner, but the noise increases by only 3 dB, resulting in a 3 dB improvement in the signal-to-noise ratio. .
However, this conventional type has problems such as the complicated circuit and the inability to reduce the power consumption of the relay station. In the case of two-way communication in Figure 5,
I'm in a similar situation.

The main object of the present invention is to solve the problems of the conventional type described above, and to provide a wireless communication system in an improved set backup system with low power consumption performance, based on the concept of using two direct relay devices with the same shift frequency. The goal is to obtain a relay method.

[Means for solving problems]

In the present invention, in a relay station for multiplex radio communication using a set backup method in which two sets are provided for one transmission wave, the received wave from the previous station is divided into two sets.
Two direct repeaters that either have the same shift frequency or directly amplify and output the received wave are used to amplify each to a predetermined output level, and the resulting two amplified outputs are mutually polarized. The receiving station changes the transmission wave from the relay station to 2
A set-preparation wireless relay system is provided, which is characterized in that two receivers identify and receive polarization planes, and the outputs of the receivers are combined or selectively used.

〔Example〕

An embodiment of the invention will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 shows the case of unidirectional communication, and FIG. 2 shows the case of bidirectional communication. In Fig. 1, at the previous station A , baseband input 1 is given to the branch circuit (BR) 2, and the current transmitter circuit (T)
3. The signal is sent out from the antenna 6 via the backup transmission circuit (T) 4 and the transmission changeover switch (SW) 5.
At relay station B , the radio waves received by antenna 7 are branched by hybrid circuit (H) 8, amplified by amplifier circuits 23 and 24, and mixed circuit (MIX) 25 which is connected to shift frequency oscillation circuit (SF) 27. ,2
6 and amplified by amplifier circuits 28 and 29, and a vertically polarized wave component 30 and a horizontally polarized wave component 31 are sent out from the antenna 16. At the receiving station C , the vertically polarized wave component 32 and the horizontally polarized wave component 33 received by the antenna 17 are combined or selected in the signal combining circuit (CB) 21 via the receiving circuits (R) 19 and 20, and are output as a baseband output 22. get. Here, in Figures 1 and 2, the shift frequency oscillation circuit (SF)
27. Mixing circuits (MIX) 25 and 26 are shown conceptually, but their specific circuits are as shown in FIG.
1,272 are switched by a changeover switch 273 to be connected to mixers (MIX) 251, 261, and one of the two shifted frequency oscillators is for backup. In this way, the shift frequencies are set to be the same in order to make the transmission frequencies the same.

Although the frequency shift method is explained in Fig. 1, it is also possible to use a direct repeater that directly amplifies the received wave and outputs it, and the same effect can be expected in that case as well. can.

Further, FIG. 2 shows a circuit configuration for bidirectional communication as opposed to the unidirectional communication in FIG. 1.

In FIG. 2, the transmitting circuits (T) 3, 4 and the receiving circuits (R) 19', 20' at the front station A are
Transmitting/receiving antenna 6, antenna duplexer 35, 36,
They are connected by a hybrid circuit (H) 34, and at relay station B , the transmitting circuit and the receiving circuit are
Transmitting/receiving antennas 7, 16, antenna duplexer 37,
38, 39, and 40, and at the receiving station C , the transmitting circuit and the receiving circuit are connected by a transmitting/receiving antenna 17, antenna duplexers 41, 42, and a hybrid circuit (H) 43. In each antenna 6, 7, 16, 17, the upper terminal is for vertically polarized waves, and the lower terminal is for horizontally polarized waves.

〔Effect of the invention〕

According to the present invention, low power consumption performance can be achieved by using a direct relay device in a set backup wireless line. Also, since there is no hybrid at the receiving station, in order to obtain the same signal-to-noise ratio, the transmitting output of the direct repeater must be
Based on the fact that it can be as low as 3 dB, it is possible to achieve even lower power consumption performance. Also,
Based on the use of vertical and horizontal components as polarized wave output, fading does not occur uniformly in both, so it is possible to expect a diversity effect due to polarization identification, and also eliminates the need for a transmitter switch. be able to.

[Brief explanation of the drawing]

1 and 2 are diagrams showing a wireless relay system using a set backup system as an embodiment of the present invention, and FIG. 3 is a diagram showing the detailed configuration of the relay station in FIGS. FIGS. 4 and 5 are diagrams showing a conventional wireless relay system using a set backup system. Explanation of symbols: A...previous station, B...relay station, C...receiving station, 1...baseband input, 2...branch circuit,
3, 4... Transmission circuit, 5... Transmission selector switch, 6,
7, 16, 17... Antenna, 8... Hybrid circuit, 23, 24, 28, 29... Amplification circuit, 25,
26... Mixing circuit, 30, 32... Vertical polarization component, 3
1, 33... horizontal polarization component, 19, 20... receiving circuit,
21...Signal synthesis circuit, 22...Baseband output.

Claims (1)

[Claims] 1. At a relay station for multiplex wireless communication using a set backup method in which two sets are provided for one transmitted wave, the received wave from the previous station is branched into two, and the shift frequency is the same, or the received wave Two direct repeaters that directly amplify and output the signal are amplified to a predetermined output level, and the resulting two amplified outputs are sent out with mutually different polarization planes, and the receiving station receives the transmission from the relay station. 1. A set-preparation radio relay system, characterized in that waves are received by two receivers by identifying the plane of polarization, and the outputs of the receivers are combined or selectively used.