JPH11274835A - Space diversity receiver - Google Patents

Abstract

(57) [Problem] To provide a conventional space diversity receiving apparatus, when used in a microcell base station represented by PHS or the like, because the installation space is small, the installation distance between antennas is sufficiently separated. Therefore, the antenna correlation is reduced, and the diversity effect is degraded. SUMMARY OF THE INVENTION It is an object of the present invention to provide a spatial diversity receiver capable of obtaining a sufficient diversity effect without the problem of antenna correlation in the above case. SOLUTION: By using one antenna and a moving means for moving an installation place of the antenna, when a reception signal level output from the antenna is equal to or less than a predetermined value, the moving means is used to move the antenna. A space diversity receiving apparatus characterized in that a receiving signal level higher than a predetermined value is obtained by moving an installation place.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a space diversity receiving apparatus, and more particularly, to a means for avoiding deterioration of a diversity effect due to a limitation of an antenna installation space.

[0002]

2. Description of the Related Art Generally, in mobile communication, a transmitted radio wave is multiply reflected or scattered by a building or the like existing between the mobile station and a base station as the mobile station moves. , And as a result, the level of the received signal in the receiver fluctuates, thereby deteriorating the communication quality. This phenomenon is known as fading, and therefore, in mobile communication, some countermeasures against fading are indispensable to reduce the deterioration of the communication quality.

[0003] Diversity receiving systems have been proposed to improve or reduce communication quality by compensating or mitigating the deterioration of a received signal due to the above-mentioned fading. There is. Among them, the spatial diversity receiving method combines signals received at each point at a plurality of points spatially separated by several wavelengths by utilizing the fact that the correlation of level fluctuations in the received signal is small, or performs reception at a large level. This is a method of obtaining a diversity effect by selecting a signal.

[0004] FIG. 3 is a functional block diagram showing a configuration example of a conventional spatial diversity receiving apparatus. The spatial diversity receiver shown in this example includes a first antenna 31 and a second antenna 32, and a first receiver connected to each of the two antennas 31 and 32 and outputting a demodulated signal to a selection circuit 33. 34 and a second receiver 35. Note that, as described above, the first and second antennas 31 and 32 are arranged apart from each other by several wavelengths so that the correlation between the received signals is reduced.

[0005] Next, the operation of the diversity receiver shown in FIG. 3 will be described. First, an incoming radio wave is received via the first and second antennas 31 and 32, and is demodulated in the first and second receivers 34 and 35, respectively, and then supplied to the selection circuit 33. The selection circuit 33 compares the two received signal levels, selects a received signal having a higher level, and outputs the selected received signal to the subsequent signal processing unit. As described above, the diversity receiving apparatus can obtain the diversity effect by always using the received signal of the higher level, so that the communication quality can be improved.

[0006]

However, the conventional spatial diversity receiver as described above has the following problems. In other words, when an antenna for space diversity is installed in a microcell (small zone) type base station represented by a PHS or the like, since the installation space of the base station is generally small, the distance between the two antennas can be sufficiently separated. Can not. Therefore, the amount of mutual coupling (the amount of power leakage) between the antennas increases, so that interference occurs between the antennas and the antenna correlation decreases, and as a result, the diversity effect deteriorates. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems related to the conventional spatial diversity receiving apparatus, and avoids the problem that the antenna correlation is reduced due to an increase in interference between antennas related to the limitation of the antenna installation space, thereby reducing the diversity effect. While preventing deterioration,
It is an object of the present invention to provide a spatial diversity receiving apparatus that requires only one receiver and one antenna.

[0007]

To achieve the above object, a space diversity receiving apparatus according to the present invention is claimed.
The invention according to 1, the use of one antenna and a moving means for moving the installation location of the antenna, when the received signal level output from the antenna is a predetermined value or less, the moving means using the moving means By moving the installation location of the antenna, the reception signal level equal to or higher than a predetermined value is obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 is a functional block diagram showing an embodiment of a spatial diversity receiving apparatus according to the present invention. The spatial diversity receiver shown in this example is a receiver 13 which demodulates a received signal via one antenna 11 installed on a turntable 20 as an antenna moving means to be described later and supplies it to a level determiner 12. And the turntable according to the received signal level in the level determiner 12.
And a rotation controller 14 for controlling the driving of the motor 20. FIG. 2 is a perspective view showing an antenna installed on a turntable 20 of the spatial diversity receiver according to the present invention.
The antenna 11 is installed near the end of the turntable 20,
The rotation of the turntable 20 changes the installation location of the antenna within a range of several wavelengths.

Hereinafter, the operation of the spatial diversity receiving apparatus according to the present invention will be described with reference to FIGS. First,
The arriving radio wave is received via an antenna 11, demodulated in a receiver 13, and then supplied to a level determiner 12. The level determiner 12 determines whether or not the received signal level has reached a predetermined value.If the received signal level is equal to or higher than the predetermined value, the received signal is supplied to the signal processing unit without outputting the rotation control signal 12a to the rotation controller 14. On the other hand, when the received signal level is equal to or less than the predetermined value, a rotation control signal 12a is output to the rotation controller 14. This rotation control signal 12a
The rotation controller 14 rotates the turntable 20 to rotate the antenna 11
Is moved. The level determination unit 12 constantly determines the received signal level and outputs the received signal to the signal processing unit even while the receiving position of the antenna is moving, and when the received signal level exceeds a predetermined value, the rotation control signal
By turning off the output of 12a, the rotation of the turntable 20 is stopped and the antenna receiving position is fixed.

[0010] When the turntable 20 makes a circuit while the level judgment of the level judgment unit 12 is equal to or less than the predetermined value, the turntable is arranged so that the antenna is arranged at the reception position where the received signal level is the highest. Control 20. Then, the level determiner 12
After the elapse of a predetermined time, the above processing is repeated while rotating the turntable 20 again to move the antenna reception position until the reception signal level becomes equal to or higher than the predetermined value.

[0011] As described above, the spatial diversity receiver according to the present invention enables spatial diversity reception with one antenna, so that the amount of interference between antennas due to the restriction of the antenna installation location, that is, the antenna correlation Can be prevented from deteriorating the diversity effect.

[0012]

As described above, according to the present invention, since one antenna is arranged on the turntable as the antenna moving means, the interference between the antennas due to the limitation of the antenna installation place is increased. This is very effective in realizing a spatial diversity receiver capable of avoiding the deterioration of the diversity effect due to the reduced correlation.

[Brief description of the drawings]

FIG. 1 is a functional block diagram illustrating an embodiment of a spatial diversity receiving apparatus according to the present invention.

FIG. 2 is a perspective view showing an antenna installed on a turntable of the spatial diversity receiver according to the present invention.

FIG. 3 is a functional block diagram showing a configuration example of a conventional spatial diversity receiving apparatus.

[Explanation of symbols]

 11 Antenna 12 Level detector 12a Rotation control signal 13 Receiver 14 Rotation controller 20 Rotary table

Claims (2)

[Claims] 1. An antenna, comprising: a moving unit configured to move an installation position of the antenna, wherein when a reception signal level output from the antenna is equal to or less than a predetermined value, the antenna is installed using the moving unit. A spatial diversity receiving apparatus configured to obtain a reception signal level equal to or higher than a predetermined value by moving a position. 2. The space diversity receiver according to claim 1, wherein the antenna is supported on a turntable.