JP2803436B2 - Radio base station device for mobile communication system - Google Patents

Abstract

PURPOSE:To provide the radio base station of the mobile communication system in which monitor/control of a radio signal sent from an antenna section is implemented by a radio transmission reception section connected to the antenna section through an optical fiber transmission line. CONSTITUTION:Part of signal 308 sent to a mobile terminal equipment 400 is synthesized with a reception radio signal 312 by an antenna section 300 and the synthesis signal is converted into an optical signal 202. The optical signal 202 is sent to a radio transmission reception section 100 through an optical fiber transmission line 206, and the radio transmission section 100 monitors a transmission radio signal 308 included in the optical signal 202. That is, the radio transmission reception section 100 detects the intensity or frequency of the transmission radio signal 308 to apply negative feedback to the intensity or frequency of the radio signal 104 sent through the optical fiber transmission line 200 to the antenna section 300, and the intensity and frequency of the transmission radio signal 308 is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio base station apparatus for a mobile communication system in which a radio transmitting / receiving section and an antenna section are separated, and more particularly to a radio base station apparatus having an improved monitoring and controlling method for the antenna section.

[0002]

2. Description of the Related Art In a mobile communication system such as an automobile telephone system, a service area is divided into a plurality of zones called cells, and radio base stations for exchanging radio signals with mobile stations in the zone are arranged in each zone. ing. The radio base station in the automobile telephone system is described in the literature (published by the Institute of Electronics and Communication Engineers, automobile telephone, supervised by Morii Kuwahara,
52), it is composed of an antenna unit, a transmitting and receiving device for communication and control, a base station control device, and the like.

In the above mobile communication system, a micro cell system which divides a service area into small cells having a diameter of several hundred meters or less to improve frequency use efficiency has attracted attention. When this microcell system is realized, the wireless base station is installed on a streetlight or a telephone pole. However, the current wireless base station includes a transmitter / receiver and a base station controller, and installing them on streetlights or telephone poles is extremely difficult in terms of the size, weight, power consumption, reliability, etc. of the device. There was a problem that it was difficult. As a method for solving this problem, a method of separating a radio base station into a radio transmission / reception unit including a radio transmission / reception device and a base station control device and an antenna unit and connecting the both via an optical fiber transmission line has been studied. (For example, a document of the Institute of Electronics, Information and Communication Engineers, Radio Communication Systems Research Group by Shibuya et al., "Radio signal collection and distribution system for microcell mobile communication by light" RCS90-12). According to this method, a radio signal transmitted / received by the antenna unit is transmitted as it is to the radio transmission / reception unit via the optical fiber transmission line, where modulation / demodulation, radio channel control, and the like are performed. Since the antenna unit installed in each cell only needs to perform conversion of an optical signal and an electric signal and amplify a wireless signal, the size and weight of the antenna can be dramatically reduced, and the reliability can be significantly improved.

[0004]

The radio base station connecting the radio transmission / reception unit and the antenna unit by the above-mentioned optical fiber transmission line needs a function of monitoring and controlling whether a radio signal is transmitted from the antenna in a good condition. It is. However, it is necessary to avoid an increase in the size of the antenna unit due to the monitoring control function.

[0005] In a future microcell mobile communication system, it is considered that the antenna section of the radio base station is installed in each microcell, and the radio transmission / reception section is installed collectively in the center station. In such a configuration,
It is desirable that the monitoring of the transmission state of the radio signal be performed collectively by the center station.

In a micro-cell mobile communication system,
The transmission output from the antenna unit is frequently changed in accordance with the increase or decrease in communication traffic or the change in the arrangement or size of cells. At this time, if the transmission output can be changed by a wireless transceiver installed collectively in the center station, it is not necessary to adjust the level in the antenna unit installed in each cell.

Further, in a radio base station connecting an antenna unit and a radio transmission / reception unit by an optical fiber transmission line, it has been studied that a plurality of antenna units share a pair of optical fiber transmission lines by using a frequency conversion technique. I have. This is because, for example, even when the radio signal frequency transmitted from each antenna unit is the same 800 MHz band, a radio signal is transmitted at a different frequency for each antenna unit in the optical fiber, and each antenna unit allocates the assigned frequency. Is extracted by a filter, frequency-converted to an 800 MHz band, and transmitted. The application of frequency conversion to a mobile communication system using such an optical fiber is described in detail in, for example, a patent specification of Japanese Patent Application No. 3-277649 “Micro base station, center base station and mobile communication device”. Have been.

In the above-mentioned mobile communication system, it is necessary to control the frequency of a radio signal very accurately in order to prevent radio wave interference and the like. Therefore, in order to increase the frequency stability of the transmission radio signal when using the above-described frequency conversion technique, it is necessary to make the local oscillator used in the frequency conversion circuit extremely stable. Further, in a microcell mobile communication system, since an antenna unit is installed outdoors, a local oscillator that is stable against a large temperature change is required. However, such a local oscillator having high frequency stability has a complicated configuration, and is large and expensive. Therefore, it is desirable that a small and low-priced local oscillator is installed in each antenna unit, and that the frequency fluctuation of the transmission radio signal due to the frequency deviation of the local oscillator is corrected by the center station.

Accordingly, a first object of the present invention is to provide a mobile communication system capable of monitoring and controlling the strength and frequency of a radio signal transmitted from an antenna unit by a radio transmission / reception unit connected to the antenna unit by an optical fiber transmission line. An object of the present invention is to provide a wireless base station device of a system.

A second object of the present invention is to provide a radio base station apparatus of the above mobile communication system which can be installed outdoors and can improve the reliability of an antenna part which is difficult to maintain. is there.

[0011]

According to a first aspect of the present invention, there is provided a radio base station apparatus for a mobile communication system, wherein an antenna section and a radio transmission / reception section are separated from each other, and the antenna section and the radio transmission / reception section are separated by an optical fiber transmission line. In the wireless base station device in which the transmission of the wireless signal is performed, a part of the transmission wireless signal transmitted from the antenna unit to the mobile station is transmitted to the wireless transmission and reception unit by the optical fiber transmission line,
The wireless transmission / reception unit monitors the transmission wireless signal.

According to a second aspect of the present invention, there is provided a radio base station apparatus for a mobile communication system, wherein an antenna section and a radio transmission / reception section are separated and a radio signal between the antenna section and the radio transmission / reception section is provided by an optical fiber transmission line. In the wireless base station device in which the transmission is performed, a part of a transmission wireless signal transmitted from the antenna unit to the mobile station is transmitted to the wireless transmission / reception unit via the optical fiber transmission line. The strength of the transmitted radio signal is detected, and the strength of the radio signal transmitted from the radio transmitting / receiving unit to the antenna unit is controlled accordingly.

According to a third aspect of the present invention, there is provided a radio base station apparatus for a mobile communication system, wherein an antenna section and a radio transmission / reception section are separated and a radio signal between the antenna section and the radio transmission / reception section is transmitted by an optical fiber transmission line. Transmission is performed, and a radio signal transmitted from the radio transmission / reception unit to the antenna unit by the optical fiber transmission line is transmitted to a mobile station after being frequency-converted by a frequency conversion circuit in the antenna unit. In the wireless base station device, a part of an output of a local oscillator that supplies a local oscillation signal to the frequency conversion circuit is transmitted to the wireless transmitting / receiving unit via the optical fiber transmission line, and the frequency of the local oscillator output is transmitted in the wireless transmitting / receiving unit. And controlling the frequency of a radio signal transmitted from the radio transmission / reception unit to the antenna unit accordingly. And butterflies.

According to a fourth aspect of the present invention, in the base station apparatus of the mobile communication system, the antenna section and the radio transmission / reception section are separated, and the radio signal transmission between the antenna section and the radio transmission / reception section is performed by an optical fiber transmission line. A mobile station that performs transmission and converts a radio signal transmitted from the radio transmission / reception unit to the antenna unit via the optical fiber transmission line into a transmission radio signal by the first frequency conversion circuit in the antenna unit. In the radio base station apparatus transmitted toward the mobile station, a part of the transmission radio signal transmitted from the antenna unit is again frequency-converted into a radio signal by a second frequency converter to which the local oscillation signal is supplied. A wireless signal is transmitted to the wireless transmitting / receiving section via the optical fiber transmission line, and the frequency of the transmitting wireless signal is detected in the wireless transmitting / receiving section. , And controlling the frequency of the radio signal transmitted from the wireless transceiver to the antenna unit accordingly.

[0015]

According to the first aspect, a part of the transmission radio signal transmitted from the antenna section of the radio base station apparatus to the mobile station is transmitted to the radio transmission / reception section via the optical fiber transmission line. Therefore, the state of the transmission radio signal can be monitored by the radio transmission / reception unit, so that a monitoring detector is not required in the antenna unit, and it is possible to avoid an increase in the size of the antenna unit installed in each zone. .

Further, in the second invention, the radio transmission / reception unit of the radio base station device detects the intensity of the transmission radio signal transmitted from the antenna unit, and responds to this to determine the intensity of the radio signal transmitted to the antenna unit. Control. Thereby, the output intensity of the transmission radio signal from the antenna unit can be kept constant. Accordingly, the antenna section does not require an intensity detector and an intensity adjustment circuit, and the configuration of the antenna section is simplified. Further, by changing the strength of the radio signal transmitted to the antenna unit in the radio transmission / reception unit, the strength of the transmission radio signal transmitted from the antenna unit can be changed. Therefore, even when it becomes necessary to change the strength of the transmission radio signal, it is not necessary to adjust the level of the transmission radio signal in the antenna units installed in each zone.

Further, in the third and fourth inventions, in the radio base station apparatus to which the frequency conversion technique is applied, either one of the local oscillator output and the transmission radio signal whose frequency has been converted by the local oscillator is transmitted from the antenna unit. Transmit to the wireless transceiver. The wireless transmitting / receiving unit detects the output of the local oscillator and the frequency of the transmission wireless signal, and controls the frequency of the wireless signal transmitted to the antenna unit in accordance with the detection. Therefore, even when the oscillation frequency of the local oscillator of the antenna unit fluctuates, the frequency of the transmission radio signal can be kept constant.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention. A mobile communication system to which the base station apparatus of this embodiment is applied includes a radio transmitting / receiving unit 100, an optical fiber
0, 202 and an antenna unit 300, a mobile terminal 400 and a mobile telephone exchange 50.
0 is included. The mobile terminal 400 and the mobile switching center 500 are similar to the devices used in a general mobile communication system, and their configurations are widely known by those skilled in the art, and thus will not be described in detail here.

Radio signal 10 including telephone signal (call signal) 502 output from modulator 102 of radio transmitting / receiving section 100
4 is converted into an optical signal 204 by an electric / optical conversion circuit 106 composed of a semiconductor laser and its driver circuit, and is transmitted through a fiber transmission line 200 to an antenna unit 300.
Is transmitted to In the antenna unit 300, the optical signal 204 is again converted into a wireless signal by an optical / electrical conversion circuit 302 including a photodiode and a front-end circuit, amplified by a high-power amplifier 304, and passed through a duplexer 320. Most of this amplified signal is transmitted radio signal 3
06 is transmitted from the antenna 310 to the mobile terminal 400.

On the other hand, a received radio signal 312 transmitted from the mobile terminal 400 and received by the antenna 314 passes through a band-pass filter 316, is further amplified by a low-noise amplifier 318, and is then demultiplexed by the demultiplexer 320. The transmission radio signal 308 is multiplexed with a part of the transmission radio signal 308 by the multiplexer 322. The multiplexed wireless signal is converted into an optical signal 206 by the electrical / optical conversion circuit 324 and transmitted to the wireless transmitting / receiving unit 100 via the optical fiber transmission line 202.
The optical signal 206 sent from the antenna unit 300 to the wireless transmission / reception unit 100 is converted again into a transmission radio signal 114 (same as the transmission radio signal 308) and a reception radio signal 112 by the optical / electrical conversion circuit 110. Duplexer 116
Separated by The received radio signal 112 is demodulated into a telephone signal (call signal) 504 by the demodulator 118. On the other hand, the transmission radio signal 114 is input to the spectrum analyzer 120, and the intensity, frequency, signal distortion, presence / absence of unnecessary radiation, and the like are monitored.

FIG. 2 is a block diagram of a second embodiment of the present invention. The base station device of this mobile communication system controls the strength of the transmission radio signal 306 in addition to monitoring the transmission radio signal 308. In the antenna unit 300A of the base station device,
A pilot signal 332 is output from the oscillator 330, and the signal 332, the transmission radio signal 308 supplied from the demultiplexer 320, and the reception radio signal 312 passed through the amplifier 318 and the limiter circuit 334 are multiplexed by the multiplexer 336. The multiplexed signal is input to the electric / optical conversion circuit 324.
In this embodiment, the strength of the pilot signal 332 is 0.1 m.
W. The split ratio of the signal from the splitter 320 to the antenna 310 and the multiplexer 336 is 1: 100. For example, when the transmission radio signal 306 output from the antenna 310 has an intensity of 10 mW, it is supplied to the splitter 332. The transmitted wireless signal 308 has a strength of 0.1 mW. Note that the amplitude of the received radio signal 312 is limited by the limiter circuit 334 before being combined with the pilot signal 332 and the transmission radio signal 308 in order to protect the electrical / optical conversion circuit 324. In this embodiment, the intensity of the received radio signal 312 input to the electric / optical conversion circuit 324 is limited to 1 mW or less by the limiter circuit 334 regardless of the intensity of the signal received by the antenna 314.

The radio transmission / reception unit 100 A of the base station device receives the reception radio signal 11 output from the optical / electrical conversion circuit 110.
2, the pilot signal 122 (same as the pilot signal 332) and the transmission radio signal 114
The pilot signal 122 and the transmission radio signal 114 are supplied to a transmission intensity control circuit 136. The transmission intensity control circuit 136 controls the intensity of the radio signal 104 based on the pilot signal 122 and the transmission radio signal 114, and
The intensity of the transmission radio signal 306 transmitted from A is stabilized at a predetermined value.

FIG. 3 is a block diagram of the transmission intensity control circuit 136 shown in the embodiment of FIG. From the pilot signal 122 and the transmitted radio signal 114, the level detectors 142, 14
4, a pilot intensity signal 146 with a voltage of x volts and a transmission intensity signal 148 with a voltage of y volts are detected. Both pilot strength signal 146 and transmission strength signal 148 are input to division circuit 150, which outputs division signal 152 of voltage y / x volts. The division signal 152 is obtained by subtracting the reference signal 156 having a voltage of z volts output from the reference voltage source 154 by a subtraction circuit 158, to form an error signal 160 having a voltage of x / yz volts. This error signal 160 is output from the intensity adjuster 16.
2 is input. The intensity adjuster 162 is composed of an attenuator using a PIN diode and a high-frequency amplifier, and functions as an amplifier and an attenuator when the voltage of the error signal 160 is minus and plus, respectively. The error signal 160 is proportional to the absolute value of the voltage.

In the transmission intensity control circuit 136 of FIG. 3, the voltage of the reference signal 156 is 1 volt. In this case, if the intensity of the transmission radio signal 306 output from the antenna 310 shown in FIG. 2 is 100 mW or less, the transmission intensity signal 144 becomes smaller than the pilot intensity signal 142 and the divided signal 152 becomes 1 or less. Become. Therefore, the error signal 160 becomes negative, and the intensity adjuster 162 acts as an amplifier, and the intensity of the wireless signal 104 is amplified until the intensity of the transmission wireless signal 306 becomes 100 mW. Conversely, when the intensity of the transmission radio signal 306 is 100 mW or more, the intensity adjuster 16
2 works as an attenuator, and the transmitted radio signal strength is 100 m
The intensity of the wireless signal 104 is attenuated until the signal becomes W. FIG.
For example, when the voltage of the reference signal 156 is changed to 0.1 volt or 10 volt,
Are stabilized at 10 mW or 1 W, respectively.

FIG. 4 is a block diagram of a third embodiment of the present invention. In the base station apparatus of this mobile communication system, frequency conversion of a radio signal is performed by the antenna units 300B and 301, and the pair of optical fiber transmission lines 200 and 202 are shared by the two antenna units 300B and 301. .
Radio signals 104 and 105 having frequencies of 200 MHz and 300 MHz are output from the two modulators 102 and 103 of the radio transmission / reception unit 100B, respectively, multiplexed by the multiplexer 117, and then input to the electric / optical conversion circuit 106. . The optical signal 204 output from the electric / optical conversion circuit 106 is distributed to the antenna units 300B and 301 by the optical fiber transmission line 200 having a star configuration. Antenna unit 300
In B, the radio signal output from the optical / electrical conversion circuit 302 has a frequency 200
Only the MHz radio signal 342 is extracted and supplied to the frequency conversion circuit 350. The frequency conversion circuit 350 includes a local oscillator 352 having an oscillation frequency of 600 MHz, a mixer 3
It comprises a 54,800 MHz band band-pass filter 356, and converts a 200 MHz wireless signal 342 into eight.
The frequency is converted to a transmission wireless signal 306 in the 00 MHz band.
Similarly, the antenna unit 301 has an oscillation frequency of 500 MHz.
A wireless signal 343 having a frequency of 300 MHz is transmitted by a frequency conversion circuit 351 using a local oscillator 353 of 800
The frequency is converted to a transmission radio signal 307 in the MHz band.

On the other hand, the antenna 31 of the antenna section 300B
850 MHz band received radio signal 312 received at 4
Are local oscillator 352, mixer 364, 250MHz
The frequency is converted to a frequency of 250 MHz by a frequency conversion circuit 360 configured by a band band-pass filter 366. The frequency-converted received radio signal and a part 358 of the output of the local oscillator are multiplexed by the multiplexer 368, and the electrical / optical conversion circuit 324 outputs the optical signal 206.
And transmitted to the wireless transmission / reception unit 100. Similarly, the antenna unit 301 converts the received radio signal 313 in the 850 MHz band into a 350
The frequency is converted to an optical signal 207 together with a local oscillator output 359 having a frequency of 500 MHz, and is sent to the wireless transmission / reception unit 100B.

The radio transmitting / receiving section 100B includes band pass filters 170, 171, and 1 having pass frequencies of 250 MHz, 350 MHz, 600 MHz, and 500 MHz, respectively.
72 and 173, the received radio signals 112, 11
3 and the local oscillator outputs 174,175. Of these outputs, the frequencies of the local oscillator outputs 174 and 175 are detected by frequency discriminators 176 and 177, respectively. The transmission frequency control circuits 178 and 179 output frequency control signals 180 and 181 responsive to the outputs of the frequency discriminators 176 and 177, respectively, so that the VCO, which is a carrier signal generator in the modulators 102 and 103, is output.
The frequency of the wireless signals 104 and 105 is controlled by controlling the oscillation frequency of a (voltage controlled oscillator). For example, the frequency of the local oscillator output 174 is x from 600 MHz.
MHz, the transmission frequency control circuit 178
Controls the frequency of the wireless signal 104 output from the modulator 102 to be (200 + x) MHz. As described above, in this base station apparatus, frequency negative feedback is applied to transmission radio signal 306, and the frequency of transmission radio signal 306 in antenna section 300B is stable at 800 MHz even when the oscillation frequency of local oscillator 352 varies. Be transformed into Similarly, the frequency of the radio signal 105 output from the modulator 103 is controlled by the frequency control circuit 179, and the frequency of the transmission radio signal 307 at the antenna unit 301 is set to 800
Stabilized to MHz.

FIG. 5 is a block diagram of a fourth embodiment of the present invention. In the base station apparatus of the embodiment of FIG. 4 described above, the frequency of the transmission radio signal is stabilized by transmitting a part of the local oscillator output from the antenna units 300B and 301 to the radio transmission / reception unit 100B. Here, the frequency of the transmission radio signals 306 and 307 is stabilized by transmitting the transmission radio signals 308 and 309 frequency-converted from the antenna units 300B and 301 to the radio transmission / reception unit 100C.

In the antenna section 300B shown in FIG. The signal is demultiplexed by the demultiplexer 320, further multiplexed with the received radio signal 312 by the multiplexer 322, and input to the frequency conversion circuit 360. The frequency conversion circuit 360 includes a local oscillator 352 having an oscillation frequency of 600 MHz, a mixer 364, a band-pass filter 366 having pass bands at 1400 MHz and 250 MHz.
The transmission radio signal 308 of 800 MHz and the reception radio signal 312 of frequency 850 MHz are 1400 MHz and 250 M, respectively.
Hz frequency signal. The frequency-converted transmission radio signal 308 and reception radio signal 312 are both converted into the optical signal 206 by the electric / optical conversion circuit 324 and sent to the radio transmission / reception unit 100C. Similarly, in the antenna unit 301, the local oscillator 3 having an oscillation frequency of 500 MHz is used.
A frequency conversion circuit 361 using 53 as a local oscillation signal source causes an 800 MHz transmission radio signal 309 and a frequency 85
The received radio signal 313 of 0 MHz
The frequency is converted to signals of 0 MHz and 350 MHz.

The radio transmitting / receiving unit 100C includes an antenna unit 30
0B, 301, the transmitted radio signal 114,
115 and the received radio signals 112 and 113 are separated by bandpass filters 132, 133, 170 and 171 respectively. The transmission radio signal 114 having a frequency of 1400 MHz is transmitted to the frequency detector 18 together with the radio signal 104 having a frequency of 200 MHz output from the modulator 102.
2 is input. The oscillation frequency of the local oscillator 352 of the antenna unit 300B is detected by the frequency detector 182, and the transmission frequency control circuit 178 is provided as in the embodiment of FIG.
The frequency of the wireless signal 104 is controlled by this, and the frequency of the transmission wireless signal 306 is stabilized. Similarly, the frequency detector 183 detects the transmission radio signal 1 having a frequency of 1300 MHz.
15 and a radio signal 105 having a frequency of 200 MHz,
The oscillation frequency of the local oscillator 353 is detected. The transmission frequency control circuit 179 controls the frequency of the radio signal 105 in response to the output of the frequency detector 183, and stabilizes the frequency of the transmission radio signal 307.

FIG. 6 is a block diagram of the frequency detector 182 shown in the embodiment of FIG. Transmission radio signal 114 of frequency 1400 MHz and radio signal 104 of frequency 200 MHz
Is frequency-converted by the mixer 184 and further
Bandpass filter 186 having a pass band of 00 MHz band
Is input to The frequency of the signal passing through the band-pass filter 186 is equal to the frequency of the transmission radio signal 114 minus the frequency of the radio signal 104. This frequency is twice the oscillation frequency of the local oscillator 352 of the antenna unit 300B in FIG. Further, the band-pass filter 18
The output from 6 is a half frequency divider 188 and 600M
The signal is input to a band pass filter 190 having a pass band in the Hz band. The frequency of the signal output from bandpass filter 190 is equal to the oscillation frequency of local oscillator 352. The output of the band pass filter 190 is applied to a frequency discriminator 176.
And the oscillation frequency of the local oscillator 352 is detected. The output of the frequency discriminator 176 is the frequency control circuit 1
78, and the wireless signal 1 is input in the same manner as in the embodiment of FIG.
04 is controlled, and the frequency of the transmission radio signal 306 is stabilized.

The present invention includes various modifications in addition to the above-described embodiments. For example, the transmission intensity control circuit 136 used in the embodiment of FIG. 2 and shown in FIG. 3 is just one example. Even if the division circuit 150 is changed to a subtraction circuit, for example, the intensity of the transmission radio signal 306 can be stabilized. Is possible. The essential point of the invention shown in this embodiment is that the output strength of the transmission radio signal 306 is detected by the transmission radio signal 114 and the pilot signal 122 sent from the antenna unit 300, and the strength of the radio signal 106 is negatively detected by using the detected power. It is to stabilize the output intensity of the transmission radio signal 306 by performing feedback control.

The frequency detector 182 used in the embodiment of FIG. 5 and shown in FIG. 6 is also an example. For example, even if the half frequency divider 188 and the band-pass filter 190 are omitted, the transmission radio signal The frequency stabilization of 306 is possible.

Further, in the embodiment of FIGS. 4 and 5, the two antenna units 300B and 301 share a pair of optical fiber transmission lines 200 and 202, but satisfy the required performance of the applied mobile communication system. The number of antenna sections sharing a pair of optical fiber transmission lines can be set arbitrarily within the range of

The first to fourth embodiments (FIG. 1, FIG. 1)
In the embodiments of FIGS. 2, 4 and 5, two antennas 310 for transmission and reception are provided in the antenna section of the base station apparatus.
314 is used, but by using a duplexer or a circulator, transmission and reception of a radio signal can be performed with one antenna.

[0037]

As described above, according to the present invention, a signal is transmitted from the antenna unit in a radio base station apparatus of a mobile communication system in which an antenna unit and a radio transmission / reception unit are connected by an optical fiber transmission line. Since the means for monitoring / controlling the wireless signal is provided by the wireless transmitting / receiving section, the antenna section has an effect that the function of monitoring / controlling the transmitted wireless signal becomes unnecessary. Therefore, not only can the antenna unit be miniaturized, but also the number of parts is reduced and the antenna unit is often installed outdoors, so that the reliability of the antenna unit which is troublesome to maintain can be improved. This has the effect of facilitating maintenance of the device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a transmission intensity control circuit 136 shown in the embodiment of FIG. 2;
FIG.

FIG. 4 is a configuration diagram of a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of the frequency detector 182 shown in the embodiment of FIG.

[Explanation of symbols]

100, 100A, 100B, 100C Wireless transmitting / receiving section 102, 103 Modulator 104, 105, 342, 343 Wireless signal 106, 324, 325 Electric / optical conversion circuit 110, 302, 303 Optical / electric conversion circuit 118, 119 Demodulator 120 Spectrum analyzer 122,332 Pilot signal 136 Transmission intensity control circuit 142,144 Level detector 146 Pilot intensity signal 148 Transmission intensity signal 150 Division circuit 152 Division signal 154 Reference voltage source 156 Reference signal 158 Subtraction circuit 160 Error signal 162 Strength Regulators 174, 175, 358, 359 Local oscillator output 176, 177 Frequency discriminator 178, 179 Transmission frequency control circuit 180, 181 Frequency control signal 182, 183 Frequency detector 188 1/2 frequency divider 200, 02 optical fiber transmission line 204,206,207 optical signal 300, 300A, 300B, 301 antenna 304 and 305 high power amplifier 306,307,308,309,114,115
Transmitted radio signals 312,313,112,113 Received radio signals 310,311,314,315 Antennas 318,319 Low noise amplifiers 330 Oscillator 334 Limiter circuits 350,351,360,361 Frequency conversion circuits 352,353 Local oscillators 354,355 , 364, 365, 184 Mixer 116, 320, 321 Demultiplexer 117, 322, 323, 336, 368, 369
Multiplexer 130, 132-134, 170-173, 186, 1
90,316,317,340,341,356,357,366,367
Bandpass filter 400 Mobile terminal 500 Switching center 502, 504 Telephone signal

Claims (4)

(57) [Claims] A modulator for generating a first wireless signal modulated by a signal including a call signal; a first electrical / optical converter for converting the first wireless signal into a first optical signal; (2) a wireless transmitting / receiving unit including an optical / electrical converting unit for converting into a wireless signal and a demodulating unit for demodulating a signal including a call signal from the second wireless signal; and a second unit for transmitting the first optical signal from the wireless transmitting / receiving unit. 1 optical fiber transmission line, transmission radio signal generation means for converting the first optical signal from the first optical fiber transmission line into a transmission radio signal, a transmission antenna for transmitting the transmission radio signal to a mobile station, the mobile station An antenna unit including a receiving antenna for receiving a received wireless signal from the antenna and a second electrical / optical converter for converting the received wireless signal into the second optical signal; and transmitting and receiving the second optical signal from the antenna unit to the wireless transmitting and receiving unit. In a wireless base station apparatus of a mobile communication system having a second optical fiber transmission line for transmitting to a transmitting unit, a second electric / optical conversion unit of the antenna unit further includes a transmission radio signal generation unit together with the reception radio signal. Having a means for converting a part of the transmission radio signal from the second radio signal to the second optical signal, wherein the radio transmission / reception unit further has means for monitoring the transmission radio signal included in the second radio signal. A base station device of a mobile communication system, characterized by: 2. A modulator for generating a first wireless signal modulated by a signal including a call signal, a first electrical / optical converter for converting the first wireless signal to a first optical signal, and a second electrical signal to a second optical signal. (2) a wireless transmitting / receiving unit including an optical / electrical converting unit for converting into a wireless signal and a demodulating unit for demodulating a signal including a call signal from the second wireless signal; and a second unit for transmitting the first optical signal from the wireless transmitting / receiving unit. 1 optical fiber transmission line, transmission radio signal generation means for converting the first optical signal from the first optical fiber transmission line into a transmission radio signal, a transmission antenna for transmitting the transmission radio signal to a mobile station, the mobile station A receiving antenna for receiving a received wireless signal from the antenna unit, an antenna unit including a second electrical / optical conversion unit for converting the received wireless signal into the second optical signal, and transmitting and receiving the second optical signal from the antenna unit to the wireless transmitting / receiving unit A mobile communication system having a second optical fiber transmission line for transmitting to the wireless base station device, wherein the second electric / optical conversion unit of the antenna unit further includes: Means for converting a part of the transmission radio signal to the second optical signal, wherein the radio transmission / reception unit further detects a transmission radio signal strength included in the second radio signal. And a radio signal strength control means for controlling the strength of the first radio signal in response to the detected transmission radio signal strength. 3. A modulator for generating a first wireless signal modulated by a signal including a call signal, a first electrical / optical converter for converting the first wireless signal into a first optical signal, and a second electrical / optical converter. A wireless transmission / reception unit including a first optical / electrical conversion unit for converting the signal into a wireless signal and a demodulation unit for demodulating a signal including a call signal from the second wireless signal; and transmitting the first optical signal from the wireless transmission / reception unit A first optical fiber transmission line,
Converting the first optical signal from the first optical fiber transmission line to a third
Second optical / electrical conversion means for converting to a radio signal, local oscillator means for generating a local oscillation signal, and transmission radio having a frequency different from the third radio signal in response to the local oscillation signal and the third radio signal. First frequency conversion means for generating a signal, a transmission antenna for transmitting the transmission radio signal to a mobile station, a reception antenna for receiving a reception radio signal from the mobile station, and a reception antenna for receiving the reception radio signal at a frequency different from the reception radio signal. An antenna unit including a second frequency conversion unit that converts the signal into four radio signals, and a second electric / optical conversion unit that converts the fourth radio signal into the second optical signal; and the second optical signal from the antenna unit. In a wireless base station device of a mobile communication system having a second optical fiber transmission line for transmitting to the wireless transmission / reception unit, the second electric / optical conversion means of the antenna unit may include: And a means for converting a part of the local oscillation signal from the local oscillator means into the second optical signal together with the fourth wireless signal, wherein the wireless transmitting and receiving unit further comprises: Local oscillation signal frequency detection means for detecting the frequency of the local oscillation signal, and radio signal frequency control means for controlling the frequency of the first radio signal in response to the detected local oscillation signal frequency. A radio base station device for a mobile communication system, characterized by: 4. A modulator for generating a first wireless signal modulated by a signal including a call signal, a first electrical / optical converter for converting the first wireless signal into a first optical signal, and a second electrical signal to a second optical signal. A wireless transmission / reception unit including a first optical / electrical conversion unit for converting the signal into a wireless signal and a demodulation unit for demodulating a signal including a call signal from the second wireless signal; and transmitting the first optical signal from the wireless transmission / reception unit A first optical fiber transmission line,
Converting the first optical signal from the first optical fiber transmission line to a third
Second optical / electrical conversion means for converting to a radio signal, local oscillator means for generating a local oscillation signal, and transmission radio having a frequency different from the third radio signal in response to the local oscillation signal and the third radio signal. First frequency conversion means for generating a signal, a transmission antenna for transmitting the transmission radio signal to a mobile station, a reception antenna for receiving a reception radio signal from the mobile station, and a reception antenna for receiving the reception radio signal at a frequency different from the reception radio signal. An antenna unit including a second frequency conversion unit that converts the signal into four radio signals, and a second electric / optical conversion unit that converts the fourth radio signal into the second optical signal; and the second optical signal from the antenna unit. In a radio base station apparatus of a mobile communication system having a second optical fiber transmission line for transmitting to the radio transmission / reception section, a second frequency conversion means of the antenna section includes: Means for supplying the local oscillation signal from an oscillator means, further comprising means for converting a part of the transmission radio signal from the first frequency conversion means together with the reception radio signal into the fourth radio signal, Transmitting frequency detection means for detecting a frequency of the transmission radio signal included in the second radio signal, and controlling a frequency of the first radio signal in response to the detected transmission radio signal frequency A radio base station apparatus for a mobile communication system, comprising: radio signal frequency control means.