JPS5843638A - Space diversity system - Google Patents

Abstract

PURPOSE:To reduce a line instantaneous cut-off rate due to fading, by making a receiving side and a transmitting side have a space diversity function, in an FM microwave radio communication system of a setting stand-by system of space diversity. CONSTITUTION:In a station A, an output from a transmitter 1 or 1' through a changeover switch SW4 is inputted to a changeover SW15, and is connected to an antenna 10 through an antenna sharing device 3. In a station B, inputs from antennas 10', 11' are inputted to receivers 2'', 2''' through antenna sharing devices 3', 16', respectively, so as to have a space diversity function. In case when an output level of the receivers 2'', 2''' of the station B has become a prescribed threshold level or below due to fading FD, an IF level detecting circuit 13 detects it, and sends out an alarm to the station A from an alarm sending-out circuit 12'. In the station A, when the alarm is detected by an alarm detecting circuit 14, the changeover SW15 is operated, and the output of the transmitter 1 or 1' is transmitted from an antenna 11 whose position is different from the antenna 10 through an antenna sharing machine 16. In this way, the station B is capable of receiving a signal without being influenced by FD.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a space diversity (hereinafter referred to as 8D) set reserve system PM micro radio overconfidence system, which combines a total of 8 DIm on the receiving side with an 8D function on the transmitting side.
D Manshiki mTru.

Figure 1111 shows a conventional 8D system FM set reserve system.
Micro#llll: A (I12F type block diagram is shown.
・In the figure, 1, 1', l#, 1# are transmitters, 2#
2'#2' is the receiver, 3.3' is the antenna duplexer,
4, 4', 5, 5' are changeover switches; 6. ．． 6
' is a hybrid circuit, 7, 7' are modulators, s, s' are demodulation amounts, 9.9' is a control circuit, 10.10', 11.1
1' is an antenna, 12.12' is an alarm sending circuit, 13.
13' is the IP level detection circuit, 14.14' is the alarm detection circuit, the left side is the λ station, and the right side is the B station.
jIiTru. The baseband signal is transmitted to the modulator 7 by I
F band, transmitters 1, 1'
In this case, the transmission frequency and output level of the overtransmitters 1 and 1' are set at the changeover switch 4. monitor and use the one closest to the predetermined value.

At station B, it was created to alleviate the deterioration of the over 11 line (III) due to fading.
13', the other is received by the receiver 21, and the other is received by the receiver 2#I, the IP band is set, and the control circuit 9 receives the 87N signal.
' to select, and operate the selector switch 5'.

The signal with the better S/N is used as the baseband by the demodulator 8'. In this case - if the 10,000 receiver is out of order and the output level of the receiver falls below the predetermined threshold due to aging, or both receivers' output level I is below the predetermined threshold. If it becomes below, IF level I
The detection circuit 13' detects this, and the alarm sending circuit 12' issues an alarm (No. 1) to the modulator 7'.

An alarm signal is sent to the opposing station B via the hybrid circuit 6', the transmission $tIexllt changeover switch 4', the antenna duplexer 3', and the antenna 10'. At station A, the alarm is detected by the alarm detection circuit 14 via the reception path explained above.However, this method t has the disadvantage that if one of the receivers i fails, only one antenna is used for reception and the SD function is lost. There is an object of the present invention to solve the above-mentioned drawbacks.
When the output level I of two receivers becomes less than a predetermined threshold, the antenna is provided with a transmission function (11111 and 81) by transmitting from an antenna that is not currently in use.

The present invention achieves the above-mentioned purpose - to receive WLT - BD@
11 of the present invention below, which is characterized by having 88 functions in addition to the 41 and @! An example of a meal will be explained according to the drawings. Figure 2 shows a block diagram of the 8-D method of the embodiment of the present invention and the FM Micro S* pass-through method, which is a set reserve method. The same symbol indicates T0t5.
．． 15' is a changeover switch, and 16.16' is an anti-converter.The difference in this embodiment from the first one is the changeover switch 15゜15.
' and antenna duplexers 16 and 16' were installed, the switch t5 and 15' of the opposite station's own station were changed, and the transmitting m1ii was also equipped with 8D equipment by using an antenna that was not used for the previous flight. ) Transmit B station 11 BJi6 as the receiving side l
il@ Then, at station A, the output from the transmitter l or 1' via the changeover switch 4 is input to the changeover switch IB, and in the normal case, the output from the transmitter 1 or 1' is input to the changeover switch IB via the antenna duplexer 38 as in the conventional case.
Connect to 0. At station B, the input from antenna 10' is the same as before (input to receiver 2# via antenna duplexer 3', input from antenna 11' is input to antenna duplexer 1).
It is input to the receiver 21I via f and I and has an 8D function.

If, for example, the receiver 21 of the B station breaks down, the B station will lose its 8D function and will only receive data from the receiver 2zi.

For this reason, the output level of the receiver 211 due to fading
When the signal becomes less than a predetermined threshold, communication is cut off.

Also, even if the receiver is not malfunctioning, communication will be cut off if the output level of the receivers 2#, 2#/ falls below a predetermined threshold value. In this case, the IP level detection circuit 13' becomes accustomed to the alarm sending circuit 1.
2' to the opposite station, and the alarm detection circuit 144 of the opposite station (station A) detects the iron alarm, as in the past, but in the case of the present invention, this alarm detection causes the changeover switch to be activated. 15 is operated 6, and the output of one transmitter 1 or 1' is transmitted from the antenna 11 via the antenna duplexer 6. As a result, since the signal is transmitted from the antenna 11 at a different position, which is not installed in order to eliminate the influence of fading, the receiving side (station B) can receive the signal without the influence of fading. This is the same even if the receiver 21 is broken and only receiver 2# is able to receive, or if the output repetition rate of receivers 2# and 3# is below a predetermined threshold due to fading. .

The aS diagram is the 8D method of another embodiment of the present invention, and the i? The main points are shown in the block diagram of the M micro wireless communication system. In the figure, 11211 and +gIj- functions are indicated by the same symbol. T017.17' is a changeover switch.

The difference between the 1M3 diagram and the 1I2 diagram is that the explanation will be given on behalf of the B station.
11' via the antenna duplexer 3.16, and normally set the selector switch 17 to, for example, transmitter III, transmit from transmitter 1 to the opposite station (B station).
For example, if receiver 2N fails and the output level of receiver 2# becomes less than a predetermined threshold level due to fading, or the output level of receivers 'll and 2M becomes less than a predetermined threshold level M. The case is the same as the explanation in Fig. 2 (, IP
Level detection tm path, alarm sending... @ path, changeover switch 1 of station A via alarm detection circuit (none of which is shown)
7 is activated and connected to the transmitter 1' side, transmitter 1/, antenna duplexer 16. Transmit via the antenna 11. This is the same as the explanation in Figure 2 (the antenna 11 is installed in a different position to eliminate the effect of fading
Since the receiving side (station B) is not affected by fading, it is possible for station C to receive the signal.

In this case, since the changeover switch 17.17' is on the IP frequency, the changeover switch 17.17' can be made inexpensive and the same as above.0 As explained in detail above, according to the present invention, both the receiving and transmitting sides have 8 DIm capability. This eliminates the effects of fading even when one of the receivers fails and the output level of the two receivers falls below a predetermined threshold, making the wireless communication line highly reliable. There is a possible effect.

[Brief explanation of the drawing]

Figure 41 shows the conventional 8D system and the set reserve system.
? s Wit Figure 2 is a block diagram of the 1i'M micro communication system which is set in the SD system according to an embodiment of the present invention and is set in reserve. The main points are shown in the block diagram of the FM micro overconfidence method of the backup method.1.1', 1#, 1 in the T0 diagram
' is the transmitter, 2 t '' e 2' @ 2' is the receiver, 3.3', 16.16' are the antenna shared trigrams, 4.4'
, 5, 5', 15, 15', 17, 17' are changeover switches, 6.6' is a bibliding frequency, 7 + 7' is a modulator, 8.8' is a demodulator, and 9, 9' are controls. Circuit, 10°10
', 11.11' is the antenna, 12.12' is the alarm sending circuit, 13.13- is the IF level detection circuit, 14°14
' is an alarm detection circuit. Brush map 4 station 190-

Claims (1)

[Claims] In the space diversity set reserve system PM micro wireless communication system, the transmitter is connected to two antennas.
When the output level I of the two receivers falls below a predetermined threshold, the transmitter of the own station transmits a signal to the opposite station, and the opposite station transmits a signal higher than the antenna that is not currently in use.
The space dipacity method is characterized by 5 f1i.