JPH05327572A - Space diversity device - Google Patents

Abstract

PURPOSE:To easily transmit a reception local oscillation signal between a main reception equipment and an auxiliary reception equipment at the time of installing these equipments apart from each other and to simplify the constitution of a phase shifter or the like for diversity with respect to the space diversity device in the radio communication equipment using a microwave. CONSTITUTION:A synthesizer 18 synthesizes an intermediate frequency signal as the output of a reception frequency converter 13 and another intermediate frequency signal inputted from a main reception equipment 1. A phase comparator 17 compares phases of the intermediate frequency signal of the main reception equipment 1 and that of an auxiliary reception equipment 11 with each other and outputs the result as the control signal of a phase shifter 16. The phase shifter 16 controls the A phase of a reference oscillation signal inputted from a reference oscillator 6 of the main reception equipment 1. A reception local oscillator 14 outputs the local oscillation signal, which has the phase fixed to the output of the phase shifter 16, to a reception frequency converter 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a space diversity device in a radio communication device using microwaves.

[0002]

2. Description of the Related Art As a space diversity device in a conventional microwave radio communication device, there is a space diversity device of a system for combining a main reception signal and a sub reception signal in an intermediate frequency band. In this type of space diversity device, the phase relationship of the receiving station originating signals used in the main receiving frequency converter and the sub receiving frequency converter must be fixed. On the other hand, recently, in order to improve the economical efficiency of the microwave radio communication device, many devices in which an antenna device and a communication device are combined have been realized. In the case of this device, since the installation locations of the main receiving device and the sub receiving device are determined by the placement of the antennas, the main receiving device and the sub receiving device are separated from each other, which makes it difficult to transmit the signal originating from the receiving station. Will occur.

As a conventional space diversity device for solving this problem, there is a device as shown in FIG. The conventional space diversity device shown in FIG. 2 includes an antenna for main reception 2, a reception frequency converter for main reception 3, a reception local oscillator for main reception 4, a phase comparator 5 for stabilizing the oscillation of the main reception station, and A main receiving device 1 comprising a reference oscillator 6 for stabilizing the main receiving station, an antenna 12 for sub receiving,
Sub-reception reception frequency converter 13, sub-reception reception local oscillator 14, sub-reception station oscillation stabilization phase comparator 15, intermediate frequency band phase comparator 17, intermediate frequency band synthesizer 18 , An output terminal 19, a phase shifter 20 for a sub-reception station-originated signal, and a sub-reception device 11 including a microwave band amplifier 21.

Further, the conventional space diversity apparatus shown in FIG. 2 transmits a reference oscillation signal oscillated by the reference oscillator 6 in the main receiving apparatus 1 to the sub receiving apparatus 11 and uses the reference oscillation signal in the sub receiving apparatus 11. The phase of the reception local oscillator 14 is fixed, and the phase of the local oscillation signal output from the reception local oscillator 14 is rotated so that the main reception signal and the sub reception signal are in phase with each other and output to the reception frequency converter 13. By doing, we are doing diversity. Since the frequency of the reference oscillation signal oscillated by the reference oscillator 6 can be made lower than that of the local oscillation signal, transmitting the reference oscillation signal to the sub-reception device 11 is far more than transmitting the local oscillation signal itself. It has an advantage that the circuit configuration is easy.

[0005]

However, in the conventional space diversity apparatus described above, the phase of the local oscillation signal in the sub-reception device is fixed by the reference oscillation signal transmitted from the main reception device to the sub-reception device, and then the sub-reception is performed. Since the phase shifter rotates the phase of the local oscillation signal in the device, a microwave band phase shifter is required, and a microwave band amplifier for compensating for the loss due to the phase shifter is also required. There is a problem in that it becomes necessary, the configuration becomes complicated and difficult, and the cost becomes high.

The present invention has been made in view of the above problems, and in a space diversity apparatus in a radio communication apparatus using microwaves, when a main receiving apparatus and a sub receiving apparatus are installed separately, The transmission of the receiving local oscillation signal between the main receiving device and the sub receiving device can be facilitated, and the phase shifter for diversity can be easily configured, thus simplifying the overall configuration of the device. And it aims at providing the space diversity apparatus which can be made economical.

[0007]

A space diversity apparatus according to the present invention is a space diversity apparatus having a main receiving apparatus and a sub receiving apparatus, wherein the main receiving apparatus includes a first antenna for inputting a main receiving signal. A first reception frequency converter for frequency-converting the main reception signal input by the first antenna into an intermediate frequency band signal, and a first local oscillation used in frequency conversion in the first reception frequency converter A first receiving local oscillator that outputs a signal, a reference oscillator that outputs a reference signal that stabilizes the first local oscillation signal, and a phase of the reference signal and a phase of the first local oscillation signal are compared. And a first phase comparator for controlling the phase of the first local oscillation signal based on the comparison result, wherein the sub-reception device inputs the sub-reception signal. Antenna, a second reception frequency converter for frequency-converting the sub-reception signal input by the second antenna into an intermediate frequency band signal, and a second reception frequency converter used for frequency conversion in the second reception frequency converter. A second receiving local oscillator for outputting a local oscillation signal of
A phase shifter that rotates the phase by inputting the reference signal in the main receiving device is compared with the phase of the output of the phase shifter and the phase of the second local oscillation signal, and based on the comparison result. The second phase comparator for controlling the phase of the second local oscillation signal is compared with the phase of the intermediate frequency band signal in the main receiving device and the phase of the intermediate frequency band signal in the sub receiving device, and this comparison is performed. A third phase comparator that controls the amount of phase shift in the phase shifter based on the result, and a combiner that combines the intermediate frequency band signal in the main receiving device and the intermediate frequency band signal in the sub receiving device. It is characterized by having.

[0008]

In the space diversity device according to the present invention, in the space diversity device in the radio communication device using microwaves, the combiner includes the intermediate frequency band signal output from the first receiving frequency converter in the main receiving device and the sub-frequency band signal. The intermediate frequency band signal output from the second receiving frequency converter in the receiving device is combined. The third phase comparator compares the phase of the intermediate frequency band signal output by the first reception frequency converter with the phase of the intermediate frequency band signal output by the second reception frequency converter, and outputs the comparison result. Is output. The phase shifter inputs a reference signal from a reference oscillator in the main receiving device and rotates the reference signal by a phase shift amount corresponding to the signal output by the third phase comparator. The second reception local oscillator outputs the second local oscillation signal whose phase is fixed to the output of the phase shifter to the second reception frequency converter.

Here, since the frequency of the reference signal can be set to a frequency sufficiently lower than the frequency of the microwave, the space diversity device according to the present invention is not for the microwave band but for the low frequency band. A phase shifter can be used, and an amplifier for the microwave band and the like can be dispensed with.

[0010]

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a block diagram showing a space diversity device according to an embodiment of the present invention. Note that FIG.
2, the same components as those of the conventional space diversity device shown in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

In the space diversity apparatus according to the embodiment shown in FIG. 1, the components different from those of the conventional space diversity apparatus shown in FIG. 2 are that, in the sub-reception apparatus 11, a phase shifter 20 for microwave band and a microwave band. Where the amplifier 21 for use is removed and the phase shifter 1
6 is a part added. Then, in the phase shifter 16, the first input end is the output end of the reference oscillator 6 in the main receiving device 1, the second input end is the output end of the phase comparator 17, and the output end is the phase comparator 15. Each is connected to the first input terminal. In the phase comparator 15, the second input end is connected to the first output end of the receiving local oscillator 14, and the output end is connected to the input end of the receiving local oscillator 14. In the reception local oscillator 14, the output end is the reception frequency converter 13
Is connected to the first input end of.

Next, the operation of the space diversity apparatus according to the present embodiment constructed as described above will be described.

The main receiving apparatus 1 converts the microwave signal input by the antenna 2 into an intermediate frequency signal in the receiving frequency converter 3, and sends this intermediate frequency signal to the sub receiving apparatus 11. At this time, the phase comparator 5 sets the reference frequency so that the phase of the reception station-originated signal input to the reception frequency converter 3 is fixed with respect to the reference oscillation signal output by the reference oscillator 6 in the main receiving apparatus 1. The phase of the oscillating signal is compared with the phase of the receiving station-originated signal, and the result is fed back to the receiving local oscillator 4.

On the other hand, in the sub-reception device 11, the antenna 12
Received frequency converter 1 for microwave signal input by
3, the intermediate frequency signal is converted into an intermediate frequency signal, and the intermediate frequency signal input from the reception frequency converter 3 of the main receiving apparatus 1 is combined by the combiner 18 and output to the output terminal 19. At this time, the phase comparator 17 compares the phases of the intermediate frequency signals of the main receiving device 1 and the sub receiving device 11, and outputs the result as a control signal of the phase shifter 16. At this time, the local oscillation signal used in the sub-reception device 11 is phase-locked to a signal obtained by phase-controlling the reference oscillation signal sent from the reference oscillator 6 of the main reception device 1 by the phase shifter 16.

As described above, in the sub receiver 11, the phase difference between the intermediate frequency signals of the main receiver 1 and the sub receiver 11 is detected by the phase comparator 17, and the phase of the reference oscillation signal is detected based on this detection result. Is controlled by the phase shifter 16, and a local oscillation signal whose phase is fixed to this reference oscillation signal whose phase is controlled is used. With these, the sub-reception device 1
1 is a sub-reception device 11 in the reception frequency converter 13.
The phase of the intermediate frequency signal can be controlled so as to be in phase with the phase of the intermediate frequency signal of the main receiving apparatus 1.

[0017]

As described above, according to the space diversity device of the present invention, in the space diversity device in the radio communication device using microwaves, the phase of the reference oscillating signal input from the main receiving device in the sub receiving device is used. Is controlled, and the intermediate frequency signal of the main receiving device and the intermediate frequency signal of the sub receiving device are in-phase synthesized by using the local oscillation signal whose phase is fixed to this phase controlled reference oscillation signal, so that it is not a microwave band but a low frequency. A phase shifter for the frequency band can be used, and an amplifier for the microwave band is unnecessary. As a result, the space diversity device according to the present invention can make the configuration of the entire device simple and economical.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a space diversity device according to an exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a conventional space diversity device.

[Explanation of symbols]

 1; main receiving device 2, 12; antenna 3, 13; receiving frequency converter 4, 14; receiving local oscillator 5, 15, 17; phase comparator 6; reference oscillator 11; sub receiving device 16; phase shifter 18; Synthesizer 19 ； Output terminal

Claims (1)

[Claims] 1. A space diversity apparatus having a main receiving apparatus and a sub receiving apparatus, wherein the main receiving apparatus is
A first antenna for inputting a main reception signal; a first reception frequency converter for frequency-converting the main reception signal input by the first antenna into an intermediate frequency band signal;
A first receiving local oscillator for outputting a first local oscillation signal used in frequency conversion in the receiving frequency converter, a reference oscillator for outputting a reference signal for stabilizing the first local oscillation signal, and the reference A first phase comparator that compares the phase of the signal with the phase of the first local oscillation signal and controls the phase of the first local oscillation signal based on the comparison result. The apparatus includes a second antenna for inputting a sub reception signal, a second reception frequency converter for frequency converting the sub reception signal input by the second antenna into an intermediate frequency band signal, and the second reception frequency converter. A second receiving local oscillator that outputs a second local oscillation signal used in frequency conversion in the frequency converter, a phase shifter that inputs the reference signal in the main receiving device and rotates the phase, and A second phase comparator that compares the phase of the output of the phase shifter with the phase of the second local oscillation signal and controls the phase of the second local oscillation signal based on the comparison result; A third phase comparator that compares the phase of the intermediate frequency band signal in the receiving device with the phase of the intermediate frequency band signal in the sub-receiving device and controls the amount of phase shift in the phase shifter based on the comparison result; A space diversity device, comprising: a combiner for combining the intermediate frequency band signal in the main receiving device and the intermediate frequency band signal in the sub receiving device.