JPH03201628A - Space diversity radio communication equipment - Google Patents

Abstract

PURPOSE:To prevent a space diversity from falling into a function shutting off state by supplying a phase shift control signal to be outputted from another communication unit instead of the phase shift control signal of a self-unit when a phase shift control operation can not be executed by the phase shift control circuit of the self-unit. CONSTITUTION:At every respective communication units 10 and 20, this equipment is provided with switching circuits 14 and 24 to selectively supply the phase shift control signals to be outputted from phase shift control circuits 13 and 23 of the self-units and the phase shift control signals to be outputted from the communication units of another channel, for which a radio frequency is made close within a prescribed range, to the phase shifters of the self units. When the phase shift control operations can not be executed by the phase shift control circuits 13 and 23 of the self units, the switching circuits 14 and 24 are changed over and the phase shift control signal to be outputted from the other communication unit is supplied to the phase shifter of the self unit. Thus, the communication unit, in which the phase shift control circuits 13 and 23 can not be operated, continues the phase shift operation by the phase shift control signal from the other communication unit until the self-control is enabled, and a transmitting operation can be executed without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Field of Industrial Application) The present invention relates to a space diversity wireless communication device used, for example, in a microwave wireless communication system.

(Prior Art) In microwave wireless communication systems, space diversity is widely adopted as one of the methods for reducing the effects of fading. Space diversity refers to arranging two antennas spatially apart and taking advantage of the small correlation between the transmitted waves or received waves by these antennas. The effect of fading is reduced by selecting or combining them appropriately.

FIG. 4 is a schematic configuration diagram of a multi-channel space diversity receiving apparatus to which a reception space diversity method is applied as an example.

This receiving device includes two receiving antennas ATa, a main and a sub-receiving antenna common to each radio channel, which are arranged spatially apart;
It is composed of an ATb and a plurality of receiving units 1, 2, . . . each provided corresponding to a plurality of radio channels. Each of the receiving units 1, 2°, . . . has the same configuration. For example, the receiving unit 1 includes two main and sub receivers 11a and llb, a combiner 12, and a phase shift control circuit 13. Then, the carrier signals received by the upper and sub antennas ATa and ATb are converted into intermediate frequency signals by the receivers 11a and llb, and then synthesized by a combiner 12, and this synthesized signal is sent to a demodulation circuit (not shown). is supplied to. Further, the phase difference between the intermediate frequency signals is monitored by the phase shift control circuit 13, and the sub receiver 1
The amount of phase shift of the transfer device provided in 1b is variably controlled. Note that this phase shifter varies the phase of the local oscillation signal supplied from, for example, the main receiver 11a.

By the way, this type of device has each receiving unit 12,...
When the phase shift control system becomes inoperable due to abnormal operation of the phase shift control circuit, an alarm signal A is sent from the phase shift control circuit itself.
S is generated and supplied to the sub-receiver. Then, for example, the output signal path of the sub-receiver is cut off to disconnect the sub-reception system, thereby stopping the space diversity function. Therefore, a problem in which erroneous phase shift control is performed while the phase shift control circuit is malfunctioning can be reliably prevented.

However, in such conventional devices, if an abnormal operation occurs in the phase shift control circuit in any receiving unit, the receiving unit must repair or replace the phase shift control circuit to restore normal phase shift control operation. It becomes possible. The Space Diversity function will remain suspended until then. For this reason, if strong fading occurs during this period, the wireless channel during which the space diversity function is disabled becomes unusable, and as a result, transmission may become impossible.

(Problems to be Solved by the Invention) As described above, in the conventional device, when the phase shift control circuit of any communication unit becomes unable to control the phase shift, a space is provided until the transfer control operation returns to normal operation. There was a problem in that the diversity function stopped, which significantly reduced the reliability of the transmission operation.

Therefore, the present invention focuses on this point, and even if the phase shift control circuit of any communication unit becomes unable to control the phase shift, it is possible to continue the phase shift control operation of this communication unit, thereby stopping space diversity from functioning. An object of the present invention is to provide a space diversity wireless communication device that can prevent the situation from occurring and improve reliability.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention takes the following measures. In other words, we focused on the fact that the frequency correlation with respect to fading is high between multiple radio channels with close radio frequencies, and the direction and amount of phase shift control are similar.
For each communication unit, the phase shift control signal output from the phase shift control circuit of its own unit and the 11ji! a switching circuit that selectively supplies a phase shifter of its own unit with a phase shift control signal outputted from a communication unit of another wireless channel that is close within a predetermined range of one wave number; and a switching control means for the switching circuit. Be prepared.

When the phase shift control operation by the phase shift control circuit of the own unit becomes impossible, the switching control means switches the switching circuit of the own unit so that the phase shifter of the own unit receives the phase shift control signal of the own unit. Instead, a phase shift control signal output from another communication unit is supplied.

(Function) As a result, even if the phase shift control circuit becomes inoperable in any communication unit, the phase shift control signal for the phase shifter of the own unit will replace the signal from the own phase shift control circuit. Since the signal is automatically switched to the signal from the phase shift control circuit of another normal communication unit, the communication unit whose phase shift control circuit has become inoperable will not receive signals from the other communication unit until self-blade control becomes possible. The phase shift control operation is still continued by the phase shift control signal.

Therefore, the space diversity function of the communication unit is maintained, and even if strong fading occurs during this period, the communication unit can reliably perform the transmission operation without becoming inoperable.

(Embodiment) Hereinafter, a space diversity wireless communication device according to an embodiment of the present invention will be described. The apparatus of this embodiment applies a reception base diversity system and is constructed as shown in FIG. In this figure, the same parts as those in FIG. 4 are given the same reference numerals and detailed explanations will be omitted.

Each receiving unit 10, 20. . . . include phase shift control signal switchers 14, 24 . ... are provided respectively. This switching device 14, 24. ... selects between the phase shift control signal output from the phase shift control circuit of its own unit and the phase shift control signal output from the phase shift control circuit of another receiving unit with adjacent wireless channels. It is designed to be selectively selected and supplied to the phase shifter of its own unit, and is switched by an alarm signal output from the phase shift control circuit of its own unit when an abnormal operation occurs.

With such a configuration, each receiving unit 10.20
．． ...During the period when both switches are operating normally, each switch 14
, 24. . . . is the phase shift control circuit 1 of its own unit, respectively.
3.23. ... has been switched to the side.

Therefore, in this state, each unit is 10, 20°...
Both phase shifters have their own unit's phase shift control circuit 13゜23,
The phase shift control signal Psi output from...

PS2. ...is supplied.

Now, in this state, for example, if the phase shift control circuit 13 of the receiving unit 10 malfunctions, the switch 14 will be switched from the phase shift control circuit 13 side by the alarm signal ASI generated from the phase shift control circuit 13. , the wireless channel is switched to the phase shift control circuit 23 side of the adjacent receiving unit 20. Therefore, from now on, the phase shifter of the sub-receiver 11b will be supplied with the phase shift control signal output from the phase shift control circuit 23 of the adjacent receiving unit 20, and the phase shifter will be supplied with the second phase shift control signal. The phase of the intermediate frequency signal of the sub-receiving system is variably controlled in accordance with the amount of phase shift specified by the phase shift control signal from the circuit 23. Therefore, the receiving unit 10 can maintain the space diversity function as is.

Furthermore, in the microwave wireless communication system, the interval between wireless channels is generally set to within 100 MHz. Therefore, the correlation with respect to fading between the receiving unit 10 and the receiving unit 20, which have adjacent radio channels, is high. Therefore, even if the phase shift control signal outputted from the phase shift control circuit 23 of the receiving unit 20 is used in the receiving unit 10, no practical problem occurs and appropriate phase shift control is performed. Therefore, each receiving unit 10
As long as the phase shift change characteristics of the phase shifters at 0.20°C are matched, even if fading occurs, the influence of this fading can be sufficiently reduced in the receiving unit 10, and as a result, a sufficiently high A received intermediate frequency signal of the same level can be obtained.

Similarly, when the phase shift control circuit 23 of the receiving unit 20 malfunctions, the phase shift control signal PS1 output from the phase shift control circuit 13 of the receiving unit 10 is supplied to the phase shifter of the receiving unit 20. Ru. In addition, other receiving units 30, 40 . ... becomes inoperable for phase shift control, a phase shift control signal is supplied from a receiving unit with a wireless channel adjacent to this receiving unit.

In this embodiment, each receiving unit 10.2
0. . . . Phase shift control signal switch 14° 24, . . .
are provided respectively, and when the phase shift control circuit becomes inoperable, the alarm signals ASI, AS2°, . . . ..., so that the phase shift control signal output from the transfer control circuit of another receiving unit with an adjacent wireless channel is supplied to the phase shifter of the receiving unit that has become inoperable or disabled. Therefore, even if the phase shift control circuit becomes inoperable, it can be assisted, and thereby the space diversity function can be maintained and stable transmission can always be performed.

Note that the present invention is not limited to the above embodiments. For example, although the above embodiment describes the case of a space diversity receiving device, it can also be similarly applied to the case of a space diversity transmitting device or a device that performs receiving space diversity and transmitting space diversity, respectively. can.

That is, first of all, in the case of a space diversity transmitter, each transmitting point 10, as shown in FIG.
At 0,200', . . ., the main transmitter 101a.

201a, . . . , sub transmitters 101b, 201b, .
.

Transmission intermediate frequency signal distributors 102, 202. ... and phase shift control circuits 103, 203 . ..., phase shift control signals Psi, PS2 . Switcher 104゜20 for...
4.... will be provided. Then, the phase shift control circuit 103
．． 203. . . . monitors its own abnormality or abnormality of the control line for transmitting phase shift control information C3I, C32°, etc. from a receiving device (not shown), and issues alarm signals ASI, AS2 when an abnormality is detected. . . , thereby switching the switching devices 104, 204° . . . to the transmitting unit side with the adjacent wireless channel. By doing this, the phase shift control circuits 103, 203 . ...
Alternatively, even if the control line becomes abnormal, the phase shift control operation of the corresponding transmitting unit can be continued, thereby maintaining the space diversity function.

On the other hand, in the case of a device that performs the above-mentioned receiving space diversity and transmitting space diversity, for example, as shown in FIG. 14 to switch the phase shift control signal PS between the transmitting unit 100 and the receiving unit 10.

Further, in each of the above embodiments, the phase shift control signal is switched between two communication units with adjacent wireless channels, but the phase shift control signal is switched between three or more communication units that are adjacent to each other. Good too. In short, phase shift control signals may be switched between any communication units as long as the radio frequencies are close within a predetermined range.

Furthermore, the phase shift control signal switch does not necessarily have to be installed in all units in the device, but should be installed only in the communication unit of the wireless channel where the space diversity function must not be stopped, so that the phase shift side a signal can be switched. You may do so.

In addition, the configuration of the switching circuit, the configuration of the switching control means, the control procedure, etc. can be modified in various ways without departing from the gist of the present invention.

[Effects of the Invention] As described in detail above, the present invention allows each communication unit to communicate with another wireless communication unit whose radio frequency is close to the phase shift control signal output from the phase shift control circuit of its own unit within a predetermined range. The device includes a switching circuit that selectively supplies a phase shift control signal output from a communication unit of a channel to a phase shifter of its own unit, and switching control means for the switching circuit. When the phase shift control operation by the transfer control circuit of the own unit becomes impossible, the switching control means switches the switching circuit of the own unit to send the phase shift control signal of the own unit to the transfer device of the own unit. Instead, a phase-shifted signal 111a output from another communication unit is supplied.

Therefore, according to the present invention, even if the phase shift control circuit of any communication unit becomes unable to perform phase shift control, the phase shift control operation of this communication unit can be continued, thereby preventing space diversity from functioning. It is possible to provide a space diversity wireless communication device that can prevent errors and improve reliability.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a space diversity wireless communication device in a major embodiment of the present invention, and FIGS. 2, 3, and 3 are schematic configuration diagrams of space diversity wireless communication devices in other different embodiments of the present invention, respectively. , FIG. 4 is a schematic diagram of a conventional space diversity wireless communication device. TAa...Main antenna, TAb...Sub antenna, i
o, 20. ...Reception unit, 118.21a
,... Main receiver, 11b, 21b,...
- Sub-receiver, 12.22. ......Synthesizer, 13.23. ...Phase shift control circuit, 14.24.
・・・・・・Switcher, 100.200. ...... Transmission unit, 101a
, 201g, . . . main transmitter, 101b, 201
b, . . . sub transmitter, 102.20'2. ...
...Distributor, 103.203. ... Phase shift control circuit, 104.204.・・・・・・Switcher, PS, P
SI, PS2.・・・・・・Phase shift control signal, ASI, A
S2. ...Alarm signal, C3I, CS2. ...
...Phase shift control information. Ta

Claims (1)

[Claims] First and second communication systems that share first and second antennas arranged spatially apart over a plurality of wireless channels and that correspond to these antennas; and these first and second communication systems. Space diversity wireless communication comprising, for each of the plurality of wireless channels, a communication unit having a phase shifter that varies the relative phase between systems and a phase shift control circuit that variably controls the amount of phase shift of the phase shifter. In the apparatus, for each of the communication units, a phase shift control signal outputted from the phase shift control circuit of the own unit and a phase shift control signal outputted from a communication unit of another wireless channel whose radio frequency is close within a predetermined range. A switching circuit that selectively supplies signals to the phase shifter of the own unit, and a switching circuit that switches the switching circuit of the own unit when the phase shift control circuit of the own unit becomes unable to perform phase shift control operation. 1. A space diversity wireless communication device comprising: switching control means for causing a phase shifter to supply a phase shift control signal output from another communication unit in place of the phase shift control signal of its own unit.